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[JAZZCNC]

The build went well. Long story short, the test did not go well. The Z axis lost steps on the up side. I ask questions in CNC message boards but was shunned and found no answers. After many weeks of trying the project was shelved. I have moved to the state of Florida upon retirement.

I'll do a deal with YOU.? We'll help you get working again and on right track and You send US some of that lovely Florida Sunshine to UK.!

Welcome.

[shipper506]

I'll do a deal with YOU.? We'll help you get working again and on right track and You send US some of that lovely Florida Sunshine to UK.!

Welcome.

That is a deal I can live with.

[DrNik]

Welcome, I'd love some of that sun too

[routercnc]

From your introduction it sounds like you want to make a wood cutting machine and have fitted 4off Nema34 stepper but are loosing steps. Couple of things:

Nema 34 sounds a bit overkill for a wood machine - I've seen them specced for lifting the knee on a mill, but for a wood cnc machine you can lift a lot of weight with a Nema 23
Nema 34 needs lots of voltage to make them work. It is possible you are under driving them. I've seen them specced on this site to run at 70V DC minimum, with a preference for direct mains drivers.
Stepper motors can be wired in different ways (series, parallel) to change their output but only if the drivers can take the current

So without jumping to conclusions too early, I think the collective wisdom on here can help you out if you provide:

1. Stepper driver make, model, and most importantly voltage being used on each axis
2. Drive system - all-thread, trapedoizal screw, ballscrew, rack and pinion, belt, other
3. Linear motion - skate bearings, v-bearings, supported rail, linear profile rail, other

Also any photos of the machine, particularly the Z axis will be a great help.

[shipper506]

I'll answer the questions as best i can first, then the upgrades I've made, then pictures (if I can figure out how to add the pictures-including some of that Florida sun I promised)

[jamesgates1000]

Hi welcome to the forum, I have been a member for a while but only just started using it. The really knowledgeable people on here have been a great help to me so far.

[shipper506]

STEPPER DRIVER
1 pc Four-axis Driver Board HY-TB4DV-M (TB6560), 3.5a, 16 micsteps

STEPPER MOTORS
Nema 34 stepper motor 878oz.in bipoler - step angle 1.8, Rate voltage 6.4, Rate Current (A) 2, Phase Resistance 3.2,Phase Inductance (mH) 15, Holding Torque (oz.in) 878, Rotor Inertia (kg.e?) 1.7

DRIVE SYSTEM
Lead screws are 1/2 " 8 starts 1 turn=1"

Anti back lash on all axis

LINEAR MOTION
skate bearings

WIRE
18 gauge wire from driver board to stepper motors and 22 gauge wire to limit switches/e-stop

POWER SUPPLY
350W 36v

[njhussey]

Well the first 2 lines says it all....TB6560 (by the way you're brave running it at 36V, surprised you've not had the magic smoke from it yet at!!!!) and Nema34 motors.

See this thread...http://www.mycncuk.com/threads/1373-...ghlight=TB6560

You're never going to get any sort of performance running Nema 34's with a TB6560. Nema 34's need 100V plus to get any sort of performance.....

[shipper506]

Im confused, you say im not going to get any type of performance out of the 34's because they need 100v however they are not rated that high voltage and all but "Z" was working fine.

The upgrades consist of new limit switches/E-stop, rewire from 22 gauge to 16 gauge on the stepper motors, and new connectors between the two modules, what i call the brains (computer and breakout circuit (software)) and the working module (Stepper motors X Y Z and limit switches (hardware)).

[routercnc]

The rated voltage is much lower than the voltage you can actually drive them at using pulses (ie what the stepper driver voltage is)
I'm afraid Neil is correct and you have built a mismatched system. 36V is way too low for Nema34. You can either accept that or wait for someone to post the technical reasons why.
You are also running lead screws not ballscrew and have anti backlash. This all adds to the friction when lifting the Z axis. To add to it further they are on skate bearings although that should be a minor factor in terms of allowing a smooth lift.
The cheapest way to stop loosing steps would be to swap out the Nema34 on the Z to a Nema23, and probably turn the voltage down a touch to be kind on the chips. Keep the acceleration and velocity at modest levels and you should avoid loosing steps.
If your leadscrew pitch is 1" per turn then I think you would also benefit from a 2:1 pulley on the Z