Threaded MT arbour?

[woodiedonald]

Hi,
would anyone happen to know where i'd get an arbour with an 1" x 8tpi or 3/4" x 16tpi thread on one end and a morse taper 3 on the other, mt2 would also do.

My lathe is threaded 1 1/2" x 8tpi and i want it to use with a secondary smaller chuck. I seen these on ebay a while ago but cant find them anymore. or if there is some kind of adaptor to make an allowance for thread sizes it'd do.

if all of thats a load of faff then nevermind, i just dont want to buy a monster chuck cos thats all that fits me only to use it occasionally.

thanks
Donald

 

[CHJ]

Don't recall seeing one other than as a tailstock mount for aiding reverse mount alignment, will browse around.

But a very important safety factor you must consider, any Morse taper fitting used in the headstock to hold a free spinning chuck must have a rear thread capable of taking a Draw bar to positively hold the taper in place.

 

[dickm]

Somebody must make them, as I have both a 3/4 by 16 on MT1 and Myford thread on MT2. I suspect the MT1 arbor was made by or for Coronet while they still existed - just possible Record got some when they took over the Coronet stuff?

Both these are obviously intended for use in the tailstock, under pressure which would keep the taper in place. For use in the headstock, Chas' advice is very important - essential that you drill and tap the small end of the taper for a draw bar before using it in the headstock.

(Later) Just had a thought - if you can't find one anywhere, might it be possible to use one of the MT to Jacobs taper adaptors, and get someone to cut the appropriate thread on it? Might not be possible because such adaptors would be hardened, but???

 

[finneyb]

What you need is a spindle thread adaptor - Axminster have some but doesn't like they have your size, http://www.axminster.co.uk/axminster-sp ... prod20851/ try ebay or lathe manufacturer.

Headstock morse taper will not hold a chuck - it is all out to hold a Jacobs chuck at 150 rpm - tried it this pm to sand some small pieces using the Jacobs chuck and sanding wheel - had to keep pushing it back into the taper; which was OK at 150 rpm and with a light chuck.

Brian

 

[CHJ]

I use these Blank Arbors to make up various fittings, you would of course have to find a local machine shop who could put the required thread on the end.
<<<<Link
Not as easy a task as it might appear as the Morse taper will have to be driven in the lathe headstock and will require a lathe with the appropriate Morse taper or adapters..

If you go this route it would be best to get the chuck first so that it would be easier for the machinist to match the new male thread clearance and register to the chuck.

 

[graduate_owner]

I was looking for a means of mounting accessories on the headstock of my graduate, which is 1 1/2 x 8. The closest thing I found was this from Axminster. It may be adaptable to your situation.

http://www.axminster.co.uk/backplates-f ... prod23301/

In case the link doesn't work, it's Order code: 900072 at £21.40

I bought the evolution chuck instead.

K

 

[flh801978]

Graduates are 1 and 1/2" 6 tpi...graduate owner...

 

[tekno.mage]

Headstock morse taper will not hold a chuck - it is all out to hold a Jacobs chuck at 150 rpm - tried it this pm to sand some small pieces using the Jacobs chuck and sanding wheel - had to keep pushing it back into the taper; which was OK at 150 rpm and with a light chuck.

Brian

That's why you need a drawbar if you want to use something in the headstock morse taper without the tailstock in place.

Another idea that *might* work for Donald is to use a suitable-sized simple collet that will fit in his MT3 taper (with a drawbar) and hold a piece of 1" round bar with a suitable chuck thread and shoulder machined on to it to fit a smaller chuck. I use MT2 collets regularly on my own lathe to hold various types of home made drives (or drills in the tailstock) as a collect uses up far less of the lathe length than either a jacobs or a scroll chuck and they run nice and concentric. You can buy the collets quite cheaply (the MT2 ones are around a fiver each) from engineering suppliers like RDG Tools.

I also have a tiny 3 jaw engineering chuck which fits either on an MT2 arbor or a 1" x 8tpi adapter (I think this also came from RDG tools), but I've not seen a woodturning scroll chuck that has this option.

BTW RDG Tools also stock 3 MT Blank End Arbors - which have an unhardened blank end suitable for machining your own thread on to.

 

[graduate_owner]

Sorry, yes you are right. It is 1 1/2 x 6. (It's an age thing). I think the Viceroy has 1 1/2 x 8.

But

wouldn't it be nice if these manufacturers could have standardised their threads over the years?

K

 

[Robbo3]

would anyone happen to know where i'd get an arbour with an 1" x 8tpi or 3/4" x 16tpi thread on one end and a morse taper 3 on the other, mt2 would also do.

