Hybrid Mill Design

[uli12us]

Yes, forget it. How big should the machine be?
That dubious concept isn't as easy as it looks. I think they have a gantry Axe on Y (if the normal X-Y is correct) only, because Hermle have a patent for a centralised Spindle. Gantry have no advantage against 1 spindle in the middle, except in a really large machine.
And your control must handle 3 of it. Can it do this.
The same for X and Z. This construction is ok, if you have a spindle with a ton or more. If not its much too complicated.
And the Z axe don't work, you have 4 guiding carriage (I hope the word is correct, the slider on the linear guide) 4 or eventually 3 is correct, but not in these layout.
You need 2 sliders per linear guide. And if you want 4 side by side each must
parallel within a rather tight tolerance.
If its for yourself and you don't want to sell it, then you can make it with a central spindle.

A gantry spindle brings no advantage, but much more effort, each Motor and driver must bought double.

The concept with the u-shaped bed is good, but all other too complicated. Unfortunately I don't know, how I can add a pdf-file.

[Chaz]

Yes, forget it. How big should the machine be?
That dubious concept isn't as easy as it looks. I think they have a gantry Axe on Y (if the normal X-Y is correct) only, because Hermle have a patent for a centralised Spindle. Gantry have no advantage against 1 spindle in the middle, except in a really large machine.
And your control must handle 3 of it. Can it do this.
The same for X and Z. This construction is ok, if you have a spindle with a ton or more. If not its much too complicated.
And the Z axe don't work, you have 4 guiding carriage (I hope the word is correct, the slider on the linear guide) 4 or eventually 3 is correct, but not in these layout.
You need 2 sliders per linear guide. And if you want 4 side by side each must
parallel within a rather tight tolerance.
If its for yourself and you don't want to sell it, then you can make it with a central spindle.

A gantry spindle brings no advantage, but much more effort, each Motor and driver must bought double.

The concept with the u-shaped bed is good, but all other too complicated. Unfortunately I don't know, how I can add a pdf-file.

Thanks. I understand most of what is being said. Ill respond later when I have a bit more time regarding some questions.

Please email me the pdf - ctintinger at gmail dot com.

Thanks

[komatias]

Chaz,

You seem to have money to spend on this which is why I am keen to see what you come up with. My suggestion on the spindle arrangement is to make the box section adjustable so that you use two of the rails as data to bring the other two in to take up the tolerances.

Getting two carriages per rail should go without saying, but you may get away with two per rail on the back and one per rail on the front.

Do you have the powersupply for the 4KW spindle?

[routercnc]

Chaz,

. . . My suggestion on the spindle arrangement is to make the box section adjustable so that you use two of the rails as data to bring the other two in to take up the tolerances.

Agree with that. My plan was for the green sections on the Y axis to have the vertical end plates arranged so that I can fix one pair of carraiges and then 'slightly pre-load' the other plate up to the opposite side so everything is aligned. This assumes the machining on the Z axis plates is good where the rails sit.

[Chaz]

The reason for the grub screws to hold the spindle was that I did not want to distort the 'box' by slotting it and then clamping the spindle but wasnt sure if the grub screw method would work.

The same for the 4 way / 4 carriage system. Im not sure how the Octagon system works on the benchmark mill .... need more info / pics and google hasnt helped.

This is why we get feedback :-)

[Chaz]

Chaz,

You seem to have money to spend on this which is why I am keen to see what you come up with. My suggestion on the spindle arrangement is to make the box section adjustable so that you use two of the rails as data to bring the other two in to take up the tolerances.

Getting two carriages per rail should go without saying, but you may get away with two per rail on the back and one per rail on the front.

Do you have the powersupply for the 4KW spindle?

Seem to :-)

The idea was built out of getting something very rigid. I like the design and if you follow this thread (http://www.cnczone.com/forums/vertic...-posts-16.html) that is the material type I wanted to use.

I believe that in most cases the machines that are made by Datron and Mori Seiki are either cast iron or some form of epoxy / cement type material.

For the spindle, yes, Im running a 32A feed on single phase. Plus, the likelyhood of using all 4KW is low.

[Clive S]

Unfortunately I don't know, how I can add a pdf-file.

I think you have to go the advanced tab and then click on attachments

[uli12us]

Ok, it works I hope. Here is the only flyer I found, where you can see, how the hermle machines were build. On page5 there is a gantry construction and page 7 shows the normal construction. These machines run since 15Years or so, without problems. The spindle for the Y-Axe is hidden behind the spindlehead in the middle of the X-axe. I don't know exaktly, but I think in this case the have a stationary spindle and a driven nut. The only obvious disadvantage of these construction is, you need at least the complete Y-way free space behind the machine.

The flyer is free downloadable on the hermle homepage, so I think its ok, I post it here, without any copyright issues.

[Chaz]

Ok, it works I hope. Here is the only flyer I found, where you can see, how the hermle machines were build. On page5 there is a gantry construction and page 7 shows the normal construction. These machines run since 15Years or so, without problems. The spindle for the Y-Axe is hidden behind the spindlehead in the middle of the X-axe. I don't know exaktly, but I think in this case the have a stationary spindle and a driven nut. The only obvious disadvantage of these construction is, you need at least the complete Y-way free space behind the machine.

The flyer is free downloadable on the hermle homepage, so I think its ok, I post it here, without any copyright issues.

Thanks. Will go through it in detail when I get some time.