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Re: Unimat 3 & 4 Collet Chucks – Message #34239 - Posted By: caryscotthere – Jan. 14, 2013 |
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The original collets and holder were for the Unimat DB200s and were available in the mid 1950s. Both were made by Schaublin in Switzerland. The collets were the E-16 type and were bored for a single size round smooth work piece. It took a lot of them to cover the many sizes of round metal
available up to 5/16" or 8mm. Later Schaublin introduced a series of 10 RS-16 collets that covered the full range of the old set. The difference can be seen by looking at the flat top of the collet. The E-16s have a total of 6 slots and the ES-16s have 12. These were discontinued sometime in the mid 1980s. I believe someone has found a German co. that now makes these old style collets. The last production sold by EMCO Maier were ESX-16 collets and holders. These have the extraction groove at the conjunction of the two tapers and the nut has a eccentric piece that when the nut is unscrewed it pulls the collet out of the holder. For a beginner I would assume that the new ESX-16 and ER-16 collets are not interchangeable with the old E-16 and ES-16 ones. Never use a ER/ESX nut on a E
or ES collet as it will instantly ruin the collet. work piece larger than the hole as it may damage the collet. Always mount the ER/ESX collet into the nut first then mount the pair into the holder body, then put the work piece into the hole and tighten. The ER series of collets were invented by a Swiss company by the name of Rego-fix. You can look at their catalog on line where you will find dimensions and instructions on how to use these. They are all designed to hold milling tools with very smooth ground surfaces. I use mine all the time to turn small dia. O1 tool steel round bar stock. Now the range of the ER collets is from ER-8 thru ER-50 and there are special designs for tapping and coolant through holes, etc. The collets are made in several countries and vary in quality. Here is a case where you get what you pay for. Name brands such as Lindex, ETC, Rego-fix, Schaublin and others will be a little more expensive than the cheap ones
made in India and other places. the holders are actually made by EMCO or at least sold under their part numbers. The current production of the holders has the M14-1 threaded hole built in instead of having a separate back plate to
be machined on your lathe. There were actually two holders for the C5. One was for the headstock spindle and the other was threaded M14-1 for the milling head spindle. The later could be used on a U3/4 all though it is a little large for them. For the U3/4 I would consider 3/8" or 10mm as the max size milling cutters to use. However, other users have indeed used much larger cutter diameters and have done good work. I believe the limit is the size of the motor. at 95 watts it is a little light to do heavy metal removal. The E/ES series collets and holders for the Unimat 3 were the same as those for the DB/SLs. There were actually two versions of the U3 holder for the ES collets. The later ones had a very large round flat faced nut and came after Schaublin stopped manufacture of them. It was probably made in Germany or Spain.
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