Parting tool holder repair

[chucketn]

I purchased the OXA tool post set from LMS at Cabin Fever a few years ago. Within a few weeks the socket of the Allen screw that clamps the blade was stripped. I contacted LMS to see if a replacement screw was available. It was not, and they sent me a replacement parting tool holder at no cost. Great service! But, now the same is happening with the replacement’s adjusting/clamp screw. The screw in these holders, if you didn’t know, is M6 right hand thread on the clamp end, and M6 left hand thread on the head end.
I am thinking of turning the head end of a M6 SHCS screw down to fit the socket of this screw, and silver soldering it into the socket. Would this be strong enough to hold up? That would give it a bigger heavier socket that might last longer.
What say ye? Any other ideas?
Chuck

 

[Swifty]

I'm having similar problems with my tool holders, the long grub screws that clamp the tools are poor quality and the hex soon wears. Mine are M8, so I have turned down the heads on some good quality M8 socket head screws and have changed them over.

Paul.

 

[tornitore45]

After silver soldering screw and new socket will be soft.
I am not clear why you want to retain the original screw, Is is a grub? LH?
I would try Mc Master for something that fit, they have a wide selection.

I have learned to replace any "functional" fastener in Chinese products from the start.

 

[chucketn]

The screw in question has both RH and LH threads. The wedge that clamps the blade is RH thread, the body of the holder is LH thread. The Allen socket is stripping, I think because it is 3.5 mm and I've been using a 3mm T-handle wrench. Does MSC carry these type of screws? The tool holder is about $24(US). I should be able to buy a lifetime supply of screws for that...

Chuck

 

[kvom]

Maybe get the proper allen wrench as a first step. You ought to be able to single-point the threads and make your own as an alternative.

 

[tornitore45]

I get it now, one screw pulls from both sides, obviously can not have a head.
Is not easy to make such screw but not beyond HSM capability.

You may bypass the problem of making a HEX socket bu milling a male HEX and use a nut driver.

Drill rod, harden and temper. Make many in one set up.

 

[chucketn]

Maybe get the proper allen wrench as a first step. You ought to be able to single-point the threads and make your own as an alternative.

Yes, that has been done. The best fit is now a 1/8" imperial Allen. Problem is the cheese soft screw is deforming more with each use, Right now, I have 2 holders that are unuseable. I can single point both RH and LH threads. What I can't do is make a hex/allen socket. If I make the screw, I'll need a LH M6 tap to make a nut or something to be able to tighten it.
In case there are folks that don't understand what I'm talking about, I've attached a picture.
Chuck

 

[kvom]

It's an M6 thread (about 1/4"). Drill and tap a smaller screw into the end of the rod, and use that screw's head to tighten and loosen. Or mill a hex into the end and use a nut driver as said above, although that part would need to protrude out of the holder.

 

[Brian Rupnow]

Chucketn--I'm not sure, but I think the socket on the end of a shcs is much larger than on the screw in question. I could be wrong on that.---If I'm right, consider getting a hex wrench of the correct side and silver soldering a 1" long piece of it into the damaged socket in the existing screw. Use a small hex socket on a ratchet wrench to tighten and loosen it.---Brian

 

[10K Pete]

What I can't do is make a hex/allen socket. If I make the screw, I'll need a LH M6 tap to make a nut or something to be able to tighten it.

Chuck

If you could find someone with a rotary broaching setup that would answer
for the hex socket. LH taps are available.

What really irks me is that the people that make this crap and those that
sell it won't stand man up and make it right. It wouldn't take much for
the manufacturers to do it right and replace parts known to be bad.
They can make that stuff by the ton and do it right!

Pete:hDe:

 

[Ogaryd]

Hi Chuck, What do you think of drilling out the LH threads in the tool holder & counterboring the rear of the holder for a flat surface. Install a long 6MM RH shcs so you can tighten from the rear of the tool holder? Gary

 

[goldstar31]

Chuck, for my offering, I would say that you are the possessor of a piece of equipment which was designed and made by people who were simply 'after your money'. They replaced one faulty part and gave you another- I have to say, crap part which was or is no better than the first. You should have sent the second part back and not 'fiddled about' with it - trying to make a silk purse of what clearly is a sows ear. Other people have more or less found the a similar set of unwelcome discoveries and have penned their findings in agreement.

