# Homemade Creations >  Small Boiler

## editor@glue-it.com

Hi, have been learning how to form the endplates for a boiler, used a hammer to round the edges:


But then decided to make a forming tool


Made two endplates for the traction engine boiler


then drilled holes and made up 7 off 3/16" pipes using brake tubing


More info around the heat treatment is here
glue-it.com

The next stage is to make up the other fittings and silver solder it all together, Best regards, Nigel

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bruce.desertrat (Dec 9, 2019),

Inner (Dec 10, 2019),

Jon (Dec 9, 2019),

Miloslav (Dec 9, 2019),

Scotsman Hosie (Feb 20, 2020),

sossol (Dec 9, 2019),

Workshopshed (Jul 4, 2021)

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## Savage11

Keep us updated OP!

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## editor@glue-it.com

I've turned up the smokebox, these are the basic forms that are coming together

The beam is just cut to size at the moment and needs to be drilled and threaded in the future.

The bottom end of the chimney has taken some time to machine, the curve was machined as a taper and then by hand I made the curve. The bottom surface that is curved to fit the smokebox was machined using a flycutter.

A nice feeling when it starts to look right.

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Scotsman Hosie (Feb 20, 2020),

sossol (Mar 6, 2020)

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## Savage11

Its coming along nicely, very cool indeed.

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## editor@glue-it.com

It's a mix of making parts, drawing the plans as I go and then sometimes remaking parts. I'm using images of a 6NHP Burrell for inspiration and gradually adding detailed design around each element. Any help with respect to the design and tooling around the manufacture would be most welcome.

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## editor@glue-it.com

I re-turned the lower chimney section


Some hand turning, take extreme caution if you're going to try this...


This was my first attempt at riveting and I made the rivet punch


As you can see I'm creating drawings as I go and will share more details on the full build: Miniature Burrell Smokebox

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Scotsman Hosie (Feb 20, 2020),

sossol (Mar 6, 2020)

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## thehomeengineer

Hi
Nice to see your build. This is a really good project. 
I have a web site which has some details of my traction engine build. It might be of help for your build. There is a couple of sections on the copper boiler making. Practical Engineering
I hope you find this is helpful towards your excellent engine build.
The Home Engineer

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## editor@glue-it.com

This originally started as a discussion around the boiler and I'll come back to that soon, In the meantime I'm gradually picking off the parts to make:

The rear wheel rims were machined from 4 inch diameter mild steel stock, I roughed out the size and then switched to a 4-jaw chuck and DTI

These then got machined with the inner beads and finished 97mm overall diameter

the treads were machined on the milling machine, this took some time to setup the 10° angle, align the wheel with a DTI in the chuck again and centre the milling bit

I'm pleased with the result, more details of the setup and discussion, drop me a line if you want to know more, best regards, Nige

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Scotsman Hosie (Feb 20, 2020),

sossol (Mar 6, 2020)

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## editor@glue-it.com

I machined one tread and then didn't take enough time setting up the opposite angle, the old saying "measure twice, cut once" is still ringing in my head and so I had to make another complete wheel, at last I have a pair:

More details are here: https://www.glue-it.com/wp/gallery/r...el-tread-pair/

I also took a picture of my parts made and bought to date:


I'm gradually creating the drawings as I go and collecting these into a set of plans - need to think about how I'm going to make these available to others....thoughts?

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Scotsman Hosie (Feb 20, 2020),

sossol (Mar 6, 2020)

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## editor@glue-it.com

My Record BS250 bandsaw is great, but not very good when it comes to cutting thin materials such as the brass I'm using for the wheel spokes. I thought up this simple modification to the table:

The MDF table is fixed to the main table from underneath, removing the gap under the fence, adding support around the blade and removing the step around the blade: Cutting Brass on a Bandsaw

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Andyt (Feb 29, 2020),

jackhoying (Feb 28, 2020),

Jon (Mar 1, 2020),

Toolmaker51 (Apr 6, 2021),

tooly (Feb 28, 2020)

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## editor@glue-it.com

this has allowed me to cutout the brass blanks quite accurately


I then bolted them together in sets of 8 and machined them, they were then bent at each end 20 degrees and bolted into the rim - more details on glue-it.com


The pound coin gives a rough size.... to those in the UK. For everyone else these are 97mm diameter (just under 4 inches)

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Jon (Mar 4, 2020),

Seedtick (Mar 4, 2020),

sossol (Mar 6, 2020)

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## thehomeengineer

Coming along very nicely

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## Altair

Thanks editor at glue-it.com! We've added your Bandsaw Brass Cutting Setup to our Bandsaws category,
as well as to your builder page: editor at glue-it.com's Homemade Tools. Your receipt:















Bandsaw Brass Cutting Setup
 by editor at glue-it.com

tags:
jig

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## editor@glue-it.com

Thanks, this simple modification to the bandsaw has worked really well, Nigel

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## editor@glue-it.com

Been making some simple calculations around fuel and steam consumption so that I can do some more sizing: 

*1.38g water per minute => 0.26g fuel / minute*

This is assuming methylated spirit burner, an engine that is 12mm bore and 12mm stroke running at 300rpm and 1.5 atmospheres at the end of the stroke. Lots of assumptions and so would really like to hear from you all with some real measurements.

