Thread: MT2 Pin-Chuck holder advice

Hi Jon
The 3/8 thread is in the other end of the morse taper, for a draw bar. You may need to make a tang up from a 3/8" bolt so you can eject it.

Ew

Originally Posted by Ueee

Hi Jon
The 3/8 thread is in the other end of the morse taper, for a draw bar. You may need to make a tang up from a 3/8" bolt so you can eject it.

Ew

Thanks Ew. That sorts out that 'problem'! Next question is how would you guys suggest I go about getting a 1.25" long shaft to thread?

I was thinking I could turn the 1" long shaft to say 6mm or 7mm DIA and then press a 1.5" long piece onto that and then turn it down to accept the 7/16" button die. Does this sound like the best way?

Thx
J

They make blank MT2 arbors with larger soft cylindrical sections too. Obviously they cost more, because they must start with a larger diameter rod to make them. Postage is higher too, as it is heavier. Here an example from Ebay, MT2 blank arbor with a 50mm long and 44mm diameter soft cylindrical section, the shank is left soft too so you can drill and tap it for whatever drawbar thread you like:
http://www.ebay.com.au/itm/NEW-2MT-B...item1c2ea6aec3

Originally Posted by cba_melbourne

They make blank MT2 arbors with larger soft cylindrical sections too. Obviously they cost more, because they must start with a larger diameter rod to make them. Postage is higher too, as it is heavier. Here an example from Ebay, MT2 blank arbor with a 50mm long and 44mm diameter soft cylindrical section, the shank is left soft too so you can drill and tap it for whatever drawbar thread you like:
http://www.ebay.com.au/itm/NEW-2MT-B...item1c2ea6aec3

Funnily enough this is the other one Ive got saved in my eBay. The only thing I thought with the Myford one is that the price is for one (not 5 like the Chronos ones) and Id be turning most of it down/away to get to 7/16...

Which would you guys go for? The Myford one that could be turned down to size, or the Chronos one that Id need to press a collar onto and then turn that down?

Thx
J

A simple way I'd go about it is to mount the M2 taper in the lathe, drill and tap the 7/16 unf and fit a HT bolt thread in it with loctite or similar. No other machining required.
Kryn

Sorry Ken, should have said before - Its a BSC (British Standard Cycle) thread - 26TPI so using a standard bolt is a no go.

I was thinking over night though that it is within my capabilities to drill out the centre and press an extension piece in and the turn the whole piece down as one. This way would save a bit of cash but more importantly give me more practice at close tolerance fits.

Think I'll go this way.

Thanks.
J

Hi J,
are you sure it is BSC and not BSB (British Standard Brass) 26 TPI.
Could you screwcut a short length of 7/16" rod to suit then drill and tap the MT blank (as has been suggested with the short section of bolt thread with the head cut off).
I am not sure of your facilities but I would turn the whole thing including the Morse taper out of a bit of 1" shaft.

Phil

Hello J,

I find this thread confusing.

I'm assuming that you want to use the Stanley pin chuck by putting it on the end of a 2MT mandrel. If this is the case the one with a 1" long 1" diameter end will turn down so that you can use a die to thread it, or since the Myford has threading capabilities, just turn it to size and single point the thread. You will of course have to set the gearbox or change wheels to get the correct pitch.

A drawbar through the spindle would be a good idea anyway ! At least there would be no danger of side loading from the turning popping out the tapered mandrel.

Apology's in advance if I'm mistaken.

Oh heck, looks like my literary skills are particularly poor & confusing - that means its time for pictures to paint some words

However, in a nutshell, yes I want the MT2 mandrel on the end of the pin chuck. I want to use it in the tailstock of my lathe.

My lathe is a metric Hercus 260 ATML and I don't have any imperial conversion gears.

As for the BSB / BSC thread. I have used this page as my source of reference:
http://www.britishfasteners.com/threads/bsc.html

It suggests BSB is a 55^ Whitworth thread - My 60^ screw gauge suggests the thread is a 60^. Also, the 7/16" is not a standard size on BSB whereas it is on BSC. Having said all that, no I'm not certain.


