Spindle to hot to touch!!!

[DSL PWR]

To get the bottom race out mig weld a small bead on the race. the welding will cause the race to shrink, and it will probably fall out.

[Kipper]

Diago,
This spindle is open and not I repeat NOT sealed ! the oil will not stay inside but run right out the bottom ! SO ! Is that proof enough for what I said ! you prooved it !
1d10t !

Mine has been running on oil for the past year or so.....One oil seal and an old plastic grease cartridge casing is all it took......Cant use tang tooling anymore though!

[slatronic]

Im guessing rusty bearings are bad. The rollers and races have rust on them. I pulled them out and put them in my little ultrasonic cleaner and noticed they were rusty. I wonder if thats what is holding the bottom race in there so tight.

I found another thread on the IH forum that goes over most of the same stuff here. Man, sometimes it takes forever to find info. There was a suggestion to use dry ice for removing race. I like that idea since it doesnt damage race but I guess if the bearing is damaged why does it matter though. The welder trick is easy enough though.

Is there a major difference between AC and tapered roller bearings? I know that tapered can handle more load but is it really that noticable? This is a second op and random job machine. Head will be tilted most of the time. Maybe another reason for grease vs oil lube. Need to start searching some more.

Thx
slater

[arizonavideo]

The only reason I see not to run A/C bearings is the standard mill is a low speed head which generally means larger tools like fly cutters and large drill bits in steel which bang the heck out of everything.

With CNC most go with a 3450 rpm motor and much higher cutter speeds and somewhat smaller cutter. With lighter loads and perhaps slightly lower run out of A/C bearings they might be a better choice but the tapper roller are the toughest thing out there for cheep.

Your learning everything new so I would keep it simple.

Setting the preload is a bit tricky because it is all done by feel and the grease must be rolled out to get the right feel. Turn the shaft a lot to press out the grease so you get the true feel of the shaft. After that if you run it and it is not a little hot after 10 minuets or so it is probably a little loose.

If your sure you have rust then you should probably replace the bearings. My mill has the Y leadscrew bearing full of rust so I guess it is normal?

[ImanCarrot]

Just one point I seem to remember you're not meant to pass a welding current through bearings- can't remember why, but someone else might know (not a welder) but I thought I'd mention it.

[Cruiser]

Just one point I seem to remember you're not meant to pass a welding current through bearings- can't remember why, but someone else might know (not a welder) but I thought I'd mention it.

If the current from welding went through bearings to get to ground, it would cause welding at each point of gap which would be the bearings, slides etc. So if doing any welding to or on a machine it is recommended to place ground as close as possible to weld point, and make sure it is a good one.

[Cruiser]

The rust your seeing might well be the iron fine that I mentioned earlier.
It is possible that locktite might have been used to hold that bearing in, If you can't get to it with a punch to break it loose, then heat may help. Locktite generally goes fluid at about 350 deg so setting it in oven at 400 till it gets hot might help then it may drop out or a quick chill will shock the race loose and drop it out. a can of freeze off ? might be the ticket here. Once you get it out if heat was used, let it cool gradual and it should be fine.

[Cruiser]

Mine has been running on oil for the past year or so.....One oil seal and an old plastic grease cartridge casing is all it took......Cant use tang tooling anymore though!

I'm curious as to how much oil you run in your spindle and how well it works. I am fully aware of being able to modify the quil for a seal at bottom, and closing slot, but my concern was filling the quil with oil would create to some extent an oil torque converter if filled with enough oil to wet the top bearing.
I was considering doing similar, but was trying to figure in some sort of pump, like a Tesla pump to oil top bearing, control volume, and pump excess to a reservoir.

[Kipper]

I'm curious as to how much oil you run in your spindle and how well it works. I am fully aware of being able to modify the quil for a seal at bottom, and closing slot, but my concern was filling the quil with oil would create to some extent an oil torque converter if filled with enough oil to wet the top bearing.
I was considering doing similar, but was trying to figure in some sort of pump, like a Tesla pump to oil top bearing, control volume, and pump excess to a reservoir.

Yeah I can understand the thinking part...I stopped a while back and just took it that if I dare try then try it and see...so far so good...5k RPM and still using the taper roller top bearing (it does get warm after a few hours without the watercooling) must make the time to change it to the AC bearing I bought to replace it...Overall very happy with it. Doubled the power of the motor with a VFD/motor package some time back.

[gda]

I'm curious as to how much oil you run in your spindle and how well it works. I am fully aware of being able to modify the quil for a seal at bottom, and closing slot, but my concern was filling the quil with oil would create to some extent an oil torque converter if filled with enough oil to wet the top bearing.
I was considering doing similar, but was trying to figure in some sort of pump, like a Tesla pump to oil top bearing, control volume, and pump excess to a reservoir.

Kipper,
Oil is not meant to be used as a liquid coolant, as in a bearing bath, so to speak. Oil is intended to form a slippery viscous film between the ball bearings, or roller bearings and race, to reduce the friction.
In the first place let me say that in all the years that I have been involved with machine tools, I have never once seen an "open" spindle, in the sense that top and bottom of the quill was not capped. I have used B&S, Bridgeport, Lagun, Cincinnatti Milacrom, Millwaukee,etc, and never have seen one.
An .080" hole in the side of the quill, lining up with a point that would allow the oil to reach the balls and race is all that is needed. If the top bearing in a quill is a concern, drill a matching hole in the housing to line up with the hole drilled in the quill, so the top bearing can be fed. when the quill is in a pre-determined up and down position.
As far as how much oil is needed, only a few drops (enough to coat the bearings and race), every 2 hours is sufficient. If your machine runs unattended, overnight, mounting of an automatic oil-drip feeder would be in order.
If you would like to have a print of a spindle that my company designed and built over 35 years ago, e-mail me at info@deangelistool.com and I will send it to you. This spindle is as tried and proven as you are going to get, it is used on engraving reducing machines, similar to the machines that the US Mint uses to engrave the master hobs for all of your coins, and these machines run for days at a time, continuous. These machines use down to .005" conical cutters, with extremely fine spiral feeds, and run at 8-10,000 RPM. This spindle is not designed for heavy milling, so they would be inapplicable for CNC, but only to demonstrate the principles of lubricating with oil. We have built over 200 of them, through the years.I have attached a snap-shot of a master hob to demonstrate what kind of detail and accuracy can be obtained with this spindle. The diameter of the design is 1 1/2", and the material is Oil-Hard Tool-Steel.
I hope this helps.
gda

[BobWarfield]

If the bearings are rusty, I'd definitely replace them. Tapered rollers or AC's, your choice. I talked to Aaron Moss (original IH owner) about this once and he advocated switching to the AC's if you swap the bearings.

RE the grease, Kluber is the really good stuff. You can buy a tube of it for about $20 direct from their site's online store:

https://www.klubershop.com/

You want Kluber Isoflex NBU 15. It's inteneded for machine tool spindles, will handle the temps, and way oil doesn't wash it away.

I think if I wanted to go with oil for higher rpm, I'd go for an oil mist system. Some more details on how that works on my spindle page here:

http://www.cnccookbook.com/CCMillBeltDrive.html

Oil mist is what most VMC's use these days. Still, for the rpms you're likely to see, a good spindle grease should be fine.

Cheers,

BW

[Kipper]

Oil is not meant to be used as a liquid coolant

Darn my last bike was oil cooled...Maybe I should have filled it with water?