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## editor@glue-it.com

I now have an input power of 128.7 Watts and an engine output power of 3.3 Watts, the Steam Engine and Boiler Efficiency is a ratio of the output and input:

Steam Engine and Boiler Efficiency = Output Power / Input Power

Miniature Traction Engine Efficiency = 3.3 / 128.7 = 0.0256 = 2.56%

So, my calculated efficiency is 2.56% that feels very high for this small system and I expect a lot more losses when I put this into practice.

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## editor@glue-it.com

Just machined the front rims, roughed out and laying on the plan


and then machined in detail



gradually getting there with this project, a piece at a time

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## editor@glue-it.com

Finally got round to making the front wheel hubs, this time I made them from brass. I had a few mishaps along the way, the first of which was cutting 5 slots rather than 6, a complete nightmare of a saturday afternoon:


Just to put them into perspective the following photo shows a hub on a matchbox:


In the end I managed to align, jig and make a pair of hubs


a few more picture of the making process are available.

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## thehomeengineer

Looks really good. Thank you for sharing.
The Home Engineer

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## editor@glue-it.com

Just had to share some images of the wheel assembly process, after hours of making parts this is the best part



Just offering up parts to check it all fits. I made a simple jig to align the centres.



I riveted the spokes to the rim with 1/16th inch steel rivets. I then soldered the spokes to the hub whilst on the jig



The final machining of the hub was done on the lathe, but I hand-cranked the hobbymat to take extra care.

Finally an image of all 4 wheels:



A lot of hours have gone into the wheels, a process of research, drawing, machining, re-machining and finally assembly.

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KustomsbyKent (Jun 6, 2020)

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## editor@glue-it.com

I've literally been back to the drawing board for the miniature traction engine to work out the detailed design of the next few parts.



The firebox is a challenge, but feels like I have a reasonable way forward. 

The engine feels a bit more tricky, plan was to create a bracket on the boiler that is brazed in place and the cylinder bolts to it, just not sure if I should use brass for this due to corrosion?

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## thehomeengineer

Hi 
I have added a link to my boiler I made to L.C. Masons design which might help. If you plan on steaming I would try and keep to a all copper construction and the boiler bushes made from bronze. I made the stays from copper.
Practical Engineering
Practical Engineering
Practical Engineering
The Home Engineer

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editor@glue-it.com (Jun 9, 2020)

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## editor@glue-it.com

Hi Home Engineer, great website and lots of information. Will have to have another look at the cylinder block and mounting to the boiler. My issue is the scale 12mm bore and stroke. Boiler is 1.75" in diameter and so quite hard to make exactly scale, but might have a go. Must admit that I hadn't realised that the bolts go through the boiler shell for the cylinder mounting. Thanks, Nigel

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## editor@glue-it.com

Just been trying to pull together reference material around dezincification of brass and to get a summary together, basically use Phosphor Bronze for all bushes and boiler fittings. 

Conditions that can make leaching worse are:
1. Slightly acidic or slightly alkaline water
2. High levels of chlorine in the water
3. More than 15% zinc in the brass alloy
4. Low flow rates and low levels of aeration
5. Relatively high tube wall temperatures

The general consensus being "why did you even ask about using brass fittings"

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## editor@glue-it.com

I had some real fun machining the hole through the firebox on the rotary table. It was all setup after doing the outside edge and just thought why not??



As you can see in the next image, the intention is that the boiler is a simple cylinder and the end sits in the firebox. The boiler has 7 flues for the hot gases to flow through to the smokebox.



I have a few videos of the machining processes

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## editor@glue-it.com

I silver soldered the mild steel boiler together



and then cleaned it up



Quite a lot to do though still on the miniature traction engine.

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## editor@glue-it.com

What is it about model engineering that makes us all sit with a beer and gaze at what we've made?



What am I going to do when it's complete?

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## mklotz

> ...What am I going to do when it's complete?



I faced the same problem with my collection of engines.

I take them around to local middle schools and provide a one hour informal (kids sitting on floor) talk on the evolution of prime movers from early atmospheric through proper steam, a detour to Stirling, and then on to steam electric generators. We talk about belt drives, reversible engines, steam pumps, and other facets of the emerging technology. Almost every aspect of the talk is a discovery for the kids; they've never heard of steam trucks and steam rollers.

The kids love it and they get to "help" me open and close valves, lubricate bearings, and use blowpipes to operate breath-powered engines.

In the interest of classroom safety, a small airbrush compressor doubles for a steam boiler.

Most of the time the teachers are dumbfounded and the kids are enchanted.

