small lathe collets needed

[rwells]

I have a small 9x20 lathe and need to turn small parts. I normally turn from 1/2 inch to 1/16" and would like to know what kind of collets are available. My bore is 25/32". The spindle mount is 1 1/2 X 8. Spindle taper is MT-3. Any info or web site info would be helpful. Thanks in advance.

Rick

 

[rake60]

Collet chucks to fit your 9 X 20 are available but they are a rather expensive item.

Little Machine Shop offers their 3047 Collet Chuck for $199

The 1-1/2 - 8 adapter is another $30
The collets are sold separately.

Rick

 

[shred]

You can get MT3 collets as well.

 

[PolskiFran]

My Atlas lathe has 1 1/2-8 thd. with #3MT spindle. It originally took 3AT collets. Their capacity is only to 1/2", but that's what I use.

Frank

 

[greenie]

Have a look at this site and there are ER collets of varying sizes, along with cylindrical extensions/fittings, that you just shove in the 3 jaw chuck and your away.


http://www.rego-fix.com/screwmachine/cylindrical.asp

Or if your game enough, make up your own ER collet holder that fits in place of the chuck, lots of ideas on the web.

 

[rake60]

Great alternatives showing up here!

 

[Airhead]

I have one of those lathes too and I have been looking at the ER collet chuck at Tallgrass tools. You can get it as a kit or all finished and ready to go. The thing I like about this is it's front closing, so it leaves the spindle bore unobstructed.

Here's a link http://tallgrasstools.com


Rick

 

[Stan]

The easiest thing is just use MT3 collets directly in the headstock and not increase the overhang on the spindle. They can be tightened with a piece of all thread rod through the spindle but that eliminates the choice of putting long pieces in the collet. If you want to use the collet for long pieces make a nut to screw onto the spindle to press the collet in. You then have to use a piece of pipe to tap out the collet from the rear.

 

[Airhead]

I got a PM asking me to compare 5-C collets with the ER series. I tried to reply but I don't think my computer sent the message, so I'm just putting here. Maybe others are intrested too.

I'm no expert on this but I'll help as best I can.

First off, the 5c collets wont fit up the snout of the little 9x20 lathes. They do make front closing chucks for them but they are big long heavy things and if you hang one of those off your spindle nose you wont have much room left between it and the tail stock! The ER collets are a lot shorter and I don't think the chuck to hold them takes up much more room than a 4 jaw chuck. One thing to look out for, they made some ER collet holders that hang out farther and also don't allow a piece of stock to pass through them. Shop carefully.

The main difference between the two is that the ERs are double angle collets and are slit from both ends. This lets them close along their whole length so that they will hold 'in between' sizes. If you put something under size in a 5c it will only hold at the very tip and if it is too much under it may not spring back when you release it. You will probably hear somewhere that the ER collets wont let stock pass through the spindle like the 5c but again, that is a function of the holder, not the collets themselves.

One advantage of the 5c collets if you are in the U.S.A. is that they are ubiquitous. You can get four and six sided blocks that hold them for simple indexing on the mill, the 'spindexs' are all made for 5c. You can also get them to hold square, hex, and lord know what other shapes.

If you want to see the subject beat to death read this thread on the HSM forum.
http://bbs.homeshopmachinist.net/showthread.php?t=13544&highlight=collets

For myself I think the ER collets are the way to go for the little 9x20, but that's just me. Another idea, if you can get by for a while turning what you need from standard sizes of drill rod or cold rolled, you could just get a couple of sizes of MT3 collets to hold you over while you're saving up for the 'real' setup. I've used the collets from my mini mill for this.


Hope this helps,

Rick

 

[rwells]

Has anyone had any experience with the lathe collet chucks such as the one from Bison, Lathmaster or The Little machine shop? I'm getting serious about using one with 5c collets on my 9x20 lathe. I do need to retain the spindle bore for long slender parts. Is it a lot of work to face off the collet adapter for my threaded spindle? I'd like to keep as much accuracy as possible. My spindle bore is 7/8"

Thanks

Rick

 

[Stan]

This is everything I use for standard size stock. The Mt3 collets will hold short pieces up to 3/4" and will pass long stock through the spindle up to 5/16". The bump bar has a brass end and it is used to tap the collet loose.

http://i272.photobucket.com/albums/jj165/sdmcw/MVC-590F.jpg[/img]]

http://i272.photobucket.com/albums/jj165/sdmcw/MVC-593F.jpg[/img]]

 

[rwells]

I read your post and the setup looks like it would do the job. Have you ever spun a collet in the spindle? I didn't want to take a chance of messing up the taper in the spindle nose. Your solution looks economical

thanks
Rick

 

[Stan]

I don't think the small lathes most of use (mine is a Logan 820 [10 x 24]) have enough power to spin a tight MT3 collet. I use the same collets in my mill and run 3/4" endmills without problem. Just make sure the collet and spindle bore are clean, dry and no burrs.

