What do you think of LinkMotion?

[mj_eshraghi]

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

[Dean12369]

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

[mj_eshraghi]

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

[MonoNeuron]

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.

[Dean12369]

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

[Dean12369]

I found this controller a few weeks ago.

http://www.instructables.com/id/Easy...r-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

[MonoNeuron]

Originally Posted by Dean12369 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

[MonoNeuron]

Originally Posted by Dean12369 I found this controller a few weeks ago. http://www.instructables.com/id/Easy...r-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.

[Dean12369]

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

[Dean12369]

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

[MonoNeuron]

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.

[MonoNeuron]

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

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.