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fretting marks on toolholders, problem? how to fix?

I used to run Techniks holders & studs in my VF-3 torqued to 50lb/ft, I'd get fretting all the time when roughing steel. I sold all that stuff and switched to Mari Tool holders and JM Performance HT pull studs on everything. I then lightly polished my spindle taper with grey scotch brite and the problem went away.

Since then I've been using the JM Performance HT pull studs for 8 years. The HT studs actually call for even less torque. The torque table printed in each package lists different specs depending on your machines actual draw bar force:

40 taper:
(draw bar / pull stud)
1600 lbs - 20.0 ft/lbs
1800 lbs - 22.5 ft/lbs
2000 lbs - 25.0 ft/lbs
2200 lbs - 27.5 ft/lbs
2400 lbs - 30.0 ft/lbs

I'm running all Mari Tool holders with the JM studs torqued to 25 ft/lbs, no lock tight, just really clean then one spray of rust preventative before installation. Running in a VF-3 they work great, I've never had one loosen off or fail. I do not grease the pull studs exterior as haas reccomends, rather I grease one pull-stud monthly and clamp/un-clamp 7-8 times to get some lube up in the balls. Then I clean all the bulk off that pull stud and continue as usual.
JM studs are where its at. I use the loctite just for some reassurance do to the low torque being used. It's surprising how little torque will start to deform the taper, this becomes even more critical in dual contact machines where a little taper swell will cause the faces to not touch.
 
I'm glad I came across this thread. I use the maroon scotchbrite on all kinds of things, as its what we have in the shop. Guess I'll get some of the grey stuff.
 
What is your air situation,equipment, I had money on bad air?
Have a California Air Tools compressor, don't have a water condenser or anything but Haas has a bleed valve that goes off every 10 minutes. Drain the air compressor about once a week, never have water shooting out of the hand-hose. Does seem to be a moisture issue tho, whether that's air or something else. Any other way you recommend testing for water in the lines?

Would you recommend getting a water condenser to be safe? If so, would something like this do the job or should I spring for a more expensive system.
 
Have a California Air Tools compressor, don't have a water condenser or anything but Haas has a bleed valve that goes off every 10 minutes. Drain the air compressor about once a week, never have water shooting out of the hand-hose. Does seem to be a moisture issue tho, whether that's air or something else. Any other way you recommend testing for water in the lines?

Would you recommend getting a water condenser to be safe? If so, would something like this do the job or should I spring for a more expensive system.
I personally do not recommend using a CNC machine without having a refrigerated air drier, neither do manufacturers. Myself have had way too many problems mainly with valves, and tool changers due to moisture in the air lines, Haas setup sheet specifies, CLEAN, DRY, AIR.
For $1,000 on Northerntool.com order you a cheap Coolair15, btw this is made by Quincy in Italy, says it on the back.
Usually recommended to drain your tank minimum daily, I would get a cheap timed "auto air tank drain". You can get one from $30-$200 that will work fine,
 
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I personally do not recommend using a CNC machine without having a refrigerated air drier, neither do manufacturers. Myself have had way too many problems mainly with valves, and tool changers due to moisture in the air lines, Haas setup sheet specifies, CLEAN, DRY, AIR.
For $1,000 on Northerntool.com order you a cheap Coolair15, btw this is made by Quincy in Italy, says it on the back.
Usually recommended to drain your tank minimum daily, I would get a cheap timed "auto air tank drain". You can get one from $30-$200 that will work fine,
I have to admit that I thought Houdini's earlier air quality post was the best one suggested so far in this entire thread. Now that I find out you run absolutely no moisture treatment I have to think he's right. Depending on your shop size, I'm not sure you need a full on dryer setup, but at least a full on water trap.

You may need a dryer if your shop is plumed like many I've seen with air hoses strung about, and no proper "drops" taken off the main line. I have 8-10" risers coming off the main line at every take-off point. Also a drain valve. This is the correct way to supply dry air, or at least help the matter. (Learned all this back in my sandblasting days.) I also have a auto drain valve on the compressor that shoots off for a second or two every time the compressor starts. Only thing about those is once in awhile they'll stick ever so slightly open. I usually hear it and swap it over to an always on plug for a few quick clean-out bursts.

Anyway... get an air dryer installed right after the compressor and another at the intake of every machine. I can't believe your machine doesn't have one right from the factory.
 
I have to admit that I thought Houdini's earlier air quality post was the best one suggested so far in this entire thread. Now that I find out you run absolutely no moisture treatment I have to think he's right. Depending on your shop size, I'm not sure you need a full on dryer setup, but at least a full on water trap.

You may need a dryer if your shop is plumed like many I've seen with air hoses strung about, and no proper "drops" taken off the main line. I have 8-10" risers coming off the main line at every take-off point. Also a drain valve. This is the correct way to supply dry air, or at least help the matter. (Learned all this back in my sandblasting days.) I also have a auto drain valve on the compressor that shoots off for a second or two every time the compressor starts. Only thing about those is once in awhile they'll stick ever so slightly open. I usually hear it and swap it over to an always on plug for a few quick clean-out bursts.

