# Best Homemade Tools >  Grinding machine for drum brakes.

## tonyfoale

Drum brakes are a thing of the past arent they? So why would I want to make a grinder for motorcycle drum brakes when disc brakes are so much better? Well, I race motorcycles in classic races. That means old farts wobbling about on old motorcycles. Classic racing organisations have eligibility rules constraining the bikes to use features from way back. Each organisation has its own rules, but the ones that I race with ban disc brakes in the categories that interest me. So instead of using nice efficient disc brakes I have to try and squeeze the maximum performance from drum brakes.
With use drums become distorted and also the rubbing surface can become very hard and shiny. This is not good for optimum braking and it requires a lot of cutting force if you try to machine it with a single point lathe tool. Hence it is better to grind which can dramatically reduce the cutting forces and strain on the tool used.

 
Here are a couple of pix. of the device that I made. Although I always grind drums using a complete wheel these photos are without a rim. It is only necessary to move the drive motor closer to enable the belt to fit onto the rim rather than the hub.

Spoking a rim onto a drum brake hub causes addition distortion to the surface of the drum and so any truing of the drum should be done with the wheel complete and not just the hub.
Many hubs are difficult shapes to mount in a lathe accuratelyeven if you have one large enough for the whole wheel, and in any case to ensure accuracy it is better to rotate the wheel about it own bearings to ensure true concentricity of the drum.
I have a lathe just large enough for a wheel and an internal tool post grinder, however I decided that it would be better to build a tool dedicated to just grinding drums.
Here are a couple of pix. of the device that I made. Although I always grind drums using a complete wheel these photos are without a rim. It is only necessary to move the drive motor closer to enable the belt to fit onto the rim rather than the hub.

 
I made a frame out of materials from the scrap box. I used a stick welder to glue the frame together and machined the assembly in a milling machine to ensure good alignment of all surfaces. 

 
I also added some fences machined at right angles to ensure good alignment.

 
I have a cross slide that I kept from an old very worn lathe that I scrapped which was ideal for the traversing axis of the grinding head. I machined on shoulder on the bottom of the cross slide base which aligns on one of my fences. The other two mounting faces are for aluminium clamps to hold the wheel axles.
Here are shown the finished frame and the base of the cross slide with the machined alignment surface which locates against the fence on the frame.

 
These two photos show a ground steel bar being used to check alignment of the wheel axle mountings.

 
These pix. show the old cross slide mounted which is the first stage of the assembly. The other shows the cross slide and QD tool post temporarily borrowed from my working lathe. Also shown is the wheel mounting method.


Detail of the wheel mounting. The wheel rotates about its own bearings and there are two of these tapered nose shafts which locate the bearings. The piece of All-Thread holds these shaft tight against the bearings. The shafts are 25mm. and so are suitable to cater for 15, 17 and 20mm bearings which are all that interest me.

 
The grinding is done with mounted points driven by a high speed (30,000rpm) turbine style die grinder. That is mounted in a fixture for the QD tool post. I made the bracket to enable internal grinding on the lathe.

 
Here we see the finished tool set up ready to grind. The lower slide does the in and out traversing of the grinding head whilst the upper one at rt. angles adjust the depth of cut.

In practice the tool works really well and I can now set up drum brakes better than I have ever managed in the past. For those interested in optimising motorcycle drum brakes I developed some simple software to help design the important placement of the friction material on the shoes. This is important to get the right balance between a brake that grabs too fiercely and one that doesnt brake well enough. That software can be downloaded FOC from the Freeware section of my web site.

A tool like this can also be configured to do car drums as well as motorcycle ones. It is just a matter of making a shaft with a fixing plate for the drum and spinning the shaft between centres or adding bearings. Without too much modification it could also be used for discs.

