[Otter1]

Tormach specifies 16" Z axis travel but I have an application that requires 17" between the spindle and the table.

I was at a trade show (Oshkosh) and asked if there was any more distance to be had. The demo guy zeroed Z with spindle at the table then ran Z till it hit the upper limit switch. Z on the display then read 17.380" and a tape measure confirmed that there was in fact 17" + between the table and spindle. That would work for me if this is a typical result but I'd like to get conformation before making an order.

Anybody done this measurement?

[apeman88]

I have not verified myself but someone else have already.

http://www.cnczone.com/forums/showth...t=62545&page=2

[philbur]

The spindle nose will actually go lower than the table surface so, I haven't check but, it doesn't necessarily follow that 17" of travel means 17" of clearance. Also it may be possible to put a spacer under the Z-axis motor mount in order to raise the head an inch or two and give more clearance, but of course not more z travel. If you are concerned before you buy, contact Tormach with details of your issue and I'm sure they will give you the whole nine yards.

Phil

Tormach specifies 16" Z axis travel but I have an application that requires 17" between the spindle and the table.

I was at a trade show (Oshkosh) and asked if there was any more distance to be had. The demo guy zeroed Z with spindle at the table then ran Z till it hit the upper limit switch. Z on the display then read 17.380" and a tape measure confirmed that there was in fact 17" + between the table and spindle. That would work for me if this is a typical result but I'd like to get conformation before making an order.

Anybody done this measurement?

[philbur]

The specs say 17" nose to table, so no worries. Get your order in.

Phil

Tormach specifies 16" Z axis travel but I have an application that requires 17" between the spindle and the table.

I was at a trade show (Oshkosh) and asked if there was any more distance to be had. The demo guy zeroed Z with spindle at the table then ran Z till it hit the upper limit switch. Z on the display then read 17.380" and a tape measure confirmed that there was in fact 17" + between the table and spindle. That would work for me if this is a typical result but I'd like to get conformation before making an order.

Anybody done this measurement?

[Otter1]

Looks like this will work, thanks for the pointers.

Otter

[Zetopan]

The spindle nose will actually go lower than the table surface so, I haven't check but, it doesn't necessarily follow that 17" of travel means 17" of clearance.

I adjusted the limit switches on my Tormach some time ago and I have 17" of
Z-axis travel above the table. The X and Y axes travels are also larger by 0.25"
and 1.00", respectively, than what Tormach states in their specifications.

[Otter1]

I adjusted the limit switches on my Tormach some time ago and I have 17" of
Z-axis travel above the table. The X and Y axes travels are also larger by 0.25"
and 1.00", respectively, than what Tormach states in their specifications.

Thanks for the conformation Zetopan.

I did notice that when I asked to see how high the spindle would go at the limit that the Tormach head was still fully engaged with the gibbs on the body(even had an additional 1/2" or so to go). This was after 17.38" of Z travel starting with spindle touching the table. Just wanted to make sure this was not unique to that particular Tormach I saw at the show.

BTW Philbur, I would assume that the lower limit switch should be adjusted to prevent the spindle going below the table but glad to hear that the specs actually say 17" nose to table. I missed that.

Otter

[philbur]

It kinda doesn't matter. Whether you hit the table or not depends on what tooling you have in the spindle, not were the limit switch is set.

Without checking it (my machine is currently in storage) I think the adjustment is limited to 1/2" or so.

It's never occurred to me before, but why is there a lower limit shut-down on the Z-axis, under what circumstance will it get tripped, surely your cutter will be chewing on the X-axis ballscrew before the limit trips.

Or have I miss-remembered something - which is not entirely impossible.

Phil

BTW Philbur, I would assume that the lower limit switch should be adjusted to prevent the spindle going below the table but glad to hear that the specs actually say 17" nose to table. I missed that.

Otter

[highspeedmazak]

You will love the Machine.

[Zetopan]

It's never occurred to me before, but why is there a lower limit shut-down on the Z-axis, under what circumstance will it get tripped, surely your cutter will be chewing on the X-axis ballscrew before the limit trips.

