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View Full Version : Anybody use their mill as a lathe?



A.K. Boomer
05-11-2006, 02:13 PM
Im going to be tooling up to do this, Im doing strickly proto-type work and its slow going and i dont mind throwing the head down once in while and truing everything in, also i really dont need a tailstock because most of my stuff is small hub type work, i figure it will cost me less than 500 bucks to tool up including a little four inch three jaw and quick change wedge type tool post that i can adapt to the table, mills might seem to have an extra looseness disadvantage because of the quill but that will be totally locked down for lathe work, the massive table and weighs might actually be a stability advantage that may counteract some of the instability from the less rigid head assembly, once the turrit is trued in all i would need to do is true the head parrallel to the table and then center to the tool post mounts no? My machinist friend says to just leave the head in the milling position but i dont think i could get used to seeing parts run that way! and also dont know how youd mount a quick change with any ridgitity, take me otta my little world fella's give me some pro's and cons, with a high emphasis on knowing that im cheap and am not buying another machine, I have a nice little DRO good to 2/10ths and that should help the measurable accuracy factor, I bought my mill to build one thing and one thing only and although it will be constantly changing and updated i pretty much know what to expect as far as the type of parts i will be running --- some work will be collet but for the most part i dont need a through hole like a 5c, thanks for taking the time to read.

Evan
05-11-2006, 02:15 PM
Anybody use their mill as a lathe?

Not yet, I haven't finished building it with my lathe yet. :D

JCHannum
05-11-2006, 02:35 PM
http://www.practicalmachinist.com/cgi-bin/ubbcgi/ultimatebb.cgi/topic/1/16138.html?

Scroll down about halfway for Don's post on the econo-lathe.

Forrest Addy
05-11-2006, 03:48 PM
Yup. Many times. I've made made a bushing or indicator stem on a mill. I even had an old 24" 4 jaw I rescued and machined to mount on a G&L horizontal boring mill spilndle. I mounted plane old lathe tools on a riser bolted to the table. It made a pretty good lathe and would take a heckova cut.

pcarpenter
05-11-2006, 05:18 PM
As someone who often gets cought up in some seemingly brilliant idea about how I can do something for less money or some creative way only to spend money I wish I could have had back later.....deep breath... I have to ask "why not spend the almost $500 on a mini lathe and some tooling". I know they get a lot of crap from people who don't own them and are sure they are junk, but I have one from my days before I had a full size lathe and it truly is just a small lathe with neat features like variable speed etc. People have made all sorts of stuff on them and they are capable of turning things between centers if that ever does become important.

Remember, the rule of thumb for turning without a center is supposedly just a few times the diameter of the part.....that ain't much. I have seen deflection results in stuff that I didn't really think was pushing it until I did the quick diameter/length math in my head.

Paul

IOWOLF
05-11-2006, 05:46 PM
Yes I do.;)

http://img.photobucket.com/albums/v11/iowolf/Millathe.jpg
but usually for turning huge stuff that will not fit into my 14" lathe,Clutch discs and such.

Bill Cook
05-11-2006, 05:51 PM
Larger parts can be mounted on a rotary table, with a fly cutter, endmill or other milling cutter running in the spindle.

For an interesting, decorative curve on a noncritical surface, an endmill with a relieved center can be used.

Shown exagerated:

http://img.photobucket.com/albums/v50/skytop19/curve.gif

BC

gramps
05-11-2006, 06:17 PM
I went a little crazy with the same idea when I got a two axis Prototype cnc retrofit about 15 yrs ago.
I built a headstock out of odds & ends and mounted it on an out rigger bolted solidly on the side of the bridgeport and overhanging the table on the left side.
Then rigged a variable speed motor to drive it.
I used a big block of aluminum I had under foot for mounting various tools and boring bars.
It was very handy for doing contour turning and one job,
making carburator chokes for racing Webers that required an accurate venturi was a good money maker.
Being an old yankee I took great pride in the fact that
I only had about $25.00 in it when I made my first cut!
(I only had to buy a belt and two seals for the head stock.
the rest was odds and ends )
I say go for it!

