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rgillard
03-19-2008, 03:01 PM
Hi Guys,

I have decided to build a very small prototype of my CNC Plasma machine before I take the plunge with the finished article. I have experienced with previous projects that building the machine of your dreams without any experience is usually biting off more than I can chew. My plan is to use some parts from old printers and steel to build up a mock unit that will draw the parts onto a sheet of paper. This will give me a much better grounding for when I go try build an 8 X 4 machine. I was hoping to use the parallel port to drive these small stepper motors.

Anyone know of a program that can output through this port?

Thanks

Ronan

samco
03-19-2008, 03:09 PM
Few that I can think of off the top of my head...

Turbocnc http://www.dakeng.com/turbo.html
mach http://www.machsupport.com/artsoft/index/index.htm
EMC2 http://www.linuxcnc.org/ <-my fav

rgillard
03-29-2008, 02:39 PM
Thanks Samco for your reply.

I have downloaded a version of Mach3 to my pc. Looks like an excellent tool.

In order to build my prototype cnc machine I have stripped down an old printer as my Y axis which has a built in bipolar motor.

I will build the X axis with a unipolar motor i have lying round and most probably a belt and some linear guides like weldtutors. I have an old motor controller board that I was hoping to drive the unipolar motor with. (rs 217-3611)

Datasheet is as follows.

http://www.rs-components.hu/ds/425_6241.PDF

My motor is a http://www.nisiki.net/Catalogues/Motors/NMB/PM55L.htm

I am a bit unsure of how to connect this motor up, partly as I do not want to blow my motherboard to shreds ( I have a breakout board in the post) but I would like to try and get things moving (well really turning).

I am getting signals out from mach3 on ports number 4 and 9 (stripped a spare printer cable)
about 3.6V for direction
and a pulsing for the step (cant actually see it on the multimeter but its slightly lighing up a LED when the X axis in Mach3 is moving)

What signal do I need to supply for the clock signal to the board.

Do I connect the step signal from Mach3 to the Full/Half Step port on the control board.

If anyone can point me in the right direction I'd really appreciate it?

Sorry if this post is in the wrong forum.

Regards,

Ronan

Torchhead
03-31-2008, 08:20 PM
You can't drive a motor directly off the parallel port. First the max drive current for a parallel port is about 15ma (.015 Amp) and it's at 3.3 to 5 VDC. It's made to drive a MOS chip inside a printer. Even some motor drives need more current than that to operate.

All parallel port from software (EMC, MACH3, TurboCNC,) use Step and Dir signals. The Step would be considered the "clock".


You are going to spend a lot of time putting together a table that will in the end be worthless (except for entertainment). Few if any of the parts will be usable in a bigger design and bigger designs with bigger motors will need different gearing, slides and linear motion components. You will end up going a lot of it twice...true you will learn from the mistakes, but if you invest an equal amount of time reading and studying this forum and the hundreds of machines users here have built it will be like going to CNC college.

Tom Caudle
www.CandCNC.com

rgillard
04-01-2008, 08:41 AM
Tom,
Thanks for your input. Its great to be getting advise from a CNC Guru. I hope to do a deal with you in the future on a plasma set up if you will ship to Ireland?

The main reason I want to build a small prototype is to learn. I am worried about spending 5000Euro on building a machine and making a mess of it. At the moment I cant even drive a stepper motor using Mach3 let alone try and control 3 axes and a tool. Id really like to gain some experience in simply controlling motors to start with. One step at a time and all that (no pun intended)

On the point of the small prototype I already have a Y axis..Straight out of a printer. I reckon I can make the X axis in one day out of scrap steel lying around. The way I learn is by reading something and then manually doing it. Its usually during the manual part that things start to click in my head. The prototype will not be extremely precise. I am just looking to move an x and y axis and try and get it to draw basic shapes to start. I have been reading the forum for about 6 months now and am just starting to get brave enough to try a table for myself. The other point is that I can work on this in my house rather than my cold workshop because it is so small.

