On Wednesday 19 August 2015 06:37:06 andy pugh wrote: > On 19 August 2015 at 11:11, Gene Heskett <[email protected]> wrote: > > Is there a source for those collars that will fit 1/4"/6.35mm > > shanks? > > Your lathe?
I need to finish the drive conversion I have about 1/4 done. That will slow it by about 3x from the figures given because of my 3/1 reduction jackshaft drive. That means maybe 450 rpms in high backgear. That will put all metal pulleys and gears in the headstock drive. Right now I have just enough power transmission ability to bore the bottom drive pulley from 8mm to 9mm and a small file to recut the keyway so this pulley fits my jackshaft. That will leave a very thin walled hub. What I'll probably do in the end is order another pulley with about 2x the teeth, and a correspondingly longer XL belt to get some rpms back. We'll see how this works first though. That, and make a steel QC holder block that sits directly on the crossfeed. The compound hasn't the correct mounting offset for the QC, so it puts the tools downforce left of the ends of the carriages H pattern way riders. A heavy cut then lifts the right side of the carriage, which in turn tips the tool into workpiece, usually with disastrous results. Moving the QC's holddown bolt 20mm, both to the right and to the front will put the tools cutting tip a heck of a lot closer to the correct position. Had I known what I now know about the basic 7x, I would not have bought it even for a $20 bill, let alone the $350 I did get it for all those years ago, nearly 20 now. But I needed a starter kit, and thats exactly what I got. A wannabe lathe kit. :( Hindsight, always 20-2 or better. > You might find that a peg in the rear end of the holders works better. > The BT30 holders that I got for my machine (second hand) all seem to > have a threaded hole, screw and lock-nut in the back that tools can be > inserted up to.This has the advantage of being dead-length, and you > need one per holder, not one per toolbit. I had assumed there was enough variation in the length of a tool that this would have required a jig to set the screw, assuming a conical tip, for the correct length when changing the tool, or that it would still require a collet per tool. Use of the collars would not appear to involve the guage setup once the collar is installed & set. Just shove it into the r8 till it hits the collar & tighten the drawbar bolt. That might need 3 arms & hands on the tool changer though. One thing I need to do is make one of those ? shaped wrench's to hold the spindle while running the drawbar bolt. The tommy bar supplied has a tip that should fit the hole, but its considerably too long and small to fit well. A safety to assure it falls out when you let go of it? Or take some measurements and make a spindle locker collar since Grizzly wants $90 for the one they sell. That is obviously way too much $ IMNSHO for something that should have been included and hidden in the price by raising it $40. DamnifIknow, but it will surely damage the spindle in time. I have some 1/2" thick hard alloy alu that should handle that job. So I guess today I put the keys to the table grooves on the jig so I can remove & re-install, and see about writing that code. Might be fun, but more likely a bit troublesome what with the g2/g3 moves that will not be on a common center, the outer of which doesn't go all the way around but leaves a projected set of ears for the clamp it to the quill bolts. I should be able to hide 2 3mm by 25mm bolts in a .500" thick starter piece's width. Or one 5mm bolt if I have one long enough. I'll have to check the hellbox drawers. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
