Help with drill-Mill conversion

**Ross77** · 14-06-2009

Let me get this right... you're drilling out the quill to allow a draw bar through to pull the ER collet chuck into the quill... so what are you planning to tap? did I miss something?

I decided against drilling all the way through the quill as I could only get a 6mm hole through the splined section and the chuck needs M10, resulting in a long thin drawbar and some sort of thresd adaptor.

Bill suggested drilling from the chuck end up into the quill and then use a bolt through the chuck to secure it (similar to some drill chucks)

So i need to to drill a 7.5mm hole in the quill and then tap it for M8, dose that make sense?

**Robin Hewitt** · 14-06-2009

Can't you just put a fancy nut through the taper knockout slot and save driling anything?

**Ross77** · 15-06-2009

Can't you just put a fancy nut through the taper knockout slot and save driling anything?

with the extra long tap at £7 and probably the same for the correct drill bit. That's looking like a good idea, it's only a 10mm slot tho so M8 tread is pushing it a bit...

Would a M6 be good enough?

Irving
Thanks for the info on inverters. just got one to play with

**Robin Hewitt** · 15-06-2009

M5 even, so long as you use a good quality screw and key. HT would be overkill, just avoid stainless and cheapies.

If you buy a box of screws you could torque one to destruction in a piece of scrap. Then you'd know

**Ross77** · 15-06-2009

M5 even, so long as you use a good quality screw and key. HT would be overkill, just avoid stainless and cheapies.

Thanks Robin. HT ? high tensile?

10mm slot width or height? It's ok to engineer a twist fit solution.....

10mm wide. Approx 30mm high. What do you mean twist fit :question:

**Robin Hewitt** · 15-06-2009

Originally Posted by Ross77

Thanks Robin. HT ? high tensile?
10mm wide. Approx 30mm high. What do you mean twist fit :question:

High tensile, yes.

No extra space in a knock out slot to twist into, they are cut to fit the taper tang.

Hopefully you will have room between the spindle nose and the chuck so you can slip a fat spanner in the gap to lever it out.

OTOH you can cross that bridge when you come to it

**Ross77** · 15-06-2009

Yeah not worried about getting it back out. just as long as it stays in:dance:

Just cut a piece of steel to go in the knock out hole, but cant find my M5 tap, why is always the one you want that disapears in to thin air......

I'm going to try this route first, If it wont hold then I'll drill up into the quill from M8 bolt. I'll get some new taps tomorrow and a selection of bolts.

Let you know if it works................

**Ross77** · 16-06-2009

It will be a miracle if i ever finish this... with every day comes a new problem

Drilled and tapped the new key for M5 but cant find any bolts long enough. (125mm). Would studding be ok? The other option is to make up a small drawbar 8mm dia. to go thro the chuck then turn down the end for an M5 thread, problem is making it strong enough and providing some sort of slot in the head for tightening.

The next challenge is deciding wether to cut down the main post and fix the head at a set height or allow it move up and down to suit the job, like a proper mill

I will need to sort out a better clamp than the existing grub screw arrangement , may be cut a slot and then bolt up to pinch the main post? would this help remove the current play, and provide an accurate reposition when moved?

**BillTodd** · 16-06-2009

Why did you abandon plans to drill & tap the quill?

Although, I think M5 should be OK. (you won't be taking it in and out all the time)

would this help remove the current play, and provide an accurate reposition when moved?

Might work.

I'm happy with the way my [ame="http://www.cnczone.com/forums/showthread.php?t=70099"]wishbone stabiliser [/ame]works if you want to copy.

**Ross77** · 16-06-2009

Why did you abandon plans to drill & tap the quill?

Cost..lol the depth into the quill is over 100mm so I needed to buy extra long taps and drill bits. In hind sight it would have been worth it tho as it is definatly the best solution. M8 bolts over 100mm no problem.

Try the cheap option First eh.

Cheers for the stabiliser idea, Not quite what i meant tho. not bothered about rotational postion. I was refering to the the existing head rocking on the post (out of tram(I think..))

In the picture of yours, is that the locking bolts I can see at the back of the head casting?