I'm looking for better software for my CNC laser and found linkmotion, is anyone using it here? http://www.solustan.com/index.php?curPage=linkmotion

I have Link Motion, this is good software and very easy for use

Got more of a chance to use it and so far I like it, I uses to use Mach to engrave but it would just punch holes in the material once it began a cut, because it does not modulate the power supply to the laser properly, but with linkmotion that is no longer a issue.

I noticed they can control Galil boards. What is the price of this software?

LinkMotion for CO2 laser machine. This 32 bit driver software works under Windows XP operating system. It will control your X and Y axis with step and direction commands, PWM power control for CO2 laser, red indicator diode control, cylindrical motion control, and will sense limit switches to position the beam at home position. This solution offers both vector and raster capabilities.
LinkMotion is a driver like a printer driver. You simply print your job to our driver from many of the popular applications. Almost no training is required if you are already familiar with one of these applications.
The price of LinkMotion is only $899 for vector output only version. LinkMotion with both vector and raster output is $1,299.
Volume discounts are available for system manufacturers and dealers/distributors.

Hi,

Is there a way to try this software? I would like to try it for impact engraving (if I can implement it based on laser engraving version) and laser engraving. I could not see any link for a demo/evaluation version. Any help really appreciated.

Thank you.

Zoltan

I noticed they can control Galil boards. What is the price of this software?

Dennis, the version of LinkMotion you want to order is LM400 for Galil boards. It is compatible with Galil controller DMC 2180. You need to make sure that you have the up-to-date version of the drivers. Version 7 or higher is just fine.

The price is $1,299 plus shipping and handling.

Solustan accepts most major credit cards. Currently, we do not accept PayPal payments. However, it is something we are looking into.

We will send you a number of PDF documents which will help you to understand the concept of "Printing" or creating Galil commands and send them to your board as soon as you click print from any of many compatible applications.

Thanks.

Dhiren Shah
Solustan, Inc.
www.solustan.com
www.LinkMotion.com

Hi,

Is there a way to try this software? I would like to try it for impact engraving (if I can implement it based on laser engraving version) and laser engraving. I could not see any link for a demo/evaluation version. Any help really appreciated.

Thank you.

Zoltan

Hello Zoltan,

We can provide you a pass word for downloading a demo copy of LinkMotion. It can be configured for rotary engraving or as you call it - impact engraving. We control,

X and Y axis for motion and
Z axis for,
- Motorized axis for Z up and down control
- Or, solenoid and air pressure control for Z up and down
- or, laser control for on and off

Also, we provide engraving fonts like 1 line, 2 line, 3 line, interlocking, Circle, etc. In all, we provide over 65 engraving fonts. You choose to use any TrueType font and in addiiton, you can use our specilaty engraving fonts. All of our engraving fonts are built with European accent marks for most European languages.

You can use Corel Draw, AutoCAD, AcceliCAD, DolphinCAD, Illustrator, ENgravelab, FlexiExpert, and others to design your job and simply, print your job to your engraving machine.

Please, let us have your E-Mail address and we will get you our demo software.

Thanks and regards.

Dhiren Shah
Solustan, Inc.
www.Solustan.com
www.LinkMotion.com

Hi Dhiren,

My address is vlaroliz@artelecom.net. I would like to try all versions:
X and Y axis for motion and Z axis for,
- Motorized axis for Z up and down control
- Or, solenoid and air pressure control for Z up and down
- or, laser control for on and off AND MODULATED
Still, I am not sure that I understood correctly. My understanding based on the above post is that LinkMotion is compatible with step/direction controller/driver, isn't it. Is your demo fully functional and just limited on time?

Thank you.

Zoltan

I'm using linkmotion on my new cnc laser which is servo.

Dhiren,

My email is (dizoita AT yahoo DOT com)

If possible I would also like to try the demo.

Thanks

Already information was sent to Zoltan. We will be sending it to DennisCNC soon. Both will be sent pass words to download demo version of the LinkMotion.

Thanks for your interest.

Dhiren Shah
Solustan, Inc.