In the last year, I made a drawbar for my mill with a compound thread (coarse thread on one end and fine thread on the other) and when I unscrew the drawbar the collet makes a very audible pop when it lets go. The same system could be used on the lathe spindle but you would lose the ability to put long material in the collet.

 

[J. Tranter]

Stan can you show the other side of that collet closer? I have a Logan 820 and was trying to figure out how to use collets in mine without having to buy a bison chuck. That looks perfect. Did you make that your self?

 

[Bernd]

I also have a 10 X 24 Logan lathe. Mine has a spindle nose adapter for the Hardinge 3C collets. Also have a couple of "pot" chucks that fit it. The draw bar is nothing more that a hollow tube with threads to match the 3C collets and a 4" hand wheel at the other end to tighten the collets up. Works pretty good.

Stan: Were can you get Mt3 collets ?

Regards,
Bernd

 

[Stan]

Over the years I have spent more time making tooling and fixtures than making engines. To me the hobby is working with metal and it is just as much fun to make a rotary table as an engine. Some tooling is a one time requirement and goes back into the scrap box while others go on the shelf fr future use. I had a full set of 3AT collets and drawbar closer which I never used because of the time spent to set it up for one use.

I had need for some 5/8" studs threaded on both ends and that precipitated the closer nut. Made out of brass because that was what I had. Nothing fancy, just bored out and threaded to fit the spindle. I suppose the perfectionists would make a curved seat to match the end of the collet but mine is just a flat surface.

To make the studs, I screwed a piece of all thread in the back of the collet with a jam nut for a collet stop and then cut the thread using the dial indicator to determine the end of thread. The chart on your fishtail gives you the depth of thread so you can roughly calculate how much you will advance the compound toward the headstock with each pass and you subtract that off the dial indicator plus a few fhou more so that you end up with a nice tapered finish on the last thread.

Collets are available from all the usual tool sources. I bought mine from Busy Bee simply because they had the best price for pretty good quality. The set I have is made in Poland and have met any precision standard that I can meet. Like all tools there is no limit to how much you spend and the level of precision you need. My experience has been that import stuff from Eastern Europe has been good quality.

http://busybeetools.ca/cgi-bin/picture10?&NETID=1138120124081727845&NTITEM=B360

At that sale price, they are only about $10.00 each.

 

[gunboatbay]

For super-small stuff I use CDCO's pin chuck set ($7.00) mounted in my 3-jaw. Everything larger I use 3MT collets. Works for me.

 

[Cedge]

My machines are all set up for 3 MT. My question is concerning ER32 collets. I'm currently using an oddball ER style collet set sold by Micromark. It works okay but the collets are of a proprietary size that I've not been able to find elsewhere. I'm looking at the idea of investing in an 3 MT/ER32 collet system so that a wider range collets are available. I'm looking for input on user satisfaction with the ER32 design. Any comments on drawbacks, advantages, etc would be appreciated. Yeah... I'd love to go R8 or 5C but that just isn't happening for now.

Steve

 

[gilessim]

Steve, I bought an ER32 collet system, M3,about a year ago, made in Poland I think, with 10 collets from 6-18 mm I think, it's very well made and was quite cheap, I use it all the time on my minimill ,I've never had a cutter slip in it and no other problems, before I just used a good quality self tightening drill chuck, but it just wouldn't hold the hardened mill cutter shanks, I think they're valid, you have about an 1.5" of nice parallel grip if you need it...recommended..Giles

 

[rake60]

Steve
Every twist bit and allmost all end mills up to 3/4" are set in ER32 collets in the
CNC machine I operate at work. I've never had one slip or fail.

I was very pleased with the R8 ER32 Collet Chuck set I purchased from
an eBay auction to fit my mini mill.

The same seller currently has an MT3 set listed up for auction.
eBay Auction Listing

It may be worth considering a bid.

Rick