Pic 1: Confirming 1.25" length required.
photo 1.jpg


Pic 2: Confirming 26TPI and 60^
photo 2.jpg


Pic 3: Confirming 7/16 DIA
photo 3.jpg


Thanks for your patience and help thus far! Im loving learning a completely new skill (not that I have any skill yet)

Jon

Jon,

Have you considered making your own Morse taper arbor for the job? It is not difficult to copy an existing Morse taper, and a 2MT can be made from either 3/4" or 19mm or 20mm stock, with minimum waste of material.

Put a 2MT centre, drill or other 2MT tool between centres in the lathe. Use an indicator in the tool post to set the topslide angle to the angle of the morse taper so there is no movement of the indicator needle as you wind the topslide along the taper, making sure the indicator tip is at the lathe centre height.

Set your stock up between centres, and cut the taper on the tailstock end using the topslide. Mounting it between centres allows you to remove it from time to time to check the fit in the tailstock or other 2MT socket, and slightly alter the topslide angle to correct any minor variation from the correct taper if necessary. When the taper is finished mount the workpiece in the headstock taper, using an adaptor if necessary, and cut the 7/16" section to the required length, using the tailstock centre to support the free end, then at least start to cut the thread for the chuck while it is still in the lathe, using the tailstock ram to ensure the die starts square on the 7/16" section.

Once set up for cutting a morse taper, I usually make a few spares for later use. You can, of course, use a larger diameter piece of stock for the spares if you anticipate needing a parallel section larger than 3/4" on future projects. If you expect to need to use a drawbar on the any of the spares, drill and tap the workpiece with a suitable thread before setting it up to cut the taper. If you do thread the small end of the arbor for a drawbar, use a centre drill large enough to provide a proper bearing surface for the tailstock centre after the drawbar has been drilled.

Frank.

Enjoy the exercise and gain the knowledge,make your own.

Hi Jon,

Originally Posted by ventureoverland

Oh heck, looks like my literary skills are particularly poor & confusing - that means its time for pictures to paint some words

However, in a nutshell, yes I want the MT2 mandrel on the end of the pin chuck. I want to use it in the tailstock of my lathe.

My lathe is a metric Hercus 260 ATML and I don't have any imperial conversion gears.

As for the BSB / BSC thread. I have used this page as my source of reference:
http://www.britishfasteners.com/threads/bsc.html

It suggests BSB is a 55^ Whitworth thread - My 60^ screw gauge suggests the thread is a 60^. Also, the 7/16" is not a standard size on BSB whereas it is on BSC. Having said all that, no I'm not certain.


Pic 1: Confirming 1.25" length required.
photo 1.jpg

You do not need to go the full 1.25" inches. One inch is plenty. I have the same chuck somewhere kicking about. Yes if I can lay my hands on it quickly, I'll take a photograph. From memory the jaws close completely and will grab a hair. The threaded spindle pushes the spring loaded jaws up a tapered cone to close them. Again from memory the jaws only move about 1/2" or so from fully open to fully closed.

Pic 2: Confirming 26TPI and 60^
photo 2.jpg

I have a sneaky suspicion that you may have to single point those threads ! The right die could be very hard to come by.

Pic 3: Confirming 7/16 DIA
photo 3.jpg


Thanks for your patience and help thus far! Im loving learning a completely new skill

Jon

Well after so many offered so much advice I thought it only fair I post a few pics of my finished chuck

MT2 Taper - Stanley Chuck #2 by Jon_Kelly, on Flickr

MT2 Taper - Stanley Chuck #1 by Jon_Kelly, on Flickr

I managed to pick up a 7/16 BSC HSS tap and a matching carbon die off eBay. Needed the tap to clean the threads in the old chuck. Carbon die worked fine.

I went for the Myford arbour in the end, purely because of the 2" x 2" stock on the end of the MT2. If I had a knurling tool I would have knurled the bit Ive left black. Still works fine though, plenty big enough to get a grip on it while tightening the chuck.

The only thing I need to do is put the arbour in the chuck and drill and tap some sort of extension bolt in the back of the MT2. When I put it in the tailstock, it slightly too short to auto-eject.

R
J

A trick I've used a time or two for tapers that are too short for the Myford tailstock is to use a thick plastic washer behind the head. That knocks the taper out when it hits the tailstock body.