Hi,
I had determined that I wanted C5 ballscrews or better when I designed and built my mill, but there is no way I can afford genuine
ground C5's....so I bought second hand. The problem with second hand is that you can't always get exactly what you want, so you have to make
your machine fit to what you can get.
I'd have to recommend getting the ballscrews and linear rails BEFORE designing and building the frame, otherwise you'll find that you have to pay
a big premium to get parts to fit your machine, when if you'd made your machine 50mm smaller (or bigger) you could have gotten such and such ballscrews for
1/4 the price.
I have made many purchases from this company:
https://www.ebay.com/str/industrialpartsshop?_trkparms=folent%3Aindustrialpartsshop%7Cfolenttp%3A1&_trksid=p3542580.m47492.l74602For the same money you would pay for new C7's you might find second hand or new old stock C5's or C3's.
I have three THK 32mm diameter, 5mm pitch, 650mm long, double nut (BNFN) C5's that I got from this company, and cost $1000USD including shipping to New Zealand.
They look like new old stock to me. I don't think they'd ever been used. I could be mistaken about that, but whatever they are in perfect condition for my machine.
I would expect to pay $2000 each new, and that's just the ballscrew, and does not count the BK25 support bearings which would easily be another $500 a pair.
I would say I got $7500USD worth of products for $1000USD, and that is quite a saving and allowed me to build a much better machine than I could otherwise
have afforded. Funnily enough I didn't have to pay GST on those either!
I got new old stock 20mm THK linear rails (648mm) and HSR cars from the same company for $700USD including shipping, and that's for three sets, ie six rails
and 12 cars. A big saving on new, not quite as dramatic as the ballscrews, but certainly made it possible to build a nice machine for the money I had. I didn't pay
GST on those either!
You may detect that I take some delight in avoiding the 15% GST that is occasioned on all products entering New Zealand, and shame to say it, it's true.
Mostly however I do pay. For instance, now if you buy off Ebay the 15% GST is automatically collected and forwarded to the NZ government by Ebay.
Most other products where the supplier does not lie about the true value of the products then customs comes after me for the GST. My favored means of getting
stuff from the US is to use a freight service offered by NZPost. I effectively have an address in Portland Oregon, and have a US supplier send it there, no trouble.
US post is good within the US just crap outside the US. Then NZPost handle the international shipping which includes me paying the required GST. So its not so much
that I don't pay GST but I look for a discount where I can get it
To reiterate I would get the ballscrews and linear rails BEFORE building the machine. If you are patient and troll through EBay you'll pick up some bargains that will
mean a much better machine than the cost would suggest.
Craig