Hi,

I got the information. I have downloaded demo Linkmotion. Thank you. I just did a fast read of pdf documents. It seems little bit complicated (for me). I did not instal the program yet. Could you tell me how I can setup the impact engraving? I mean to engrave a picture by impact with the command of power impact (solenoid Z). What is the limitation of demo version?
Thank you.

Zoltan

Hello Zoltan,

It is a driver and not an application. Once you get it to install properly, there is very little to learn here because you get to use your own favorite application. LinkMotion is compatible with many standard applications that you can use.

The demo is good for 30 to 40 jobs before it will stop sending jobs.

It appears that your machine has step motors in X and Y axis and an air controlled solenoid in the Z axis.

At the time of installing LinkMotion, and almost at the end of the installation, you will be asked to select your application.

Select Virtual Controller for engraving.
For choosing your machine, select one of the Newing Hall machines. These are automaticallt set for engraving with solenoid in the Z axis. You can change your resolutions in terms of microsteps and linear distance traveled per one revolution of the motor. There are other selections that you can check out in the LinkMotion applet.

You can address your three axis, solenoids, spindle motor, home switches, etc. from a parallel port. You may need a breakout board.

Attached is the information on the wiring of the parallel port.

Thanks and regards.

It took me a sec to figure out a few things myself, but follow the above pdf and it's a cinch, and it's amazing how well and smooth everything runs. Using link motion takes advantage of the full baud of your computer, not like other software that is limited to 45k mhz. When using it with a laser for engraving it modulates the laser perfectly, until now I was not able to do laser engraving as the other software could not ramp the laser power it would just turn it full on, making nothing but holes where the laser turned on.

with the Galil controller DMC 2180 can it do both vector and raster i know befor it was not able is it now ?

I have a modified shopbot using Mach 3 software. I need to replace this with some other software which supports laser operations. I have through of using the synrad laser units. please inform wether your software is compatible with synrad products. I have geared steppers on the machine. I need to Laser engrave on Granite slabs.

Dear Dhiren Shah

It will be appreciated if you send me the trial version of Linkmotion for Co2 lasers. Please let me know what is the problem with Galil boards for working in Raster mode ? Is it a limitation of Galil boards ?

Best Regards
M.J. Eshraghi

Solustan offers three different products for laser solutions.

1. LinkMotion LM300 Virtual Controller driver for laser machines using parallel port and XP operating system. All you need is a breakout board, motor drivers, and power supply to get your laser system going. If your laser system can handle PWM input for laser power control, we can provide PWM as a function of XY speed. The solution includes vector as well as raster processing capabilities.

2. LinkMotion LM400L for DeltaTau/Laser board for machines with step or servo motors. Use DeltaTau's PMAC boards with all the classic features of laser systems including PWM controls, vector and raster processing.

3. LinkMotion LM500 for Scanlab galvo control boards for CO2/Yag Galvo Control systems. This is a high speed marking system.

In all of the above cases, LinkMotion driver software allows you to process your jobs directly from popular software programs like Corel Draw. You do not need to learn another software program to conduct your business.

Please, visit the following web page to view our special pricing for a limited period of time:
www.solustan.com/specials

Now, Mr. M.J. Eshraghi, you asked about GALIL boards for laser control. We worked with Galil engineers and provided a specification covering both vector and raster processing including PWM capability for power control. In the opinin of Galil engineers, PWM and vector were not the problems. However, they thought that their boards would not be able to run more than 1.5 inch per second in the raster mode. We think that the typical requirement would be 20 to 40 inches per second. Yes, it is a limitation of processing power and memory available to store a couple of lines of information when a user plans to raster a line about 20 inches long and at a density of 500 to 600 DPI.

Solustan will send you a separate link to download the demo version of LinkMotion.

Thanks for your interest.

Dear Dhiren Shah
Thank you for your prompt reply.
I want to use Delta tau motion control boards, but they don't respond me about the price of their products. Could you please tell me which Delta tau boards is compatible with linkmotion driver. I'd like to use a standalone card. Is PMAC2 PCI lite (4 axis) compatible with Linkmotion. I want to use it for Co2 laser marking Machine.
I am outside of USA, Do you ship your products to Japan, United Arab Emirates(UAE) or Iran. Please inform me about different ways of paying money and shipment details.