With regard to connecting my current setup as discussed previously:

If I connect a 24V power supply to the stepper control board,

Connect the direction signal from the parallel port (Mach3) to the direction signal on the stepper control board

Connect the Step signal from the parallel port(Mach3) to the clock input on the stepper control board

Set the full step/half step input and the preset to 0. So I should be in half step mode .

Do I need to connect the ground of the parallel port to anywhere?

Do the signals from Mach3 need to be amplified in any way?


Thanks again for your help.
Ronan..

Torchhead
04-01-2008, 09:04 AM
For your driver card:

A lot of your questions are specific to the driver card you have. The amount of drive current needed (from a parallel port) is determined by the inputs on the drive card. Some require no buffers, others may not work off the low current lower voltage outputs of recent parallel ports.

Your driver card may have an 'enable' pin that needs a logic signal (high or low?) to let the signals through.

No ground to the motor card = no signal. You have to have a ground return for the logic signals. On some cards/drivers the common is a +5 (supplied externally in most cases) and the step and dir signals are active low, meaning they are the ground return.

Sometimes trying to use poorly documented or poorly supported electronics can end up in a long learning curve that will cause frustration and often stops the project.

Tom Caudle
www.CandCNC.com

millman52
04-03-2008, 05:21 PM
You might be interested in a learning kit that is avalible on ebay. Do a search for a store named "Hubbard CNC" Once you find the store look for educational or similar titled sub heading.

I'd highly reccomend you use at minimum a opto isolated break out board for your experiments. It will go a long way toward protecting your parallel port on your computer.

rgillard
06-30-2008, 06:49 PM
Hi Guys,

Its been a while since I got time to spend on my CNC dream machine. I am still hoping to build a small prototype machine that will draw out shapes with a pencil first, before I plunge into the real machine. I got an hour or two of this test rig started tonight.

I cut two lengths of 42mm pipe that I had lying about.

I cut four pieces of 80mm x 3 box section which will be used to hold the pipe. (similar to weldtutors machine).

I made up two trucks for carrying the gantry

I also stripped down an old printer that I had. There is a bipolar stepper motor in it and I am going to use the printer ink head carraige as a Y-axis. I need to buy a bipolar stepper motor driver for this motor. Is there any way to find out what Voltage and current this motor needs to operate properly. It is an epson EM-293 8X0905A. I have searched Google on this and not found anything useful... Is there any test I can do to find this out. I also have to go and buy a DC power supply so I would like to buy one that will run these motors.I was looking at a triple power supply which outputs 5V and 12V @ 0.5A and 0-30V with adjustable current up to 2.5A Because this is only a test rig I wasn't going to buy top of the range control boards. If anyone could advise me I would be most appreciative.

Regards,
Ronan

MonoNeuron
07-23-2008, 10:54 AM
Hi,
For the size 17 steppers that you have there all you need is an old PC computer power supply. It has the 12 volts for the motors and 5 volts for the controller supply. (if you need it). The more voltage you have the faster the motors will go but there is a trade off on torque which drops off considerably with speed and 12 volts is ok.
I built a small router a while ago using size 17 steppers and PC power supply to test how good they were and also try out some model plane 3 phase motors and they are surprisingly powerful for their size. I still had to gear them down a bit, about 3:1 , but they perform admirably. It took about 14 days to build with a lot of head scratching. :-)
Here is a link of it on YouTube.
http://youtube.com/watch?v=-cOkD-4wF2I

If you buy a driver then get a microstepping one with 8 or 10 steps per step. Don't go for the full step or half step unless you have a 5 phase drive and motor which give you 500 and 1000 steps per rev respectively. Half and full step on a bipolar motor is very jerky and adds to vibration and noise.
Have fun with the build.
Rich.

rgillard
08-30-2008, 09:43 PM
Hi Guys,

I have bought myself a bipolar microstepping control board. I want to use this control board to move a epson 600 stepper motor. Even though this will be a microstep with a small stepper motor it will be a big step for my CNC Dreams. I have taken a power supply out of an old PC. There is 12V and 5V outputs. I hope I can use this to run the motor.

But before I go blowing up stuff I wanted to show how I'd set it up and then if there are any major mistakes maybe they will be pointed out before I make a mess of things.

