the reason i am looking at this controller is that i have read that it is quite easy to blow a stepper driver, particularly when you dont know what you are doing. with this board that only means you need the driver board and not the whole thing as is the case with single board units.

power supply wont be a problem. like you said, will just keep an eye on the bay from now on for a deal.

with regards to the linear stuff i have come to the realisation that this will not be my last cnc machine. what seems to be the norm here is that you build your first machine and use that to build your second. i know my linear idea is tricky and will take some time to get right but i have lots of time now and i do have lots of patience to get it right. also i am pretty handy with the table saw and router. when i get it modeled i will post some pics for feedback.

i like that TR12x3. the price aint bad either, i might just go for that. it seems i will have to get the ends turned down to fit bearings and coupler. i will have to find someone local to get that done, might know a guy.

i had a good look around the dryline site but i cant decide which size rails and bearings i need. guess thats just my lack of mechanical training.

with reagards to 2e0poz points i do see the logic in buying the propper stuff and under normal circumstances (have a job) i would definatly just spend the £500 on linear bearings and be done with it but i really dont have the cash at the moment. that might change in the future but for now this idea of mine wont cost much to try. i already have mdf and i have a load of ball bearings which might do the job, all i need is some alu angle and a lot of time (being unemployed, time is not a problem). i am not sure i know what you mean about mounts, could you elaborate?

the reason for not doing any construction right now is there is no point in cutting a load of mdf only to find the design change and stuff going in the bin. in my mind its better to just get the design finalised and then as 2oepoz says, you get it made in less than a week.

i can see the advantages of propper linear bearings but i just cant afford them at the moment plus i am not convinced they would really make that much difference to my machine given i will just be cutting mdf or ply. assuming i can get my the home made linear tight engouh and pay close attention to minimising chassis flex i think it will work out fine.

like i said this is my first machine and it will have specific uses. no doubt i will make another more elaborate one soon after this is completed and if i have a job at that time i will put all the propper stuff into it.

thanks for all the advice guys even if i dont take all of it, its just a budget thing. i am getting pretty excited about all this, keep having ideas flying around my head. cant imagine what i will be like the day i fire her up