None of the axis limit switches take any cutter dimensions into account.
When it is adjusted correctly the lower Z-axis limit will at least prevent the
head from impacting the table with the more than 2000 pounds of force that
the Z-axis drive can generate. If you feel confident about not needing that
limit switch feel free to remove it from your Tormach - but I will definitely
be keeping all of my limit switches.

[philbur]

I think you miss my point. If the tool can hit the table before the limit switch is tripped (which is the case) what is the purpose of the limit switch. How often do you run a cycle without a tool in the spindle. Under what conditions will the low limit on the Z be tripped? Do you adjust the position of the limit switch according to the tool length?

With X and Y and the upper limit on Z the limit switch stops you running the ball-nut up against the ballscrew end stops, quite a noisey and panic inducing experience. But with a tool in the spindle how is the lower limit switch activated unless the tool has already gone through the table.

Have I missed something here.
Phil

None of the axis limit switches take any cutter dimensions into account.
When it is adjusted correctly the lower Z-axis limit will at least prevent the
head from impacting the table with the more than 2000 pounds of force that
the Z-axis drive can generate. If you feel confident about not needing that
limit switch feel free to remove it from your Tormach - but I will definitely
be keeping all of my limit switches.

[Zetopan]

How often do you run a cycle without a tool in the spindle. Under what conditions will the low limit on the Z be tripped?

When engraving with a rather small cutter and an excessive Z-axis negative
feed is encountered, the cutter will generally shatter or it may less likely cut
into the table (my smallest cutters are 30 mils in diameter). In either case
the spindle would not hit the table and cause really serious damage. When
using a larger cutter it is possible to machine into the table causing greater
damage, or with a large enough cutter even try to machine the ballscrew or
ball nut. Similarly, the X-and Y-axis limit switches will not prevent damage to
a workpiece or even the spindle or head when a bad movement is performed
causing the cutter or the head to slam into the workpiece. Likewise for the
head hitting the workpiece with a z-Axis down when a workpiece is mounted
on the table. In this case the cutter is does not hit the workpiece, the head
does.

The Z-axis ballscrew has a finite length (at least mine does) which means
that the ball nut could run off of the end of the ballscrew on an excessive
Z-negative movement. Tormach does have complient stops on all of their
ballscrews, and assuming that this is true for the lower Z-axis as well the
lower complient stop should be hit before actually trying to run the nut off
of the end of the ballscrew.

While it is currently impossible for the lower Z-axis limit switch to adjust for
the cutting tool length or the workpiece height, that doesn't mean that the
lower Z-axis limit switch is always worthless. If it really bothers you, just
remove it and sell it on eBay. I am not going to complain about the lower
Z-axis limit switch if I screw up the programming when my SpindleMaster is
installed (it has several inches of overhang and additional diameter, much
larger than any normal cutter). I do like the limit switch for preventing the
spindle from impacting the table when engraving, but that would never be a
feature that I would plan on saving me from bad tool path programming.

[philbur]

If it really bothers you, just remove it and sell it on eBay.

An uncalled for and stupid comment to a reasonable question. It doesn’t impress and adds nothing to the discussion.

So you have swamped what I thought was a very simple question in a great deal of irrelevancy so, in case you did not understand, I will simplify and repeat.

If I recall correctly on my machine, to trip my lower Z limit the spindle nose (without a tool mounted) actually has to be below the plane of the table surface, or at least so close to it that it makes no difference. So, here comes the question so pay attention, under normal operating conditions /with a tool and tool holder mounted in the spindle) how is it physically possible to have the head low enough to trip the lower Z limit switch. A simple to the point answer will suffice. If you don't know the answer it's possibly best just to say so.

When engraving with a rather small cutter and an excessive Z-axis negative feed is encountered, the cutter will generally shatter or it may less likely cut into the table (my smallest cutters are 30 mils in diameter). In either case the spindle would not hit the table and cause really serious damage.

I would consider the result of any cutter rotating at 4,000 + rpm contacting my table as serious damage.

I know I'm going to regret this but - what is a Spindlemaster.

I could go on but feel I'm wasting my time.

Regards
Phil

[Andre' B]

If I recall correctly on my machine, to trip my lower Z limit the spindle nose (without a tool mounted) actually has to be below the plane of the table surface, or at least so close to it that it makes no difference. So, here

I consider that a bad machine design choice. Being able to put the spindle nose any closer then 2 or even 3 inches to the table is a complete waste of Z travel, it will almost never be used, better to move those inches of travel up to the top where they will do some good when one is trying to put a 11" tool 10" into a part.