Best regards
M.J. Eshraghi

Hi DS420,
I am interested in your product. Do you have demo software of link motion
to study before decision?

Dear Dhiren Shah,
Link motion is software driver which use with parallel port DB-25 pin or not?

Dear Dhiren Shah
Unfortunately my internet connection has time out when I wanted to download the demo version of Linkmotion for Co2 laser which you sent for me. Now I have a High speed internet connection, but when I click on the link It says that you had limited the download of the file. It will be appreciated if you send me another link to download it.

Best Regards
M.J. Eshraghi

No problem. Will send you another link for you to download. Remember, our demo program includes all different types of drivers we build for various boards and products. Please, make sure and install the right one for you to be able to look at and understand the features of the applet that comes with the driver.

Dear Dhiren Shah

Thank you for your previous prompt replies.
I want to buy Turbo PMAC Clipper which is a new product from deltatau. Can I use Linkmotion with this board ? Is Linkmotion Compatible with this board or I should use old boards like "PMAC2 PCI" ?


Regards
javad

I have been trying to get the LinkMotion to work for 4 days now. I have installed it on three different computers all of which will run it to a limited degree. The last one I attempted was a 3.3 Pentuim 4 with 1.5 GiG of RAM. The software often crashes when a job is sent. I have yet to get both Homing working at the same time. The signal is there for both axis but one axis blows right through it to the limit. I have spent well over 60 hours trying to debug this system and I don't consider it very reliable for the cost. I feel like I have waisted a lot of time and money. Mach3 works much better but does not have the PWM control for my laser.

Hello Stymee1961,

1. Would like to know more about the crashes you are experiencing. Please, provide us your phone number. We can call you Monday and work with you to understand and resolve your problems.

2. We can help you at the same time and work with you to resolve your issues for issuing home command successfully.

3. Once we resolve the issues, we can puiblish them here for the benefit of others.

Thanks.

DS420

I had a very bad experience with the company. Bought Linkmotion at a trade show was it assured it worked with XP. Got the ver. for WIN2000 or prior. The ver. for XP ended up being a beta ver. spent many hours on phone with tech. sppt. Eventually it worked, there's better out there.

MrBill

I tested the Demo. It works great.

Hey Kelinginc,

What kind of Laser are you using with this software?
Let me know about some details of your setup and settings.

Stymee1961, did you start to use the software already, did the problems solved?

lamicron,

Many problems still exist and it is not profitable for me to use it. The vendor pretty much left me to solve the problems myself. They told me an revision would be provided for the home orientation problem, but I have not received anything. The only time I seem to get any response from them is when my complaints get posted here, but that makes them very angry.

Dear DS420
Thank you very much
best regards
M.J. Eshraghi

Dear DS420A
Thank you very much
best regards
M.J. Eshraghi

Hello,

Does anyone out there have a zip file DEMO version of Link Motion that has the 30-40 cuts still operational?? Dhiren sent me a zip of 1.6 that he thought still had the demo cuts enabled, but it had been recompiled to eliminate the test cuts. I want to do some test cuts before I decide whether to but it or not. The current demo versions jog and all just fine, but won't cut. If anyone out there has an older demo that allows cuts, please contact me.

Thanks
Don

HI
this is the first time im posting on this Forum which i joined more than 2 years ago when i built my very first CNC machine which was a Hotwire cutter.

I used stepper motors which i scavenged from old floppy disk drives,and then i built an MM2001 interface which worked marvelously a year after i built it :) Anyway my machine worked really nicely and i was well chuffed with what i had created.considering i built most of it in my small bedroom.Okay enough about me

I would now like to build a CNC laser cutter.

I have read a couple of reviews of the Linkmotion driver/software.it looks great and im well keen on using that on my machine.the problem is i have no idea what controller i can use for a 3 axis laser cutter.

What kind of interface will work with LinkMotion.I preferably want circuit diagrams as i enjoy building circuits.I can etch large-ish PCBs and program PICs.

