1200mmX900mmX170mm 4axis cnc

[Zeeflyboy]

I am thinking to make the base of X axe support plate 300mm, is it ok or too much?
I quess that to find the length of the ballscrew for x axis etc, I have to substract the legth of baseplate from the legth of the rail,right?

So 1200mm for Xaxis subtract 300 =900mm for balscrew plus f plus space for the end support bearings bk and bf.

300mm is more than enough.

Yes, although there is no real harm in having a slightly longer ball screw travel than the machine travel of course if it helps you in locating motors/bearing mounts. The only downside is possibly slightly more expense and a slightly lower critical speed if you get a screw longer than needed.

I was very happy with the TBI and HIWIN stuff I got from aliexpress, all machined to my own specs. Haven't used it in anger yet of course so can't fully comment but quality appears top notch, was most impressed with the ballscrew machining as it was done to an impeccable standard. The seller was this guy https://www.aliexpress.com/store/278...4b24ae2bMdgpHS although you just want to email them for a full quote rather than buy the individual parts from the store. I dealt with a guy called "John" (I doubt it lol) who was very helpful... his email was just john "at" topper-hz.com and you then pay through a special order on aliexpress so you benefit from the payment protections there.

Worth a quote perhaps. They do all the c3/c5 ground or c7 rolled.. just ask for what you need. They offer their own brand stuff too which is much cheaper but I can't comment on the quality too much... I got a couple of small c5 12mm ground ball screws and they seem ok. Not as smooth as the TBI stuff out of the box but I haven't really looked any closer at them yet as they are for a future project.

Shipping is always going to a be a bit expensive when you are shipping a lot of heavy and large items half way around the world, but if the price is good enough to begin with then that's the trade off! Shipping for me (4 x 16mm screws, 2 x 12mm screws, 2 big 25mm rails, some 20mm rails, lots of carriages and motor mounts, bearing mounts etc came to about $240 via fedex.