It is possible to make a new apron gear case 10F-11 using lathe only.

[Dranreb]

A few years ago I made a repair to my gear case, this survived well until the other week I noticed it was moving again, a close look showed that a new crack had appeared across the other side of the part: http://www.hobby-machinist.com/showthread.php/9309-Atlas-apron-gear-case-10F-11-repair

Something better had to be done so as I had a lump of ally handy I got started, excuse the state of my saw, had it for 20 odd years on site work and it now lives behind my miter saw..

This was my first mistake, my inexperience showing here!



Faced it off in 3 jaw.



Laid a broken spare case on and marked the slotted holes.



Transferred the centres around to the other side.



Drilled holes and trial fit, so far so good.





Made a transfer guide by trial and error to mark the spindle hole.



As you can see this is just SOTP engineering, no actual measuring has been done yet, a bit like drawing around my hand and tracing when I was a kid, that's still working for me!

Bernard









[h=2][/h]

 

[Dranreb]

Fly cut faced of and squared up the sides using my T slotted cross slide.



After drilling the spindle hole it was reamed to size as I just happened to have a 1/2" reamer handy. I have since been told it was a bit risky using the tailstock as even a tiny misalignment would have ruined the job, but luckily I'd previously adjusted my TS using the two collar method to cut within 1 thou, and even though the ram has a tiny bit of droop further out, my transfer guide goes in the hole with a nice sliding fit..



Turned of the face to leave a boss as per the original.
This is where the mistake of cutting the piece triangular in the first pic reared up to get me, dialing the hole into the 4 jaw was a challenge to say the least! next time I'll do all the turning while the block is still square...



Turned it round an spaced it off with parallels to clear the jaws and spent ages dialing it in again!



Mounted it in my Myford milling attachment to cut out the area below the gear, I figured this was needed to let any chips drop out of the housing, used two sizes of cutter.

If you like helicopters this can be quite a pleasant part of the job as the noise made by the big cutter is exactly like having a Chinook in the shop with you..
This seems to be at the edge of what can be done with this attachment, and I think I was lucky to get away with it. All gibs tightened up it still flexed alarmingly.



Sorry this pic needed turning



Bernard

 

[Dranreb]

More shaping on the T slotted slide, this was a whole lot better, milled pretty good with light cuts.

Wood router bit in use, this step wasn't needed at this point, the gear relief bevel cut could have been done later when there was less material to remove.









Bernard

 

[toolman]

Very nice, I'll take one in stainless please! :roflmao:

 

[chuckorlando]

Thats pretty impressive milling on a lathe. At least in my limited experience. Nice work man

Did i read that wrong, or did you use a wood bit?

 

[iron man]

He did use a wood bit on the bevel I have been guilty of the same thing on a radius I needed and a carbide router bit was all I had it worked nice.. Ray

 

[Dranreb]

Very nice, I'll take one in stainless please! :roflmao:

Ha ha! I think making one in nice leaded steel would be a challenge too far, no chance with stainless..

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Thats pretty impressive milling on a lathe. At least in my limited experience. Nice work man

Did i read that wrong, or did you use a wood bit?

Thanks Chuck, yep wood bits work OK with ally choosing the right speed helps a lot, the carriage stop you can see in one of the pics was all done with wood bits.
As Iron man's right and there's a good range of cheap useful radius cutters, the last pic in this thread shows the result.

http://www.hobby-machinist.com/showthread.php/14858-Another-carriage-stop-design

Bernard

 

[sgriggs]

Outstanding work! It's amazing the number of milling operations you can do on a lathe. It makes me want to buy a 4 jaw chuck.

Scott

 

[Tony Wells]

Nice job, Bernard. You learned some things, and showed folks a few techniques they probably hadn't even thought of.

Good job of taking pictures as you worked, too. Most of my projects are on and off the machine and I never even think about pictures until it is over. I am kind of a single minded person, so pretty focused on the job at hand, whatever it is.

I think you should leave the 4 jaw on your VMC, btw :roflmao:

Oh, and I want to know how you got my saw out of the storage shed, used it, and brought it back without me knowing!

 

[thomas s]

Well done Bernard this is something I need to do to my lathe also.

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Well done Bernard this is something I need to do to my lathe also.