Thanks a stack for any advice.I got my Hotwire cutter working on my 18th birthday,i want to see if i can get a Laser cutter working by the time i turn 21 :P

Dean

Dear Sir
Please take care about choosing interface, At first you should confirm with linkmotion, then buy any board. I don't understand what do you mean by 3d laser cutter. The best offer of the linkmotion is the deltatau boards which can work in vector and raster mode, but you should be careful about selecting deltatau boards, because their software is not compatible with all of the deltatau boards.
galil boards work in Vector-mode only.
If you don't need high speed, and you can leave your computer until the job finishes, you can use virtual controller. the speed in this case is low, and if your computer hangs, your job may be could not continue.

regards
MJE

Thanks for your reply MJE

I mainly want to do Vector cutting,and im hoping that my computer will just be reliable enough not to hang.
what do you mean by virtual controller? can i build one easily?

All i said about the 3D cutter is that i have designed a 3D model in Auto cad of the table that i want to build.its going to be a normal table design,i just made up plans for using cheap simple rails,i will share the drawings when i have finished them :)

thanks
Dean

I think linkmotion for 3 or 4 axis machine can help you. but first I suggest you to read these files:
http://www.solustan.com/downloads/LkVCBro.pdf
http://www.solustan.com/downloads/LM&VC.pdf
http://www.solustan.com/downloads/FAQ.pdf
http://www.solustan.com/downloads/Virtual-MCB.pdf

In this file they described about virtual controller:
http://www.solustan.com/downloads/ParallelPort.pdf

I think you can easily made one.

You mean that your machine will be able to produce 3d mechanical parts ?
What kind of laser you are going to use? CO2 laser ?

Anyway, I strongly recommend you to going to this page:
http://www.solustan.com/about
and ask them directly about your special application. They will respond you (sometimes it takes more than one time, But finally they will answer) and give you information. because my information is based on their website and maybe is not complete.

Sincerely yours
M.J.E

Hi Guys,
I have Linkmotion and find that it does do a great job and modulates the beam very well but it still locks up the mouse sometimes after a raster cut. This may be about 1 in 10-15 times so it's not too much of a headache and I can restart my computer in about 1 minute or so.
My setup which works very well is as follows...

* 3GigHz Pentium 4 with 1 Gig Ram (Faster the better) Don't try anything under 2.5 GigHz as it's a waste of time.
* C10 breakout board from CNC4PC $25. Nice little board and simple to wire. Be careful with the breakout boards as I have 5 of them sitting here that were not suitable because Linkmotion is VERY specific on the pinouts ,especially pin 14 which is for the laser modulation, which cannot be changed and some boards convert the signal from 5 volts to 12 volts then back again which WILL NOT WORK for the laser set up. Get the C10 as its cheap and reliable and easy and Bob is a nice bloke to deal with.
* 3 Gecko 201's . I don't know about the Vampire drives but if you can afford them then get them as they are supposed to be unbreakable. With the 201's, if a wire on one of the motors breaks or falls off it will destroy the drive. Either way it will be a good setup. (or 3 SINGLE Xylotex drives which I find are very good as well. You need the single boards because of the pinout situation discussed before)
* build your own power supply for the drives. You only need a transformer, bridge rectifier, BIG Capacitor and some time. It's that simple.
Power for the laser is a different story......
* I bought a ULS 30 watt RF laser after a bad time I had with a Chinese made, USA bought, glass laser tube which turned out to be $800 worth of paper weight and then throw in another $800 for the power supply.
* Photocopier first surface mirrors are fine for the low powered lasers like mine. I just cut them into pieces about 20mm square and glued them on an Aluminum backing with Silastic
* Zinc Selenide lens for the optic with a focal length of 2.5 inches. Anywhere from 2" to 7" would be fine but you will have to build your table to suit the different length. Don't get Gallium Arsenide because it won't transfer the red pointer beam through it for spotting. That's if you are going to use a red pointer beam.
* Air assist is mandatory as you won't get more than 20" of cutting without clogging up the lens with sticky smoke residue. I use a high volume electromechanical Aquarium pump which are supposed to be reliable. You can use an air compressor if you want but I didn't like the extra power consumption and noise and it's cheaper with the aquarium pump.
* If you have a low power laser then don't worry about a Honeycomb table top as all it will do is allow air to get underneath the job and burn or char the edges. I used a normal flat piece of galvanized steel plate which works well and also is good with magnets to hold down the job. Martensitic Stainless steel is also good but expensive. Austenitic Stainless won't attract a magnet. My stainless steel top ended up costing $150 for 30"x50" with folded edges. Any cutting residue from paper or cardboard will just rub off with normal water and a cloth. I tried Turps, Metho etc when I first tried to clean the top and it wouldn't shift the residue then as a last resort I tried water and it turned out to be the best. just rubs straight off with ease.
That's all I can think of right now but feel free to ask any more ?'s
Rich.

