Quote Originally Posted by Jonathan View Post
Have you bought the ballscrews yet and/or decided how to drive the longest axis as I remember discussing it in a previous thread?

Are you going to add some pieces of box section in at 45 degrees at the front and back of the frame to make it stronger and stop it turning into a parallelepiped under high acceleration? I'd also add at least one vertical support in the middle, assuming you're planning on cutting aluminium as otherwise it wont make a tangible difference. Looks like a strong base otherwise.

How are you mounting the 2100mm rails such that they are not bent beyond tolerances? The rails I have for my machine are 2200mm so I've been planning on using self levelling epoxy to get the required accuracy.

There's some good stuff in that eBay link, however the price he says he paid for the spindle implies he got the parts from England not China, so he'll be expecting closer to England prices...

Anyway, to answer the question, you'll struggle to find the longest rails on eBay for a reasonable price, but it shouldn't be difficult to find a good deal on the 400mm rails. Clearly search for worldwide listings. 15mm rails will be fine, just make sure you get ones which have 4 rows of balls not 2.

As usual Jonathan, all the right questions, firstly i will be using rotating ballnuts rather than rotating ballscrews and these will provided by YOU when the time comes as discussed previously,and the frame its self will have the advantage of a welded steel box 100mm deep 2mm thick to contain water, and re-inforced with 50mmX50mm angle iron every 18", this will be for the plasma cutter, this also when used as a router will have a removable bed made from tig'ed 40mmX40mm extruded aluminium profile, the gantry will be reinforced with 3mm steel along its complete length at the rear of the two 100mmx50mmx3mm gantry parallels although this is overkill by any streach of the imagination, and certainly stronger than the usual aluminium profile used to build this type of machine, including the last one of this size i made from aluminium, which did the job perfectly. But what i was really looking for was prices for the rails not advice on the build as the question would indicate.
the problem with importing rails, is the length, is a problem as stated by the overseas suppliers i have contacted.

Rick