If you are working on thin plates with short tools you should have a sacrificial plate between the part and the table anyway.

[philbur]

It seems like such an obvious error that I had assumed there was a reason for it that I had not yet identified. I don't think the design of the Tormach was just thrown together. So?

Phil

I consider that a bad machine design choice. Being able to put the spindle nose any closer then 2 or even 3 inches to the table is a complete waste of Z travel, it will almost never be used, better to move those inches of travel up to the top where they will do some good when one is trying to put a 11" tool 10" into a part.

If you are working on thin plates with short tools you should have a sacrificial plate between the part and the table anyway.

[philbur]

It could possibly be due to design constraints on the height/mass and required stiffness of the column and that the "standard" ballscrew length was greater than required. So it hangs out the bottom rather than add height and mass to the column.

The Tormach was apparently designed within certain parameters to make it shipping/handling freindly.

Phil

I consider that a bad machine design choice. Being able to put the spindle nose any closer then 2 or even 3 inches to the table is a complete waste of Z travel, it will almost never be used, better to move those inches of travel up to the top where they will do some good when one is trying to put a 11" tool 10" into a part.

If you are working on thin plates with short tools you should have a sacrificial plate between the part and the table anyway.

[MichaelHenry]

Phil,

On my mill, the spindle nose can be brought no closer than about 3/4" of the table. That's just the bare nose though, and a holder or even most cutters mounted directly in a collet would be able to strike the table. A soft limit for low Z might be useful to avoid table hits, but I don't think they are enabled in the Tormach version of Mach3.

OTOH, my workpieces are almost always elevated a couple of inches or more above the table so I'd have to be constantly fiddling with soft limits. I'd be strongly temped to use sub-plates if a lot of workpieces needed to be mounted directly to the table.

Mike

[TimTheToolMan]

Knowing that each machine has it's own "personality", one of the first things I did after setting up our Tormach was to characterize it. I use this Master Layout for most jobs just to make sure I don't do anything crazy. It was done in Ashlar Cobalt (solids).

I realize Cobalt is not the most popular app out there (although I've been in LOVE with it for almost a decade now), but Ashlar has a very simple and free app for converting to any number of popular formats. Just visit ashlar.com and download "Cobalt Share". Open my document with that, then export to whatever you want.

I'll try attach it here, but I'm not certain if it will tip the size limit scales of the forum. If I'm not successful and you'd like a copy, please send me a private message with you email address.

[keen]

Tormach specifies 16" Z axis travel but I have an application that requires 17" between the spindle and the table.

I was at a trade show (Oshkosh) and asked if there was any more distance to be had. The demo guy zeroed Z with spindle at the table then ran Z till it hit the upper limit switch. Z on the display then read 17.380" and a tape measure confirmed that there was in fact 17" + between the table and spindle. That would work for me if this is a typical result but I'd like to get conformation before making an order.

Anybody done this measurement?

Hi - I had to squeeze a tall block in today and managed to tweek up the Z ref switch a little and now get 452mm (17.79") after the ref return position, between the spindle nose and the table. Warning to anyone doing this: Never rush a jog and risk the wrong direction after hitting the Z switch - you will have little safety distance/time before a crash. - And dont tweek too far or you could crush the lub lines! (I dont see a soft bump stop on mine here).

[TimTheToolMan]

Hi - I had to squeeze a tall block in today and managed to tweek up the Z ref switch a little and now get 452mm (17.79") after the ref return position, between the spindle nose and the table. Warning to anyone doing this: Never rush a jog and risk the wrong direction after hitting the Z switch - you will have little safety distance/time before a crash. - And dont tweek too far or you could crush the lub lines! (I dont see a soft bump stop on mine here).

From my master layout (spindle face to table), I get 17.7025" Z, 18.0499" X and 10.1537" Y total envelope. With my master tool in the Z drops to 14.072".

I've not "tweaked" anything yet, but I do see where I have another 1/4" or so on the Z if I need it.

With the work we do, I can't see ever needing anymore. Of course, having said that...I'll need it tomorrow!