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asterix (Sep 19, 2022),

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carloski (Nov 11, 2021),

Crusty (Sep 20, 2019),

Frank S (Dec 22, 2016),

high-side (Sep 13, 2019),

Home-PC (Nov 12, 2021),

jcorpx (Sep 12, 2019),

mwmkravchenko (Sep 11, 2019),

olderdan (Dec 24, 2016),

Paul Jones (Dec 24, 2016),

Quinton 357 (Sep 11, 2019),

Seedtick (Dec 24, 2016),

sossol (Jan 14, 2018),

thevillageinn (Sep 18, 2022),

Toolmaker51 (Dec 26, 2016),

Vyacheslav.Nevolya (Jan 1, 2017)

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## Frank S

Tony I like it. When single point turning on a lathe it is often hard to get under the Bilby layer ithout having to machine out more than you actually want.Your grinding method makes perfect sense

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mwmkravchenko (Sep 11, 2019),

Paul Jones (Dec 30, 2016),

tonyfoale (Dec 23, 2016),

Toolmaker51 (Dec 26, 2016)

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## tonyfoale

> Tony I like it. When single point turning on a lathe it is often hard to get under the Bilby layer ithout having to machine out more than you actually want.Your grinding method makes perfect sense



"Bilby" layer, I think that should be Beilby but no matter. Until now I had never come across that term, it is nice to start the day with some new knowledge, thanks for that. My problem will be remembering it.

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Toolmaker51 (Dec 26, 2016)

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## DIYer

Thanks tonyfoale! We've added your Drum Brake Grinder to our Motorcycle category,
as well as to your builder page: tonyfoale's Homemade Tools. Your receipt:















Drum Brake Grinder
 by tonyfoale

tags:
grinder, brake drums

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## Frank S

> "Bilby" layer, I think that should be Beilby but no matter. Until now I had never come across that term, it is nice to start the day with some new knowledge, thanks for that. My problem will be remembering it.



 Yes, I sometimes drop letters or even manage to arrange them it totally useless sequences. 
The keyboard on my laptop also jumps and will start off trying to complete sentences wherever it wants at times.
The Beilby layer is sometimes formed by air or work hardening due to heat, friction or percussion. The use of a sharp prick punch on the surface of a sample can also be used as a way to determine fatigue areas even where no apparent cracks are yet visible on the surface, where constant flexing has occurred over a long period of time.

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Paul Jones (Dec 30, 2016),

PJs (Jan 2, 2017),

Toolmaker51 (Dec 26, 2016)

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## tonyfoale

> The Beilby layer is sometimes formed by air or work hardening due to heat, friction or percussion. The use of a sharp prick punch on the surface of a sample can also be used as a way to determine fatigue areas even where no apparent cracks are yet visible on the surface, where constant flexing has occurred over a long period of time.



Yes. I am well familiar with the concept, it was the name that I didn't know until today, thanks again.

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## crazypj

Nice tool,

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## crazypj

Nice tool, been thinking about making 'something' for a while as I've built a load of wheel last few years and bought a cheap Chinese multi axis 'milling' vice which I never ended up using
What is the outer diameter of that drum though? I'm assuming your using 18" or 19" wheels so it must be huge as there doesn't seem to be enough clearance if it's 180mm drum (maybe just camera angle?)
Oh, found picture, it was the red Suzuki with FFE (funny front end  :Thumbs Up: )

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## tonyfoale

> Nice tool, been thinking about making 'something' for a while as I've built a load of wheel last few years and bought a cheap Chinese multi axis 'milling' vice which I never ended up using
> What is the outer diameter of that drum though? I'm assuming your using 18" or 19" wheels so it must be huge as there doesn't seem to be enough clearance if it's 180mm drum (maybe just camera angle?)



The frame was made to take up to 19" wheels although I don't anticipate anything other than 18". The hub in the photos is from a Kettle. Dual sided 200mm diam.




> Oh, found picture, it was the red Suzuki with FFE (funny front end )



That one was made as a project bike for SuperBike magazine. It is in private hands now but is still being used by its owner for track days, sprints and road use. Not bad for a 30 year low production machine. In fact I built around 7 or 8 of them and I know of 5 or 6 that are still in use or being restored. Here are a couple more pix. It had a key-less controls, Ignition, lights etc. controlled from the number pad protected by a PIN number. That was back in the 80s.

