Thread: Roton US not replying

Originally Posted by Greg Q

McMaster Carr will not ship to new customers overseas, and lately they won't ship if they even suspect you'll export the goods privately. It is the most vexing thing because I'd probably use them for everything. They are the favoured supplier in the US. There's a long and stupid story behind that policy.

Now, back to your question about grafting in a new piece of acme...that's what I'm going to do too. There are many threads on Practical Machinist - Largest Manufacturing Technology Forum on the Web in the South Bend forum about doing exactly that.

My plan is to do as you describe but to use Loctite to bond the two pieces together. The Loctite vendor assures me this will work.
Greg

Maybe a friend in the USA can buy it for you and then post it to you .. They, McMAster C , haven't got the size I need in precision , it is only available in the general loose fitting stuff ...so I missed out again . Loctite is fine .... don't bother with the pins . MIKE

Originally Posted by Stustoys

Hi Dean,
Careful what you ask for

I dont see anything wrong with your idea. If you had the gear you could silver solder it but that will just give you more problems. One thing you could look into is a tapered brass pin like the ones used on lead screws. That would of course mean getting your hands on a tapered reamer. I'm guessing that is would give you a stronger joint but really, how strong does it need to be(I think knurling would be the hardest work a crosslide ever has to do(?). If would make it easier to get apart, but how likely is that?

Stuart

Yes. Seems to be my lot lately and not only on this forum. Sigh. I never said I was not up for a discussion, which I usually get LOL. Maybe I should ignore more stuff and just go with the flow sometimes? Problem is I am to old to change now!

Anyway you are right about the required strength of the join except that as my lathe is worn the cross slide ways are a bit tight at the outer section to try to reduce slop at the working face. Just a bit more firm to move. I would have thought that a steel pin would be stronger than a tapered brass one.

The gear uses a woodruff key to stop it from turning but I don't know what stops it from moving along the shaft although it drops into a hole in the cross slide so it would be held captive by this to a degree.

Just went and looked. Machined face either side so just thrust washers each side would hold it. Remember I have never seen this gear. I have calculated its size etc and just have to make it now.

Dean

Greg and Mike. I will give it a try. Now what diameters would be best? My shaft is 5/8 diam at the connection point. Would root diam of the acme be ok as this would give max strength to the rod portion or should I go a bit smaller to increase the strength of the existing shaft portion? I was thinking of about 3/4 inch long. My shaft has a section of root diam or so at middle end of thread about 12.5mm long. Used in turning the thread originally one supposes.

Dean

I usually eyeball those dimensions...about 2/3 of root diameter would be my scientific wild-assed guess. I don't think it would take a lot more than 1/4". Maybe 3/8"?

What kind of lathe is this?

Greg

Have a look at this thread. Its long, but covers all the ground you plan to tread...

Making a new Cross Slide Acme Screw - Practical Machinist - Largest Manufacturing Technology Forum on the Web

Also this guy's site covers the South Bend repair in detail, and likely answers all of your questions. In fact, Steve Wells is reputed to be a knowledgeable, friendly guy. Maybe he has some 1/2-10 LH stock Morrisman??

Greg

Originally Posted by Greg Q

I usually eyeball those dimensions...about 2/3 of root diameter would be my scientific wild-assed guess. I don't think it would take a lot more than 1/4". Maybe 3/8"?

What kind of lathe is this?

Greg

It is a Nuttall lathe. About 32 inch between centres and, well it has a 14 inch face plate but a gap section that is also missing in action. Swing in gap about 20 inch.

Dean

Originally Posted by Greg Q

Have a look at this thread. Its long, but covers all the ground you plan to tread...

Making a new Cross Slide Acme Screw - Practical Machinist - Largest Manufacturing Technology Forum on the Web

Also this guy's site covers the South Bend repair in detail, and likely answers all of your questions. In fact, Steve Wells is reputed to be a knowledgeable, friendly guy. Maybe he has some 1/2-10 LH stock Morrisman??

Greg

Greg, it's actually 1/2 - 8 LH I need . Steve Wells is worth a try ..but he probably won't have it . That is a great post on the Practical Mach. forum, by that TEX guy ...I saved it all to a memory stick . Just goes to show nothing is impossible ..but he's using good equipment , which helps . MIKE

Originally Posted by Oldneweng

Yes. Seems to be my lot lately and not only on this forum. Sigh. I never said I was not up for a discussion, which I usually get LOL. Maybe I should ignore more stuff and just go with the flow sometimes? Problem is I am to old to change now!

Just throw your hands in the air and go do something in the shed for a while, seems to work for me most of the time.

Originally Posted by Oldneweng

I would have thought that a steel pin would be stronger than a tapered brass one.

Steel would be better still, your comments on brass pins put me on track to a brass taper pins and I didnt get off lol
I think I'd go with Loctite and hope Greg's guy is right, if not you can blame Greg and add a pin later.

Just to throw another idea out there(thought possibly not for this job), what about a hole taped M3 or M4 with a taper tap run far enough through that a grub screw pulls up tight before it comes out the other side?

Stuart