Broaching Keyways with the Lathe

[tonyfoale]

I do not want to hijack this thread, but would like to have a dialog with Tonyfoale and Marksbug, in regard to cylinder re-sleeving and honing/sizing.

Well you could continue here, start a new thread or use email. If you keep it on this forum then you will get the advantage or maybe disadvantage of more people's input.

[Paul Jones]

hemmjo,

Don't worry about hijacking this thread because sharing experiences and information is the basic mission of HomemadeTools.net (HMT). We all learn from the comments, posts and mistakes because it is a learning experience. Take this thread where you want to go with your experiences.

Regards,

Paul

[hemmjo]

This thread caught my attention, as I have done some broaching on my lathe. I have cut keyways in gears and pulleys and cut splines to make a "wrench" to remove the sprocket from a 10-speed bike wheel.

Then Tony and Mark chimed in talking about honing. Currently I am in the process of rebuilding the engine from a little jet boat. Same call them Jet Ski, but this is a sit down style. !998 TigersShark, 770. I have two of these that I bought with non running engines. I got one running by swapping good parts from the second engine. None of the shops around here do this kind of work anymore. It is time for me to get set up to do it myself.

The jug is 2 cylinder, it is too big for me to mount in my lathe and bore as I could on a single cylinder engine. I do not have a mill to use. I have been thinking about mounting the cylinder on carriage, and mounting my Lisle 15000 hone in the chuck to work on these cylinders. I would need to make a second universal so the hone is free to find its place in the cylinder. I can remove the gear and hand wheel from the carriage so I can slide it easily, perhaps making a lever set up to slide it between stops to hone the cylinder. My lathe has a pan with drain etc so I can recirculate honing oil. The question is.... should I try it? All of the hones I see are set up to operate vertical. Will gravity make the cylinders out of round?

The second question is in regard to sleeving. I now have two of these engine to rebuild since I bought a 3rd engine to get more parts. It is actually in pretty good shape, so I hope to end up with 3 engines for 2 boats. I have put sleeves in an old Ford farm tractor those sleeves pressed out and back in. I have been reading about sleeving 2 cycle engines some show boring the old sleeve out, others show heating the cylinder then pressing the sleeves out. I am not sure how to tell how these are removed.

That is what I am thinking about now....

[marksbug]

even a sunnen ck 10/cv 616 are soft at the end, not much but not a jerk to the other direction. they also have a dwell lever so you can stop the stroke where you need it to stop to either straighten a wonkey bore or keep bores straight. I dont forsee a issue using air cylinders. many hones already do ( cheeper kinda knock offs of the sunnen hones) and a dwell valve could also be incorprated. Ive not run a air operated hone, but have seen some in shops,Ive a few thousand hone jobs on sunnen hones ck&cv& rod hones/bushing grinder&valve guide hones. there is no better equipment than sunnen.and they aint cheep, thus lots of knock offs.I knew the man& his sons who desinged the ck hone and sold it to sunnen way back when.it was a 2x8 wood frame, most of it was wood and had been used since it was made up untill a few years after the dad died about 15 years ago.I wonder where it is now I havent seen any of them in a few years.
there are many aspects to honing cylinders correctly. most shops dont.

[tonyfoale]

hemmjo,

You might find this previous post of mine to be of interest.
http://www.homemadetools.net/forum/c...5286#post81520
In fact that might be a better place to continue this theme, maybe be easier for people to find as the subjects are more related.

As you are only ever likely to have a limited number of cylinders to hone I would suggest that you didn't bother too much about making some form of powered stroker. It is not unusual to drive the hone vertically with a hand drill or similar power source, stroked manually. When using a heavy drill it is quite common to support it with a long spring. A commercial setup using such a setup is likely to have a recirculating and filtered lubricant flow to wash away the junk. I only need to hone cylinders occasionally and I simply put the cylinder in a tall bucket and fill it above the cylinder with fluid. The cylinder sits in the bucket on a screen which allows the particles to sink below. It has a pump, filter and some hose to keep things clean.
With a bit of testing you can adjust your hone speed and stroking rate to get the helix angle that you want.

You might also find this of interest.
http://www.homemadetools.net/forum/i...769#post102422

[olderdan]

Topslide keyway slotter
I have never liked the idea of racking the lathe saddle back and forth to cut keyways, it puts undue wear on bed ways and over strains the rack feed parts.
Much better to use the top slide as a ram with the saddle locked down, this is not my idea as I saw it in the Model Engineer years ago and at least one manufacturer offered this as an attachment. With a 4:1 ratio on the lever it makes light work of a keyway with the added possibility of tapered bores being keyed. I have seen gear teeth internal and external cut by this planing method but have not tried it myself.
Parts are simple to make, all it takes is to remove the feed screw and fit a suitable forked adapter and a lever of your choice, I clean and oil the slides before and after and have noticed the slide is much smoother after having had a good workout, it does not move much in general use apart from taper turning.

[Paul Jones]

olderdan,

I agree with your assessment of not liking to use the lathe saddle for broaching keyways with the metal lathe. My example was for performing a 5mm keyway broaching for two my missing change gears. The method was just to get started with single point threading for Imperial threads (the missing 40T gears). Using the lathe for keyway broaching is only a temporary solution and not a long term production method. After my initial HMT article about using my 12" swing lathe for broaching the missing/replacement change gears, I now have several arbor presses and lots of various Imperial and metric broaches for doing this type of work. I plan to add a several ton hydraulic press to my set of tools to make the keyway broaching even easier and much faster.

Regards,
Paul Jones

[old kodger]

To hyjack this thread just a little, a method I have used with some success, is to spin up a plug to suit the bore, then for square keys, drill down the "joint" line. half of the diameter of the drill will drill the job, the other half will drill the plug. maximum diameter is at the joint so all you have to do is square up the bottom, instead of having to "broach" all of the material out.
With respect to the removal of old liners, what I have done before is to weld straight down the barrel in three or four places round the bore, when the weld cools it shrinks the liner just enough to press it out easily.