PDA

View Full Version : xyoltex motors + gearing ratios + possible too much weight



Ch4iS
2nd June 2008, 12:07 AM
Ok, ive gathered they are 200 steps per resolution,

I am having problems with reducing the gear ratio for my y and z axis. X axis has tons of room so I would have no problem gearing it down.

I worked it out that without lowering the gear ratio and just using a 10 tooth alu pulley hub with 200 steps

200 steps a revolution
55mm of belt per revolution

= 0.275 mm per step

I just want to know if that resolution is good for general cutting of MDF ect. I dont plan to be doing any masterpieces with this machine as I will build a 2nd to do that with the first.


Also can you slow the machine right down? as at the current ratio it whould be flying around the cutting table. reason is I am building from a steel construction (box tubings mostly). X and Y axis moves quite freely (Z axis to add more Kg's) and can move with little power but I found I need to lower the speed in order for it to stop backlashing ive read is all this possible via the software?


Also are the Xyoltex stepper setup motors able to do 1/2 steps or 1/4 steps as I have been reading?


Any answers are much appreciated :)

rodm
2nd June 2008, 03:43 AM
Hi Blue^ray
If your motors can drive the screws as is then don't use reduction pulleys. At some stage you will want your machine to run as fast as it can go. Rapids (movements between cuts) can reduce job time considerably if you have a fast machine.
Speed if fully controllable through the software (Mach3, etc). You do this in the motor tuning of Mach3.

To understand steps it goes something like this.

The motor are typically 1.8 degrees which is 200 steps per revolution. ie 200 by 1.8 = 360 degrees. Xylotex boards come with 1/8 microstep enabled so if you leave this then you have 200 steps time 8 microsteps which gives you 1600 steps per revolution. Getting better already. :2tsup:
You then have to factor in your leadscrew. If it is say 10 TPI then for every 10 revolutions you move your axis one inch or 25.4mm. So for one revolution of the screw it is 25.4 divide by 10 = 2.54. ie 2.54mm per revolution of the screw.
Combinig the two you have 1600 steps per revolution divide by 2.54 = 629.92steps per mm.

Now taking this a step further this makes the resolution of your machine the inverse of this number or 0.0016mm which is why CNC machines are so accurate.

I hope that helps you.

Ch4iS
3rd June 2008, 01:48 AM
Hi Blue^ray
If your motors can drive the screws as is then don't use reduction pulleys. At some stage you will want your machine to run as fast as it can go. Rapids (movements between cuts) can reduce job time considerably if you have a fast machine.
Speed if fully controllable through the software (Mach3, etc). You do this in the motor tuning of Mach3.

To understand steps it goes something like this.

The motor are typically 1.8 degrees which is 200 steps per revolution. ie 200 by 1.8 = 360 degrees. Xylotex boards come with 1/8 microstep enabled so if you leave this then you have 200 steps time 8 microsteps which gives you 1600 steps per revolution. Getting better already. :2tsup:
You then have to factor in your leadscrew. If it is say 10 TPI then for every 10 revolutions you move your axis one inch or 25.4mm. So for one revolution of the screw it is 25.4 divide by 10 = 2.54. ie 2.54mm per revolution of the screw.
Combinig the two you have 1600 steps per revolution divide by 2.54 = 629.92steps per mm.

Now taking this a step further this makes the resolution of your machine the inverse of this number or 0.0016mm which is why CNC machines are so accurate.

I hope that helps you.


Thanks for that rod :), ill post some pics when I get my faulty cut-off saw back tommorow as it was faulty.