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editor@glue-it.com (Sep 28, 2020)

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## editor@glue-it.com

A very small block of mild steel forms the firebox door and an even smaller block on top is the blank from which I'm making one half of the hinge



then after an hour or so with the manual milling machine I had the outline of the door hinge



I think this solid version is much better than my rough initial idea of using brass angle - two misaligned holes for rivets doesn't help the look either

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## editor@glue-it.com

The firebox door now has working hinges and a latch, it is so small and I've just had to look at it for quite a while to work out how to make it. Not sure it is scale, but hopefully it will look right on the finished engine, a few more details of the build here



a short video of it working

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## editor@glue-it.com

The smokebox door has taken me in a number of directions in my pursuit to create the lettering. Finally I might have got the process and now just need to hone it, but as the outer ring on this image is just 35mm in diameter I am rather pleased with the result to date



I've detailed the process of brass etching using inkjet paper and a laser printer so I can share it with everybody. Great for everything from making name tags, keyrings and miniature parts.

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## editor@glue-it.com

Creating the hinge for the door has been a bit scary, so much has now gone into the parts. So, I created an elongated hinge and a jig to ensure alignment.



This next image shows the result



Once silver soldered the brass tube was then cut into the sections, this just ensured it was all aligned.



It's not perfect, but at this small scale I'm pleased.

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Jon (Dec 3, 2020)

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## DIYer

Thanks editor@glue-it.com! We've added your Hinge Jig to our Model Making category,
as well as to your builder page: editor@glue-it.com's Homemade Tools. Your receipt:















Hinge Jig
 by editor@glue-it.com

tags:
jig, soldering

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## editor@glue-it.com

I squared up the ends of a piece of square mild steel, set a flycutter to the diameter of the smokebox and so machined one surface.



Then some work on the rotary table and finally I riveted it to the smokebox



the axle is next

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## editor@glue-it.com

The axle is 3/16" square mild steel, machined with a 6° taper on each face from just off-centre to the hub. 



The wheel is held on the axle with a 6BA bolt and washer in the end of the axle. The hub cap fits over the top and is secured with 3 off 10BA bolts



This all now rotates and rocks on the steering bracket under the smokebox.



I will piece together another video to show the parts and build to date of this 1/20th Scale Burrell

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## editor@glue-it.com

Brass plaque etched again and this time nearly perfect, this time I used acetone to clean the plate before applying the resist.

The brass plaque is fixed with two countersunk bolts, these will be nearly hidden by paint in the end.

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## editor@glue-it.com

How many times do you machine something and afterwards think "I wish I had done that the other way around"?

Well, this was the case with the chimney for the Burrell



I machined this from 3/4" round mild steel with a 2.5° taper. The issue is I machine the outside first which meant the whole thing was then supported by a narrow neck section with a thin wall. So the inner surface cut at the same taper with a boring bar did chatter quite a lot. Issue is the bar was small (this part is not very big) and had quite an overhang.



The good side is the outer surface is very clean and this is the one you will see more of, maybe I go it right.

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## editor@glue-it.com

Managed to make the brass top for the chimney and silver solder it in place

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olderdan (Jan 22, 2021)

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## editor@glue-it.com

Just marked out the hornplates in brass, I extended them further to include the main body. This was mainly down to the scale.

I use a large blue permanent marker rather than engineers blue and on brass it works really well



I then cut them out on the bandsaw - I back the brass with MDF when cutting on the bandsaw, this works really well



Finally just assembled the parts to show progress and how the hornplates/body works

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baja (Jan 27, 2021),

Jon (Jan 24, 2021)

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## editor@glue-it.com

I wanted to solder the hornplates and tub together. I'd already used some rivets, but wanted to lock it and stop any rotation to improve the accuracy. However, even though this is a very small traction engine I found the 75 Watt soldering iron a bit inadequate. So, what about soldering with a hot air gun? It's quite normal in the electronics industry.



I used a hot air paint stripper, in this case a 1600 Watt unit. Lots more heat and it works over a bigger area.

Well, this worked really well and I found it much better than an open flame torch as these can create oxides on the surface.



I have some more baffles to add to create a floor, water tank etc and I think I will be going back and using this approach again.

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billster (Feb 3, 2021),

chainsawd (Feb 3, 2021),

H.L (Feb 3, 2021),

johncg (Feb 3, 2021),

trigger (Feb 2, 2021)

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## trigger

Playing with the nozzle shape will give your heatgun some serious capabilities in smaller or complicated areas.Adding a reostat makes it a super tool for precise temp application.

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## Elizabeth Greene

Could you share what solder you used?

Thanks!

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## editor@glue-it.com

> Could you share what solder you used?
> 
> Thanks!



Just taken a picture of the reel of solder


Looking this up online: Draper Expert SW3, 19227 250g Reel of K60/40 Tin / Lead Solder Wire - and no longer available as it contains lead.

