1. #1

    I just saw these 500mm racks on rs-online. It's hard sourcing longish rails here in my country so I'm thinking of butting 3 of these for my Cnc machine. Will it work? Also I saw some delrin racks, will these work for a cnc router?

    ^Thanks a lot.


  2. got a link?

  3. #3
    I was looking around for Rack and Pinion the other day, and the longest available seems to be 2 metres long.
    I would use a full length if you only need 1500mm
    Delrin Racks would wear out pretty fast on a CNC Router I would imagine.


  4. #4
    Shouldn't be a problem the rack on my lathe is made up of 6 or so 100mm sections, (don't know why) the ends have been perfectly cut and then they have also been dowel in place as well as the screws.

    Alternatively you could leave a small gap between the racks (gear teeth will push against the sides not the trough) and use a short piece placed on top (upside down) to set the correct distance (add a bit of epoxy or tread lock if you are worried.)

  5. Try WMH Transmissions This is where i got my Linear guides and bearings from.. excellent service and next day delivery to! Based in Tamworth

  6. Bet they won't do next day to the Phillipines tho!

  7. I would for 7000 :D

  8. #8
    Thanks for all your answers guys,

    Here's a link. They don't have the actual pictures so I'm not sure if ross77's suggestion will work.

    lol Thanks for offering to send them here, adCNC.

    I guess I have to search harder. If I can't find them here, there's always mcmaster-carr in the US, but it's gonna be a whole lot harder on the wallet.

  9. Since RS dont manufacture anything, there must be someone else stocks the same part... 5min with Google finds http://www.qtcgears.com/RFQ/default....les/khk144.htm Look at SR2-500 third section down, identical spec with DXF/PDF/DWG files. These are not 'machined ends' (thats elsewhere in the catalog) so i suspect these don't butt, you will have to machine the ends. Indeed you can tell this from the measurements. Circular pitch = Module * pi = 2 * 3.1416 = 6.2832mm so 80 teeth would be 80 * 6.2832 = 502.656mm which is the length of the 'machined ends' version. These have a length of 505mm!

  10. #10
    Here's a link. They don't have the actual pictures so I'm not sure if ross77's suggestion will work.
    Sure it will just get the angle grinder out, or better still bench grinder, and shorten to the right length. dosnt matter if you go a bit over just leave a coresponding gap.

    Click image for larger version. 

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    This is from a stair lift, not really precision kit, but you get the idea.

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