Ok so in Mach3 I have set the outputs for the x-axis to

ENABLED has a green tick
STEP PIN# 3
DIR PIN# 2
DIR LOWACTIVE has a red x
STEP LOW ACTIVE has a red x
STEP PORT 1
DIR PORT 1


So I will connect my parallel cable from my pc to my breakout board and the step signal should be in pin 3 and my dir signal should be in pin 2. On my breakout board there is a 5V input and a ground. There is also a VDD (it looks like that anyway) and a ground. What am I supposed to connect to this. Im not sure whether I got literature with the board but I cant locate it if I did.

On my motor control board I need to give it a ground and +VE Input voltage. I was going to use a 12V input from the power supply . On the power supply (see pics) it gives the DC output voltage and currents. The model is PS-230WRE. Is this a 230W power supply? If so there is a +5V which gives out 23A, +12V which gives out 9A, -5V which gives out 0.5A and -12V which gives out 0.5 V. Which 12 V am I looking to connect to power the motor? 9A seems like a lot for a small motor and the board is rated for 2.5A 30 V Output drive Capabilites. I have kind of answered my own question there but clarification would be nice. Just for interest sake does anybody know which PC components run off which voltages? Also on the control board there is a pot which needs to be adjusted for VREF. How do I find out the Motor Current for the motor in the printer. The table is TAble 2 in the pic..I have looked for datasheets on them before and could not find them... There is a pic of the table included.

Wiring up the motor coils and step and dir should be straight forward after that.

Hopefully someone can tell me whether im on the right track or not...

Best Regards,
Ronan..

rgillard
10-07-2008, 07:14 AM
Hello All,

I finally got home from China to do a little work on this project. I tried last night to jog a motor using Mach 3. Firstly I connected the breakout board to the PC and gave it the +5V from an old PC Power supply. I used some LED's and resistors on a breadboard to firstly make sure I was getting a signal to the breakout board. For the direction signal I got a voltage of 5V when the x axis was moved in a negative direction and approx 0V when the motor was moved in a positive direction. For the Step signal I got either a constant 5V or a constant 0V depending on whether the the active high was enabled or disabled. I was happy enough that I had signals to this point.

I then used the 12V output on the PC Power Supply to power up the stepper driver board. The green light came on and there was no smoke. I connected up the motor properly and the step, direction and ground connections. I left the enable input empty. When I powered the board up with the motor connected the motor locked up and I could hear a high pitched noise. However, when I tried to move the motor the signal from the breakout board was now only 1.8V (not enough to cross the 2.9V minimum high signal). Can anyone tell me what I am doing wrong. There are 2 inputs into the breakout board (see doc) Both Are 5V. On the power supply there are many connectors. I picked one randomly and took 1 ground and two 5V(red) cables off that one connector. Do I need to take the 5V from two different connectors?

If anyone can point me in the right direction I'd really appreciate it.

Ronan

MonoNeuron
10-09-2008, 09:31 PM
Hi Ronen,
Make sure you have the pin on the emergency stop in Mach3 shorted, or set up, as this will stop the pulses from the program from being sent. (Pin 10 I think????) You have had it running so I think you already know this.
Also check you parallel cable to see if all the wires have the same resistance. I had one once that was different on some of the step pins which caused the step signal to go high or low whenever it felt like it.
Watch the set up videos on the ArtSoft web site to get some more insight on the program and how to set up the relevant pins/ports.
Also check for ground loops. Don't connect both ends of your shielded cables to ground etc.
I hope this helps.
Rich.

TOTALLYRC
10-10-2008, 01:14 AM
Hi Guys,

I have bought myself a bipolar microstepping control board. I want to use this control board to move a epson 600 stepper motor. Even though this will be a microstep with a small stepper motor it will be a big step for my CNC Dreams. I have taken a power supply out of an old PC. There is 12V and 5V outputs. I hope I can use this to run the motor.

But before I go blowing up stuff I wanted to show how I'd set it up and then if there are any major mistakes maybe they will be pointed out before I make a mess of things.

