Thoughts on using ER40 collets in older MT4 Deckel spindle ???

[Brian]

Yes, the difference is big, the Deckel holders once completed are shorter than the standard threaded or tanged MT4 holders. I used an abrasive chop saw to get 90% of the excess material off the butt end, also getting thru the case hardening on the tools and then put them in that socket to clean up the face and bore, and re-thread the ends to use the S20 chunks. Those I just drilled and tapped 1/2"-13 and loctited setscrews into them and then loctited that mess into the holder.

OK, this is a faced off, drilled and tapped holder, ready for the S20 "chunk".



This shows the piece of S20 thread, that I have drilled and tapped 1/2-13 with a short piece of 1/2-13 threaded rod inserted into it...



and the whole thing, loctited and ready to go install in the mill.



OK, now for your $64k question.... those 16mm to 20mm adapters you were pointed at, they are for using BT40 or other 40 taper that has metric threads... I think those may be called SK40, or maybe NT40. They also make that adapter in 5/8-11 to use with CAT40 tooling. You cannot use NMTB 40 tooling in the Deckel without modification... again, the way they are shaped, they have a long sleeve on the butt end and would have to be trimmed back, probably re-threaded and who knows what else. So, while 40 taper is 40 taper, it doesn't mean they all interchange.

Captive draw bar... find a parts diagram, been posted on here many times, and you will see, the draw bar slides in from the tool holder side, then has a threaded collar on the top/outside end that keeps the draw bar from falling back out, and allows the draw bar to be pulled tight. This way, once you install a tool, it's sucked tight into the spindle taper, then, once you want to remove it, the draw bar unthreads maybe 1-2 turns, the section over the S20 stud hits a shoulder in the spindle, and as you continue to unthread the draw bar, it "pops" the tool loose from the taper. So no beating the crap out of the draw bar like you do with R8 and a Bridgeport style machine.

When I first got my Deckel, I thought I'd make new draw bars and just use internally threaded MT4, even went so far as to blueprint the draw bars, but then I found that even the standard MT4 collets and end mill holders were too long, would have to be shortened (if I wanted that same self ejecting feature). So rather than have a complete abortion of a machine, it was easier to find a way to duplicate the Deckel tool holder profile on readily available tool holders. In the long run you will be much better off to stick as close to stock as you can, and find tools that work, rather that have some half ass modified machine.

 

[traditional-tools]

Yes, the difference is big, the Deckel holders once completed are shorter than the standard threaded or tanged MT4 holders. I used an abrasive chop saw to get 90% of the excess material off the butt end, also getting thru the case hardening on the tools and then put them in that socket to clean up the face and bore, and re-thread the ends to use the S20 chunks. Those I just drilled and tapped 1/2"-13 and loctited setscrews into them and then loctited that mess into the holder.

I'm going to do this on my lathe. I know you mentioned you don't have one. BTW, your tooling looks just fine.

You cannot use NMTB 40 tooling in the Deckel without modification...

In that regard, the MT4 is not as bad as I had thought...still that would be a huge amount of work to convert all the tooling.

Captive draw bar...

This clears that piece up also...I was thinking I was missing something as I don't see a hex on the top to tighten/loosen the drawbar on mine, and the rigger said you just unscrew the top and it pushes the collet out. Now I understand what you are saying...the drawbar is inside, the top only turns the drawbar which is inside the spindle...I didn't realize that, so thank you for pounding that into my thick head...I was thinking that the entire drawbar pulled out the top of the spindle...

as you continue to unthread the draw bar, it "pops" the tool loose from the taper. So no beating the crap out of the draw bar like you do with R8 and a Bridgeport style machine.

I honestly hadn't realized that yet, but was curious about the top of the spindle, and since my machine is 20 miles away under a tarp, it's hard for me to go check...

I do have the Deckel DVD and will look for those pieces specific.

I just got a 5/16" Deckel collet from another PM member, I'm sending him a 1" collet in return (I have 2 of those). This helps us both out.

