Need Help!- Supported rail linear shafting....

[toofdecay]

Anyone know of a supplier that will sell them in custom lengths???

Ive been lurking here for a long, long time - I am on the last leg of pretty cool project, but cannot find anyone who sells 16mm/.625in supported linear rail cut to length.

I do not have the means to cut standard lengths down at this time.

Any help would be greatly appreciated.

[Walky]

This guy can sell you custom lengths if you contact him directly:

eBay My World - linearmotionbearings2008

Just don't expect the lengths to be perfect (might be a few mm off), but that's usually not such a big deal for supported rails. BTW, the holes in the aluminum supports he sells are hand made (in case you're expecting them to be exactly spaced).

[toofdecay]

anyone in the US bought from these guys? Any problems with shipping and what not? I wonder if these are hardened or plated or anything...

[Walky]

Yeah, those are hardened rails, I don't know the details but I guess they're chrome plated (I'm not an expert regarding different types of rails, so I don't really know if there are non-chrome linear rails). If you ask him he'll probably be able to tell you the exact thickness of the chrome. I've been using those 16mm supported rails for over a year on my main machine and they still look like new.

This guy (his name is Chai) is probably the most well known chinese seller around CNCZone, I'm sure some other customers will show up in this topic (and you can search the forum for more feedback about him anyway).

[toofdecay]

hey thanks, Ive been searching, he seems to have a good reputation.

[sirkossorg]

I ended up paying more than I expected because Customs flagged my order. Even with the additional tax (he declared the items had no value to Customs), I felt like I got a good deal, and Chai was good to deal with on my order.

[toofdecay]

Just as an aside....


This was such an easy transaction, it almost hurt my feelings.

Good quality linear shafting cut at custom length, delivered to my front door (FROM FREAKING CHINA!!!!) in 6 days. (CHINA!) Wow. What is happening to this country.... Ive been trying to get this same product locally from several industrial distributors (not to call anyone out but I live in Wichita, KS) only to be laughed at, not taken seriously, quoted rediculously high prices or given blank stares and shrugged shoulders.

Screw that nonsense, Ill have no further qualms buying from Mr. Chai. The ballscrews that he lists on eBay are becoming more and more tempting.....

This is the best forum on the net. Period. Good people, no trolling, everyone helps each other out. What is most incredible to me, is that this is probably the highest concentration of intelligent people that youll ever run across, and no one knows it! (except for us!) That in itself is the best part!

BTW - Ill be posting a really interesting (to me anyways) build thread shortly involving a Bridgeport Tru-Trace/DIY XY table/DIY quill z-axis hybrid monster conflaguration of epic proportions. BOLO.

[Ski Builder]

I do wonder about the tolerances of this rail and if I can use it in my design.
Those of you that have ordered from him was there play or slop in the rail/bearing interface?
I want to use it for my main length linear rail for an 8 ft span. I also would like to use it 90 degrees to how it pictured for sale. Is this a bad idea to support a 2.5ft AL gantry structure for a router?
I guess it depends on weight.

[Walky]

Originally Posted by Ski Builder I do wonder about the tolerances of this rail and if I can use it in my design. Those of you that have ordered from him was there play or slop in the rail/bearing interface? I want to use it for my main length linear rail for an 8 ft span. I also would like to use it 90 degrees to how it pictured for sale. Is this a bad idea to support a 2.5ft AL gantry structure for a router? I guess it depends on weight.

The open bearing blocks are adjustable by a set screw (sometimes they have two of them) so there's usually not noticeable play as long as you use at least two blocks per rail.

I use them at 90º and it works great:

CNC jogging - YouTube

CNC jogging - YouTube

Those are 16mm supported rails (the gantry is about 1 meter long and full aluminum).

I don't recommend going with 12mm rails, they are not as accurate as the 16mm ones. I haven't tried 20mm and more so I have no idea if they are even better than 16mm, but for most applications this should be enough (I've even cut aluminum with them on my machine).

It's usually a good idea to replace the bolts that join the rails to the aluminum supports, since some of them might be stripped on arrival (maybe they are tightened too much on assembly). I think they are M6 bolts for the 16mm rails. It's not a big deal and only takes a few minutes to do so.

[Ski Builder]

wow Walky that is awesome. Thanks for the quick reply.
Curious what rails you have in the gantry tough to tell from that pic. Do you have build thread on that thing? same type from Mr chai?

Im new here and trying to research and get a realistic budget together. I know its expensive.
That looks like a similar idea to what I have in mind.
Steel frame and AL gantry and steppers?
I was going to go rack and pinion for the lengthwise,(X?) but that single acme screw looks good to me and its one less motor.
Just some steel angle under the gantry?
thanks

[Walky]

Sorry, I don't have a build thread on that one. All of the rails I buy are from Chai, can't beat the price really. All three axis on that machine are supported and 16mm.

I didn't use ACME screws, I used 16mm ballscrews with a 10mm lead for X and Y, and for the Z I used 3/8" all-thread with two DumpsterCNC AB nuts placed back to back.

The steel angle under my gantry is a piece I found at a scrapyard that just happened to be about the right length.

I've seen some double X screw setups where a central motor moves both screws by using a timing belt and pulleys.

For a really long X axis I'd definitelly go with rack and pinion if possible, to prevent screw whipping.

Double X screws (or R&P) prevent side play, which might or might not be an issue depending on the machine's design and what you expect from it.

[Ski Builder]

Great. Now im looking at motors and drivers and i see these chinese packages for 3 or 4 nema 23 with drivers and breakout board in the 425oz? Size for like 150. I am reading here as much as i can but what size motors do i need for this type of build? I also assume not all motors and drivers are created equal i thought i was looking at 150 a driver for the ghecko ones. Still unsure about allot of these terms and devices so i am anxious to get stated but i need a budget so i have an idea when i may be able to use this thing. Thanks.