Alexander toolmaster ( deckel fp1 ) clone

[balibalistic]

Also... This thing is very misaligned. Is this how it should be? I can't get the collet it engage tight. It just half ass sits in the. Once I put it in the machine it'll hold end mills fine.. But... Until now I'm all r8. So er is all new to me.

 

[ballen]

This thing is very misaligned. Is this how it should be? I can't get the collet it engage tight.

(1) Yes, you absolutely need a drawbar! Otherwise the collet holder will slip, damage the taper on your machine spindle, then chip the cutter and use that to destroy your workpiece.

(2) If this is an inexpensive "made in china" holder and it's badly machined (not concentric) return it. Some of the made in china stuff is incredibly good, some of it is incredibly bad. I have seen new china chucks and collet holder with more than 0.1mm (0.004") of runout. It's junk, but apparently more profitable to pass onto end users than to throw it away or melt it down.

 

[jariou]

balibalistic,

When you say,

This thing is very misaligned. Is this how it should be? I can't get the collet it engage tight.

, are you referring to the the retaining ring in the collet that is off center?

For ER collets, you are supposed to push the collet in the nut from the back. It will then be held by that ring. Screw the nut loosely in the toolholder then put your cutter in the collet and tighten.

When you do the reverse after milling something, that same ring will allow you to retract the collet from its seat in the chuck by just unscrewing the nut.

If that is not what you are talking about then forget my comment.

Good luck with your new (to you) machine.

Jacques

 

[balibalistic]

Yep.. That's what I meant.. Thanks man! Ok guys how do I find out what thread size is inside this mt4 collet chuck? It doesn't say anywhere..I may have to get out my radio and die set and screw the taps in to figure it out??? I can turn a new draw bar on one of my lathes no problem

 

[balibalistic]

Tap and die*

 

[jz79]

balibalistic,

When you say, , are you referring to the the retaining ring in the collet that is off center?

For ER collets, you are supposed to push the collet in the nut from the back. It will then be held by that ring. Screw the nut loosely in the toolholder then put your cutter in the collet and tighten.

When you do the reverse after milling something, that same ring will allow you to retract the collet from its seat in the chuck by just unscrewing the nut.

If that is not what you are talking about then forget my comment.

Good luck with your new (to you) machine.

Jacques

I'm not sure if it so with high quality expensive ER collets, but the ones I have, sometimes need a bit of "help" to center and seat properly, meaning - when I put an end mill in and start to tighten up the nut, I'm trying to wiggle the end mill with the collet in the seat while tightening the nut, this seems to make the collet seat better and be more consistently concentric with the holder

regarding the draw bar, the thread is most likely M16

 

[balibalistic]

Ok before threads, the whole in the collet chuck is .540". And from what I gather most of these seen to have an M16 thread. Does this seem correct? Can I turn this bad boy on an old SB 9a?

 

[jz79]

0.540" is just under 14mm, which is the tap drill size for M16

 

[balibalistic]

Ok looks like I need to get get am M16 tap.. don't know if my local hardware carries those.

 

[jz79]

you can probably get away with some soft steel turned to 0.627", then single point 13tpi thread on it on the lathe, don't screw the draw bar in too deep, 1-1.5 diameters will be enough, and use that as a temporary measure, you basically need some tension on the MT to keep it from working itself loose, you should be fine with that for smaller end mills till you get the proper M16 draw bar made

 

[balibalistic]

Thank you so much.. Just the info I needed!

 

[jz79]

one thing though - use a dark sharpie and paint the MT shank of the ER holder, then insert it in the milling head, but not all the way, just as it starts to grab, and turn it back and forth a bit, remove it and look at where it was rubbing, it should have rub marks all along the taper, or at least top and bottom, if not, you might want to investigate...

 

[balibalistic]

I put the taper in just lightly..I mean barely and it faced so tight I had to use that tool that came with the mill and a 16oz steel hanger to get it out..I couldn't believe it. Would there be anything wrong with using brass or bronze as a draw bar? I have tons of it. I mean it's just being used for light pressure it should work fine?

 

[AlfaGTA]

That ER collet closer nut has an eccentric retaining ring for a reason....
Makes it easier to install and remove the collet from the nut.....
To install: tilt the collet slightly and hook the groove in the collet with the thickest part of the retaining ring taking advantage of the tilt, then straighten the collet which will push the retaining groove that is not engaged past the
thin part of the retaining ring...sort of like a hinge....The narrow portion of the retaining ring will allow the collet to snap into more easily position,,
On removal do the opposite, forcing the collet to tilt pulling the retaining groove in the collet out of the narrow portion of the retaining ring....

I have a Lyndex collet chuck that takes TG100 collets (better grip than the ER's IMO) On that setup there is no offset in the retaining ring....to remove those collets from the chuck nut, i have to use a tool (provided)
A tapered ring that i push on to the long end of the collet, which compresses it and allows the groove to come free of the nut...

As already pointed out...be sure to load the collet into the nut, fit the nut to the holder then insert the tool and tighten...
NEVER place the collet in the holder and then install the nut....That will damage the holder and collet, as well as making removal of the collet difficult if not impossible...

Draw bars should be made from steel.....

Cheers Ross

 

[balibalistic]

Thanks fellas..

Ok I'm trying to just get this machine in use. I trammed it today, which only required an e/w adjustment of .003. The nod was under half thou so I didn't bother touching it.

Can I simply make a 2" piece of steel, turned down and threaded add mentioned above, thread the other side for the original 3/8 draw bar and tack it in place.?

 

[balibalistic]

That didn't work.. Wrong thread. I might have to buy another chuck. I dunno what freaking thread this shit is. Frustrating.

 

[balibalistic]

M16 or 5/8-11? That sounds right? Maybe I did try 5/8-11?

 

[thanvg]

Hi there,

as far as I know, MT4 tooling comes with M16 or 5/5-11 tpi thread for drawbar. It would not be too difficult to make the one needed for your application on a lathe and it's even easier to test which one you have.

However, drawbars on these machines are a bit more complicated than a simple threaded rod, provided that they follow the Deckel example, which I guess they do. Original drawbars have a female buttress thread (S20x2) which mates with the respective male thread on the small 355 collets and the original MT4 tools of the machine. From your pictures I see that you have both at least one 355 collet and a respective drawbar, thought the head of the drawbar does not seem original to me. Also, the drawbar on these machines is bound on top of the quill so that it will eject the tool when unscrewing. Very useful feature, saves you from hammering your spindle to get the tool out.

What you'll choose, depends on your tooling (or the tooling you wish to acquire). In my case, on my older Deckel copy I chose to keep the original drawbars on both spindles. This allowed for using a couple of original MT4 arbors I had for holding face mills and drill chucks or for working horizontally. I modified an MT4 ER32 collet chuck and fitted a S20x2 thread up it's back, so it also worked with the original drawbards. Staying original also allows for using the 355 collets which are the next best option (compared to MT4 collets) regarding overhang, which is a big thing in these Z headroom deprived machines, especially with the tilting table on.

BR,
Thanos

 

[balibalistic]

Ok so the hole through the quill is .540 and a 5/8-11 is around .620. Should I make an insert that will screw into the collet chuck, then drill the insert to accept a 3/8" draw bar that will screw into it?

 

[balibalistic]

That worked! This thing will take deep cuts. Jesus. You wouldn't expect such a little machine to perform like this.