OK, I want to see if this exists before I take the time to try and make one. I am looking for something that has a 4mt taper on one end and a flange that gets tightened down to my 1 3/4-8 lathe spindle via a huge threaded collar (almost like a collet nut lused on ER collet holder). On the inside this whole ordeal has an angle that accomodates an ER collet and on the outisde the approriate thread for a collet nut. Just picture something that looks like one of those CAT or NMTB tool holders but is in 4MT taper and with a nut for tightening it down to the spindle.
Larger SIP BORING-MILLING machines use a #4 morse taper, and I have er collet chucks for them. However, it sounds like you want almost a custom holder to somehow attach to your lathe with the 1 3/4 -8 thread. Good luck. It certainly can be manufactured, but I'd be amazed if you found anybody who makes something so specific.
MT3 to ER32 collet adapters are commonly available; with a drawbar for the MT3 end. Don't know about an MT4 version, but you could always get a MT3 to MT4 sleeve, chop off the back, check for concentricity and carefully Loctite it together. You'd use a drawbar into the MT3 portion, rather than a spindle retainer.
Mad Machinist
All the way from UK I looked on your US Ebay and straight away found
4 Morse ER collet holder. Look at Item No 260558753023
It doesn't clamp onto your nose but the Morse 4 and drawbar should be all you need.
Just make a 'screw on' cover for the nose thread to protect it.
Rgds Davy Crocket
Now that is what I am fantasizing a poor mans accu chuck. Giving me the ability to work near the chuck. Does the collet seat have to be ground? I was just thinking that the collet holder would have to be centered to the taper in order to get a good TIR.
I finish turned everything after I had mounted it on the spindle so it had to turn out concentric... The ER collets are 8 degrees included angle, I just used the compound slide to get it done.... I know it is not perfect, but it seems to work...
Now that is what I am fantasizing a poor mans accu chuck. Giving me the ability to work near the chuck. Does the collet seat have to be ground? I was just thinking that the collet holder would have to be centered to the taper in order to get a good TIR.
The OP says, "I am looking for something that has a 4mt taper on one end and a flange that gets tightened down to my 1 3/4-8 lathe spindle via a huge threaded collar (almost like a collet nut lused on ER collet holder)"
Not sure why he want's to double up on the hold, sounds hard to do and to no advantage I can think of. Screw it on the "1-3/4-8" nose or use the 4MT but not both.
Re your, "collet holder would have to be centered to the taper in order to get a good TIR," all sorts of stuff hangs off of various D pins and threaded spindles with accuracy as good as the spindle it'self. The MT in the bore doesn't have an edge inherently. The fit to the face behind the spindle threads squares it up and a little care with the treading, combined with the 30° shoulders on the threads to help center it and ground fit to increased diameter of spindle behind the thread, keeps mine accurate.
Just one more suggestion, and you can use ordinary collets if you have any, or buy an R8 set.
Picture below shows an adapter that I made to screw on to my lathe nose.
Started off with a ready made nut from an engineering shop. 1 and 1/2" x 8 threads
Screwed it on nose up against a thick washer , and turned registers to suit my nose.
Reversed it on nose and bored front face to take a solid disc.
Shrunk fitted the disc.
Drilled and bored and turned front taper to accept my 20mm Collets.
Made suitable hollow drawbar.
Works fine and allows long stock through the mandrel.
Sounds like what you're looking for is an ER40 chuck that fits your lathe spindle mount and not really the MT4 inside.
But, there is a guy on ebay selling new Hertel ER40-MT4 chucks for ~$50. I picked one up for the tailstock on my lathe. The nut alone is worth almost 1/2 that. It has a tang, so you've have to cut that off and fab some sort of drawbar mount (just weld a nut?)
Sounds like what you're looking for is an ER40 chuck that fits your lathe spindle mount and not really the MT4 inside.
But, there is a guy on ebay selling new Hertel ER40-MT4 chucks for ~$50. I picked one up for the tailstock on my lathe. The nut alone is worth almost 1/2 that. It has a tang, so you've have to cut that off and fab some sort of drawbar mount (just weld a nut?)
Once I'd decided on what to me seemed the optimum for my 1-9/16 spindle bore, I began watching ebay for bargains. I was looking for TG 150 and I was the only bidder on a new in the box TG150 Dapra mill collet chuck with the orphan NMTB45 taper, $10. I used the chuck for my dimensions and an accurate taper guide while the expensive nut with the extractor spring was what I was after. The rest I had in my shop. I was satisfied with the "pay" I earned the day I made it.
Anyone that might need that new 45 taper collet chuck body can have it for the postage.....
LinkBack URL
About LinkBacks
4MT-ER adapter
Reply With Quote
Originally Posted by .RC.
Bookmarks