I haven't tried this with lead free solder, will have to have a go. I must admit that I pick up reels of solder at car boots as these are normally the older lead based solders and much better for a lot of the hobby work that I do.

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## editor@glue-it.com

Here's an image of the simple rivet anvil that I made to support the rivet head whilst I hammer it closed.

It's made from a piece of 1/4 inch thick mild steel and has a 4mm blind hole in the end. In this hole sits a piece of silver steel that has a concave impression to support the rivet. I hardened and tempered this piece of silver steel. The punch is not fixed in the bracket just in case it needs changing.

Also, I sandwich the mild steel bracket with a sheet of aluminium in the vice as this then adds some compliance and so more easily maintains the clamp load. You might think this piece of soft aluminium would work against you, but it has compliance and so allows the force to be maintained after micro movements of the parts. Either way the anvil stays in place better with the aluminium than without.

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Philip Davies (Feb 12, 2021),

Scotsman Hosie (Feb 13, 2021),

Wildwilly (Feb 11, 2021)

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## editor@glue-it.com

I've machined the Phosphor Bronze rear axle bearings and bolted them into place with 12BA bolts - the 1.05mm diameter tapping drill is difficult to deal with let alone the tap. Anyway, all 6 fixings are in place now.


Then I just had to put an axle in place, this is just temporary as I need to make a differential yet


The engine was designed so that the drawing in elevation would fit onto a sheet of A4 paper. Then here it is sat on top of my A4 sized notebook. The traction engine is 263mm long, 122mm wide and 176mm high.

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## Wildwilly

Interesting, but with only the one picture of the rivet anvil, it is very hard to comprehend. A video of this in use would be explanatory I believe. Thx.

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## editor@glue-it.com

> Interesting, but with only the one picture of the “rivet anvil”, it is very hard to comprehend. A video of this in use would be explanatory I believe. Thx.



Hi, I will see if I can video using it, might have to try some different angles so that it is possible to understand fully. Thanks for the feedback, Nigel

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## editor@glue-it.com

> Playing with the nozzle shape will give your heatgun some serious capabilities in smaller or complicated areas.Adding a reostat makes it a super tool for precise temp application.



Hi Trigger,
Sadly the old Black & Decker hot air gun gave up after 27 years. So, I had a look around and bought one of these Seekone Heat Guns. It's just arrived, so will see how I get on with it. But, I mention it as it has temperature control (sadly I think open loop) and a range of nozzles that can focus the air:


Will update you all once I try it out. Best regards,

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## editor@glue-it.com

I've had some fun making the flywheel for the Burrell. It's only small, but took some work to machine it from solid cast iron.

The initial flywheel design was a tad heavy.



So, I had another go at visually improving the flywheel.



My quick video of the steps in the process, hopefully you will enjoy the "hand powered belt sander"

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## DIYer

Thanks editor@glue-it.com! We've added your Rivet Anvil to our Anvils category,
as well as to your builder page: editor@glue-it.com's Homemade Tools. Your receipt:















Rivet Anvil
 by editor@glue-it.com

tags:
rivet, anvil

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## editor@glue-it.com

> Interesting, but with only the one picture of the “rivet anvil”, it is very hard to comprehend. A video of this in use would be explanatory I believe. Thx.



Hi, I film some video of me rivetting the towbar onto the tender, hope this helps

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## editor@glue-it.com

Finally I'm making that small boiler, this is the first boiler I've made. Although it's very small and below the size that requires independent testing (less than 3 bar litre) my plan is to hydraulically test it and do all of the normal sign-off testing that is required.



Would be good to hear from people who have experience making boilers and testing them.

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chainsawd (Mar 17, 2021)

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## editor@glue-it.com

This boiler is just 117mm high and you can see it here alongside the traction engine:



I have now hydraulically tested this to 2x working pressure



I used a simple garden sprayer - a small modification to the nozzle to fit a pipe. This easily gets to 100psi and I think it would get to 200psi - need a gauge.

I've written a brief article on making the boiler.

I will share more on testing as I need to ensure no issues under steam.

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## editor@glue-it.com

A simple modification to the sprayer nozzle and you have a pump that can pressurize a water volume at over 100psi - perfect for hydraulic testing





the fixed nozzle of the sprayer seals against the rear flange of the new brass fitting


I had to use cable ties to keep the pipe secure on the nozzle with the pressure

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## editor@glue-it.com

Lighting the methylated spirit burner on this small vertical boiler can be quite tricky, I made a slow-motion video to show the problem:




Note: don't try this at home

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## editor@glue-it.com

I needed a grate for the fire, but cannot cast iron and so made one from solid. This meant I needed a jig to hold the disc:

 

The jig was made from aluminium and it meant I could flip the part over and so machine both sides without damaging it. There were a few steps to making a cast iron grate, but it was very enjoyable. I think the finished part looks good even though you will only ever get a glimpse of this in reality.