When I first got my Deckel, I thought I'd make new draw bars and just use internally threaded MT4, even went so far as to blueprint the draw bars, but then I found that even the standard MT4 collets and end mill holders were too long, would have to be shortened (if I wanted that same self ejecting feature). So rather than have a complete abortion of a machine, it was easier to find a way to duplicate the Deckel tool holder profile on readily available tool holders. In the long run you will be much better off to stick as close to stock as you can, and find tools that work, rather that have some half ass modified machine.

I completely agree with you, and I don't want any bastardized machine in my shop either. I will go to the trouble to make the tooling to fit the machine properly. I have most of what I need, and can get straight shank to use in the collets also. I definitely don't want to beat the collets out, and it makes sense that the Germans wouldn't do that to begin with...

Really, the S20x2 system is quite good in regards to retention and holding, it's just not very convenient to replicate when needed. It seems many Deckels are sold with entire sets of tooling, so it's really a moot issue for many.

BTW, looking at the threaded end of a collet, I see there is a non-threaded portion between the thread and body of the collet. My guess is that space is where the collet gets tightened and released from the spindle. I am starting to see what you have explained to me. I am getting antsy to get the Deckel at home and get it powered...hopefully there isn't any problems with electrical...

Thank you so much. I owe you at least a cold one if we ever meet up...

Cheers,
Alan (playing with his Nichols mill today...)

 

[Erik]

Alan, if you go look at their website now you'll see they have original Schaublin ESX25 collets in inch sizes on sale.
They are pictured with their boxes.

Other stuff is from China, I'm sure.

Cheers
Erik

Erik,

One thing that is not clear is whether RC Machines tooling is Chinese or not. Elvind says they were not finished as nice as would be expected from quality tooling, and there was no name on the tools he had bought from them.

I'm not trying to dis RC Machines, just want people to understand that you should ask when you buy from them.

Cheers,
Alan

 

[traditional-tools]

Alan, if you go look at their website now you'll see they have original Schaublin ESX25 collets in inch sizes on sale.
They are pictured with their boxes.

That's XLNT to know, thanks for letting me know. I will ask them about those collets, those look nice and there is about 11 different sizes.

Other stuff is from China, I'm sure.

I figure much of the tooling I see on the web that is cheap in Europe is. Seems hard to find good quality tooling, even in Europe.

I will say I'm impressed with the quality of all the Deckel tooling, even the collets are ground and polished nicely. Really quality tooling they provided, and the accessories are all very nice for the mills.

Once I get my tooling together I'm sure I will enjoy this machine for many years to come...

Cheers,
Alan

 

[pistonskirt]

Alan

Something to be wary of if new to Morse taper spindle tooling is that it is a self locking system so does not "require" the draw bar for retention in the spindle.

If your spindle taper & tooling are in good condition only the lightest of pinch on the drawbar is required, more or less just enough to stop the drawbar shaking loose. Even then I have a length of flat alluminium bar through which to impart a hammer blow to the head of my MT4 / ER32 holder which is often required to release it, particularly if the spindle has got warm.

You will regret the time you over tighten the drawbar I can assure you

regards

Brian

PS/ Obviously this does not apply to MT4 collets, just solid shank tools / adapters

 

[bryan_machine]

pistonskirt - deckel drawbars for mt4 have a back shoulder that rests on a shelf in the spindle - so at least in theory unscrewing the drawbar should act as an ejector.

are you saying this does not work and you have to use a mallet on a deckel?

OR is this a general warning for mt4 for ordinary cases - which is surely true it is famous as self holding taper - but which maybe does not apply so much to a deckel?

 

[pistonskirt]

pistonskirt - deckel drawbars for mt4 have a back shoulder that rests on a shelf in the spindle - so at least in theory unscrewing the drawbar should act as an ejector. are you saying this does not work and you have to use a mallet on a deckel?

Yes the Deckel drawbar is self ejecting but there is only so much torque you can put on a 13mm square shaft & the damage to ones knuckles when it does let go is usually unpleasant.

