I made an air driven drawbar, spindle does not need to be locked as "inertia" holds it enough for the drabar to tighten or release. 'Twas important to fit this as reaching the top with a spanner is stretching it a bit!

Bernard, very little space actually.

Thanks for suggestion, I will look into re-turning such a shaped nut a bit thicker then, not sure how rough the top it needs to rest and bearing against actually is…….I wonder if a trustbearing could work with enough space and machined such ballsl/needles cant drop inwards, that would eliminate any drag as it presses the MT4 out.

Location pin is not that important, I have run my R8 without one quite satisfactorily.

Hi, Old Mart…..I do not fully understand how you did exactly the following…

I bought a steel threaded bar from farm workshop 16mm same thread as original toolbar(I determined the olenght to accommodate all, hacksaw it off). At the top I added a long nut and lock it with a short nut just like you, in my case those go down in the spindle hole no problem. However I can only insert the bar from the top, its too long from the bottom, so if I want to copy what you did, I must hacksaw a short piece of drawbar, screw Bronze Nut on it, then position it with loctite into the spindle, then unscrew that, and screw the drawbar from the top.

1-Where exactly you cut the threads blank…I am not sure how you exactly went about this…
—-In my case I think I dont need to cut threads blank…….? Its 16mm right through.

2-I assume your drawbar screw from the top through the Bronze Nut with a space as indicated into the in my case MT4 tool and you can tighten lock it as usual. If you unscrew the drawbar the pressure is in the treads of the Bronze nut forcing out the MT4 tool in my case….?

Thankyou
Chris

Qwote:

Some measuring will be necessary before any work is carried out.

I cut the thread on the 7/16" -(11.11mm)-en 19T drawbar blank on the lathe, and put about 2 1/2" -(50.8mm)-on either end.

I made the bronze nut (in black) long enough to Loctite securely with a flange thick enough to not be in any danger of breaking off.

Hi OLd Mart, it seems the part I dont understand correctly is how you assemble your new Drawbar with the Brass Nut, and if the threads in Brass Nut is different than the rest of the drawbar not like in my case the threads in the MT4 section you draw into the MT4 of the spindle.

Your Drawbar….
Threads for taper tool……small space….threads for Brass Nut(Now glued in spindle pocket)…….rest of drawbar through spindle……Top of Drawbar ……Nuts plus Long Nut.

If its the same, I may make the Brass Like part and use a short temporary bar screw it on, and insert/glue it to spindle small pocket…………

If I can understand how exactly your drawbar components/threads arranged on it, I can figure out if it will work in my situation……There is no way I can insert it from the bottom at the required lenght without removing parts of the mill, however if I can use a temp short bar with screwed on Brass Nut, I can insert and glue it that way-??

Edited By Chris Mate on 14/05/2022 06:33:25

Hi Old Mart, it seems for me seeing I have to insert it from the bottom with your successfull option, which is problematic for me. I did make an option that worked, but I had to tighten it with 4x 4mm grubscrews after inserting the drawbar from the top town, but it does not have the easy torgue yours would have, and seeing the drawbar is in centre of taper its difficult to clean the the taper.

I did setup a kennametal boring bar vertically mounted in a square block(I made one for each boring bar I got for toolpost), I can see I can bore this carefully, it might take very long because of stickout and somewhat dangerous operation. I abondioned this, because I dont know if the swarf could end up in the spindle bearing, seeing the manual says oiling/greasing it from the hole in the spindle for drawbar.

I am back at the One – Wack method, and to make this more satifying, I used an smaller handwheel from old tablesaw, machine it to take socket for original drawbar, it reminds me of the wheel on an old Singer knitting machine. So I tighten the drawbar whith handwheel take it off and use mill. Then mount it, loosen drawbar(no spanners), take it off, One WAck and MT4 is out. I think I have to stick to this then. I really liked your method, but not prepared to take mill apart yet.

I have ZX-45(ZX-7045) Drill/Mill a drill modified to be a mill, its better than trying to mill with a drill press, also manual=ZAY7045. I have a lot to buy before I can do all sorts of milling, waiting for a Walter Shoulder mill 40mm, it seems everything is out of stock now, was promised 7 days then after I paid its a month.

I will see if I can come back to this much later on if I need to. Thanks for all the info.

Edited By Chris Mate on 16/05/2022 14:02:09