xylotex problems

[justCNCit]

Hi. I am running a gantry setup with 1 Y axis slave. Recently I installed 2 dial indicators to act as home position for the gantry to check what the motors are actually doing. This was because startup crawl was really annoying me and I wanted to know how bad it was.

Not only it is bad, but somehow the xylotex 4 axis box is losing huge steps? Roughly 1/16 off after moving it 3 feet forward and then back to position. I'm using a desktop computer with windows XP. Ran drivertest, which went fine. Is this a known issue? Maybe geckos are the way to go

[CWBAILEY]

The greatest cause of lost steps in any setup is :-
1 Not enough power for moves from standing position
2 Stepper with not enough torque

Even though the stepper motors have plenty of torque in machining the load put on them can exceed their capacity when asked to move a gantry from standing to rapid or high feed rate. The same problem can occur when the power supply has not got enough power for peek load.

The problem can be solved by increasing the capacity of the power supply or adding capacitors to the power supply (just like accumulators) to give increased power when high load moves are required.

[justCNCit]

I would have no idea how to modify the power supply. I can slow down accelerations.

Edit: I understand what a capacitor does but I'm not an electrical engineer and would need to be sure it's the solution to the problem before attempting that

[rgammage]

Hello

A friend of mind had a CNC mill losing steps until he tried the free Linux CNC offering EMC2 and has had no problems since. The issue with all Windows programs is they take total control of all interfaces and just when you need a pulse to be output ..... it goes and does something different! Also your computer MAY be a little slow.... or short of resources (memory mainly) .... that will affect its performance.

Trying this costs nothing to try .... but time!

Regards
Richard

[ger21]

This was because startup crawl was really annoying me

What do you mean by startup crawl?

What kind of motors and power supply so you have? What screws? What are your accel and velocities set to?

I use a Xylotex on my 30"x45" router with no problems, but I run it very close to the point where It can lose steps. It's very important to keep screws lubricated, and make sure there's no binding anywhere at all.

[justCNCit]

Xylotex 4 axis box. Startup crawl is when the drive is turned on from rest and the magnets pull the screw a few thou off zero. 10 tpi 5 start. Feed 100 ipm. I forget what acceleration it was, not high. The axis motors not aligned great, I don't know how to get it better than align by eye though. 400 oz motors, full stepping.

[ger21]

Startup crawl is when the drive is turned on from rest and the magnets pull the screw a few thou off zero.

I believe all stepper drives will do that. That's why you use home switches.

You should be using 1/8 stepping instead of full stepping, you should get smoother running than with full steps.

I also forgot to mention that I use dampers on my steppers. Without them, the machine would be almost unusable.

Gecko's are definitely a better option, but you should be able to get the Xylotex to work adequately, but you may need dampers.

For my X and Y axis, my accel is set to 10. I can't go any faster reliably, but I can get 190ipm on my Y axis, with 250oz motors and 1/2-8 2 start screws.
Here some video with and without the dampers.

Stepper Motor Damper Test. - YouTube

Stepper Motor Damper Test. - YouTube

[victorofga]

i have a 3 axis xylotex from 2003... it is working very well.. thats why decided to buy a 4 axis control from xylotex, informed as design is same..
so i was sure..

recently i tried out the 4 axis with 270(approx) motors..
it was crawling bad, and asked xylotex, also ger21 answered me, need to put on balancers or dampeners...

im not sure i will do that.. the originallly purchased working almost noiseless... with halfsized motors about 90 ounces motors,
xylotex told me they are good quality motors (powermax)..

im not expert of cnc drives.. i dont know about distorted signals or other issues..

edit

ger, i saw this video.. and hat off you.. youre really expert.. but my decision was buying a control, wired together and hook on the router..
i could buy parts, i did buy a complete solution, and now i can not use my complete solution... not to mention, on the old i DO NOT use dampeners...
i can go slow or fast it works... i can set mach to 50K pulses and 1/8 lead screw makes almost 140 ipm...

i just wanted larger motors voiding losing steps on a longer run

i just seeing the controller i purcahsed in 2003 working better this moment than the new 4 axis control...
if design is did not changed, then i suspect it is only some settings..


best regard

since 2003 i had no any issue withthis xylotex control.. however i have to tear back the new one, and this time i using the old...

[justCNCit]

I have dampers that can be installed. As for home switched I am not sure what exactly to buy. They say microswitches are inaccurate.

[ger21]

I've read from a lot of people that microswitches can be very accurate, at least within .001-.003"
But I use these electronic ones, which cost about $10 in parts.
http://www.cnczone.com/forums/open_s...made_easy.html

[justCNCit]

It occurs to me that Mach 3 is most likely setup only for 1 home switch per axis, so having a home switch for each side of the gantry on return is impossible

[ger21]

If you have slaved motors for the axis, each can have their own switch, to square the gantry during homing.