Ok so in Mach3 I have set the outputs for the x-axis to

ENABLED has a green tick
STEP PIN# 3
DIR PIN# 2
DIR LOWACTIVE has a red x
STEP LOW ACTIVE has a red x
STEP PORT 1
DIR PORT 1


So I will connect my parallel cable from my pc to my breakout board and the step signal should be in pin 3 and my dir signal should be in pin 2. On my breakout board there is a 5V input and a ground. There is also a VDD (it looks like that anyway) and a ground. What am I supposed to connect to this. Im not sure whether I got literature with the board but I cant locate it if I did.

On my motor control board I need to give it a ground and +VE Input voltage. I was going to use a 12V input from the power supply . On the power supply (see pics) it gives the DC output voltage and currents. The model is PS-230WRE. Is this a 230W power supply? If so there is a +5V which gives out 23A, +12V which gives out 9A, -5V which gives out 0.5A and -12V which gives out 0.5 V. Which 12 V am I looking to connect to power the motor? 9A seems like a lot for a small motor and the board is rated for 2.5A 30 V Output drive Capabilites. I have kind of answered my own question there but clarification would be nice. Just for interest sake does anybody know which PC components run off which voltages? Also on the control board there is a pot which needs to be adjusted for VREF. How do I find out the Motor Current for the motor in the printer. The table is TAble 2 in the pic..I have looked for datasheets on them before and could not find them... There is a pic of the table included.

Wiring up the motor coils and step and dir should be straight forward after that.

Hopefully someone can tell me whether im on the right track or not...

Best Regards,
Ronan..

If the motor locked up and made a high pitched noise when you powered it up,you are very close as that is what it is supposed to do. That means that you have holding torque and the driver isn't fried.

Just for testings sake, set the amps low like .5 or 1 amp and monitor the motor temp. If it gets too hot to comfotably touch go lower on the amps. If it doesn't get warm at all you can go higher. Steppers run warm to almost hot near their max power output.All of the better drives offer idle current reduction which allows max power during moves and prevents overheating when sitting still.

Having a power supply with more amps is ok, it jst gives you more room for future expansion. The driver will limit it to what is needed. Any of the +12v outputs will do, just make sure the polarity is correct.

Try changing from the red x to a green check for the enable low. both step and direction. With what you using for components it might be trial and error.


Please don't get too upset but my opinion is you are trying to reinvent the wheel with your test rig.
It is actually harder to do what you are doing than to buy a plug and play setup from any of the guys that post/advertise here on the zone.

Tom from candcnc has already helped you and he has several great offerings and excellent support. I have worked with him, the guys from keling cnc, and Mariss and company from Geckodrive. All are excellent people and back up there product with customer service and support that is probably better than they should be offering. But I am not complaining.:)

You could always get the electronics and motors first to make sure it all works out before you do/buy any hardware. Althought the hardware isn't a 5 second job, I have found that I am more motivated to do the harware once I know that the electronics are working.

Many of the plug and play systems come with the XML file for mach3 which eliminates all of the guess work for settings and such.

I am here to answer any questions I can.
Mike

rgillard
10-29-2008, 09:18 AM
TotallyRC,

Yes the motor locks up and makes a high pitched squealing sound.
I Just have a voltage drop once I connect the breakout board of 3.2V. When not connected to the driver board I have 5V output but once I connect the step and direction it drops to 1.8V. Lo signal is approx 0V. I have left the enable input empty as stated in the PDF attached and I have set the jumper J6 to enable. I connected the ground from the breakout board to the ground connector beside the enable input...I have adjusted the VREF so that the motor does not overheat when powered up. I selected different pins as outputs to rule out pin 2 and 3 having a problem. This really should be very simple but I'm obviously doing something elementary wrong which is causing this problem.

As regards the test rig, it really is only going to be two printers joined together. Nothing major at all really. I will eventually buy a full setup off CandCNC but at the moment I can not afford it. When I can I hope I will have a slightly clearer idea of how the whole system works..