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## jdurand

Interesting, I would have done it using square bars and welded or bolted from the back depending on need.

Surely looks solid!

I do like the look of things that are carved from a block with holes where people might not expect them.

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## editor@glue-it.com

> Interesting, I would have done it using square bars and welded or bolted from the back depending on need.
> 
> Surely looks solid!
> 
> I do like the look of things that are carved from a block with holes where people might not expect them.



I probably could, but the beams are only 3mm wide and 3mm apart. Welding could be done with solid bars. Not sure I can easily find steel square tubing. 

I agree, there are many ways of doing this.

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## editor@glue-it.com

I'm in the process of making two fireboxes, one for methylated spirit and the other for coal. I know, why?



In all honesty I just wanted to have a play and see. This way I can learn about firing with coal and see how hard it is with a tiny boiler. The boiler with the firebox and chimney is just 105mm tall (~4 inches). Air, coal mass, thermal mass, air draft etc is all going to be an issue. I will go through this and share my pains.

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## editor@glue-it.com

This small boiler is driving me a bit mad, I'm struggling to get the heat into it. It gets to temperature and pressure, but it takes ages considering the meths burner I'm using.

So I decided to instrument the boiler with thermocouples and to then do some measurements.



I'm using a Pico Technology measurement board and software, very easy to use. I will share the data and my analysis.

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Jon (Apr 5, 2021)

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## jdurand

Problem with small boilers is surface to volume ration is bad. A lot of radiating surface with a small volume.

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## editor@glue-it.com

> Problem with small boilers is surface to volume ration is bad. A lot of radiating surface with a small volume.



Yes, and I've made this worse by making the length versus diameter quite large - the opposite of a sphere...

However, when I "turn the wick up" on the burner it gets hot very rapidly. So, a lot more work to get the balance of this design right.

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## editor@glue-it.com

Making some big assumptions I've made a very simple mathematical model of the boiler


Then using the cooling curve data I've estimated the heat loss to be 35W at the operating pressure of 40psi (140°C).

This then allowed me to look at estimating the heat input from the first design of the methylated spirit burner. It is a bit variable, but probably expected as it uses a chicken feeder and there is some air flow.



The heat input for this first design is around 54W. This is why I was seeing a very marginal capability for this boiler.

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## editor@glue-it.com

I've now run a few experiments to understand the optimum distance between the spirit burner and the boiler. Normal practice is that the hottest point is at the tip of the inner blue flame, however, there is a depth to the boiler surfaces as shown by this diagram.



So, using the simple assumptions, a new firebox and some more measurements on the instrumented boiler I get the following curve:



This plot shows that the peak in heat output is when the burner is around 85mm from the base of the boiler. Also, it shows that this firebox and burner is producing nearly double the amount of heat that the original design generated.

I checked this calculation by looking at the boiler temperature versus time data. The original firebox and burner took just under 8 minutes to take the water from 60°C to 100°C. The new firebox and burner took just over 2 mins 30s for this same temperature change. You have to consider heat losses and heat input, but this makes sense.

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## editor@glue-it.com

I wrapped the boiler and electrically heated it so I could estimate the heat loss. This way I could then compare unclad to maximum cladding.



At the designed operating point of 40psi and 140°C bulk water temperature the heat loss unclad is ~35W and with maximum cladding it is around 12W.


The cladding is a lightweight fleece, then a aluminium coated bubblewrap.

This has made me realise that I could make a low voltage miniature immersion heater - I will post something on this.

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## editor@glue-it.com

I think I now have most of the parameters for an optimised design of the firebox for the small vertical boiler. At last I can finish it and get back to the traction engine. So, I ordered a bar of 2" mild steel hex. However, when it turned up I just couldn't turn it into swarf....



So I thought I could make the firebox from sheet metal, trouble is my sheet metal skills are not that great.



However, I'm quite happy with this, now to add a door for the meths burner and some louvres for air.

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## editor@glue-it.com

I've been struggling to get heat into the boiler. So I instrumented it to understand the heat losses and to optimise the burner location. 

Then I made two types of steam raising blowers.

Left: compressed air jet Right: electric suction fan

What is interesting is that both give a similar performance. Below is my calculated heat input to the boiler versus time for the two blowers and you can see them switched on, off, on and then finally off.


The heat input to the boiler using the simple methylated spirit burner increases from ~50W to ~350W with either blower on.

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## editor@glue-it.com

A video describing the blowers and the data

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rlm98253 (May 12, 2021)

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## editor@glue-it.com

Finally I'm back to the 1/20th scale Burrell traction engine. My new problem to solve and design is the cylinder block.

I have an idea for creating a plate that is silver soldered to the boiler and forms the joint. The cylinder is then mounted one side and the boiler the other.



Me offering up the Stuart 10V that is 1.5x too big at 3/4" bore and stroke. The Burrell will be 12mm bore and stroke.



This bracket would be easiest made from brass, however, it's best to avoid using brass due to dezincification.

