[SScnc]

I'm designing a new CNC router and need some advice please.

1( where is a good place to buy linear rails ?

2( I need the X rails to be 100 inches, can/should these be purchased full length or can these be "butted" together for longer runs ?

3( can these be mounted upside down or sideways or do they need to be oriented as shown in the picture ?

Thanks,

Steve

[OCNC]

The first question is always 'How much money do you want to spend?"

[mactec54]

SScnc

The linear rails in the photo can be oriented any way you want, But like they are in the photo is the highest load carrying position

Buy them in one piece, trying to line them up would not be fun

There are many places to buy them PBX is one but look for the best price, they are all much the same quality

[SScnc]

The first question is always 'How much money do you want to spend?"

The least I can and get the job done

SScnc

The linear rails in the photo can be oriented any way you want, But like they are in the photo is the highest load carrying position

Buy them in one piece, trying to line them up would not be fun

There are many places to buy them PBX is one but look for the best price, they are all much the same quality

Okay thanks, I'll continue to look around. It seems like there was an ebay seller "linearmotion2008" I think but haven't found him yet. The reason for asking about the orientation is my concern of debri getting on them. On my home built version I have brushes on the trucks to clean the debri, is that required with the blocks that run on these ?

Also, is 16mm diameter sufficient for a 100" run ? They will be mounted on 2 x 3 steel tube frames.

Thanks for the help !

[DonFrambach]

It seems like there was an ebay seller "linearmotion2008" I think but haven't found him yet.

Here's a link to "Linearmotion2008"'s store: items in linearmotionbearings store on eBay!

[SScnc]

Thanks Don, I was leaving the "bearings" part out of the name. I wrote to him asking about 100", 20mm sets so we'll see what kind of price comes back.

I just noticed a thread lower down about GMT rails so I looked them up HERE and I found a pair ~104" long incl. 6 blocks for only $300. That seems like a reasonable price to me (?)

Any thoughts or opinions anyone ?

[FandZ]

I would contact PBX and see how much they would charge for rails that fit your length requirements. For blocks, I saw some on eBay with both the top and side setscrew adjustments for 10 bucks shipped. Be sure to get the ones with the adjustments.

I ordered mine from glacern and am happy with my purchase but after seeing those blocks I think I may have been able to save a hundred or 2. Then again the cheaper rails seem to have different aluminum supports that are not as square and flat as the ones from glacern. Either way you go I'd get the 20mm rails.

[Walky]

Yeah, it will be better if you get at least SBR20, mainly because it will probably handle shipping better than SBR16. If you plan on using a single central screw to move the gantry, it might not be a bad idea to get 3 bearing blocks for each gantry side to help reduce racking.

You can use the rails like in the pictures or sideways, just don't use them upside down, there would be too much weight forcing the bearings open. The bearings have seals to protect from debris, but it helps to design the machine in a way that reduces the amount of stuff falling on the rails. That said, I must admit that I'm extremely irresponsible with my own machine, dust falls on the X axis SBR16 rails all the time and it's still going strong after a couple of years (I plan to fix this after a machine redesign, though).

[Walky]

I would contact PBX and see how much they would charge for rails that fit your length requirements. For blocks, I saw some on eBay with both the top and side setscrew adjustments for 10 bucks shipped. Be sure to get the ones with the adjustments.

I ordered mine from glacern and am happy with my purchase but after seeing those blocks I think I may have been able to save a hundred or 2. Then again the cheaper rails seem to have different aluminum supports that are not as square and flat as the ones from glacern. Either way you go I'd get the 20mm rails.

Getting them locally would be a good idea if you're willing to pay extra, especially for such long rails. I recently got a bent rail from China (It's happened to other people too, it's rare, but happens, it happened in my 7th or so purchase; hopefully I was sent a replacement free of charge). It's not a "factory bend", but rather most likely bad handling (looks like the aluminum support got hit with something hard somehow). I suspect Probotix's rails must be pretty much the same kind, maybe also from China, but I doubt they'll sell you defective rails (I've had an excellent experience with them when buying drivers, great support), so it might be a safer bet to do that and get only the bearing blocks from overseas.

[DonFrambach]

Thanks Don, I was leaving the "bearings" part out of the name. I wrote to him asking about 100", 20mm sets so we'll see what kind of price comes back.

I just noticed a thread lower down about GMT rails so I looked them up HERE and I found a pair ~104" long incl. 6 blocks for only $300. That seems like a reasonable price to me (?)

Any thoughts or opinions anyone ?

I bought a much small set of rails from Glacern. They have worked fine. In addition, the packaging was outstanding. Secure packaging will be essential for your very long rails!

[mmonti]

order from Glacern, they have a great prices on sets of 2, supported rails and bearings cheaper than anyone Ive found yet.