Ronan

TOTALLYRC
10-29-2008, 10:11 AM
TotallyRC,

Yes the motor locks up and makes a high pitched squealing sound.
I Just have a voltage drop once I connect the breakout board of 3.2V. When not connected to the driver board I have 5V output but once I connect the step and direction it drops to 1.8V. Lo signal is approx 0V. I have left the enable input empty as stated in the PDF attached and I have set the jumper J6 to enable. I connected the ground from the breakout board to the ground connector beside the enable input...I have adjusted the VREF so that the motor does not overheat when powered up. I selected different pins as outputs to rule out pin 2 and 3 having a problem. This really should be very simple but I'm obviously doing something elementary wrong which is causing this problem.

As regards the test rig, it really is only going to be two printers joined together. Nothing major at all really. I will eventually buy a full setup off CandCNC but at the moment I can not afford it. When I can I hope I will have a slightly clearer idea of how the whole system works..

Ronan

Well according to the attached pdf, when you have a high signal, it must be at least 2.9 volts. If all you are getting is 1.8, then of course it will never work.

This is the point where I am in over my head. Maybe someone else can step in.
But just for the sake of asking, which breakout board do you have?

Mike

rgillard
10-29-2008, 10:56 AM
Please see the Breakout board PDF attached. Yes a high voltage of 1.8 will never work. Could I be possibly making some mistake with the grounding of the driver board. The ground is taken from the breakout board nearest output pin 17 and connected to the ground on the breakout board. I have taken two 5V outputs(red) and two 0V outputs(black) from the PC power supply to supply the power to the board. I have taken a 12V output(yellow) and a 0V output(black) from the PC power supply to power the board. As I say without having driver board connected I get 5V and 0V as outputs from Mach 3. Once I connect driver board I get 1.8V and 0V as outputs when x is Jogged..Enable into driver board is empty, jumper J6 is in the enable position and the board is set up for microstepping. Now I could get my hands on another stepper motor and another power supply and eliminate the problem. Maybe I'll try that if I don't get any better ideas.

Thanks for your fast response.

Ronan

TOTALLYRC
10-29-2008, 11:33 AM
Please see the Breakout board PDF attached. Yes a high voltage of 1.8 will never work. Could I be possibly making some mistake with the grounding of the driver board. The ground is taken from the breakout board nearest output pin 17 and connected to the ground on the breakout board. I have taken two 5V outputs(red) and two 0V outputs(black) from the PC power supply to supply the power to the board. I have taken a 12V output(yellow) and a 0V output(black) from the PC power supply to power the board. As I say without having driver board connected I get 5V and 0V as outputs from Mach 3. Once I connect driver board I get 1.8V and 0V as outputs when x is Jogged..Enable into driver board is empty, jumper J6 is in the enable position and the board is set up for microstepping. Now I could get my hands on another stepper motor and another power supply and eliminate the problem. Maybe I'll try that if I don't get any better ideas.

Thanks for your fast response.

Ronan

I would try a seperate 5v power supply for the breakout board.
See if you have an old wall wart power supply left over from some discarded rechageable tool or something. Verify that it puts out 5v and try that.

These are just some of the problems you get when using no name components.
If this was from candcnc or cnc4pc, you could call one of these guys up and have had it runing already.
If you are geting 5v and 0v on the direction pin when jogging one way and then the other, without the driver board attached and much lower with it connected, something is drawing too much power for the breakout board. The stepper motor really wont have anything to do with it.

You canalso try hooking up just the driver board without the motor connected, this will take the stepper out of the equation.

Mike

MonoNeuron
10-29-2008, 07:25 PM
Some of the newer power supplies need to sense something on the motherboard for them to work and supply the full 12 volts (or maybe 5 volts). I am not an electronics wiz but someone told me that a few years ago and I have a lot of old PS's that are about 8-10 years old that work fine for me. Try another supply.

In your drawing you don't show the GND being connected up from your drive to the breakout board but you mention you do in your post (next to pin 17) so that should be fine. There isn't very many GND's on the board for the pins so all your GND's will be going to only a couple of terminals which doesn't leave much room for them.