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## editor@glue-it.com

Back onto the traction engine and whilst waiting for material for the cylinder block I roughed out a steering wheel.



This is 22mm in diameter (~7/8")

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## editor@glue-it.com

I turned the other side, filed the spokes and then tumbled it for an hour.



It's not perfect, might have to make another one, but were traction engine steering wheels perfect anyway?

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## editor@glue-it.com

I've now added a fast handle to the wheel. A complete steering wheel for the Burrell, around 6 hours of work

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## editor@glue-it.com

The cylinder block has taken some thought. The single cast iron block bolted to the boiler forming a seal felt difficult to achieve at this scale.

My solution is to create a saddle with an upright backbone that becomes the mounting plate. This part can then be silver soldered to the boiler. 

This saddle part is shown with the green cross-hatching, the boiler shell with orange cross-hatching.

This is the roughed out part sat on the traction engine

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## rendoman

That project is wonderful!

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editor@glue-it.com (Jun 25, 2021)

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## editor@glue-it.com

> That project is wonderful!



very kind, thanks

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## editor@glue-it.com

I thought it was time to just talk about the Miniature Traction Engine and show everybody how I'm approaching some of the build:

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Jon (Jun 25, 2021),

rendoman (Jun 25, 2021)

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## editor@glue-it.com

I've been machining the cavity around the Burrell cast iron cylinder.



however, my first task was adjusting the HV4 rotary table to remove any play. Not mentioned in the instructions, so I had to find out for myself:



I found I had to:

1. rotate the worm drive out of use so the table can be rotated by hand
2. loosely tighten the caphead bolts, not too tight or the table won’t rotate
3. adjust the grub screws so that you can just feel they are bottoming out
4. tighten the caphead bolts, I tighten one and then the opposite one.
5. if you cannot rotate the table then backoff slightly until you can
6. adjust the grub screws to be tighter and so back the washer off
7. you can now use the leverage to feel for play in each direction
8. go back around steps 4 to 7 until the table has no play, but can still rotate

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## editor@glue-it.com

The steering worm and wheel are quite small and so I had to make a 6mm diameter 2mm pitch hob to finish cutting the profile in the wheel.

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Home-PC (Jul 14, 2021)

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## editor@glue-it.com

Making the parts and assembling the steering bottom end has been quite enjoyable. The worm and wheel are working really well, a really good snug fit.



I can now turn the steering wheel and the steering drum rotates. Now I just need to add the chains and I will have a working steering system.

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KustomsbyKent (Jul 14, 2021),

rendoman (Jul 14, 2021)

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## editor@glue-it.com

Here is the steering system working

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## editor@glue-it.com

Just made the crosshead guide or trunk guide. 



Not quite a scale crosshead for a Burrell, but I wanted something that works at this scale. I might still put it back in the lathe to tweak a couple of the dimensions to make it more compact.

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## editor@glue-it.com

The crosshead guide has been concerning me, so I bolted it to the cylinder. The marking out for the bolts took some time to think about and achieve. 



The crosshead guide in context actually looks ok, I might thin down the wall thickness. 1.5mm could go down to 1.2mm

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## editor@glue-it.com

Now onto the crankshaft. If you remember my earlier design discussions I was struggling to see a way to getting a 6mm throw and hence 12mm stroke. Well, there are a few things that help this: 1. offset of the cylinder and curvature of the firebox 2. ability to lift the bearing blocks slightly 3. two-piece crankshaft and hence single piece conrod big-end.

So here is a sketch of the crankshaft:



I assembled and silver soldered this with a single piece main shaft. That made it easy to align everything and machine surfaces. One of the last actions was to then split this main shaft and machine back to the internal web faces.



Just to prove it still splits into two:

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EnginePaul (Jul 27, 2021),

Paul Jones (Jul 28, 2021)

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## editor@glue-it.com

I've lifted the bearing blocks 1.5mm and I now have clearance to the firebox



it's tight, but that was always going to be a challenge with this 1/20th scale Burrell.

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## editor@glue-it.com

The cylinder saddle is firstly being bolted to the boiler, thus ensuring alignment before I silver solder.



The homemade phosphor bronze bolts are to avoid the possibility of dezincification of brass parts that are permanently fixed to the boiler.

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## editor@glue-it.com

I machined the Burrell valve chest out of a piece of solid brass and then made the centre valve shaft bearings as one.



Once this was silver soldered together I then machined out the centre.



Hopefully the bearings for the shaft are still aligned.

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## N00b Machinist

This’d’ve made Joe’s heart glad.

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editor@glue-it.com (Aug 30, 2021)

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## editor@glue-it.com

The steam valve in this 1/20th scale engine is challenging and so I thought I would talk through the options:

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## editor@glue-it.com

Having machined the valve chest and cover I needed to create the nameplate. At first I thought it should be just a capital N for me, but in the end I decided it should be a proper Charles Burrell nameplate.

