Milling machine spindle rust

ovidiumght · Feb 6, 2020

I just bought a horizontal milling machine for scrap money. It came with a tool in the spindle, I managed to remove the arbor, but now I found some rust in the spindle.

This is a hobby, so I don't need it to be super accurate. I have a lathe, but no experience with milling machine.

What do you think about this, is this still usable, or I should sell it for scrap again

johnoder · Feb 6, 2020

Get a bearing scraper and remove the rust, then a little shine up with scotch bright

Its hardened and ground so you won't be removing metal

Here is a very cheap bearing scraper, though not near to you

Vintage Decurved Pointed Ball Bearing Scraper Unmarked 1/2" x 7" | eBay

ph

ovidiumght · Feb 6, 2020

Thank you, unfortunately I am from Romania, it would be to complicated to order this tool from the us.

I can't find a tool like that here. I will try some scotchbrite to remove the rust, hope the taper will run relatively true.

Larry_D · Feb 6, 2020

If you're just trying to salvage it and not scrap it, I'd start by trying to remove most of it gently with scotchbrite, etc. Then get a good toolholder and lap it with some preferably non-charging lapping compound, like Timesaver.

Stan Canada · Feb 6, 2020

ovidiumght said:
I just bought a horizontal milling machine for scrap money. It came with a tool in the spindle, I managed to remove the arbor, but now I found some rust in the spindle.

This is a hobby, so I don't need it to be super accurate. I have a lathe, but no experience with milling machine.

What do you think about this, is this still usable, or I should sell it for scrap again

View attachment 277847
View attachment 277848
View attachment 277849

There is no much rust inside, at least according to the picture.
Get used tool holder, I assume it is 40 taper and apply fine lapping compound on it. You also can weld a cross bar to this holder for easy handling.
Put holder in the the spindle and start to rotate back and fourth. After finish clean surface inside spindle. Should be good for home use.
Good Luck

atex57 · Feb 7, 2020

Myself I would never again use Scotchbrite or other soft abrasive on a spindle as it will cut everything including the good spots inside. Trying to lap it with a tool holder will embed grit into the spindle along with ruining the holder. The best I have seen is to get a fine grit NEW stone, soak it in solvent or even diesel fuel and carefully work the rust out using the long edge of the stone. Scotchbrite can work if you are very careful and work only a small spot at a time.

Ed.

cranium · Feb 7, 2020

How about naval jelly and 0000 steel wool?

Paolo_MD · Feb 7, 2020

I agree with the other comments that this is a minor issue.

Perhaps I'm stating the obvious. However, my suggestion is to first evaluate if everything important (and expensive) in the machine works fine. Are all the gears, bearings, clutches working as intended?
Once you decide it's a keeper or you manage to repair whatever important is broken and determines if it goes back to the scrap yard or you keep fixing it, you could dedicate time to finishing touches like removing the rust from the spindle.

It would be very frustrating spending a few precious hours cleaning it up thoroughly and, perhaps, repainting it for then discovering that you have a few gears broken or a speed/feed selector is completely trashed.

Paolo

ovidiumght · Feb 7, 2020

Thank you for the suggestions. I was thinking that the spindle rust is the deciding factor and I don't have what to do with the milling machine.

Regarding other problems...where do I start.

The feed motor and feed gearbox is missing. I was thinking I can fix this by adding a 3 phase motor with a gearbox and a vfd to control the feed speed.

There are some parts missing from the electrical panel. Again I was thinking I will add a vfd to control the main motor.

The coolant pump and pipes are missing.

The table moves in all directions, the x axis has a rack and pinion arrangement, and the rack has half a tooth missing at the end, but I imaine that's not a big problem.

Also the table has some deep marks in it, was thinking to fill them up with epoxy or something like that.

The gearbox looks good, no missing teeth that I can see. Everything is clean in it. Gears change nicely(with it off for now).

The thing is it was very cheap, something like 200 euro for 1.5 tons of iron, and I also need a project more than a milling machine

donie · Feb 7, 2020

I am dealing with bringing back a rusty mill, the spindle being a extra concern, I used a mix of acetone and auto transmission fluid, and hand scrubbed the spindle bore with a brass brush first then "lightly" used the scotchbrite. I found its best to get the lumpy rust off first with a brush and solvent of some sort. Then any abrasive use will be much lighter.