3/4" x 16 MT2 arbour £4.95 with free p & p
- http://www.ebay.co.uk/itm/RDGTOOLS-2MT- ... 51addd8583

Can't find it on the RDG website, only on the RDG Ebay outlet.

HTH.

 

[CHJ]

would anyone happen to know where i'd get an arbour with an 1" x 8tpi or 3/4" x 16tpi thread on one end and a morse taper 3 on the other, mt2 would also do.

3/4" x 16 MT2 arbour £4.95 with free p & p

Can't find it on the RDG website, only on the RDG Ebay outlet.

HTH.

Good find and nearest yet, but only safe for use in the tail stock to aid locating chuck and attached turned item for centring on a faceplate for reverse turning etc. as it stands.

If it can have the tang removed and drilled and tapped to take a draw bar then it would be safe to use in a headstock.

 

[Inspector]

If you cant find someone to thread a blank arbour you can use the MT3 collet suggested earlier with a Veritas lathe chuck/faceplate adaptor from LeeValley. http://www.leevalley.com/US/Wood/page.a ... 69091&ap=1

Perhaps the best alternative would be a spindle adaptor that threads directly to your machine.
http://www.woodturnerscatalog.com/p/5/- ... le+adapter

Pete

 

[Robbo3]

Good find and nearest yet, but only safe for use in the tail stock to aid locating chuck and attached turned item for centring on a faceplate for reverse turning etc. as it stands.

If it can have the tang removed and drilled and tapped to take a draw bar then it would be safe to use in a headstock.

Have now received one of these & hope to use it on my newly acquired 7"x14" metal lathe.

As a complete novice with metal, how should I go about shortening the arbor to allow it to be threaded to take a draw bar?
I've not yet had a need to use a parting off tool, if that's the correct tool to use.

If the worst comes to the worst perhaps I can butcher it with a hacksaw (& get all decent engineers turning in their graves - no pun intended).

 

[dickm]

As noone seems to have replied to this......... don't worry too much about "butchering" with a hacksaw. All you are doing is producing a flattish surface into which you can drill a tapping hole; it won't be seen when in use, and you can always hide it in a box if anyone visits .
IF the adaptor has a centre hole in both ends, then you could mount it between centres on your metal lathe and use a drive dog to rotate it, BUT parting off is one of the less easy tasks on a metal lathe so would not be a good idea until you have a bit of experience.

Just go for it with the hacksaw!
Of course, it may be hardened, in which case you have a problem either way!

 

[Robbo3]

Thank you dickm, that's given my confidence a boost.

I meant to measure the tang today. It may be just wide enough to allow an M4 thread & I just happen to have some M4 theaded rod.

If it's hardened I may break out the angle grinder. :evil:

 

[dickm]

Hmmmm. My inclination would be to go for something a bit thicker than M4. With a chuck on the end, you will want to make sure nothing can move, so it's possible M4 wouldn't give enough tension. If you've got an angle grinder, it might be worth grinding a bit further up the taper so you can go to M6.
But others may think differently.

 

[Robbo3]

Update.
Managed to measure the tang & it's 6mm thick, so decided that it's not worth the risk of trying to tap a 4mm thread.

To my untrained eye the arbour didn't look to be hardened & it wasn't advertised as such, so I drilled a small pilot hole through the tang into the main body. This gave me a centre to work to once the tang was removed with the aforesaid hacksaw, as well as allowing tailstock support whilst facing off the end to hide the teeth marks. From there it was a fairly straightforward job to drill & tap an M6 thread.

I think my wood turning skills can manage to make a tapered block for the outboard end.

I don't know if I'm missing something but the use of a drawbar, even a thin one. must surely be the equivalent of bringing up the tailstock for support. :?

 

[tekno.mage]

I don't know if I'm missing something but the use of a drawbar, even a thin one. must surely be the equivalent of bringing up the tailstock for support. :?

Using a drawbar prevents the MT arbor from working loose in use - particularly important if you are using something like a Jacobs chuck in the headstock to hold either some tooling or the work and you do not have tailstock support in place. For instance, I use a small screw held in a Jacobs chuck as a screw chuck for making small knobs. Although I do the roughing stages with the tailstock in place, I then remove the tailstock to finish shaping the knob - particularly the top of the knob which is the part that shows the most and must be perfect. There is a risk that the whole Jacobs chuck & arbor assembly could come loose (especially when making cuts that put axial pressure on the work) and I really wouldn't want that to happen at around 2000rpm! The drawbar prevents this.