Steam Tractor 3/4" (Rudy K)

[Flyboy Jim]

I don't know squat about making gears Kim..............but dang that sure looks nice to me! 

It'll be neat to see how it looks meshed up with it's partner.

Jim

[scc]

That's great progress Kim,    My excuse for not gearcutting was that my machines were not big enough, so I took the easy option and farmed them out.  I know we are on a different scale here but I am full of admiration for your approach and workmanship.  Well Done indeed

Terry

[fumopuc]

Hi Kim, great success. Good to follow your learning curve.

[Kim]

Thanks Jim, Terry, and Achim,
I really appreciate the encouragement!

It'll be neat to see how it looks meshed up with it's partner.

I think I'm going to wait till I've made a few better gears.  I'm not sure I want to see this one fraternizing with those old hook-toothed gears that I made earlier

Kim

[Don1966]

Your taken all the appropriate steps Kim and the gear does look great. I would say your on your way to happy gear making buddy...... it's important that all beginners read Ivan Law's book
"Gears and Gear Cutting" to get an understanding of gears and cutting them. Money well spent....

Don

[Kim]

Thanks Don,
Yes, I've got Ivan Law's book.  I've read it and refer to it frequently.  As with many things, it makes more sense to me once I've actually tried to do it!  It's a fairly inexpensive book, and I agree, it is well worth the money!

Thanks,
Kim

[Roger B]

Still following along and trying to understand gear cutting    I am still buying mine 

[crueby]

Kim, that last one came out great!

Roger, I think the gear cutting is one of those things that makes more sense once you have actually gone through the process for real. Follow the steps from the book, and it becomes clearer. Do some and then try a bevel gear set, thats a very cool process!

[b.lindsey]

I think you are doing great Kim. Onward and upward and you will get there.

Bill

[Kim]

Thanks Roger, Chris and Bill,

Roger, I think the gear cutting is one of those things that makes more sense once you have actually gone through the process for real. Follow the steps from the book, and it becomes clearer.

Couldn't agree more!  I read the book and understood it.  Then I actually tried it and had to go back, re-read the book with different eyes, and figure it out again.  And all the great advice and encouragement has helped immensely!

Kim

[Kim]

Sometimes, life just conspires to keep you out of the shop, you know?

Regardless, I’ve made some headway over the last few weeks.  Now that I feel I’m starting to get the gear making process down, I decided I’d batch a few things to save on setup time.  So I turned 3 different buttons (all 48 pitch; 20 tooth, 66 tooth, and 80 tooth cutters), shaped them, heat treated and tempered them, then used them to make the cutters.  Unfortunately, somewhere in there, I lost the 48-20 button , so I’ll probably have to do that one over unless I find it somewhere soon.

But here are the cutters I made for 66 and 80 tooth:


Then I made a blank for the 66 tooth, just under 1.5”.  But for the 80 tooth, I needed some 1/4” thick brass that was 1 3/4” in diameter (ish) and I had no brass bar that big.  So, I decided to put a couple of my failed attempts at 120 tooth gears to good use and try brazing them together to use for this blank.

I cleaned the 1/8” disks then spread some flux across both of them, and put a few small pieces of silver solder on one half.  My plan was to line them up on a 1/4" bolt and hope that gravity would be enough to pull them together.  This seemed to work fine Here it is just before I put the two pieces together. One is on the fixture, the other is sitting on the side, waiting to be placed on top:


It took me a couple of tries (I’ve never silver soldered anything this large before), but I think I got it.  You can see a few places where I held the heat too long in one place and it started to puddle.  I’ll get better. 


Out of the pickle bath, but before cleaning up.


And here I’ve turned it down to the 1.708” required for the 80 tooth blank.


Believe it or not, that was two shop sessions for me (last weekend and today).

Next time out I’ll probably re-do the 20 tooth button and make that cutter.  Then I’ll work on the gears.

Kim

[vcutajar]

Kim, when you said puddle, those that mean that the brass was meltimg? 

That was a great idea to recyle.

Vince

[steamer]

Making tools to make tools, to make parts is very satisfying!!!

Nice job Kim!

Dave

[Kim]

Thanks Dave!  Yes, making the tools to make the tools to make the parts adds a lot of time to the build, but it really is satisfying!  And since I look at each part as its own project anyway, it's kind-of moot how long it takes. I'm working on a different project every time I go out to the shop!

Vince,  yes, your right.  When I said puddling, what I meant was that I melted the brass into a little puddle - so it looked like I was welding, not when brazing. 

Kim

[Kim]

After getting the 80 tooth blank to size, I decided to cut it now so I didn’t have to take it off the mandrel. 

I have changed the way I establish the center line for gear cutter.  For the first several gears (or trial gears  ) I was touching the gear cutter off the top of the gear blank, then bringing the cutter down by 1/2 the diameter of the blank plus 1/2 the width of the cutter.  But that wasn’t giving very good results.  So, now I’m using this method to get the cutter on the centerline; I put a dead center in the 3/8 collet on my RT, and center the point of the cutting edge on the dead center, like so:

The back lighting really helps me see the points better.

Here’s a series of me cutting the 80 tooth gear;








After that, I did the same for the 66 tooth gear.  The biggest issue with this gear was that 66 is not easily divisible into 360.   So, all the settings for the RT were peculiar.


I’m quite happy with how these gears are turning out, and now I think there is no question but that I will be re-doing the 120 and 16 tooth gears that I started with.

Kim