The Jalopy Journal
Discussion in 'The Hokey Ass Message Board' started by gbritnell, Jan 15, 2014.
I wet my pants when I saw the thread about the 302. The trans thread made me giggle like a schoolgirl, and now I'm just sitting here with a goofy look on my face. Stunning work, I wish I had 10% of the skill and knowledge.
Ok, I'm back with this evening's additions.
The next part is the pinion carrier. This was also made from 6061 aluminum. This piece is nowhere near as complicated as the housing but has some detail to it. I started with a piece of round stock and turned and bored it for the bearings. The part was then mounted on a mandrel and put in the dividing head to cut some ribbing onto it.
The part was then stood up vertically in the mill to step off the radii around the mounting ears. The brass plug that you see is a witness plug. It is cut a couple of thousands larger than the required radius then the milling cutter is lightly bumped into it moving around until the boss is formed.
Here's what the two side look like after machining.
The next step was to go in with burrs stones and files to smooth all the contours out.
The next step was to thread the main housing and the bearing caps for the bearing adjusters. This had to be done on the lathe because of the bastard thread size and the shallow depth required. A mandrel was made up about .0015 larger than the bearing bores and the housing was bolted to it using the caps to hold it tight. The proper thread pitch was set up and each end was threaded.
The adjusting caps were turned threaded and slotted from steel.
Rembrant, Michaelangelo, DaVinci, and gbritnell. If this was Greece you would be on Mt Olympus.
When building miniatures like this, the trans and my engines a need for special tooling is a given. The next parts would be the input shaft and then the U-joint yoke. These would have to be splined and there is nothing available so spline broaches had to be made. These are made from tool steel, hardened and drawn. You can see 3 tools in the picture. Each one is progressive. The first has a pilot and shallow cutting teeth. The next has the first row of teeth to match the first cutter so it will be guided into the first cut, followed by progressively deeper teeth. The final cutter is the same as the second except it has the full depth teeth. The bushing with the spines cut into it was the test plug to make sure the cutters worked as they should.
The last picture is the cutter I made for cutting the matching splines into the input shaft.
The two halves of the spool/ring gear carrier were next. These were machined from iron. One piece has a flange to which the ring gear bolts and the other half is sandwiched between. Inside the two halves there was clearance machined for the pinion gears. These run on hardened shafts.
On the inside of the spider gears you can see another set of splines. I didn't have, nor could I make the tooling to cut anything that deep so in the designing stages I found commercially available spline bushing that I could use. These had the O.D. cut to a press and pin fit into the spiders. The spline bushings would accomodate the axles.
Thanks for sharing your laboratory.
Your skills are truly exceptional.
I don't have any machining sequence pictures of the U-joint yoke, just some of it finished. It was made from steel. It started in the lathe and had the round shapes cut. The next step was to broach the splines in it like the test bushing. When that went ok the final machining steps, drilling and milling were performed.
The spool with the spider gears and ring gear were bolted up. All the bearings and seal were pressed in place and the pumpkin was assembled. I blued up the gear teeth and tried for the best match that I could given that the gears weren't ground nice and smooth. For any work that they'll get they should work very nicely.
In this last shot you can see the nose of the input shaft mounted in a bronze bushing pressed into the case.
To get the proper offset spacing both vertically and horizontally I ended up with a gear ratio of 3:1. Ok for street use but a little short for the strip.
You are a WIZARD!
We are not worthy!
That's all for tonight. Tomorrow I'll resume with the banjo housing and axles.
I dont know which bothers me more, that you have the talent to do this, or that you have the spare time to do this.
I am speechless.
Awesome work, something I wish I had the skill to do.
I guess I showed up late, but where can I find the other two pieces of the drivetrain? I just have to see them as well.
What more can be said for this gentleman`s skills?
Good luck.Have fun.Be safe.
Thankyou so much gbritnell. Yes you are an artist with amazing machining skills.
And I suspect you like a challenge.
Geoff aka whodaky
well we got a mini motor guy and a mini rear end guy. Now we need a mini tranny guy. Soon we will be building mini t-buckets.
Crazy! I think I would have made a couple more while I was at it
Wow that work is awesome. Do you wear any magnifying glasses or anything when doing the close work?
It's all the same guy! 😳
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So cool. It's all I can do just to fix a normal sized one.
I'm blown away by your knowledge and abilities,thanks for sharing.
Posted using the Full Custom H.A.M.B. App
Here's the links to the other 2 pieces.
For some of the smaller pieces I use one of those headband magnifiers.
Thanks for the great responses. I'm glad to share my work.
Ok, we'll try and finish this up today.
The next part was the axle housing. Being that the full sized piece is a stamping and weldment I had the option of doing the same. The only thing was what kind of metal to make it from. I thought about steel but due to the forming and shaping involved I decided on brass. When it was finished it would be painted or powder coated black anyway.
I started with the center area (banjo housing) by cutting 2 pieces of brass and edge soldering them together.
A fixture plate was made up to locate and hold them for drilling the mounting holes and cutting the center area out.
One piece was drilled for clearance and the other tapped. This would serve to hold the pieces together for construction and also for the mounting studs to hold the center section in place.
The inner opening isn't quite a perfect oval so I laid out the shape and bumped as close to the lines as possible. This would be filed smooth later on.
The next step was to make some long bolts and spacer tubes to hold the pieces in there proper alignment and spacing. The pumpkin was bolted in place to make sure everything fit as planned.
I used thicker plates then would be the proper scale so that I could form the radius on the outer edge without breaking through.
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