The first one was OK:



but I thought I should make a few more and select the best.

So, another 4 and I think the best one is this one:



The black is just permanent marker for now to give some contrast so I can see if it is ok. In the end it will be painted.

I had a lot to live up to as my dad made this clock and etched the face over 30 years ago. He created the mask using a UV sensitive film and creating a photographic plate (in darkroom he had built into the roof space of my childhood home).



PS: this clock keeps good time.

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rlm98253 (Sep 3, 2021)

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## editor@glue-it.com

Looking in more detail at the steam valve design. The schematic looks reasonably simple. However, I've been looking at a number of references to try and improve my background knowledge of steam valve design.

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## editor@glue-it.com

In preparation for silver soldering the phosphor bronze saddle to the boiler I've been running some coupon tests.

Effectively looking at applying silver solder in different locations on the bolted sandwich of copper and phosphor bronze.



Interestingly the silver solder happily tracks (capillary action) through the joint, including through the threaded section.



The right hand side configuration appears to have given the most complete joint. I then sectioned the joints:



You can see that on the LHS the thread of the bolt has voids where silver solder has not tracked completely through all interfaces. 

Left and right hand side parts are consistent through the images, although I have had to mirror some of the images to make this consistent (this doesn't affect the results).

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Ralphxyz (Sep 9, 2021),

yvonf (Sep 8, 2021)

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## editor@glue-it.com

Around the saddle I want to mask so that I can control how far the silver solder goes. I did some research and there are lots of options from liquid paper to yellow ochre. However, the option readily available is the graphite pencil:





This appears to have worked ok.

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## editor@glue-it.com

I've been stuck for a few months, a total roadblock on how to make the steam valve. Especially as I have machine this into the PB saddle that itself has had lots of hours put into it. But, after a clean up of the workshop it is back on the bench. I will solve this problem.




There are a few more items on the list of next things to do on the Burrell

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clydeman (Nov 2, 2021)

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## editor@glue-it.com

I made the decision to make the steam control valve a remote valve. 




The best bit is I made a decision and this allowed me to move forwards. So I could then silver solder the saddle to the boiler.

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KustomsbyKent (Nov 2, 2021)

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## Canyonman44

Looking Good!!!!!!!

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editor@glue-it.com (Nov 4, 2021)

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## editor@glue-it.com

The double eccentric will give me forward and reverse, however, I thought it was going to be tricky machining it. I think it turned out ok.

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## editor@glue-it.com

For the vertical boiler I came up with a multi-layered insulation. For the Burrell traction engine this needs to be shrunk down to 1.5mm in thickness, quite a challenge.

So, I have built a boiler thermal new test object.



It's heated in the centre using a 50W ceramic heater (4mm diameter). I will then use the cooling curves to estimate the heat loss.

I will look at the maximum insulation and then a few more sensible options.

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## editor@glue-it.com

A short video showing the setup with the end supports:



Interesting to see the thermal conductivity of wood and where balsawood sits on the curve.

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## editor@glue-it.com

After a lot of help from a fellow steam model engineer I've managed to make and silver solder the boiler end plate stiffeners in place.



I think I'm a gluten for punishment pursuing the silver soldering in a kiln. The Easy Flo 24 did not flow as well as some of the lower temperature silver solders.

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nova_robotics (Nov 22, 2021)

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## editor@glue-it.com

The boiler test object is generating repeatable cooling curves



This is great, but what is the heat output of the object



So I now have a curve that gives me heat output against a delta temperature compared to ambient.

Next is the maximum insulation versus the unclad boiler:



This shows quite a significant difference:



Interestingly this boiler is just a piece of copper pipe and so I can compare my heat loss data of the unclad boiler to published heat loss data of copper pipes:



That looks like not a bad match considering we don't know the surface condition of the copper pipe.

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## editor@glue-it.com

The old flat smokebox door really annoyed me. So, after making a tool to machine a radius of 71.4mm I turned a domed door.



I then annealed and pressed the brass plaques to shape, I used a sheet of rubber and two blocks of wood in the vice to do this.



It's only a small change, but I think it looks much better.



The engine with radiused smokebox door sat on my A4 notebook.

Merry Christmas and Happy New Year to everybody who has supported me over the last year, Nigel

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## editor@glue-it.com

I've now got the door hinge made and the brass plaques bolted to the door. Moving forward again after deciding the flat smokebox door wasn't good enough.

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carloski (Jan 11, 2022)

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## editor@glue-it.com

I've now made the Burrell door handles and the locking system, this now all works at 1/20th scale.


This hopefully shows the basic locking system. 

The Burrell door lock is a T-head bolt with flat sides on the threaded section. This bolt goes through the door from the back, a handle with a slot then goes on allowing the bolt to be rotated. A second handle with a threaded not then allows the bolt to be pulled up tight.

In the smokebox a beam goes across the diameter of the opening and has a slot in it to allow the bolt head to go through. Then the bolt is rotated and hence the T-head gets a purchase on the beam.