Hi Rich

thanks alot for your reply.

I was hoping to find a circuit diagram for a breakout board that i could use for Linkmotion.I like to build circuits and things.Mainly to keep costs down,but if i can get one for around $50 (including shipping to South Africa) i will be pretty happy.
On my CNC foam cutter that i built a few years ago,they used very simple ULN2803 ICs to run the steppers,i think those are just darlington pairs in the chip.the motors i was using were very low current draw for amazing power.I am planning to use the same type of motors again for this project,i can maybe use similar type driver boards wired up to the Breakout board?


Power supplies are not a big deal (except as you say for the laser).I have some pretty neat power supplies already,probably the biggest one i have is 12v 14A DC supply,should be more than adiquate for running some fairly big motors.

Im sorry to hear about the bad time you had with your first laser tube.thats what i was planning to use on mine :( i did find one seller that had sold about 10 tubes and power supplies where the people had said in the feedback comments the Laser worked perfectly,so i figured he might be worth a try.What was the problem you had with your laser?

Im planning to use a 60Watt laser,would those photo copier mirrors still work for that? Could i use a flat steel cutting surface for that power laser?

And also i found some Focus lenses on ebay,they were 12mm diameter and had a 2.5inch focal lenth.In the diagrams on the page is shows using two lenses seperated by 2.5 x FL.is that true or can i get away with using only one lense? Ok i did also notice that they are Gallium Arsenide so they not much use to me as i want to use a red spotter. I have a green laser pointer,any ideas if that will pass through the lense?

Sorry about all the questions to the answers you gave me ;)

regards
Dean

I found this controller a few weeks ago.

http://www.instructables.com/id/Easy-to-build-CNC-Mill-Stepper-Motor-and-Driver-ci/?ALLSTEPS

Could anyone tell me if this would work with linkmotion or any other CNC laser software ou there? im expecting to have to modify things slightly,like maybe pin outs on the LPT plug.Other than that im hoping,as far as the design of the circuit is concerned,this will work to run the two motors i need for my cutter.

And since the software needs to control laser power,what else will i need to connect to the parallel port to facilitate this?

as always i appreciate any help or suggestions.

Dean

Hi Rich

**thanks a lot for your reply.
**What was the problem you had with your laser?

## I bought my laser tube first because I needed to know what the sizes were so I could build the machine to suit so I had it sitting in the box for about 8 months waiting to be put into use . This turned out to be the life expectancy of the tube and it had leaked, or whatever they do, and went from 30 watt to about 10 watt which was unusable for my application. Finish most of the table off first THEN buy the laser tube. Others here have had great success with their glass laser tubes and some are still going after 1.5 years. They are the lucky ones. I didn't want to buy another $800 paper weight so I went for the long life RF tube and haven't looked back. It should last my working life time. (I hope)

**Im planning to use a 60Watt laser,would those photo copier mirrors still work for that?

## You will have to try it out for yourself but my mirrors don't even heat up by any detectable degrees so I guess it may work. They are free so go ahead and try. What have you got to lose except your time.:)

**Could i use a flat steel cutting surface for that power laser?

## Yep. You need about 125 watts to cut very thin steel so 60 will be fine.

**And also i found some Focus lenses on ebay,they were 12mm diameter and had a 2.5inch focal length.In the diagrams on the page is shows using two lenses separated by 2.5 x FL.is that true or can i get away with using only one lens? Ok i did also notice that they are Gallium Arsenide so they not much use to me as i want to use a red spotter. I have a green laser pointer,any ideas if that will pass through the lense?

