What material should Camlock cams and stop bolts be made from?

[Matt-Aburg]

After reading all this, I would get it welded as someone suggested and use a pipe. On making a 60 dollar part... waste of time and energy... Just order it and be done...

Maybe use the weld option after trying to make custom shaped driver as @Susquatch suggests.

 

[TorontoBuilder]

I had a similar problem on my Smart & Brown (classic little English lathe, about 50 years old), all 3 cams were broken/split. I suspect the damage was from using an under sized key. The cams on my 30 year old Enterprise lathe were the same (cool). Anyway I went to a used machine dealer - they were scrapping a nameless little Asian lathe, the cams were also the same (all D1-4 in my situation). Perhaps I was just lucky, but the cams may be common to that size mounting configuration.

The little retention screw/buttons/ spring - those are not the same, but were easy enough to figure out.

Granted D1-3 does seem the as common, but consider sourcing from a used machine?

Funny you should say that... I did reach out to a UK company that breaks down colchester lathes to sell the parts. I wanted to see if they would break down a headstock which they normally sell whole, in case I need a new spindle

 

[TorontoBuilder]

What a mess, my sympathies!

I'd have thought the cam locks would be hardened. Hardened steel on hardened steel makes an excellent bearing surface (look at all the 100 year old watch lathes that still are perfect) but soft steel on soft steel will gall, which is also called cold welding where there is contact. If this is what has happened, penetrating oil isn't going to fix it, although lubrication will make it easier if you can break the contact/cold welds (if that is even what has happened....but I'd guess there's a good chance of that being the problem, seeing how soft that cam is)

This stuff was just discussed on another forum

https://www.amazon.de/-/en/F%C3%B6rch-SCREUBFIX-TURBOKRAFT-SOLUTION-DEFECTS/dp/B08L6RKR12?th=1

Apparently it works, and is more effective than the old dodge on using valve lapping paste. Speculation was it has jagged particles of carbide in it so really bites into things.

Might worth a try. I'd be thinking a close fitting key out of something tough, say a HT chrome moly and this stuff.

The other thing on disassembly is that sometimes you can avoid breaking things or brinelling bearings by using lots of little taps vs a massive WHACK. Maybe an air gun? The high volume of impacts of an air wrench for example might be the thing.

Making a spindle is a big job. I made a few but never that large, its exacting work. Just getting a bore straight, that long and of that diameter presents challenges. You'll need more HT chrome moly lol. If it get so bad you've damaged the spindle, I'd say new bearings are in order as well. Ugh. Hopefully it doesn't get to that but if it does, is it worth it?


..........................................

Idea two.....get the spindle out of the lathe an on a mill. Start pecking away at the jammed up cam with a small carbide endmill until things can be pried apart

excellent comments.

i did mention this is my dream lathe right? I plan on making precision tiny tiny parts for model steam launches on it. I also got it so inexpensively that I can afford to invest some money. But pretty much only for either one used spindle, or one used bearing set. I have a trustworthy supplier that closely inspects and sells used parts out of the UK.

As they seem now, the bearings feel fine and undamaged. I will assure that I don't damage them. So if the spindle did need replacement if would be financially feasible to make a new one on the assumption that I could rely on the kindness of one acquaintance with a cylindrical grinder. I sure do not want to have to do that though.

I wish I had a hardness tester. I'd test one of the other cams before I proceed with any further steps.

 

[Dabbler]

I wish I had a hardness tester. I'd test one of the other cams before I proceed with any further steps.

You *cannot* test hardness in situ with a commercial diamond point hardness tester. You can use hardness files *if* you had a surface to work with. Ultrasonic is out of the question for small parts like cams - you will get only a ballpark reading at best.

You already know that the cam is soft-ish. It would not have galled like it did with a hardened cam, and a nitirided one would have sluffed the surface.

You need a lot of light impacts to free a frozen cam, if it is possible at all. if metal chips got in there and galled the cam surface, and it was over-tightened, then there is no freeing it that way. Take stock and see what is vulnerable here: the bearings. No matter what you don't Brinell your bearings. You will throw away the lathe if you do.

If you can get a new cam for 60 bucks, then the way is clear in my mind. drill it out, and for gosh sakes, don't use any abrasive method. Keep in mind the stud interface will likely be hard, as it is very common for chuck studs to be nitrided, so it might chowder your drill bit. not too biggie of a deal, but something to watch for.

If you are worried about hard cam, use a stubby carbide drill meant for hard drilling. be prepard to break at least one or 2.

 

[Former Member]

Look if its a galled issue you need to create some space, do you have ox/ac torch to heat the cam, red hot isn't required but close as you need the heat to penetrate. By doing this you will cause it to expand causing compression on the cam and when cooled retract and give some play. Use penetrating spray to cool as it will wick into the joint adding further lubrication.

At this point you have a shot of removing it.

If not at least you've knock any hardness out of it making it easier to drill.

I've found heat is a wonderful tool as a release agent.

Careful, we don't want to read in the GTA that a house burnt down because some guy was using a torch in an unsafe manner, enough fires this week already.

 

[TorontoBuilder]

You *cannot* test hardness in situ with a commercial diamond point hardness tester. You can use hardness files *if* you had a surface to work with. Ultrasonic is out of the question for small parts like cams - you will get only a ballpark reading at best.

