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Dennis WA
04-24-2011, 04:25 AM
As a newbie I would appreciate some help please.

I have a set of 3/4" shank M100 DEX toolholders that I use on my Colchester Student. They were supplied with CCMT 31.51 inserts (ISO equivalent CCMT 090204) retained by a torx T15 screw.

I try to keep my costs down, but these inserts are not too common on eBay - is it possible to use a thicker insert such as the commonly available CCMT32.51, (ISO CCMT 0903XX or CCMT 09T3XX)?

ANSI - ISO - THICKNESS
1.5 - 02 - 0.094" (3/32" or 2.38mm)
n/a - T2 - 0.109" (7/64" or 2.78mm)
2 - 03 - 0.125" (1/8" or 3.18mm)
2.5 -T3 - 0.156" (5/32" or 3.97mm)

Many Thanks
Dennis

MrSleepy
04-24-2011, 05:29 AM
How will the extra thickness affect the centre line...do you pack your m100s to get the right height..or are they set to the right height.

I have noticed that many Ebay sellers package 25mm x 25mm (or larger) insert holders with a couple of packs of inserts for a price only slightly higher that you'd pay for the inserts alone.
And its an easy job to remove metal from the bottom of the holder to get the centerlines to match.

Sometime ago ..Evan posted a great thread on using cermet inserts.. and I was able to get two boxes of tungaloy cnmg inserts with a larger than needed holder for essentially the value of the inserts...and 10 minutes of milling made it into a useable and very solid holder.

Rob

PixMan
04-24-2011, 06:47 AM
That is a very rare, almost proprietary insert. Ouch. I had no idea they existed, and am quite surprised that Micro 100 would use them. OTOH, since they don't make inserts (that I know of), it behooves them to make tooling that you have to go back to them to buy replacement.

You have a few courses of action here. First you could alter the pockets on the tools to take the thicker, common inserts. This can be very risky to insert stability because of the 7 sides of the inserts and their relationship to the screw hole. The screw has to be offset toward the pocket walls by just a few thousandths (or microns if you prefer) so that it "pulls" the insert into the pocket. Too close and the screws won't start. Too far way and the inserts don't seat against one wall or more.

Second option is to use the thicker inserts and have to worry about the screws being too short and the cutting edge above center. Or, you may face the same issue cited above, where the insert is no longer seated. I do believe this my be the case. Get a common 32.5x size insert and test it.

You could park the toolholders into the "I should have looked into this further" bin, and get some standard tools. Watch out for the Ebay specials! They are often China-made CRAP. Buy brand names (from companies known for making inserts, preferably) and get specific about which styles you really use. Those POS kits with 6 holders are cheap, and still not worth the money IMO. You use one 90% of the time, another 10% of the time, and the other 4 look pretty. Put the money into holders you'll use, good ones, that use common inserts.

Lastly, just bite the bullet and get the Micro 100 inserts that fit. Painful, I know, but that's really the best practical option until a bargain on standard ANSI/ISO holders avails itself to you.

Best of luck to you whatever you choose to do.