## same mob I bought the laser tube from and my GaAs lens. The 2 lenses together will NOT work as they say it will with the very fine beam and parallel kerf width. Go back to your basic schooling and you will see that its not possible. There are lens experimental web sites on the internet so you can do a search on Google for a bit more info if you so desire.

##I have no idea if it will pass a green laser through. You could always look up the wavelength and then cross reference it with the pass through wavelength of the ZnSe lens.

**Sorry about all the questions to the answers you gave me ;)

## No probs. That's why your here and thats why I answered. I am not a laser professional,I work as a mechanic, but I have gained a fare bit of info on what to use and what not to use after 3 wood routers and 1 laser cutter.

regards
Dean


Warm regards
Richard

I found this controller a few weeks ago.

http://www.instructables.com/id/Easy-to-build-CNC-Mill-Stepper-Motor-and-Driver-ci/?ALLSTEPS

Could anyone tell me if this would work with linkmotion or any other CNC laser software out there?

And since the software needs to control laser power,what else will i need to connect to the parallel port to facilitate this?

as always i appreciate any help or suggestions.

Dean

The Linkmotion software acts as a driver so it should work because all you are doing is transmitting pulses from the software to the drive.
This type of drive is only full wave drive so don't expect it to be very smooth. It will also be noisy due to the large steps. If you can afford it go with the micro stepping drives. I went down the path of full step drives first off and couldn't wait to get rid of them after seeing how a micro stepping one worked. Now I won't go back and I am now using 5 phase drives which are even more smooth than the 2 or 4 phase ones (but expensive)
If you like building circuits then by all means build one. If you want a usable high speed laser then buy the drives as in the long run you will want them anyway and you won't have wasted your time or money on other stuff. I have about $3000 worth of experimental drives, motors and crap laying around all over the place that I can't use because I didn't know what I wanted in the first place. THEN I FOUND CNCZONE.
Remember, you are building a laser cutter, probably the pinnacle of homemade machine building so get some good stuff to go with it even if it takes you a few more months to save up.
The things I have outlined WILL get you up and running with the minimum of fuss and it will be cheap in the long run.

Pin 14 is picked up from the breakout board, as discussed earlier, for the PWM of the laser modulation and is connected to the modulation input on the laser power supply.

Rich.

Hi Rich

Oh dear,i dont like the sound of that less than a year life expectancy.i wonder if it maybe had something to do with it not being used? or if it was faulty from the start.

i was just wondering with the flat steel bed,would it not reflect the laser and start melting things like Depron from underneath?

When i saw that diagram with the two focus lenses i thought there was something wrong there,i have had no experience with lenses and such but had my doubts about getting a longer straighter beam.

As for the mirrors tho,since i dont have any old photo copy machines i will just buy some of those gold ones off ebay,they not too expensive.

I wanted to google the green laser thing today but i completely forgot.

I build concert stages for a living (going to Saudi Arabia on monday actually) all the guys i work with think im nuts because of my apparently Bizarre interests.i go kite boarding,fly rc planes and helicopters,work on cars and will generally have a go at fixing anything :)

Cheers
Dean

Hi Rich

Thats a good point,my foam cutter was very rough at first,i had to spend quite a bit of time setting up the time between pulses to get it to run smoothly-ish.

As you say this is the pinnacle in home built machines,do it properly the first time or its just gonna be one of those things that frustrates you to the point you have lost interest in by the time you finish it,or you just never finish it and end up with a very very expensive dust collector.

while im at it i might aswell get two new motors aswell,i only need two gecko drives,for some reason i had 3 stuck in my mind.Any suggestions on motors? im still working on the drawings for my table,so far its looking light,yet strong.

I will post some screen shots of my design when i have completed them.So far im going to be running on chrome pipes normally used for towel rails,two on each X-Axis and two on the Y-Axis.i have 3 roller blade bearings running on each pipe,one of which is on the bottom to stop things de-railing.No uneccessary friction and no chance of things binding.

