Refurbishing a neglected mini-mill

[Seb]

I just bought my first machine tool of any kind, a used X2. It is the HF version with the R8 taper. I measured spindle runout at about +- 0.001 inch (dti on outside of spindle). I feel like a little kid on christmas. I paid $300 for the mill, a clamp kit, a set of 11 R8 collets, and a little drill-press vise totally unfit for milling work.

It was so cheap because the mill has some surface rust, and the table has a couple of little dings. The dovetails and leadscrews are clean (they were kept oiled and greased), but all other unpainted metal surfaces have some rust, including the table and the column.

Here's the refurbishing work I've done so far:

Took the table off (but left the saddle and head on). Took the Y leadscrew bellows off.

Wiped all the old chips and gunk and grime off with a brand new paintbrush, rags, and WD40. I degreased everything I could reach, including the screws and ways.

Scrubbed at the rust with a copper dishwashing scrubby pad and WD40; much but not all of the rust came off. There is no pitting underneath.

Sprayed LPS2 on all exposed metal, wiped the excess off with a clean rag. I know lithium grease is prefered for the screws and ways, but I don't have any on hand so I put LPS2 there too.

Put the table back on and adjusted all the gibs.

Made my first chips! Whoo!


Ok, that's where I'm at. There's still some rust spots left here and there where my Copper + WD40 scrubbing wasn't enough. There's lube on the screws instead of grease. Other than that I think it's in pretty good shape. I haven't opened the transmission but it sounds ok.

How did I do? And what should I do next?

[MIKE JEFFERS]

make something

best way to find if anything else is needing attention

[billfle]

My first milling machine was an X2 (Hare Forbes HM10). I have made many things with it and just love it. I have recently upgraded to an X3 as the work I am doing is a bit much for the HM10. I had to rebuild the gearbox as I stripped the plastic gears. My fault but the fly cutter was a bit oversized. They are a wonderful small machine if treated as such. I motorised the X axis with a windscreen wiper motor and variable speed DC controller. I fitted digital scales on the vertical and X axis. My son has it now and has much work for it. There are occasions when doing small jobs that I wish I had it back. They are an excellent starter and certainly suited to small hobby work. I would recommend one to beginners and the not so critical. They really do need metal gears as the plastic ones are not really suitable, especially when they strip before the sacrificial gear does.

regards

Bill
Hobart, Tasmania

[ktb100]

post a pic, let's see it

[redgreener]

That sounds like a good find. As long as the metal isn't pitted you are good to go; that surface rust just darkens and "seasons" the metal, and is useful in itself as a rust-inhibiting finish, like bluing on a firearm(or "browning" in the old days). Anyway, I also have an X2, it is a great little machine if used within its limits. Make sure everything is tight--especially the gibs, get you a good milling vise, and have fun making chips. I have put one of those belt conversions on mine, and I really like this. A spindle lock is also very handy for changing tooling and such. Enjoy!
CS

[fatal-exception]

I would suggest replacing the gib adjustment set screws. They are made out of butter, and it's no fun when they twist off...

The belt drive upgrade is well worth the money for the increased spindle speed and the reduced noise. http://www.stirlingsteele.com/beltdrive.html

Scotch Brite pads + WD40 also work magic at removing rust.

If you need any parts for the machine, let me know.

Paul

[Seb]

Originally Posted by redgreener Make sure everything is tight--especially the gibs, get you a good milling vise, and have fun making chips. I have put one of those belt conversions on mine, and I really like this. A spindle lock is also very handy for changing tooling and such.

Yep, a vise, the belt conversion, and a spindle lock are all on the short list. The long term plan is ball screws and servos on all 3 axes.

For now, I want to try to make the easily-made parts of the belt drive, maybe from Hoss' plans.

For the spindle lock I'm thinking of building this one from mini-lathe.com.

Originally Posted by fatal-exception I would suggest replacing the gib adjustment set screws. They are made out of butter, and it's no fun when they twist off... The belt drive upgrade is well worth the money for the increased spindle speed and the reduced noise. http://www.stirlingsteele.com/beltdrive.html Scotch Brite pads + WD40 also work magic at removing rust. If you need any parts for the machine, let me know.

The gib adjustment screws seem fine to me, and they have a low-stress job. Maybe you got screws from a bad batch?

I've heard that Scotch Brite pads are more abrasive than copper wool and they will scratch the underlying metal, so I wanted to start with the safest method. I might try Scotch Brite next... The guy I bought it from had used Mistic Metal Mover to clean the rust off a small part of the table and that looked really good, I might give that a try over WD40.

Do you have spare parts for the X2 lying around?

[redgreener]

Be sure and wait until AFTER your belt conversion is up and running to make your spindle lock. Otherwise, it will probably be wasted effort because the belt drive requires a different top plate and such. Because of this a commercial kit would not work for my machine, but I was able to build one that works fine.
One other mod I am going to do is install the air spring, to get maximum head travel. LMS carries this kit:
http://www.littlemachineshop.com/pro...2258&category=

From my experience, a good 3" mill vise makes a big difference; it greatly improves accuracy and minimizes chatter. And of course, the X axis power feed is also a future mod, this is just too cool and useful to pass up. Geez, buying the basic mill is only the beginning. Getting it all tricked out takes a while....for your entertainment, here is a pic of the belt drive and spindle lock:

[maxboostbusa]

I have made Hoss' belt drive and spindle lock. They work well together and are cheap and easy to make. You will need a lathe for the pulleys and I ground a special bit to cut the grooves for the belt but all in all less than 3 hours just messing around with it. The part that sucked was the Top plate has a shallow pocket machined into it and a large pocket milled through the part. When I was doing a cleanup pass around the large hole I forgot to clear the chips and a 1/2" endmill at around 1800 rpm found a large piece of the center that was cut out. BOOM end mill bound inbetween it and the side of the part shattering every gear except the motor gear and my steel intermediate gear I had already toasted. So the mill was down. Finished drilling the holes on my drill press and made some jigs up to hand feed the stock around and mill the pocket out on the drill press. Looks like Hell but the mill is up and running again now and I am going to make a new topplate.

[Seb]

Originally Posted by redgreener Be sure and wait until AFTER your belt conversion is up and running to make your spindle lock. Otherwise, it will probably be wasted effort because the belt drive requires a different top plate and such.

Originally Posted by maxboostbusa I have made Hoss' belt drive and spindle lock. They work well together and are cheap and easy to make. You will need a lathe for the pulleys and I ground a special bit to cut the grooves for the belt but all in all less than 3 hours just messing around with it.

Thanks for the tips guys.

maxboostusa, is a 7x14 lathe enough? There's one for sale locally, maybe I should go buy that too.

Geez, redgreener wasn't kidding, the mill really is just the beginning. Some might think it insane of us to buy a $500 piece of equipment and then spend $1500 upgrading it...

[maxboostbusa]

I made my parts on a 7x10. Its a little slower than a big lathe but will do the job. I just finished up a few parts a few minutes ago and came in to get a drink. Now I'm back out to tear the lathe down and do a 14" bed extension. After I finish the CNC conversion on the mill this week next project is going to be extending the 14" bed to somewhere around 20-24", then CNC.

[Vern48]

New fun.
I built my own 3 speed belt drive. Gives me 6000rpm when needed.
I replaced the bearings to 10,000rpm specs.
I did my mini lathe bearings recently and used angular
contact bearings. They fit right in perfect.
The lathe never ran smoother.
Steel wool and 3in1 oil works good on rust.
Recently bought a new lathe as well.http://www.bellmachineryltd.com/new_xima_cq6125v.htm