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olderdan (Dec 24, 2016)

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## olderdan

Great machine and a solution to a common problem, it certainly beats my method of gluing diamond cloth on sacrificial brake shoes and riding round the block a few times.
Great web site by the way, I will register soon out of interest.

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Paul Jones (Dec 30, 2016),

tonyfoale (Dec 24, 2016)

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## tonyfoale

> Great machine and a solution to a common problem, it certainly beats my method of gluing diamond cloth on sacrificial brake shoes and riding round the block a few times.
> Great web site by the way, I will register soon out of interest.



Dan,
I have done similar, and it can remove the glaze and restore some braking but it doesn't do much for an out of true drum.

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## tonyfoale

Delete....

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## Dr Stan

Very good design & execution. I'd made one change which would be to include a way to use a single diamond dresser to true up the grinding wheel. Otherwise you'll have chatter from the out of round and not concentric wheel.

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## kjrhowell

Love your idea regarding grinding of old motorcycle brake drums. I had occasion a number of years ago to repair a set of drums from Yamaha road racing motorcycle. These four leading brakes were notorious for heat warping and were a real pain in the ass to keep in top shape. I set up a grinder attachment in my lathe to do the actual grinding of the drums. Working slick for the three or four I had to do. I've followed your work on motorcycle chassis development for a number of years and have been very impressed with your ideas and designs. I have a picture of design that you developed for a three wheeled tilting motorcycle. Did you ever build one of these bikes? I have had an interest for a number of years to build such a bike and was impressed with your design for a trike utilizing what I believe was a BMW boxer engine layout.

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tonyfoale (Dec 25, 2016)

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## tonyfoale

> Very good design & execution. I'd made one change which would be to include a way to use a single diamond dresser to true up the grinding wheel. Otherwise you'll have chatter from the out of round and not concentric wheel.



I always true grinding wheels with a diamond, internal or external. I get no chatter.

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Paul Jones (Dec 30, 2016)

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## tonyfoale

> Love your idea regarding grinding of old motorcycle brake drums. I had occasion a number of years ago to repair a set of drums from Yamaha road racing motorcycle. These four leading brakes were notorious for heat warping and were a real pain in the ass to keep in top shape.



I can agree with that. They were large and so they made some sections too minimal to keep the weight down, with the results that you point out.




> I've followed your work on motorcycle chassis development for a number of years and have been very impressed with your ideas and designs. I have a picture of design that you developed for a three wheeled tilting motorcycle. Did you ever build one of these bikes? I have had an interest for a number of years to build such a bike and was impressed with your design for a trike utilizing what I believe was a BMW boxer engine layout.



Unfortunately, that TTW (Tilting Three Wheeler) was one of the very few projects that I started and didn't finish. However, I have over the years been involved in numerous tilting projects as a consultant. One right now actually. I wrote the TTW chapter for the SAE book "Alternative Vehicles in the 21st Century" by R.Q.Riley. That is a very interesting book if you get a chance to read it.

Is this the design that you were thinking of?

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## Jon

Congratulations tonyfoale - your Drum Brake Grinder is the Tool of the Week!

With last week's win for your Horizontal Milling Machine, that's two in a row! This is a rare feat around here, and you're in excellent company - previous two-in-a-row winners are Brendon, with his Marking Gauge followed by his Dovetailing Bench and mklotz, with his Bench Block Enhancements followed by his Model Cement Mixer.

Big week around here, especially considering it was a holiday, and we still haven't caught up on the backlog of new entries. Other nice entries this week included a Toe Jack by DanLins, a Panavise Prismatic Jaw by mklotz, an Extendable Air Nozzle by frugalolegeezer, a Cupholder Camera Mount by Harvey Melvin Richards, a beautiful and cleverly-photographed Serving Spoon by Christophe Mineau, a Brake Line Bending Fixture by astroracer, as well as two highly detailed write-ups by rgsparber, for Dremel Drillpress Improvements and Crush Collet.

tonyfoale - after your first win, the prize is a $25 online gift card, in your choice of Amazon, PayPal, Giftrocket, or bitcoin. Please PM me your current email address and gift card choice and I'll get it sent over right away.