Laters
Dean

Ha ha ha ha ha.
That's funny because all the blokes at work here think I am an eccentric because I dabble in these things but I think they were eating their words when the laser was finally up and running and producing parts for my lovie's shop. They are saying the same things now with the plasm cutter I am building. I suppose it's in their nature. :-):)
I wouldn't ever put myself in the category of the famous inventors because I am just a hack but I suppose they went through the same thing with the general population. We could always spend all of our lives and money in the pub and be labeled "normal" and die at age 53. That sounds like fun..........but not to me because I want to leave a legacy to the kids when I die or to someone who will appreciate the effort put in not to mention the gooey happy feeling I get in my guts when something incredible works out.

Now, back to the question.
When the laser strikes the bed it is dispersed because the bed isn't very reflective (unless your crazy and have polished it). A certain amount will be reflected back but the beam wouldn't be the same width as the incoming beam due to the dispersion. It's the inverse law coming into play. Light power is directly proportional to the inverse square of the distance (or something like that)

Try and get mirrors that are bigger than 15mm or 5/8" because it will make laser alignment SO much easier. I started out with 10mm gold mirrors and have a lot of burnt shirt sleeves to prove how hard they are to align and to keep there. That is why I ended up using the mirrors from a Photocopier because they were free and I could make them the size I wanted. Bigger is better and 20mm would be ideal. It gives you some latitude.
Rich.

At a later time I will take some closeup photos of my set up which runs on 1" square tubing, 4mm thick, set at 45 deg angle. I thought I needed a roller underneath to hold the gantry down but found out I don't. The whole gantry is just sitting on top of the rails and has enough weight to not jump off and is driven with toothed belts. Have a look at my setup on youtube and although it looks very complicated at first, it isn't. It's actually very basic.

YouTube - Home Built laser

My wiring looks like 2 octopus's fighting but it works and I haven't had any trouble with it after the 6th time I rewired everything due to problems with software and drivers and computers. 8 months of trouble shooting later I got it to work. Never thought I would.

I have a build log here as well with some info you may want to read.
Use what works for you and what you can get but make sure you aren't wasting your money on rubbish.

http://www.cnczone.com/forums/showthread.php?t=33485

You may not like what I have built but you should be able to get some ideas from it.
Rich.

According to these guys im a freak of nature,i dont smoke,drink or behave like a rabbit.

There is nothing quite like that warm fuzzy feeling when you have just created something amazing.Thats another reason i like to also build as much of what ever im working on.that way i really feel like i have achieved something.And not have someone come along and say Oh all you did was put together a bunch of stuff someone else designed.

I think the mirrors i found on Ebay are 1inch diameter,those should work ok.

Im just watching the videos on youtube of your setup,its very nice,i actually found that a while back i just didnt realise it was yours.
Now that you mention it maybe using aluminium angle laid down on the open end would give me the same effect as the square tube mounted at 45 degrees.I may go down that route,just depends on what I can get hold of first,the chrome pipe or the Aluminium angle.The more i think about it the Ali angle is the better way to go,i save two bearings and the contruction (looking at the fuzzy picture in my mind) seems more simple.i will do two drawings,one of my current idea and one of the new idea.

I used a similar setup with my foam cutter,two lengths open side up withe the bearings running inside that.only thing was i used threaded rod,so i was limited to 950mm travel due the the length of threaded rod that was available.It also slowed things down,but that thing was strong :P
I want to use toothed belts tho for my laser,where did you get yours?

i should make my own thread for my build,since we not just talking about linkmotion anymore...I will figure it out in the morning/later.its bed time now :-z

We all have our own ideas,and these forums are great ways to get inspiration to improve on our ideas.The more people that build these machines the easier it becomes for the next person.I can see already that its probably easier for me than it was for you,since you just gave me all the information which you probably had to search for everywhere.

thanks
Dean

I just finished a video of the differences between a table top with a flat steel plate and one with the honeycomb top.
Here is the link.
http://www.youtube.com/watch?v=Pfp9NAaI8rU
This is for a low powered laser and probably wouldn't make much difference to a high powered one, say, 60 watt and above.
It all depends on the thickness of the material you are cutting so the slower you go the more chance of the gases combusting.
Rich.