2+2+3 More Plasma builds, double the joy ! 3X2M and 2.5X1.5M cnc plasma build.

rodw wrote:

Tommy, thanks. I also see that they have steppers listed there with encoders but Lam don't list them on their own site. NOr do they have drivers with encoder inputs I can see. So would you close the feedback in Linuxcnc if You went that way?

From what i have used regarding stepper drives, These are the only ones that would justify putting encoders on motors and closing the loop in Linuxcnc as the have an input that says BOOST !!! That can be used to be activates the instance the step count sent from stepgen does not match the steps from the encoder so it will add more current to the motor giving the motor a better chance at catching up. Be aware that by default that boost pin is reversed, so active high will drop the current, can be changed with the software and the usb programmer for it.
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rodw wrote:

I was kinda thinking 4 NEMA 23's at around 260 oz/in 3 amps (say Lams M1233051), DS1076 drivers, 70-80 volts with 5:1 reduction drives on a rack and pinion drives should smash a light (say 30kg) gantry

And probably also do the same with a DS1044 on a 48 v SMPS

What do you think?

Or should I use a Toroidal and Lam's power supply modules?

That seems all good, and with that reduction it will be also usable as a router for sure. I did try to surf the gantry yesterday at 10m/m for over 10 minutes i was jumping on it, and they never stalled. That is with Nema 23 motors at 1.8A, 1:3 reduction and a 15 tooth 3mm pitch pulley, so 15mm per revolution of the motor, or ideal for plasma cutting.
BTW, Lam do make stepper drives with encoder feedback and there was one type on sale at mechapro.de
www.mechapro.de/shop/Stepper-motor-drive...286.html?language=en
www.mechapro.de/pdf/DDS1_Flyer_EN.pdf
That one is very reasonable considering the quality is very high, i could not kill a DS1044 on purpose even by reversing the power supply or shorting motor wires to anything.

The Z's are coming, the Z's are coming !

And tandem Y axis are finished on both machines !
Looong day, it is 2:50AM, so in a bit i will be chasing some dreams, but i doubt i catch anything, i dream about once a year.
Here is a short video of both axis moving at 15m/m, or "breaking them in" as car guys would say.
Enjoy, and thank you all.
Regards,
Tom.

This was tough, i sure know how to complicate everything !
This is the final implementation of the Z axis, after many, many others i tried and discarded them for being to heavy/bulky/ugly. :

The profile is 28.5cm long and 34mm wide inside so not much space there for all the stuff that i had to put inside
Travel is 165mm, screw can do 220mm, but the bearing took 100mm inside, so i got left with only 185mm to work with.
I might get rid of those screws on the top, but that would limit travel by 15mm, so that would leave 150mm of usable travel. Do keep in mind that there is another 10mm travel for the floating part of it, so the only unused space inside is 10mm used by an alu plate connecting the rods inside and holding floating stuff and leadscrew nut, here is a picture of the floating part in the UP position:

And in the DOWN position, notice there is no sensor/switch there, will have to put that in when i dismantle it to make another one, and maybe take some pictures, :

Here is the back side, plain and clean ( well not cleaned yet, but there is nothing there ) :

And here it is extended to the bottom limit :

Took two full days to make, several injuries to the left hand ( the one holding down the stuff while the right hand does the damage ), had to use a bit smaller motors (Nema 17), the leadscrew is 8mm pitch and 8mm thick by some miracle of very nice quality, 16mm round rails on the inside with 4 linear bearings, total weight just under 3KG and 128mm wide. The mounting on the machine will have to be done on the sides as there is no place for anything on the back side, any screws there will interfere with the movement.
More on the way.....

rodw wrote:

2 days! I took 3 months!

That is just for the Z axis, but since the day was not over yet i started putting parts together for another 3 and decided on removing the long protruding screws, so it will be just a box with a motor !
The main problem, i am running out of aluminium ! Not good, not good.
You took 3 months for the whole machine, i really hope not just for the z Axis ?