Need MT3 collets, opinions or other sources?

[jester69]

Hello,

I recently bought a used Smithy. I got it quite reasonably, and plan to learn machining with it. I know many have less than glowing opinions on combo mill-lathes but it will make better parts than what I had (nothing) and relieves a frustration I have had for years because I just wouldn't use a machine tool enough to justify the big bucks for new etc.

It came with a lot of stuff tooling wise, but a lot is missing as well. I need collets, apparently mt3 is uncommon enough in the bargain basement that my options are somewhat limited. Will either of these e-bay specials do the trick?

http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW

http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW

other thing I need is a live center, will this one be a good (enough) one, or am I better off spending the extra dough to get one with multiple types of points, cones etc.

http://www.harborfreight.com/cpi/cta...emnumber=38574

Finally, I do have the chuck that takes the drawbar, will tapping it out with a mallet drive me crazy enougn that I should get one with the flat bit for the tailstock.

Sorry to ask such dead basic questions, but the research I can do as a newbie won't give me the eye of a machinist instantly, and I hate to waste money If you have any other good sources for reasonably priced good tools (ha) i'd love a pointer.

take care,

Jester

[sch]

If you think about it you really don't need a full set of MT3 collets. The 1/8
and 1/4 inch, if used as tool (end mill) holders, require speeds that the machine really doesn't feel comfortable or can't operate at. Consider what size endmills you are likely to use and get the MT3 collets for that size. The second ebay listing doesn't have the drawbar thread listed, need to know if it is metric or not. www.victornet.com (Victor Machinery in N.Y.) has sets and individual MT3 collets and is a good company to deal with. Smithy also sells the collets. Other than that either Ebay set would suffice, but you won't use half the collets.

Re the live center, one listed is ok, but I would suggest getting an MT2 live center and use an MT3/2 adapter. From experience cutting close to the end of a work piece mounted on a center or threading can be dicey with the larger head on the MT3 size. The MT2 head is smaller in diameter and less
interference with the tool holder occurs. All I use on my 12x36 lathe is the
MT2 head and I have both. FWIW Bison or Skoda live centers are very nicely made and worth the few extra $.
Steve

[sch]

deleted

[Halfnutz]

SCH's right. I do about 90% of stuff with a 3/8" collet or holder. But a full set is nice if you have the cash. If your gonna get the set, look into a quick change set though, theyre about the same price and very handy

Ive heard good stuff about Smitty's. Its probably a great first machine. If you catch this bug, youl be eyeballin a 3 million dollar Mori with a builtin helicopter pad within a week anyway, so it doesnt matter, just have some fun with it and learn alot.

As far as the drawbar goes, I bought a copper mallet from Harbor Freight for ten bucks and I like it fine.

[jester69]

Originally Posted by sch Consider what size endmills you are likely to use and get the MT3 collets for that size.

I hate to prove I'm completely new at this yet again, but what are the most common sizes?

Also, I have seen "end mill holders" and collets. I'm guesing with the collets you can do side milling & the "end mill holders" you cant.

I'm getting excited about this.

Buying a workbench for it tonight, sears has a good one on sale about 33% off:

http://www.sears.com/sr/javasr/produ...id=00959831000

take care,

Jester

EDIT: Halfnutz said 90% is with 3/8 usually, so that makes sense as a first collet. I can buy more as the need arises probably.

[sch]

If you look at an end mill there is a cutout in the shank. EMH have setscrews that screw into that recess and clamp the end mill in place. The endmill should be pulled down so the setscrew is clamped in the top of the cutout. This prevents the endmill from moving down under milling torque (endmills are shaped like screws after all). Collets have no such positive clamping and endmills can occasionally pullout under milling forces and cut at the wrong depth. In practice a lot of people never use anything other than (R8) collets for holding endmills in bridgeport size mills with no trouble at all. One slip of a collet on a critical workpiece or after you have already spent 3hours getting to where you are might change your mind. EMH for smaller collets are inexpensive (same as MT3 collets or less) and don't subtract much from the workpiece envelopet. 3/4" EMH are huge (holder 1.9" diameter 3" long) and on 3n1 not very usable. End mills come in lots of sizes but you can do a lot of work with just 3/8 and 1/2" sizes. As you go below 1/4" even for HSS bits, the recommended spindle rpm for cutting steel bumps up against the max rpm for the machine. Aluminum cutting speeds are at least 2x those of steel. Either holder works for end or side milling.
Steve