Soft end MT mandrels – soft att the way through ?

Advert

New Replies

Report Bug

Help/FAQs

Soft end MT mandrels – soft att the way through ?

This topic has 22 replies, 14 voices, and was last updated 22 June 2015 at 16:20 by Tim Stevens.

Viewing 23 posts - 1 through 23 (of 23 total)

Author

Posts
17 June 2015 at 11:48 #193851
Mike Davies 2
Participant
@mikedavies2
Hi,

I'm going to build a lathe backstop for my Boxford and want to use a shop-bought MT3 soft end mandrel for the nose piece.

I've found apparently suitable types at Arc Eurotrade but need to know whether they're just surface hardened on the taper, or whether that part is hardened all the way through ? I will need to bore right through the mandrel to take the stop rod and also thread the end for a drawbar so if they are hardened through the body that's a no go for my application.

Anyone drilled through one of Arc's MT soft end mandrels and know the answer ?

Thanks,

Mike
Advert

17 June 2015 at 11:48 #17744
Mike Davies 2
Participant
@mikedavies2
18 June 2015 at 12:07 #193994
Brian Wood
Participant
@brianwood45127
Hello Mike,

Welcome to the Forum, I hope you find many useful things to engage your interest.

In answer to your question, unless I am going stupid in my old age, I can't find soft end MT stubs in the Arc catalogue.

They do sell open ended MT sleeves which might be a solution for you, they are quite useful in other applications for locating drawbar tooling in the smaller MT sizes as well.

Regards

Brian
18 June 2015 at 12:13 #193995
Mike Davies 2
Participant
@mikedavies2
Hi Brian,

They are here on Arc's site : **LINK**

Sleeves would be no use for what I want.

Mike
18 June 2015 at 13:45 #194007
Brian Wood
Participant
@brianwood45127
Hello Mike,

I was looking at the paper catalogue, they don't include these in that, or at least the in the copy I have. #9

So, sorry, I can't help you, but of course Arc would know the answer. Why don't you call them? They are very obliging.

Regards

Brian

Edited By Brian Wood on 18/06/2015 13:46:03
18 June 2015 at 14:02 #194011
John Stevenson 1
Participant
@johnstevenson1
Just got a new ARC one out the drawer.

Soft in the core, up to a point.

1/4" went thru OK as did the 5/16" follow up drill but the 3/8" drill in the picture went thru but was starting to hit hard spots at the small end of the taper.
18 June 2015 at 14:38 #194017
Mike Davies 2
Participant
@mikedavies2
Hi John, sounds like my idea of threading the small end M14 x 1.5 to suit some M16/M10 hydraulic pipe I have is a non-starter then. I'll have to revert to Plan B which is to use an M12 stud in the end of the pipe and drill through it 8mm. Shame as 10mm would have made for a sturdier stop rod and I want it for locking screws when turning them down.

Many thanks for your help and to all who answered,

Mike
18 June 2015 at 14:44 #194018
Vic
Participant
@vic
Let's see some pictures when it's finished Mike.
18 June 2015 at 16:08 #194028
maurice bennie
Participant
@mauricebennie99556
Hi Mike arceuro has MT3 blank end arbors 1.25" 1.5"" each with3/8" thread 40mm with12mm thread .

I have the metric one and have made a hollow draw bar with 12mm bolts each end ,drilled 8mm,and hexagon heads turned down to fit in tube,(leave shoulder to line bolt up ) .Bore conical hole in bolt head so thin tube will find easy way through.. You will have to make all to fit in the spindle before soldering together.

Hope this makes sence Maurice
18 June 2015 at 16:14 #194029
Lambton
Participant
@lambton
Blank end arbors are shown in Arc paper catalogue No 9 on page 14 – half way down on the right-hand side of the page.
18 June 2015 at 16:17 #194030
Capstan Speaking
Participant
@capstanspeaking95294
Posted by Mike Davies 2 on 18/06/2015 14:38:57:

Hi John, sounds like my idea of threading the small end M14 x 1.5 to suit some M16/M10 hydraulic pipe I have is a non-starter then. I'll have to revert to Plan B which is to use an M12 stud in the end of the pipe and drill through it 8mm. Shame as 10mm would have made for a sturdier stop rod and I want it for locking screws when turning them down.

Many thanks for your help and to all who answered,

Mike

I'm afraid so Mike. I was machining one yesterday and found that the shank is through hardened and the hardness protrudes a bit into the soft head and gradually fades out.

They're good for making a bit holder but not much else. You cannot drill through with normal drills.

If you could find an old morse shank drill it would be the other way around. You could part off the hard flutes and have a soft shank.
18 June 2015 at 16:50 #194032
Frances IoM
Participant
@francesiom58905
there is a comment in latest MEW #230 page 9 re softening an ARC supplied taper by baking for 30min at full temp [unspecified ?250 deg C] in oven
18 June 2015 at 17:28 #194035
Brian Wood
Participant
@brianwood45127
Oh dear, thank you Lampton for correcting me, I overlooked them completely.

