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  1. #1
    Join Date
    May 2011
    Posts
    212

    Rails placement for X-axis

    I recently started my build and I'm about to start drilling holes for the rails on the base for the x-axis.

    Would I want to place the rail high up, or lower down on the aluminium bar with regards to sideway forces on the gantry?

    See the attached pic. (Text is in Norwegian, but you'll get the idea)
    Attached Thumbnails Attached Thumbnails rails.jpg  

  2. #2
    Join Date
    Aug 2008
    Posts
    409
    higher is better if it means your gantry uprights will be shorter.

  3. #3
    Join Date
    May 2011
    Posts
    212
    Quote Originally Posted by Phife View Post
    higher is better if it means your gantry uprights will be shorter.
    The rails is not going to affect the height of the uprights. There is going to be a flat bar running underneath the base as a part of the gantry.
    Attached Thumbnails Attached Thumbnails high.jpg   low.jpg  

  4. #4
    Join Date
    Aug 2008
    Posts
    409
    Still, the upright part above the rail you want to be as short as possible, so the higher up design is better as it leave less distance from rail to gantry top.

  5. #5
    Join Date
    May 2011
    Posts
    212
    Quote Originally Posted by Phife View Post
    Still, the upright part above the rail you want to be as short as possible, so the higher up design is better as it leave less distance from rail to gantry top.
    All right, thanks allot Phife.. farthest up it is. Have a good one:cheers:

  6. #6
    Join Date
    Oct 2011
    Posts
    0
    henrikm,
    I am a little bit ahead in my design, but we seem to be working on the same details. I am of the opinion that if you drive from the bottom plate with a single screw, you will get better triangulation with mounting the rails higher. If, on the other hand, you drive from the sides with a twin screw, placing the screw axis plane above the plane of the rails seems to be the best way to deal with gantry inertia.

    Question for you, since you are also in Europe, where are you sourcing your parts and materials for this build?

  7. #7
    Join Date
    May 2011
    Posts
    212
    Quote Originally Posted by LBSamurai View Post
    I am of the opinion that if you drive from the bottom plate with a single screw, you will get better triangulation with mounting the rails higher. (...)
    I have a single screw on my bottom plate, so high it is then

    Question for you, since you are also in Europe, where are you sourcing your parts and materials for this build?
    The aluminum stock I got through work from a Norwegian supplier. Think I payed something in the area of 5 euros/6 usd per kg.
    The screws, rails, blocks and so forth is from linearmotionbearings2008 on ebay. The motors (nema23) and Gecko540 is from cncrouterparts.com.

    I still need to get a hold of a spindle and a vfd. Most likely a Hitachi X200 vfd and a chinese watercooled 2,2 kW spindle. Not sure where to buy yet.

    Yesterday I got most of the Z-axis sorted out. Going to get started on the ball nut mounts today. Will post some new pics later.

  8. #8
    Join Date
    Oct 2011
    Posts
    0
    Quote Originally Posted by henrikm View Post
    I have a single screw on my bottom plate, so high it is then



    The aluminum stock I got through work from a Norwegian supplier. Think I payed something in the area of 5 euros/6 usd per kg.
    The screws, rails, blocks and so forth is from linearmotionbearings2008 on ebay. The motors (nema23) and Gecko540 is from cncrouterparts.com.

    I still need to get a hold of a spindle and a vfd. Most likely a Hitachi X200 vfd and a chinese watercooled 2,2 kW spindle. Not sure where to buy yet.

    Yesterday I got most of the Z-axis sorted out. Going to get started on the ball nut mounts today. Will post some new pics later.
    Wow, it looks like we're on the same sheet of music. I'm going with the same vendors for linear motion components and electronics, but I am still looking for the best deal on extrusions and Al plate. Looks like Valuframe UK is going to be my source for extrusion, since my design is based around 60/120mm. I think the Al plate will be the part to ruin my budget here. I need some specific cuts and precision drilling, since my manual mill is in storage for now. I'll probably try to source that through the RFQ channel on this forum, as I imagine a job shop in Germany would be very costly. Thanks for the response.

  9. #9
    Join Date
    May 2011
    Posts
    212
    Quote Originally Posted by LBSamurai View Post
    Wow, it looks like we're on the same sheet of music. I'm going with the same vendors for linear motion components and electronics, but I am still looking for the best deal on extrusions and Al plate. Looks like Valuframe UK is going to be my source for extrusion, since my design is based around 60/120mm. I think the Al plate will be the part to ruin my budget here. I need some specific cuts and precision drilling, since my manual mill is in storage for now. I'll probably try to source that through the RFQ channel on this forum, as I imagine a job shop in Germany would be very costly. Thanks for the response.
    Keep me updated on your build. Would be fun to compare designs. I'm planning to have most of the machine ready before new years, but don't think I can afford a spindle/vfd for a couple of months. Do you have a build log?

  10. #10
    Join Date
    Oct 2011
    Posts
    0
    Quote Originally Posted by henrikm View Post
    Keep me updated on your build. Would be fun to compare designs. I'm planning to have most of the machine ready before new years, but don't think I can afford a spindle/vfd for a couple of months. Do you have a build log?
    I have most of the design work completed in SolidWorks. I didn't want to start a thread without something to show on the first post, or else it is not a build log . I'll get something up soon, I want to show my design before I begin ordering parts. Are you working on a build log yourself?

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