Ammco Brake Lathe Part 2

[@MakingStuffUp1]

The gears ground up by the aluminum housing. I repaired many of these by cutting down the gear back to center and making steel slaves to support the gear. Drilling out the housing and installing two steel sleeves should be done with both parts bolted together. Option two. Install a clutch pilot bearing on both sides of the gear. I can help you with this worm gear. PS make sure the shaft slides smooth or the drive pins will bind.

[@houseofbrokendobbsthings5537]

MakingStuffUp1: Thanks for your thoughts. Solid advice. I wound up with much like you described. _Dan_

[@houseofbrokendobbsthings5537]

Also sleeved the housings

[@colmone5592]

I think that you are wrong. The internal bore of the gear is concentric with the teeth on the outside. Therefore these are ok and it is the bearing surfaces which were somehow machined off-centre. The bearing surfaces and 'o' ring grooves could be built up to be on centre. The casing surfaces could be bored to be round and on centre and then sleeved with suitable bushes. It looks as though the drive had a long keyway (or two) tobe driven by the gear. The keys may have run the length of the shaft somehow being retained. That's how it looks to me anyway.

[@houseofbrokendobbsthings5537]

Thanks - good to have all things on the table. I hadn't thought of the housing bore center line being off. Very strange wear to egg it the way it is at present. I noticed the gear tooth and the local ridge were concentric to the teeth. That is some good news as I can establish that as a true center and turn the bearing surfaces true again to the gear center. The bearing surfaces would be thinned but still workable and I could dodge broaching the pretty small bore (.325 in with .125 key ways). Hard to show how nasty the housing bores are worn. Again thanks for watching and commenting.

[@houseofbrokendobbsthings5537]

colm one Thanks again you made me think a bit which it tough to do 😁. What if the slug was punched off center, and the bearing surfaces turned using one end or the other. Then this mistake was followed by the gear machining and tooth production. That would provide the gear to be true to the shaft and the bearing surfaces to be off as we see in the video. Just trying to figure how they machined the bearing surfaces to be so far off and the gear true to the arbor. The housing bores look equally beaten. Let me get a shaft into the output bore hole (the only unbeaten bore) and see if that shows anything. _Dan_

[@colmone5592]

I think originally just the bearing surfaces were machined wrongly. This eccentricity would force the worm gear too closely into contact with the worm (wearing it) and would also wear the casing bearing surfaces at the furthest point from the worm.

[@alexhidell4546]

@@colmone5592 Dan. You're on the right track. FYI--I am a Ammco Technician. You have to turn the brass gear down (both ends) and make a new groove for an O-ring. Then you have to re-bush the housings on both sides. Often the worm gear is worn down beyond spec--and there are no new parts available as the Ammco 7000 Hustler machine is obsolete and PTO parts are not available. I rebuild these PTO drives quite often. And I have a few worm gears as spares. Contact us at [e-mail].

[@pierresgarage2687]

Hope your gear is bronze not brass, bronze will last so much longer... I would get the bearing surfaces concentric with the center bore since the gear seems from here pretty concentric. then make all the sleeving in the casting itself, the main challenge here is to find the exact original center in order to make your gear and pignon mesh as smothly as possible with the right tolerances. As for the Acme screw, is the gar removable from the shaft, if so, remake a shaft with the proper tolerances, if gear isn't removable you can machine a center and make the shaft as mentionned previously. If possible get some material that matches the original characteristics as the original material, like I say only if possible. As far as O rings, you refit to a new size as needed, that won't match the original but not critical in your situation. Not sure you'll wear tha machine as much as it's been so far, then a little play won't mater as much... This is an interesting project to learn about concentricity, sleeving, threading, fitting, etc... Quite a good array of problems to solve in one part... ;) Keep us posted on your progress, Pierre

[@houseofbrokendobbsthings5537]

Pierre's Garage: Pierre thank you so much for your thoughts and coaching. I was able to get the center reestablished pretty well with the driven shaft hole through the housing. I made an alignment arbor for the housing bore size and used a Bruce Whitham cheat (likely everybody but me already knew it when he showed it). Since I had a bore and a shaft trued to it - line up the spindle and go. I will use the worm gear as is for now - but also use it to play on my lathe to make another gear blank. Never done that before and I have think my lathe is up to it. I remain the weak link in the shop. 😁 But there is only one fix for that.... Again thanks - for stopping by my channel. Also, thanks for the tool reviews - I do have a few boring bars bigger than what I showed. Without your review how would I know what to order next😁. I thought being a mechanic was expensive... Then I learn shop machines are cheap - tooling is the real money. No end ever. My old large Bokum boring bar is with everybodies friend Mr. Randy Richards in his smoky forest out west. He will give it real usage where I had it on my desk for a few years. _Dan_

[@tomsuica8731]

They did not drill it oblong, that is wear in th bronze. you can see where the original surface was on 1 side and that it was concentric with the bore . Did not show it it was spinning when assembled probably did not .

[@AlfonzoLopez-s3x]

No le entiendo ni vwrga