Ah well, Anno Domini or something

I have a feeling the offerings from Chronos are more forgiving regarding hardening in the central core, but it is a while since I bought any.

Brian

Edited By Brian Wood on 18/06/2015 17:30:52
18 June 2015 at 17:53 #194040
John Stevenson 1
Participant
@johnstevenson1
Posted by Capstan Speaking on 18/06/2015 16:17:36:

I'm afraid so Mike. I was machining one yesterday and found that the shank is through hardened and the hardness protrudes a bit into the soft head and gradually fades out.

They're good for making a bit holder but not much else. You cannot drill through with normal drills.

If you could find an old morse shank drill it would be the other way around. You could part off the hard flutes and have a soft shank.

Capstan,

See my picture above, this is one I did today to test the current batch that ARC has.

All the drill were normal HSS drills but long series.
18 June 2015 at 18:27 #194044
IanT
Participant
@iant
A while back I was trying to drill into a "soft" blank arbor and thought I'd found a really hard one – as I just could not drill into it. However, closer examination revealed a piece of 3mm drill broken off in the centre hole – courtesy of some careless person somewhere in foreign parts. Fortunately – I was able to remove it with thin nosed pliers – but it really had me going for a while!

Sorry – a wee bit off topic…

IanT
18 June 2015 at 20:18 #194056
Capstan Speaking
Participant
@capstanspeaking95294
Posted by John Stevenson on 18/06/2015 17:53:49:

Posted by Capstan Speaking on 18/06/2015 16:17:36:

I'm afraid so Mike. I was machining one yesterday and found that the shank is through hardened and the hardness protrudes a bit into the soft head and gradually fades out.

They're good for making a bit holder but not much else. You cannot drill through with normal drills.

If you could find an old morse shank drill it would be the other way around. You could part off the hard flutes and have a soft shank.

Capstan,

See my picture above, this is one I did today to test the current batch that ARC has.

All the drill were normal HSS drills but long series.

Mine destroyed the edge of an HSS toolbit with 10mm of the soft end still to go. It wouldn't surprise me if they vary.
I still recommend that Mike uses the shank of an old drill.

Don't get me wrong though. These blanks are a godsend and I still have a morse 2 one I'm going to drill just deep enough to be a boring tool holder.
18 June 2015 at 20:26 #194057
Anonymous
Posted by Brian Wood on 18/06/2015 17:28:47:

I have a feeling the offerings from Chronos are more forgiving regarding hardening in the central core, but it is a while since I bought any.

Quite so, I bought a half centre from Chronos many years ago. It wasn't hardened at all, so at least it would have been easy to drill. It was, of course, replaced immediately.

Andrew
18 June 2015 at 21:43 #194067
Neil Wyatt
Moderator
@neilwyatt
I've never had any problems machining the 'soft' end including drilling into the first part of the shank.

Neil
20 June 2015 at 10:39 #194193
Mike Davies 2
Participant
@mikedavies2
Posted by Frances IoM on 18/06/2015 16:50:28:
there is a comment in latest MEW #230 page 9 re softening an ARC supplied taper by baking for 30min at full temp [unspecified ?250 deg C] in oven

Hi Frances, thanks for your intriguing post. I did buy the MEW I found in the shops but it was the special edition and doesn't have any references to letting MT adapters down. Can you quote the relevant part for me ? Or is it really just as simple as baking it at 250 degrees C for 30 minutes and letting it cool slowly in the oven ?

Thanks again,

Mike
20 June 2015 at 11:15 #194195
Ian S C
Participant
@iansc
Would it not be a good oppotunity to have a go at making a taper. When I first got my lathe, one of the things I did with it was make drive centres for wood lathes in MT 1, 2, and 3, and live centres.

Ian S C
20 June 2015 at 11:22 #194197
Capstan Speaking
Participant
@capstanspeaking95294
250 is nowhere near the range for annealing carbon steel.

**LINK**

**LINK**

It will need to be a dull red hot.

If it is not done in an oxygen free atmosphere, the surface will suffer too.
20 June 2015 at 11:45 #194200
Steve Withnell
Participant
@stevewithnell34426
I've used a number of these soft end mandrels from ARC over a period of time the first use:

All I did with this one was drill and tap a 12mm hole 50mm deep to create a backstop for my lathe chucks. I didn't have any issue at all with using 'normal' drills or taps.

Another application was to make a mandrel for holding slitting saws (or "Shitting Saw" as an ex- boss's PA once titled a business investment proposal), but I probably didn't drill close to the shank for that application.

I have noticed that some are not as "nice" to machine as others, so maybe they are not consistently 'soft' from batch to batch.

Steve
22 June 2015 at 16:20 #194489
Tim Stevens
Participant
@timstevens64731
Would it be possible to use a 3MT collet of a relevant size? If the internal collet size is bigger than 12mm (the drawbar size) then an extended drawbar (reduced in diameter at the end to clear the M12 thread) could carry your stop-rod.

Or if not, why not?

Cheers, Tim
Author

Posts