You already know that the cam is soft-ish. It would not have galled like it did with a hardened cam, and a nitirided one would have sluffed the surface.

You need a lot of light impacts to free a frozen cam, if it is possible at all. if metal chips got in there and galled the cam surface, and it was over-tightened, then there is no freeing it that way. Take stock and see what is vulnerable here: the bearings. No matter what you don't Brinell your bearings. You will throw away the lathe if you do.

If you can get a new cam for 60 bucks, then the way is clear in my mind. drill it out, and for gosh sakes, don't use any abrasive method. Keep in mind the stud interface will likely be hard, as it is very common for chuck studs to be nitrided, so it might chowder your drill bit. not too biggie of a deal, but something to watch for.

If you are worried about hard cam, use a stubby carbide drill meant for hard drilling. be prepard to break at least one or 2.

This reminds me of the spiel my master bombardier gave me in the pits when I was preparing to toss my first grenade. After I tossed the grenade trying to cornhole an old tire I was so excited to see the explosion that my MB had to pull me down behind the wall to look thru the viewing port.

Thanks again Dabbler and everyone else for the pulling me behind the wall so I don't get shredded.

 

[Dabbler]

MB had to pull me down behind the wall to look thru the viewing port.

Apparently a common problem for first-timers.

 

[TorontoBuilder]

So today is the day.

I'm going with the "weld a square chunk of metal into the cam" suggestion.

If that does not work I'll be in the market for a D1-3 three jaw scroll chuck as well as an independent 4 jaw chuck

 

[Susquatch]

So today is the day.

I'm going with the "weld a square chunk of metal into the cam" suggestion.

If that does not work I'll be in the market for a D1-3 three jaw scroll chuck as well as an independent 4 jaw chuck

That's too bad it has to come to that. But ya gotta do what ya gotta do..... I'm hoping for a good outcome.

 

[thestelster]

So today is the day.

I'm going with the "weld a square chunk of metal into the cam" suggestion.

If that does not work I'll be in the market for a D1-3 three jaw scroll chuck as well as an independent 4 jaw chuck

Our thoughts and prayers are with you in this challenging time.

 

[TorontoBuilder]

Pretty anti-climatic.

Two minutes to grind a bolt end square, one minute of which was holding the grinder to prevent it spinning round the room while it wound down...

Two pops of the welder, one very light turn on the wrench and bob's your uncle, that cam was loose.

The cams all show signs of abuse, and being over-torqued. On the affected cam the broaching of the wrench hole even came thru the cut-out for the stud. The metal looks soft and cast, and all the cams fractured and broke off pieces at the same groove where the retention screws retain the cams.

The spindle seems okay according to a DTI. No pics of that, sorry.

Most of the time spent today was cleaning brother's colchester lathe, removing the cross slide and truing it on the mill table ready to be milled to accept magnetic tape.

 

[Susquatch]

Pretty anti-climatic.

Woooo Hoooo!

Seems like a celebration is still in order! Congrats TB!

 

[TorontoBuilder]

Woooo Hoooo!

Seems like a celebration is still in order! Congrats TB!

I'm super stoked it only took like 5 minutes out of the days work and now I can wire up the motor to the VFD and give the lathe a decent test.

I've been quite eager to see how good, or bad the headstock and gear box seals are. I'm replacing the motor eventually so I'm not too concerned about it.

I did celebrate... sort of. But early. I stopped at Wendy's on the way to the shop and bought a "Son of Baconator" for a late lunch. When the cam came out so easily the treat felt justified, but I felt so guilty though I told my wife when I got home.

I also tested a few things on my swiss made mini-mill to prepare to power it up and see how good the spindle actually is. So far, the only issues I can see are related to the indexing heads for faceting jewelry and I'm uncertain of the purpose of this lever on the motor. It may be a lock for the shaft, but it doesn't lock fully...

I'll test it with the VFD tomorrow as well...

 

[Susquatch]

I did celebrate... sort of. But early. I stopped at Wendy's on the way to the shop and bought a "Son of Baconator" for a late lunch.

They used to have a mushroom melt I liked.

Why do these outfits try stuff like than and then divorce them?

 

[TorontoBuilder]

They used to have a mushroom melt I liked.

Why do these outfits try stuff like than and then divorce them?

I dont know.

I dont usually buy burgers at all. Or take out food even. Not even Tims

But baconators just drip grease and have bacon... With the move to eat more and more vegan meals sometimes I am craving beef and bacon

 

[Susquatch]

I dont know.

I dont usually buy burgers at all. Or take out food even. Not even Tims

But baconators just drip grease and have bacon... With the move to eat more and more vegan meals sometimes I am craving beef and bacon

I like a good burger, steak, roasts, turkey, chicken, fish, etc etc etc.

Not so fond of roots, green stuff, and fungus.

 

[TorontoBuilder]

I like a good burger, steak, roasts, turkey, chicken, fish, etc etc etc.

Not so fond of roots, green stuff, and fungus.

I personally love parsnips, carrots, turnips, onions, garlic, and mushrooms. Oh and Potatoes are not bad.