4th Axis to RH end of Table

[wbleeker]

I was wondering whether anyone has done anything to be able to use their 4th Axis to the right hand end of the table? With the ATC it would seem to be the way to go, I don't have an ATC but thinking in the future I might have, so how about an angle plate to bolt the 4th axis to? Maybe out of 1" plate with some side gussets, this would allow the axis to be bolted on with the stepper motor on top and facing the operator, clear of the control panel allowing full movement as well as getting the cable closer to the socket.
I don't know whether Tormach offer a Righthand version of the 4th axis to suit the ATC equipped machine either, I had a look but couldn't find anything. That would solve the problem for new buyers.
Will

[philbur]

Lubrication may be a problem.


Phil

so how about an angle plate to bolt the 4th axis to? Maybe out of 1" plate with some side gussets, this would allow the axis to be bolted on with the stepper motor on top and facing the operator, clear of the control panel allowing full movement as well as getting the cable closer to the socket.

[outofsquare]

I have been researching the Tormach for our application, if you purchase the 8 inch 4th axis (standard) then you will not be able to use your ATC, but if you purchase the 8 inch tilting 4th axis then yes it will work with the ATC perfectly as its bolted on the right side of the bed, not sure though if the smaller 4th axis will give you any trouble on the left hand side, & how much clearance you will have to the ATC Im not sure.

[TXFred]

I you could modify the 4th axis to put the stepper behind the axis, with a belt drive connecting the motor to the worm gear.

That would solve the clearance issue, but then you cannot put the 4th axis on its back anymore.

Frederic

[wbleeker]

Outofsquare, that solution is fine for new buyers, I am thinking more for existing users. Taking what Fred said and putting a belt drive on for the stepper will solve the control panel clearance problem while not changing the internal lubrication of the 4th Axis, now if we were to build a platform to mount the rotary table on which incorporated a cutout for the stepper motor we would be able to use the 4th Axis both ways just with a bit of a Z height sacrifice.
Will

[Zetopan]

Anyone interested in an example of a 2:1 Rotary Table can examine my Yuasa
Rotary Table modifications. Since I already had a very robust 8" Yuasa table
and I wanted to make a custom 4th (and 5th) axis I converted my Yuasa over
to CNC instead of purchasing a Tormach rotary table for my Tormach PCNC1100.

Another reason is that I created a custom enclosure for the mill and folding the
drive makes for a much shorter and more compact rotary table, so my enclosure
could be smaller and still contain the rotary table. This rotary table can also be
used on either end of the mill table. Although I personally have no need for a
right side mount others with the Tormach automatic tool changer may find this
of some use. My hand wheel would be more difficult to get to on the right side
of the mill table, but if you select your rotary table with the hand wheel drive
on the opposite end of the rotary table as mine, a right side mill table mount
would be ideal.

I have photos showing the front, side, and rear views as well as what I did to
the driven timing pulley and hand wheel to reduce the rotary inertia to allow
for faster acceleration (the top speed remains the same). Since I am adding
a homemade trunnion table and 5th axis, I wanted the rotary table to be very
strong and I was willing to sacrifice some speed as well as forgo any horizontal
usage (the Tormach does circular interpolation just fine), so I mounted a water-
proof stepper motor (same as used on the X axis) behind the table.

I kept the hand wheel because it is invaluable when mounting a work piece on
the table when the mill is unpowered, and the 2:1 drive ratio also reduced the
inertial load on the motor by 4:1. The lightening holes in the driven pulley and
the hand wheel reduced the rotary inertia by about 25% (the hand wheel in
particular is very heavy).

Also be aware that you would need to unlock the Mach3 software to alter the
steps per degree setting. Doing this voids your warrantee if you still have one
on the mill. My mill was long out of warrantee when I created the 4th axis.

See this link for the photos:
http://groups.yahoo.com/group/tormac...57598/pic/list

[TXFred]

now if we were to build a platform to mount the rotary table on which incorporated a cutout for the stepper motor we would be able to use the 4th Axis both ways just with a bit of a Z height sacrifice.

I thought about this some more.

The stepper bolts up with four bolts in a square pattern. If the new motor mount attaches to those four bolts, then you could index the motor mount so that it is behind the table when vertical, and beside the table when the table is horizontal.

I think this could be done with four parts. You need the new motor mount, which can be as simple as a piece of channel iron. You need a pulley that mounts to the table's shaft. You need a matching pulley to mount to the motor's shaft. And lastly, you need a drive belt. This system could probably be made in a single afternoon.

Frederic

[wbleeker]

Fred, thats the best idea so far! I have no need for it yet as I don't have an ATC
at the moment, it's a bit of an effort to get one here without getting stuck with expensive freight and Australian Government Taxes, I may have to visit some relatives over there and bring one home with me!
I hope someone does this to their 4th Axis though so we can see how it works.
Will

[philbur]

If you're going to change the drive layout you may as well just buy a RT locally and get started.

Phil

Fred, thats the best idea so far! I have no need for it yet as I don't have an ATC
at the moment, it's a bit of an effort to get one here without getting stuck with expensive freight and Australian Government Taxes, I may have to visit some relatives over there and bring one home with me!
I hope someone does this to their 4th Axis though so we can see how it works.
Will