Help with drill-Mill conversion

[BillTodd]

My brain must be playing tricks on me, I could have sworn it was 125mm last time I measured it.

It'd have to be 125mm to screw into the quill ?

You'll need to mill/file a slot into the block to clear the end of the taper (the draw-screw must pull the taper into the quill - it's not just there to stop it falling out)

[Ross77]

It'd have to be 125mm to screw into the quill ?

That'll be it then....

You'll need to mill/file a slot into the block to clear the end of the taper (the draw-screw must pull the taper into the quill - it's not just there to stop it falling out)

Damm you people have good eye sight. Realised that after I made the key....Thought about grinding a bit of the chuck, but dont want to damage it. Theres not much of the quill at that point to support it tho, might have to remove to bevelled edge. This option isnt looking so good now.

Decided to drill for both options just in case the key idea fails. May help someone else who wants to do this but dosnt have a lathe.

Started your drill extension holder tonite. should work fine. Just my poor machining skills letting me down now. Still practice makes perfect, (havent used a lathe for 15 years)

[Ross77]

Ok quick up date.

M5x100mm bolts arrived and modified the key to clear the chuck. Glad I didnt grind any off as I can now sill use the wedge to knock out the chuck.

Should make some good progress tomorrow as I've finally got a full day in the workshop :dance:

[Ross77]

Ok. drilling the quill has turned into a nightmare, made the drill extender and drilled it no problems, however I couldnt get a 6.8mm bit locally, so thought a 6.5 would be ok. However the tap was extremly tight.

So I measured the narrowest part of the thread on an M8 bolt and it was 7.2mm, Re drilled the quill with a 7mm bit but the tap still jams when only a quarter of the way in :sad:

Dose this sound correct or have I just got a useless tap? (new but a Machine Mart cheapy)

[Ross77]

What thread exactly are you wanting to make?

An M8 tread, inside the quill for the full length of the tap (30mm or so)

[Ross77]

So what pitch is the thread you require? 8mm 1.5=6.5mm drill.....I'm hoping you have an M8x1.0 tap for a 7mm drilled hole? Use cutting fluid it helps ;)

8mm with 1.5 pitch......Must be the tap then. Have I buggered it by drilling the 7mm hole?

I have used cutting fluid as well

[Ross77]

By my number crunching.. :D you have 0.25mm of thread left....Do you have a 9mm tap for round 2 :D

Very funny. I have a few hens teeth tho...Its still a very good fit when i screwed a bolt in......Is this likely to be the tap then. now problem with buying a better tap, just want to make sure I need it.