I use the old C10 breakout boards from CNC4PC, $25, which have a GND next to every pin which makes it so much easier and neater and you don't have to cram in 8 wires into a very small terminal block.
I don't know why the board developers do this?????
If you blow up the buffer chips on the board then Arturo can send new ones for about $4. It's a no-brainer.

Change to another parallel port cable and rule that out ( I have found the cheap ones to be the best. Go figure! )

Make sure pin 10 is shorted to the GND (for the emergency stop in Mach3)
or just set the port to 0 (zero) for pin 10 in Mach3 software and it won't try to detect the signal.

Check you parallel port is set to the right setting.
Go to Control panel, System, Hardware, Device manager and click on Ports, printer port (or the card you have in the PCI slot) then click on Resources tab and read/write down the first Hex number in the list and that is your port setting you type in Mach3 port settings tab in the pin set up menu.

Oh, You have been to the Mach3 web site and watched or downloaded the tutorials on how to set it up.......haven't you! This will be very beneficial.

http://www.machsupport.com/videos.php

Change only 1 port at a time or you will get confused and not know where you are at.
Try setting step to high or low and the same for dir to see if it changes.

Check the wires on your motor again and make sure with an Ohm meter you get continuity from the same coils. (with the motor disconnected from the board)

Not much else I can think of to help now so all I can do is keep my fingers X'd for you and hope you get it sorted
Richard.

MonoNeuron
10-29-2008, 08:48 PM
Double post. I will try to erase it.

Torchhead
10-30-2008, 03:20 PM
It would appear from just looking at the card that both the inputs and outputs are BOTH opto isolated. If that is the case than the outputs are basically open collector transistors. Depending on the Motor Drivers the inputs may or may not have a source of current (pull-ups). It's also possible the outputs are pulled up to separate supply at the breakout card and if you don't have it hooked up there will be no current drive.

I counted 17 optos on the card and that is more than all of the possible inputs even using it as a Port2 card (mostly inputs). On a Port1 card you only have 5 inputs that need opto isolation. All the others are outputs in MACH.

The provider of the card should be able to answer simple hookup questions. The instruction manual should be clear about the nature of the outputs and inputs. If all you got was a picture (the PDF from their website) then you may have a long learning curve.

I went to the web site (MDFly.com) and recognized it. The wording and lack of any manuals (and low pricing) indicates to me the source of all the wiz-bang electronics is China even though their EBAY address is in the US. I was doing some design work with RFID stuff and they came up in a search. In the end I hesitated buying from a vendor named : My Dream Fly.:eek:

TOM CAUDLE
www.CandCNC.com

rgillard
10-31-2008, 09:41 AM
Last night i decided to hook up to the driver board with manual inputs. So I used a wall wart to supply 5V through a manual switch for the step and set the direction to 0V. When I powered it up, board getting 12V from the PC power supply and 5V signal from the wall wart, the motor started to move. It was kinda jumping around a bit and not moving in any particular order. When I turned off the 5V supply as the step the motor stopped.

I then hooked up to Mach 3 and the motor was still vibrating a bit. I sent it a setpoint and the motor actually moved.. I could not believe it..It actually moved quite smoothly, but when the software reached its setpoint the motor started to jump about again. I adjusted the VREF value which controls the current and the motor stopped moving but it also would not move with Mach3.I adjusted it again and got the motor moving but it was still moving under no signal. I was running other programs at the same time. Is this just noise causing this and can I stop it. Thanks everyone for your help so far...

MonoNeuron
10-31-2008, 05:44 PM
"When I turned off the 5V supply as the step the motor stopped."


The motor will run but you won't get good results. (as you found out) It's hard to tell without looking at what you have.

It may pay you to draw (or photograph) another diagram of what you have so we can tell exactly how you are hooking everything up.
Your getting closer though .........not long now.

I still think the breakout board is making things a little harder than they should be. Get another one, now! (so much easier and a hell of a lot less trouble. Cheap is not always better)

Get the C10 from CNC4PC $25

A few more days won't make any difference to you except you may still have some hair left.