In my experience if the Deckel drawbar has been overtightened, or heavy milling has been done and / or the spindle has warmed & cooled my MT4 tool holders need a clout to free the taper without causing me or my machine undue stress.

regards

Brian

 

[AlfaGTA]

I will add what Brian says ;
Caution should be used when running a machine with the MK4 spindle. If running for some time , then a tool holder change , one may have extreme trouble removing
the changed holder...Spindle taper grows when warm from use...insert a room temp holder and you get an instant shrink fit....
This is where the Deckel collets are a much better choice!
Cheers Ross

 

[traditional-tools]

Now, here is the same collet with my straight to MT4 sleeve that I have cut down... slid over the collet showing how much needs to come off the small end...

Brian,

As luck would have it, I spotted one of those 2" OD straight sleeve with MT4 taper on the inside, for only $19 on ebay...I can use it like you are using it here, to work on the MT4 tapers and turn them into MK4.

Thanks for that tip.

Cheers,
Alan (just sold 200 bf of hard maple CHEAP eariler today to make room for the Deckel )

 

[traditional-tools]

Now, here is the same collet with my straight to MT4 sleeve that I have cut down... slid over the collet showing how much needs to come off the small end...

Brian,

As luck would have it, I spotted one of those 2" OD straight sleeve with MT4 taper on the inside, for only $19 on ebay...I can use it like you are using it here, to work on the MT4 tapers and turn them into MK4.

Thanks for that tip.

Cheers,
Alan (just sold 200 bf of hard maple CHEAP earlier today to make room for the Deckel )

 

[traditional-tools]

Paul had a die, so he was (way back then) threading 2 or 3 feet of stock at once on the lathe. As for Elvind's link for the 16mm to 20mm, that won't do you any good with "standard" MT4 tooling, you can't screw one of those in the ass end of any available MT4 tool and have it work, the length will be way too long. Now, if you cut it back as I detail below, they will work.

Brian,

Yes, Paul did do it on a lathe, but sold the lathe to a friend of his. He sold me a 6" section, and said this works well, but I noted it was .5 mm smaller in diameter and the edge of the buttress threads are slightly flat. He said he works fine though.

Now I'm starting to understand better. Even the spring collets are a PITA in the sense that the sleeve gets stuck in the taper even after the collet falls out.

I was down at my yard and looked at the spindle on the vertical head. Lucky, as I had thought it does have the sleeve in it for the spring collets and there was 1 spring collet in there. However, after the collet dropped out, the sleeve was stuck in the taper and I didn't have anything appropriate to tap it out with so left it for the time being. The good thing about the spring collets is that there's import sets available fairly cheap, so at least those collets are available. I have MK4 collets also, so I should be ok for collets, and will have the ER25 in addition.

(PaulD if you see this, there's my Wife's Previa in the background )



Cheers,
Alan

 

[Brian]

Those are the "20mm" collets used on the Deckel tool and cutter grinders, they are definitely a bit more readily available. I believe the 20mm to MT4 adapter will come out of the spindle if you tighten that ring that has spanner slots in it that you can see at the bottom of your head stock. As the ring hits the spindle face, it will pop out the adapter. I don't have one and have never used it, but pretty sure that's how they work.

 

[traditional-tools]

Those are the "20mm" collets used on the Deckel tool and cutter grinders, they are definitely a bit more readily available. I believe the 20mm to MT4 adapter will come out of the spindle if you tighten that ring that has spanner slots in it that you can see at the bottom of your head stock. As the ring hits the spindle face, it will pop out the adapter. I don't have one and have never used it, but pretty sure that's how they work.

That makes sense, but I didn't have a spanner and could only tighten so much by hand...didn't seem to go up far enough to pull the sleeve out. A spanner would take care of that most likely.

After I get the mill home I will have more time to check these things out.

I got a 2" sleeve with MT4 internal and will make a short sleeve to hold MT4 for modifying.

Slowly gathering the tools I need. I brought my fritz box (electrical) home but still haven't got the mill home yet.

Cheers,
Alan