Gramps

PaulT
05-11-2006, 07:25 PM
I use my CNC BP clone mill as a CNC lathe occasionally and it works great. I leave the head in normal position, chuck the workpiece in a collet in the spindle, clamp a quickchange holder in the vise and let 'er rip.

I have a 12" manual lathe, but I use the "mill/lathe" when I need to cut parts I can't easily do manually.

After seeing how well it worked I bought a 4" 3 jaw chuck that has an integrated R8 shank. These can be hard to find (the 3" ones are much more common) but after poking around for a while I found one on ebay, brand new for about $100., an quality wasn't great but was acceptable for occasional use.

I'm trying to put a picture of a tapered piece I cut on the "cnc lathe" but I don't see how to post a picture so I guess I'll have to let that slide.

Paul T.

A.K. Boomer
05-11-2006, 07:53 PM
Good advise thanks guys, Paul that chuck is the exact one im looking into getting , does the R8 bolt on to the chuck or is it all one machined piece? and i know it goes without saying its china right? its getting crazy --- if anything is made here anymore i cant afford it, although i sored a nice kurt anglock 5 inch last week on e-bay (used of course) thanks

CCWKen
05-11-2006, 08:40 PM
Heck yeah!

I've also use the lawn mower as a string winder;

The shreder as a barbed wire winder;

The truck bumper as a fence puller;

The tractor as a tree timmer;

The dozer as a septic collapser;

and dozens of other tools for finger pinchers! :D :eek: :p

Kidding aside, it does work.

Evan
05-11-2006, 08:46 PM
I once signed a courier waybill with my pocket knife. Cut through all the copies too. Made an X. I was unhappy with them. They didn't argue...

cruzinonline
05-12-2006, 11:06 AM
Couldn't resist throwing in another war story (must be getting old). ' Bout 20 years ago we were on a site and broke a lead screw on a protable bring bar. The screw was just all thread with a fit at each end for a bronze bushing. The plant was union and we weren't so we couldn't use their lathe and they were just too busy to make us a new one. The other option was to drive bacck to Savannah and pick one up, bout 4 hours away. So the supervisor pulls a McGyver, grabs an 8' 2x4, some nails, a 4" side grinder and an electric drill motor. Lays the all thread on the 2x4. puts a nail on each side at both ends and bends them over to "capture" the screw. Has me chuck up the drill and spin it while he grinds the bearing fits with the side grinder. He even had the balls to pull out his mic and check while he was grinding. I think that leadscrew is still in that bar....uuuhhhmmmmm... got to check that out next time I get back to the shop.

PaulT
05-12-2006, 01:39 PM
The R8 chuck has the backing plate and R8 arbor machined as one piece that the chuck bolts on to. The one I got is a chinese "no name", but not too bad.

I tried to find the company name for you but I'm drawing blanks, it was a small outfit and I didn't figure I'd every buy anything from the again so I don't think I kept their contact info.

I pretty sure I found it by searching under "R8 chuck" on Ebay, it was from an online store on Ebay, not an auction item, just a "buy now" listing so if you search using that string you should be able to find it.

3" chucks are easier to find, the 4" one was a little tougher.

Good luck-

Paul T.

IOWOLF
05-12-2006, 01:52 PM
Look in your Ebay history, or Paypal history.

kap pullen
05-12-2006, 04:54 PM
All you have to do is mount your right angle head and load the job in the collet.

I've done that on the Prototrak at work for little contouring jobs.

Also mount the die head in the bridgeport spindle, part in a vee block and have at it.

My bridgeport (cnc) wants to go home (z axis) at the end of every cycle but I've done some jobs on the Anilam at work ysing the x-z axies.

Kap