Everything will become clearer when you finally figure it out and you will hook and unhook everything so many times you will be able to wire up a machine without looking at any manuals.
A picture is worth....... (you know the story)
Rich.

rgillard
11-19-2008, 06:42 PM
Hi Guys,

Thanks for all the help so far. I am starting to look into materials for my final table. I have been having fun playing with the stepper motors from the printers and now am looking to start buying materials.

One thing I was wondering is how straight the 80/20 aluminium lengths are. I was thinking of making a gantry similar to the Torchmate setup. Aluminium extrusion with a hiwin linear rail bolted to the t-slots.

I see that some people use steel lengths with machined surfaces to ensure the material is perfectly flat before bolting the hiwin rails on. I am going to make my gantry about 5 feet wide to accomodate a 4 foot wide sheet. Is one hiwin rail enough on its own to carry the torch/router...

Thanks,
Ronan

MonoNeuron
11-19-2008, 07:22 PM
Well done on getting the motors turning.
If you got to the 80-20 web site you will find all the info you need on what properties they have but to cut a long story short they will be straight enough for your application.
The guide rails will work far better if you have 2 of them in parallel. 1 each side for the Y axis and 2 far enough apart so they don't interfere with each other on the X axis. I have seen people put 2 rails about 1 1/2 feet apart on the x axis which is a waste of material and complete overkill for rigidity. I have mine about 4" (100mm) apart and they are fine. On their own they have a great deal of rigidity but you still get a very slight amount of flex through the mounting as well as the guides. In short......2 are better than 1.

Get yourself a set of cheap 'metal' electronic vernier callipers as they help a great deal in setting things up.

Set up the first one as close as possible to where you want it using a gage or verniers off the side etc. then when you make the Z backing plate, attach that to the fixed one and use it to align the next one then drill the holes or bolt in loosely until all are even, then tighten. This way they will both be parallel to each other.

Keep up the good work and don't forget to post pictures. More info is gained this way instead of writing and we can pick it to pieces....(just joking)
Rich.

rgillard
11-20-2008, 02:25 PM
The guide rails will work far better if you have 2 of them in parallel. 1 each side for the Y axis and 2 far enough apart so they don't interfere with each other on the X axis. I have seen people put 2 rails about 1 1/2 feet apart on the x axis which is a waste of material and complete overkill for rigidity. I have mine about 4" (100mm) apart and they are fine. On their own they have a great deal of rigidity but you still get a very slight amount of flex through the mounting as well as the guides. In short......2 are better than 1.

.

Hi Rich,

Are you talking about the rails or the trucks that run on the rails here?. Can you send me a link to your build thread (thats if you have one). My plan is to finalise the design by Christmas and then start buying gear in January. Hopefully by next summer I will have started to piece the jigsaw together.

Thanks,
Ronan

MonoNeuron
11-20-2008, 07:25 PM
I don't have a build log because I didn't have time to do one this time around but I did take a few pictures just in case someone wanted them and also as an archive next time I build one. It took me about 2 weeks to build and another 2 weeks to get the software sorted out but I am still having issues with Mach3 stopping in the middle of a cut and showing a reset state.

I was talking about the actual rails and not the trucks although you will still need 2 trucks per rail. It all adds up to a much stiffer setup.
The 50 x 100 x 4 mm steel rectangular section I used was only about 1-2 thou (0.002") out over the whole length so it was adequate for the job in hand and perfectly acceptable for a machine of this type and gives very good rigidity. I used to make everything out of aluminium but have found that it really doesn't matter for the weight, you just need strength and a slightly slower acceleration curve.
Rich.
P.S. I hope the pictures are big enough and you can see enough detail in them.

MonoNeuron
11-20-2008, 07:29 PM
I forgot.
I have gone away from the 3/4" 2 start thread and have installed a 12 start thread for the X axis. A whole lot faster on the rapids.
I will have to do a video of it soon and get it posted.
Rich.

MonoNeuron
11-20-2008, 07:37 PM
here are some more if you need them.
The motors are Vexta 5 Phase and the drives are UDX5114 bought from a chip manufacturing plant in Malaysia.
I like the 5 phase stuff as it gives you 500ppr in full step or 1000ppr in half step so it gives you a pretty good resolution and a very smooth drive.
Rich.