Quote Originally Posted by MartinS View Post
You're planning to beef up the side rails, add the bed whilst you're at it.

Much advice has already been given to you and there is sooo much more on this site from some VERY talented, knowledgeable and experienced people :

http://www.mycncuk.com/forums/253-DIY-Router-Build-Logs

Don't get too hung up on the design of CMM's.

Time you put a new blade in your hacksaw!
I have to completely agree, without all the advice from the people here I would not even have remotely come this far!

Currently I am reading through some of those build logs to hopefully find a good one about the PSU section of the build. All the electronics are pretty clear to me, but the interface between machine voltage and net voltage. I see that a lot of people build their own transformers, which is definitely an option, but I am still looking into that. Most of what I am still missing on the machine side mostly related to the spindles and which I want to have in hand, before commiting there.

If all goes to plan, I thus want to sort out the electronics over the next two weeks and then move on to buying parts. That is when I want to make a final pass and move on to the next step, if there is not a flaw that needs sorting out. Once I do move on to buying, I will probably make a proper build-log post as well.

I am also scouring the posts for something related to cutting forces and speeds, to be able to dimension the steppers. As far as I could gather from various posts here, I would pretty much always like to use the steppers in bipolar parallel connection, and using that, getting all the info and all the steppers I can find, I have not found a single one, so far, capable of driving two 2510 ballscrews at 7.5mm/s rapids... who would have thought? :D So I am thinking about moving to a one-stepper-per-screw setup. With that, however, I am still looking at one of AndyUK's first pieces of advice to me and hesitating. So I am thinking about putting a timing belt between the two motors to synchronize them as well, but I don't know if that is a good idea or if it even works. Looking at the motor calc sheet, however, there is a motor that would permit me to get 6.1m/s rapids with only a single motor, as well as letting me cut at 2.1m/s with 50N of cutting forces. But then again, I am still searching for posts on speeds to look out for.