The handles were made as one part based on them being so small and then I split them into two parts later.


Still lots to do

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## editor@glue-it.com

I’ve been thinking about the Burrell gearing for some time. Calculating the overall ratio, estimating the maximum torque and speed of the traction engine. 

I think 1000rpm is a good top speed for this small double acting engine. The rear wheels are 97mm OD and the gearing gives me around 10:1 

My simple calculation says that this will give me 1.1mph or ~0.5m/s which feels reasonable for an engine that might run on my dining table.

This is very similar speed to a Mamod Wagon with 2000rpm, 16:1 and 75mm OD wheels

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## editor@glue-it.com

12mm bore at 60psi is ~45N on the conrod

14mm stroke means ~0.32Nm of torque at the flywheel

hence 3.2Nm at the wheel

the drive wheels are 97mm OD and so hence 32N of tractive effort and the engine will be around 1.8 to 2kg

Also, I'm likely to run at a pressure of 45psi mostly and so I think around ~24N

That should be fine

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## editor@glue-it.com

Just been working out how to get to 10:1 as an overall ratio and where the layshaft can go.



then some calculations of the options (using excel)



and I think I have a sensible result



Next step is cutting some gears  :Smile:

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## editor@glue-it.com

the first prototype differential for the Burrell, some way to go yet, but hopefully you can see what I'm trying to achieve

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nova_robotics (Mar 1, 2022)

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## editor@glue-it.com

a still image of the gears here

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## editor@glue-it.com

I have to firstly say a huge thanks to JG for sorting out the angles and cutting of these bevels. I thought I knew how to cut them and they would be easy....how wrong I was  :Sweating: 

I spent a happy hour (no drinking) setting out a 9.5° angle on the milling table and then aligning the rotary table to it.





Now I have to go and cut those gears. Must admit that the cost and effort required in fitting the DRO has been paid back several times over...and it isn't the simplest thing to fit  :Big Grin:

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## editor@glue-it.com

The differential has not started again, but there is a different angle on the Burrell. 

I have to say a big thanks to JG for contacting me and offering to calculate the correct angle for the bevels. As you probably saw in the above youtube they don't run that well. JG's calculations showed that the angle needs to be close to 9.5° rather than 20°, hence last post on setting out the 9.5° on the table.



Since then I have managed to re-cut the crown wheels. Perhaps I should not have re-cut them, but there was enough material in them still.



plus, this has thinned down the whole assembly. Although, note that the next image isn't using the correct pinion wheels - they are to be made from scratch again as 10T and 9.5°



Thanks and remember the whole story of this design and build is in minute detail here: Miniature Traction Engine

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## editor@glue-it.com

The differential has taken some time to get to even operate. However, after making some shims to space the crown wheels correctly I have something that operates.




I might still re-make this, but for now I know I can get something that works as a differential. In practice it will not actually see that much work and so it is probably ok.

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## editor@glue-it.com

I thought this little differential warranted a bit more of a video around it's assembly, the shims and me "running it in" at a stupid speed....

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johncg (Apr 6, 2022),

KustomsbyKent (Apr 19, 2022)

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## editor@glue-it.com

Just machined a solid phosphor bronze rear axle for the Burrell. OK, this isn’t a solid rear axle like a 1960’s muscle car. This is an actual solid round phosphor bronze bar that supports both rear wheels to rotate independently and then the differential sits on a separate layshaft.



and then just so that you get an idea of the scale

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clydeman (Jun 15, 2022),

DIYer (Nov 10, 2022),

Jon (Jun 16, 2022)

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## rendoman

Wow! impressive work!

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editor@glue-it.com (Jun 15, 2022)

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## editor@glue-it.com

Just been silver soldering the parts for the rear hub caps and thought I would share the process of using easy flo paste, very easy to get great results on small parts

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## editor@glue-it.com

I've had a bit of a break from building this, however, in the last few days I've sorted the rear axle and the rear hub caps. Now I think it is taking shape. On my latest status page of the Burrell Traction Engine there are even more images.

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## editor@glue-it.com

Finally the Burrell is back on the workbench and I've made the connecting rod from 3 parts

Here with the phosphor bronze big end in place. Hopefully the matchstick gives you an idea of scale.


The conrod was assembled from 3 parts

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## editor@glue-it.com

Spent a few hours making the eccentric pushrods and then testing them on a drill:



The two eccentrics gives the ability to run the steam engine in forward and reverse. I need to make up the slider, crank and handle etc




They need a bit more fettling and finishing of the eccentric pushrods, but I'm happy for now.

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## editor@glue-it.com

The differential sits on the layshaft and this takes a bit of thinking about. Hopefully the following image helps.



The drive and neutral is achieved by sliding the crankshaft gear out of mesh.




Lots more to do, but gradually getting closer to completion.

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kboy0076 (Dec 5, 2022)

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