Congrats again and nice job!  :Thumbs Up:

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tonyfoale (Dec 30, 2016)

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## tonyfoale

> Congratulations tonyfoale - your Drum Brake Grinder is the Tool of the Week!
> 
> With last week's win for your Horizontal Milling Machine, that's two in a row! This is a rare feat around here, and you're in excellent company



Wow that's two surprises. Many thanks again. Not what I expected when I joined the forum and not I was aiming for. However, now you have put me under pressure, I am very competitive and so I find myself thinking what I can do to pull off 3 in a row. I'd better start typing.




> - after your first win, the prize is a $25 online gift card, in your choice of Amazon, PayPal, Giftrocket, or bitcoin. Please PM me your current email address and gift card choice and I'll get it sent over right away.
> Congrats again and nice job!



Amazon and Paypal are the only 2 of those that I use. If the Amazon card is valid for either the UK or Spanish Amazons then I'll go for that. My email address is in my signature below.

Again many thanks

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## Frank S

Keep up the good work Tony

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## Jon

Thanks, just sent it out. Congrats again  :Big Grin:

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## NeiljohnUK

Good use for an old optical bench, I use optical bread-board off-cuts to make bases and work surfaces for some of my small machines too. Olderdan's method is similar to Jurid's abrasive coated brake pads we sold in the 80's for cleaning up disc faces and removing the surface layer, these days with most pads being significantly harder with lots more embedded metallic elements the discs wear much faster, so such tricks are no longer required, changing discs every 2-3 sets of pads being the norm now.

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## DotWeb

Well, https://www.practicalmachinist.com/v...-lathe-344580/ may be helpful here!

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## tonyfoale

> Good use for an old optical bench, I use optical bread-board off-cuts to make bases and work surfaces for some of my small machines too. Olderdan's method is similar to Jurid's abrasive coated brake pads we sold in the 80's for cleaning up disc faces and removing the surface layer, these days with most pads being significantly harder with lots more embedded metallic elements the discs wear much faster, so such tricks are no longer required, changing discs every 2-3 sets of pads being the norm now.



I got the optical table to use as a motorcycle frame building jig, but that is a very occasional use and as it takes up a lot of room I use the surface for mounting other things.

   
Click images for full size.

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## NeiljohnUK

Best use I've seen outside of an optics lab, though that ones a little small, some of our set-ups use four 2m by 4m ones solidly linked together and floated on air legs.

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## tonyfoale

> Best use I've seen outside of an optics lab, though that ones a little small, some of our set-ups use four 2m by 4m ones solidly linked together and floated on air legs.



Mine is 1.2 x 1.9 m. I lived in the US for 3 years and bought 3 from an optics company in Boston which was downsizing. The other two were much larger and they went to my employer. Mine came with very solid legs with air bag support at the top. When I returned to Spain I had a container for my stuff, this table, mill, lathe, motorbikes etc. just the normal stuff that anyone would accumulate in 3 years. However, there was no room in the container for the original legs and so I built a new support structure when I returned here. Three legs with height adjustment at the top.

 Click image for full size.

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## DIYSwede

Thanks Tony - are the 3-leg distances of your stand the same as the original support's?
As your table doesn't seem to be supported neither at its Bessel nor the Airy points,
I wonder about how these dimensions came about.

Cheers
Johan

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## tonyfoale

> Thanks Tony - are the 3-leg distances of your stand the same as the original support's?
> As your table doesn't seem to be supported neither at its Bessel nor the Airy points,
> I wonder about how these dimensions came about.
> Johan



As soon as you put some heavy loads on such a table the idea of leg positioning for minimum sag or slopes etc. in the unloaded condition become somewhat irrelevant. In optics work you will generally be placing light weight objects with minimal effect on table stability and great accuracy is paramount. For my use there were other considerations, one being the maximum sensible area between the legs for a storage shelf.
Engineering is about what works and this works.

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## DIYSwede

Thanks Tony, for sharing exactly those considerations and criteria.

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