Me, I'm too old to fall for a load of similar problems and if you look at the matter coldly and rationally, things are going to get no better. You might get a replacement but it will be just another heap of bother. Frankly, I would suggest that you go back to tried and tested tooling and put all this experience behind you. The tried and tested tooling's are at the cheapest a four way front tool holder which requires no milling but is only 3 plates of metal joined with bolts and the lathe tools held with easily replaceable and cheap cap screws. You can make a helluva lot of 4 way tool holders for one weak and watery so called improvement. the lathe tools, once set get a shim or shims glued to the bottom of each one. If you use carbide inserts, all that you have to do is replace or turn the insert and for hss users like me, merely add a minute bit of more shim after grinding and honing.

For the rear tool post, you can get away with - three more bits of block which require no milling and your parting tool, held upside down with replaceable cap screws. If you want to go the whole hog, you make up a George Thomas rear parting tool- and forget these hassles--- and get on with life. My GHT tool has survived several lathes----- and a crowd of now departed model engineers who knew better.

Again, it up to you. Either listen to a first class engineer who was a mate of Westbury, Tubal Cain, Chaddock and Cleeve and actually did it all for ---Nothing- or someone was wanting to finger your pocket book..

Regards

Norman

 

[chucketn]

This parting tool holder is the second one from LMS to have this issue, LMS replaced the first one totally without charge when I e-mailed and asked about getting a new screw. I can't fault their customer service. The first one failed within a few weeks of purchasing the set, The second lasted over a year, so I wouldn't expect a replacement again. I think I can repair it with a permanent fix.

Chuck

 

[10K Pete]

Hi Chuck, What do you think of drilling out the LH threads in the tool holder & counterboring the rear of the holder for a flat surface. Install a long 6MM RH shcs so you can tighten from the rear of the tool holder? Gary

This fix sound really good to me. Eliminates the special screw, allows you
to use a known good screw available anywhere, and would be easy to do.

I have a couple of holders of that type but haven't had any trouble with
them but if this happened to me, that's the fix I would go for.

Pete

 

[chucketn]

Hi Chuck, What do you think of drilling out the LH threads in the tool holder & counterboring the rear of the holder for a flat surface. Install a long 6MM RH shcs so you can tighten from the rear of the tool holder? Gary

I have a buddy that's a retired toolmaker. He says he might have some replacement screws. If he doesn't come through, that's the next step.
I think I've got a temporary fix on them this morning. I sorted through my box of Allen wrenches and found one that is a better fit. I'll paint it or something to make it stand out.
I also have a few inquiries out at Sandvic, MSC, and Tormach, the actual maker of the tool holder.

Chuck

 

[chucketn]

Chuck, for my offering, I would say that you are the possessor of a piece of equipment which was designed and made by people who were simply 'after your money'...

Again, it up to you. Either listen to a first class engineer who was a mate of Westbury, Tubal Cain, Chaddock and Cleeve and actually did it all for ---Nothing- or someone was wanting to finger your pocket book..

Regards

Norman

I agree with you, Norman. It is what it is.
If my pensions were a bit bigger, I would certainly invest in better tools, my car would be a Cadillac instead of a Chevy, I would be wintering in Florida, etc., etc.
Part of the fun of this hobby is learning, figuring stuff out, and making improvements. I have no qualms with the quality of the tool holder. The set it came with has served me well for the price I paid. It actually could have been my heavy handed use that caused the issue.
I think the suggestion by Ogaryd is probably the way to go, in this instance, if my buddy doesn't come through. That is the type of info I was looking for, or a link to a site where I could get a better screw. I have bought boxes of better quality cap screws, set screws, etc., as I can afford them and replaced many on the tool holders. I just haven't been able to find the particular screw I need, and making an exact replacement is beyond my capability.
Please don't take me wrong, I am just trying to do the best I can with what I have. Sometimes better quality is the most direct answer, and I truly understand that.

Chuck

 

[Draw-Tech]

Yes, that has been done. The best fit is now a 1/8" imperial Allen. Problem is the cheese soft screw is deforming more with each use, Right now, I have 2 holders that are unuseable. I can single point both RH and LH threads. What I can't do is make a hex/allen socket. If I make the screw, I'll need a LH M6 tap to make a nut or something to be able to tighten it.
In case there are folks that don't understand what I'm talking about, I've attached a picture.
Chuck

Hi Chuck
Got away from soft hardware, buy going to unbreako socket screws, and making my own holder. I have attached a couple of drawings, that if you have a milling machine available, you can modify the mounting dovetail to match your holder.
Jack

View attachment Cutoff_Tool_Holder Assembly.pdf

View attachment Cutoff_Tool_Holder.pdf