Chester 626 and Warco VMC spindle size

[AdamParticipant @adam]

Hi everyone, I just acquired an as new chester 626 aka warco vmc with a mt3 spindle. I can't fit a mt3 drill bit in as the flat on the end seems to hit something (like it's too long) but my mt3 collet holder and borer fit OK. Is this normal for these machines? It's as though the hole for the draw bar is too narrow for the nib on the end of the drill bits. Otherwise Im please with this machine whom I purchased from another user on here (big thanks).

Thanks

[AdamParticipant @adam]

[Dave HalfordParticipant @davehalford22513]

It is too long – you need to grind the flat / tang off

[VicParticipant @vic]

I’ve not had any problems like this with my VMC. Obviously the draw bar is removed and the drill needs to be rotated until it seats properly.

[AdamParticipant @adam]

Hi, yes the straw bar is removed. When I look up into the spindle it has the taper and it just ends with a hole for the draw bar. I wonder if the taper was not machined deep enough as the supplied draw bar doesn’t reach my tooling. A longer draw bar I can make or buy a replacement spindle. I wonder if anyone would know the depth of their mt3 spindle.

[VicParticipant @vic]

I’ve not looked into the spindle of my VMC but it must end in a flattened socket to drive the tang on my MT drill bits? Other tooling without a tang are held firm by a draw bar.

[BazyleParticipant @bazyle]

Find a tool that does fit, degrease the end, stick a dollop of plasticine on the top, squirt some WD40 up the spindle to make it non-stick, shove the test tool up it and get an impression of the free space and shape of it.

[VicParticipant @vic]

You can check the dimensions of your socket against this:

**LINK**

It may be that the spindle on your machine was never cross milled to accept tanged tooling? I guess the only way to know for sure is to remove the spindle.

[Martin ConnellyParticipant @martinconnelly55370]

This has been stated numerous times but let's say it again, the tang does not drive a morse taoer drill, it is for ejection purposes only.

Martin C

[AdamParticipant @adam]

Thanks guys. I measured the depth of the mt3 hole and its 85mm. I managed to take a photo of the inside but I can't seem to upload it

It looks like it's just a few mm too short for the drills to fit as when I install them there is only slight sideways play but you can feel its bottomed out too. There is no slit milled in the top for tang tang of the drills.

[DanielParticipant @daniel]

Hi Adam,

FWIW, I just tried a tanged MT3 in my Weiss wmd30lv, and it fit fine.

It would seem seem that the spindle socket is short, but that appears implausible, unless all the models, in that series, are as such.

Just to reiterate, have you tried turning the tool whilst pushing upwards. It is a very positive fit.

ATB,

Daniel

[VicParticipant @vic]

Posted by Martin Connelly on 31/03/2019 23:36:01:

This has been stated numerous times but let's say it again, the tang does not drive a morse taoer drill, it is for ejection purposes only.

Martin C

No need for the rudeness Martin but many machines, mine included don’t even have an ejection port.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Adam on 31/03/2019 20:24:39:

Hi everyone, I just acquired an as new chester 626 aka warco vmc with a mt3 spindle. I can't fit a mt3 drill bit in as the flat on the end seems to hit something (like it's too long) but my mt3 collet holder and borer fit OK. Is this normal for these machines? It's as though the hole for the draw bar is too narrow for the nib on the end of the drill bits. Otherwise Im please with this machine whom I purchased from another user on here (big thanks).

Thanks

My understanding is that Morse Tapers come in two basic forms; with and without tangs.

The tang is essential to machines (mainly drills) with an ejector slot or some other mechanism for dismounting the tool. MT tooling is also available without the tang, instead being threaded to take a drawbar.

Logically it makes sense for the Chester to NOT expect a tang. Tangs are most useful on a drill where most of the cutting force tends to tighten the grip. Milling applies strong sideways forces likely to break a taper grip: milling needs some positive way of keeping the grip tight, like a drawbar, which won't work if a tang is in the way.

It's a triple gotcha:

• tapers with tangs that won't fit in certain machines unless you grind the tang off!
• tapers without tangs that can be difficult to remove from machines expecting a tang.
• otherwise compatible tools that can't be swapped between different MT3 machines.

If your drills are only for use on the Chester, I'd grind the tangs off.

To add to the confusion, I've also come across MT tooling that doesn't have a tang or a drawbar thread. I think these are intended to fit lathe tail-stocks where a shorter than normal taper helps reduce overhang and vibration.

Dave

[AdamParticipant @adam]

[AdamParticipant @adam]

This is when you look up into it. I called Chester and they said you can't put morse taper drills in the machine. I assume it's the same for warco units too. So my mt3 drill chuck won't fit either, but my draw bar is too short to reach my boring head and collet holder so I do wonder if its been machined slightly short. No matter I can make a longer draw bar easily.

[AdamParticipant @adam]

Well this evening I made a longer draw bar, Whitworth one end and m12 the other so I can just turn it around whenever I need to change tooling. Took my first cuts and it is so much more sturdy than my old little mill drill. Liking it so far!

[AdamParticipant @adam]

[Phil H1Participant @philh196021]

Adam,

I have just tried a No2 Morse tapered drill (with a tang) into the spindle of my Chester 16V milling machine and it won't fit. So I guess it has a similar spindle/ draw bar geometry to your larger, No3, 626 version.

Phil H

[AdamParticipant @adam]

Tha ks Phil, I appreciate that. I'm not too fussed about the mt3 drills as I don't recall needing them on a drill, only for boring on the lathe. I do use mt2 drills a lot but I can simply machine the tang off the mt3-mt2 adaptor. I just did another job on the mill, custom engine mounts and it's so nice to work with.

[Bill Davies 2Participant @billdavies2]

Given that MT tooling will be pulled in using the draw bar, is there a risk that a de-tanged drill might be very difficult to eject? I'm presuming that these spindles don't have a slot for a drill drift. A morse taper tool, jammed in, in the usual way, can have a fearsome grip due to the wedging action.

 

Edited By Bill Davies 2 on 02/04/2019 17:13:33

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