Surface Grinder Cross-feed Nut

[thestelster]

Fantastic job!

Thank you.

- did you see any difference in thread fit on the leadscrew after it was mounted in the CI block?

Haven't tried yet. I'll let you know later this morning.

- just curious, when it comes time to replace the nut insert from the CI block, what's the plan?

Hopefully, when that time comes I'll be turning parts on Swiss lathes in the big machine shop in the sky. (Or maybe cleaning out putrid coolant sumps in a really hot place down under, and I don't mean Australia!!)

Seriously though, with only about 0.001" shrink, I should be able to just press it out.

 

[thestelster]

1 step closer to completion. Drilled and tapped 2 #8-32 button head cap screws, one on each end, to act as a dutch key.

Looking at the schematic, there seems to be a stop collar missing, so I'll hopefully do that tomorrow.

 

[Mcgyver]

Fantastic job!

Indeed! Great job, great photo's and great write up covering a very professional approach to an advanced project - you should think of submitting works like this to Home Shop Machinist. Seriously.

 

[thestelster]

Indeed! Great job, great photo's and great write up covering a very professional approach to an advanced project - you should think of submitting works like this to Home Shop Machinist. Seriously.

Wow!! Thank you @Mcgyver for saying that. Where's the blushing emoticon?!!

I would never have thought about making a submission to a magazine. (Is there money in it? )

 

[thestelster]

I made the stop collar as per the parts schematic. It uses 2- 1/4-20 set screws with brass pads. But of course I don't have set screws that short. The parts list calls for the set screw to be 1/4" length. I might cut down the 3/8" long ones I have. Or order brass tipped ones. Never the less, I can start putting everything back together.

 

[PeterT]

Its always the parts you DON'T have isn't it? Depending on how much fiddle-fart time you want to spend vs buying them
- solder or epoxy brass pad onto steel set screw
- turn some 1/4-20 thread from brass but make a slit on end for screwdriver (vs hex)
- drop a small brass disc into hole & then use regular steel set screw. I've done this myself but I would not recommend if hole is deep because getting it out can be fun.

 

[Susquatch]

Drop a small brass disc into hole & then use regular steel set screw. I've done this myself but I would not recommend if hole is deep because getting it out can be fun.

@thestelster - Peter has lots of good ideas.

Unless the set screw has a high torque requirement, I like hard lead balls for this. Or you can make a plug by dropping molten solder into a drilled hole the right size. In both cases use them under a regular steel set screw with a cupped end. Forget getting them out. They can just stay there.

 

[PeterT]

I thought about the solder, I've seen that used against on solid shafts. But if its acting against the threads, might just get chewed up?

 

[Tecnico]

Myford handles this by dropping a disc of (annealed?) copper in the hole before the set screw.

D

 

[jcdammeyer]

1 step closer to completion. Drilled and tapped 2 #8-32 button head cap screws, one on each end, to act as a dutch key.

Looking at the schematic, there seems to be a stop collar missing, so I'll hopefully do that tomorrow.

So pretty.

 

[thestelster]

Well, she's done, except for those 2 set screws. I might as well just order them. Everthing moves well, so all is good.

 

[jorogi]

Well, she's done, except for those 2 set screws. I might as well just order them. Everthing moves well, so all is good.

Excellent, so now you have figured out all the bodges you should see if you can make a perfect one, then when mine craps out I'll help you clean out your shop a bit.

 

[Susquatch]

I thought about the solder, I've seen that used against on solid shafts. But if its acting against the threads, might just get chewed up?

Maybe, but I don't think so. If there are threads under it, the lead slug would just conform to the threads and spread the load even more. On the other hand, if the threads perform an auger function, almost anything in there is toast.

 

[thestelster]

Maybe, but I don't think so. If there are threads under it, the lead slug would just conform to the threads and spread the load even more. On the other hand, if the threads perform an auger function, almost anything in there is toast.

Well, on UN threads which are pretty shallow and fine, a soft material might work fine. But with 10tpi acme, we're looking at least 0.050" deep and 0.050" between threads, so a soft material, I would think, will get squashed and possibly jam up the works. I think that a brass or bronze piece that can span the crest of two threads would be perfect.