5c collet adapter and drawbar

[MattH]

Been working on a system to use 5c collets in my Boxford lathe which has a L00 spindle.
It's been going well so far and I am pleased with the results.


First job was to turn the internal thread on the drawbar pipe. I wanted to get this done first as it's the trickiest job:


After one test run I managed to turn a 20tpi thread that ended up a perfect fit:


Next I turned a piece of 2" bar to match the internal taper in my spindle (don't know for sure but think it's a weird Morse 4.5). I managed to turn an excellent fit but putting a DTI on the compound and adjusting the angle for zero runout. Blueing the spindle showed this:


I then bored it all the way through for a tight sliding fit on the body of a collet and then adjusted the compound with the help of the DTI again to turn the 5C taper:


I turned a spacer for a loose sliding fit over the end of the drawbar with a counter bore on one end to fit over the end of the lathes spindle. This holds the drawbar centrally in the spindle and gives a bearing surface for tightening the drawbar (the large slug is the blank for the handle):


This shows the collet in the adapter and screwed into he drawbar:


Test fit in the spindle nose:


The drawbar is 1 1/4 and the spindle bore is 1 3/8ths:

 

[MattH]

Here is the end spacer in place, showing the space left for the handle:


I might end up welding the handle onto the pipe, haven't decided yet. I will be turning the handle and milling it to make it user friendly:


All that needs doing is the handle finished and a stud machined into the taper adapter to match the keyway in the collets:



Just need to figure out how to clamp the taper adapter in the mill to drill and tap it.

 

[CRB]

Just need to figure out how to clamp the taper adapter in the mill to drill and tap it.

Excellent job MattH.

I think you have half the job done, regarding the pin for the register.

You could use one of the collets to grip a spindle which is in turn gripped by a threaded sleeve acting upon the adaptor itself.

I assume you have Vblocks.

 

[roofman]

great job

 

[MattH]

Excellent job MattH.

I think you have half the job done, regarding the pin for the register.

You could use one of the collets to grip a spindle which is in turn gripped by a threaded sleeve acting upon the adaptor itself.

I assume you have Vblocks.

Cheers, I was thinking along these lines. It does mean that I will either have to drill though above the keyway in the collet very carefully or drill into the collet.

 

[mike 109444]

IF you drill 4 holes round the "handle" billet then no need to mess with it any more as if you drill say 1/2" holes they should allow you to use your chuck retaining ring C spanner (one less tool kicking around!)
You might need to balance that large a piece of steel. Use some lead stick on weights to get balance then drill holes opposite weights to get balance then remove weights.

 

[mike os]

how are you holding the chuck mounting nut?

 

[MattH]

I plan on taking a lot of the material away when machining the handle. I'm hoping not to need tools to tighten the drawbar, with a 20tpi thread I wouldn't of though that much torque is going to be required.

 

[MattH]

how are you holding the chuck mounting nut?

The pictures show the taper protector fitted on the spindle, the chuck locking ring screws to this and is locked in place.

 

[ford34/2]

Been working on a system to use 5c collets in my Boxford lathe which has a L00 spindle.
It's been going well so far and I am pleased with the results.


First job was to turn the internal thread on the drawbar pipe. I wanted to get this done first as it's the trickiest job:
View attachment 61065

After one test run I managed to turn a 20tpi thread that ended up a perfect fit:
View attachment 61066

Next I turned a piece of 2" bar to match the internal taper in my spindle (don't know for sure but think it's a weird Morse 4.5). I managed to turn an excellent fit but putting a DTI on the compound and adjusting the angle for zero runout. Blueing the spindle showed this:
View attachment 61067

I then bored it all the way through for a tight sliding fit on the body of a collet and then adjusted the compound with the help of the DTI again to turn the 5C taper:
View attachment 61068 View attachment 61069

I turned a spacer for a loose sliding fit over the end of the drawbar with a counter bore on one end to fit over the end of the lathes spindle. This holds the drawbar centrally in the spindle and gives a bearing surface for tightening the drawbar (the large slug is the blank for the handle):
View attachment 61070

This shows the collet in the adapter and screwed into he drawbar:
View attachment 61071 View attachment 61072

Test fit in the spindle nose:
View attachment 61074

The drawbar is 1 1/4 and the spindle bore is 1 3/8ths:
View attachment 61075

wow I do like that, might be a project on the horizon-- very similar set up L00 and same internal taper, always an argument , I say 4.5 Mt, Americans say Jarno13. Fortunatly I have the reducing nose piece and some colletts just never sorted out the drawbar and proper reducing for the 5C. (140 Harrison)-- will you need a keyway in the reducer to fit the headstock keyway-- Harrison originals havent got it?
No excuses now.

thankyou

Stan

 

[MattH]

If you have a Mt adapter for your spindle the setup will be easier as you could clock it up in the 4 jaw and then set the angle externally. I had to use a finger gauge to set it inside of the nose which made it a bit more of a fiddle.

 

[MattH]

Managed to get the adapter clamped securely. I had a spare lock nut from my bridgeport leadscrew vernier that just happened to be a spot on fit.

I drilled and tapped it for an M3 grub screw. I will cut it to length and epoxy it into place.

 

[MattH]

Turned and fitted the handle today. Used a 2/1000th interference fit and heated the handle up with a propane torch. I don't think I'm going to need to fix it in any other way as it seems solid.
I need to mill some slots in the outside so I can use my lathes C spanner to tighten it down. I don't have a way to index it on the mill so I'll have to figure something out.

 

[CRB]

Turned and fitted the handle today. Used a 2/1000th interference fit and heated the handle up with a propane torch. I don't think I'm going to need to fix it in any other way as it seems solid.
I need to mill some slots in the outside so I can use my lathes C spanner to tighten it down. I don't have a way to index it on the mill so I'll have to figure something out.

View attachment 61194 View attachment 61195

You could set your three or four jaw chuck up with a spacer under one jaw, mill, then rotate the chuck and place the spacer under the next jaw, and so on. I would also think that marking the circumference with the paper band method would be quite sufficient for your needs.

 

[doubleboost]

Very nice
I will be making something for my ER 32 collets
My new Harrison lathe has the same spindle nose

 

[ford34/2]

can you not utilize something like this?

Stan

 

[MattH]

I could but the C Spanner for my chuck is sat right next to the lathe and will fit on the radius.
Milling some slots is no harder than drilling the holes for a smaller pin spanner so it just saves having two tools.

 

[MattH]

Finished the drawbar handle today. Forgot to take any pics of the milling setup. I clamped my 3 jaw chuck to the opposite end as suggested and used it to roughly index the handle by 120 degrees.
Milling wasn't fun as there was a lot of vibration, but I took shallow cuts and it's so finished now.
Now there is something to grip I can pretty much tighten by hand.

 

[HughF]

As the new owner of this great little lathe, nice to see the work that went into making the 5c adapter. Catch up soon Matt, Hugh

 

[MattH]

Lol, missing one for the new lathe so have to go it all over again.