Anyway... get an air dryer installed right after the compressor and another at the intake of every machine. I can't believe your machine doesn't have one right from the factory.
At the very least, a water trap at the compressor, auto drain on the tank, and a Motor Guard M-30 or M-60 at the machine. But I stand by the CNC machine, you should have a refrigerated drier.
 
At the very least, a water trap at the compressor, auto drain on the tank, and a Motor Guard M-30 or M-60 at the machine. But I stand by the CNC machine, you should have a refrigerated drier.
If I get a refrigerated dryer would I need the water trap, auto drain (assume so cuz this is just for the compressor), and motor guard as well?

Only have one machine so would rather not spend $800 on a refrigerated dryer just yet (tho willing to if it really makes the difference, will pay for it one way or another). Would this product ($190 3-stage filter w/ water trap [5-micron filter], coalescing filter [0.01-micron filter], and desiccant air dryer) plus an auto drain on the tank get me 90% of the way there?
 
It would help, but check the reviews for that product before buying it. It may be that you'll want a better version, and you also need to monitor the desicant and change it out when it loses function.
 
Cool the air between the pump and tank, with an auto drain water trap before the tank. I do this and never have to drain any water out of my tank and never see any in the traps in my shop, ever.
 
Helps being on the dryer side of the state. ;)
Yes it does, but running the hot air out of the pump through 30' of copper in a cold water bath does remove a lot of moisture from the air no matter where you are. I am surprised after coolers aren't more popular on compressors.
 
+1 on the JM products studs. If you want a real education on studs call them and chat with the owner, he is very knowledgeable and taught me quite a bit.

I have a torque wrench set to 27.5 ft pounds and a Mari socket for stud set up. I have a dual contact machine and have a good fit up with taper and flange proved out with Prussian blue.

I’d recommend that anyone questioning drawbar torque or taper fretting check their spindle and holder with some Prussian blue.
 
I don't know... that desiccant dryer at the end makes me nervous. I'd put it in the middle and let the dryers output be filtered before going downstream. Doesn't that desiccant shed a little dust? And as was mentioned... needs repeat service.

Unless your machine manufacturer requests no oil in the air, I'm not sure you'd need the filtering and oil suppression that the coalescing unit will give you. You put a filter/water trap/regulator (all-in-ones work) at the compressor and another at the machine and you'll probably be good. I think standard issue filter elements run in the 5 to10 micron range anyway. Try your local Grainger or the likes of.
 
If I get a refrigerated dryer would I need the water trap, auto drain (assume so cuz this is just for the compressor), and motor guard as well?

Only have one machine so would rather not spend $800 on a refrigerated dryer just yet (tho willing to if it really makes the difference, will pay for it one way or another). Would this product ($190 3-stage filter w/ water trap [5-micron filter], coalescing filter [0.01-micron filter], and desiccant air dryer) plus an auto drain on the tank get me 90% of the way there?
You could even buy a Harbor Freight POS $500 refrig air drier, You still should have a water trap and a auto drain, its the cost of owning a CNC. My first little Haas MiniMill and I still knew to buy a refrig air drier, been in a world without one, no bueno!
 
JM studs are where its at. I use the loctite just for some reassurance do to the low torque being used. It's surprising how little torque will start to deform the taper, this becomes even more critical in dual contact machines where a little taper swell will cause the faces to not touch.
I torque my BT30 JM studs to 15ftlbs dry and never had one loosen up in almost 300k tool changes. I think Big K says no loctite.
 
+1 on the JM products studs. If you want a real education on studs call them and chat with the owner, he is very knowledgeable and taught me quite a bit.

I have a torque wrench set to 27.5 ft pounds and a Mari socket for stud set up. I have a dual contact machine and have a good fit up with taper and flange proved out with Prussian blue.

I’d recommend that anyone questioning drawbar torque or taper fretting check their spindle and holder with some Prussian blue.
here are results of a blue spindle taper check, think I used a bit too much but what do people think? it made contact everywhere, but less on that one side.
IMG_2397.jpg
 
Pull the keys out and take the retention knob out. Then use much less bluing on the newest tool holder you have.
You’re checking the spindle taper to toolholder interface. So gentaly place the tool in the spindle and blue up the spindle socket. Have some lint free wipes and IPA handy to clean the blue after each spotting. Spot a few times and play detective. Get familiar with good blue application and technique, it’s trial and error. Check with a mirror to see where the high spots are.
Clean the blueing out of the spindle each time. You’ll develop a pattern and notice some printings are different, that’s normal toss out the outliers and reprint.
Did you find any knicks in your taper?
Those are identified by concentric lines around the shank. If there are knicks stone them out and repeat.

Get a good picture in your brain, then reinstall the keys and check the taper with just the right amount of blueing. How much of the taper is contacting?

I ran a beat up hurco with a quite bell mouthed taper. The tools would only make contact on the last 30% of the taper by the pull stud. I would get serious fretting if I attempted heavy cutting.
Again, play detective and you will have your answer.
 








 
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