I would suggest to not remove all the staining from the corrosion, that may damage the tooling fit. I tested the spindle above with a good toolholder and blue dye, it looks good enough.

ovidiumght · Feb 7, 2020

Wow, that's a nice looking spindle!

Also, do you know if 46 weight hydraulic oil is ok for the gearbox and oil pump?

donie · Feb 7, 2020

The mill was pretty rough,

I don't know about that oil, the wrong type of oil holds contaminants in suspension like automotive engine oil, but a lot of people use that oil anyway.

ovidiumght · Feb 7, 2020

Mine is worst

I was thinking hydraulic oil because it has no detergents that keep the particles in suspension, but I am not sure about the weight.

Here are some higher quality images of the spindle:

tdmidget · Feb 7, 2020

A hydraulic oil that is not classed as anti-wear or AW should be alright. It may also be called R&O oil, circulating oil, or turbine oil. These oils will separate water rapidly and allow contaminants to settle out.

donie · Feb 7, 2020

good to know on the hydraulic oils.

here is mine as found

Paolo_MD · Feb 7, 2020

ovidiumght said:
Thank you for the suggestions. I was thinking that the spindle rust is the deciding factor and I don't have what to do with the milling machine.

Regarding other problems...where do I start.

The feed motor and feed gearbox is missing. I was thinking I can fix this by adding a 3 phase motor with a gearbox and a vfd to control the feed speed.

There are some parts missing from the electrical panel. Again I was thinking I will add a vfd to control the main motor.

The coolant pump and pipes are missing.

The table moves in all directions, the x axis has a rack and pinion arrangement, and the rack has half a tooth missing at the end, but I imaine that's not a big problem.

Also the table has some deep marks in it, was thinking to fill them up with epoxy or something like that.

The gearbox looks good, no missing teeth that I can see. Everything is clean in it. Gears change nicely(with it off for now).

The thing is it was very cheap, something like 200 euro for 1.5 tons of iron, and I also need a project more than a milling machine

The major challenges I see with your machine is that it is a production mill with a rather short table and rack and pinion, instead of a leadscrew on the long axis.

For many jobs, these aren't big limitations, especially if you can set solid stops for the X travel. Avoid at any cost any urge of climb milling or getting into any situation in which the cutter would move on the X axis toward a taller section of your piece, since you could get into a very dangerous crash (the rack would drive the pinion under the power of the spindle, whereas a leascrew and nut would limit any climbing into the part to the sole backlash).

It doesn't look there is much room between the table and saddle. But, with some ingenuity, perhaps you might be able to replace the rack and pinion with a leadscrew and nut (with the nut bolted on the saddle and the leascrew traveling with the table).

Paolo

ovidiumght · Feb 8, 2020

Thank you Paolo, that makes sense, I was wondering why it had a rack and pinion vs a leadscrew.

I managed to start it today. At low rpm it makes some noise, I suspect a bearing in the gearbo might be shot. It only happens at 80rpm, at 100 and up it's ok. The oil pump works and it pumps oil to the bearings, so that should be a good sign.

Here is a video of it running:

YouTube

J_R_Thiele · Feb 8, 2020

Evapo-Rust(R) Is Available At These International Suppliers

No one has mentioned Evaporust. It will remove the rust, and not affect the base metal.
While submerging the part is ideal, it is not necessary. I frequently use strips of paper towels to keep the surface moist giving it time to work, then use a brass bristle brush. If you can warm the metal surface it will work faster. If it dries on the surface, it leaves a sticky film- but does not rust. It can be washed off with a towel damp with water.

ovidiumght · Feb 8, 2020

I cannot get Evaporust in Romania. There are some german alternatives, but haven't tried them yet.

Bill D · Feb 9, 2020

ovidiumght said:
I cannot get Evaporust in Romania. There are some german alternatives, but haven't tried them yet.

EDTA mixed with water is almost the same as evoporust. It will dissolve rust a the rate of one gram of EDTA will neutralize one gram of rust. It is cheap as a powder. Maybe you. can use the coolant pump to keep things wet with towels.
Bill D

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