Bearing / Linear Motion Design?

Design of structural and load bearing framework.
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larry104
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Re: Bearing / Linear Motion Design?

Postby larry104 » Mon Mar 28, 2011 5:02 pm

Inspired by the image Awesomeness posted in this I created this little test setup.
Linear Motion.jpg

There are no special tools required. It uses 12 bearings per axis (but at least the cheap ones; you could use the v-groove idea I suggested on the bottom to reduce the number of bearings to 8). Also wear should be better than using the

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Awesomeness
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Re: Bearing / Linear Motion Design?

Postby Awesomeness » Mon Mar 28, 2011 6:37 pm

Very nice. How well do the bolts hold up that go through the edge of the board? I notice you used chipboard, but wonder how it would do in MDF since MDF is very weak through the edge like that (even the act of drilling splits it sometimes).

How well does the aluminum c-channel fit over the end of the board?

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larry104
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Re: Bearing / Linear Motion Design?

Postby larry104 » Mon Mar 28, 2011 7:06 pm


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beermkr
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Re: Bearing / Linear Motion Design?

Postby beermkr » Thu Mar 31, 2011 11:52 am

How are the bearings in the holes located? Is there a way to adjust the spacing on the bearings?

The channel I used was a full 3/4 inch inside and fit over the edge of the MDF nice and tightly.

I like the idea of a single block but like the adjustability of my separate design.

Awesomeness, I promis I will get a picture tutorial of the design done soon. I have been SWAMPED at work lately and am just catching up on stuff now.

R/
Mike Pensinger
Chief Brewer, The River Company Brewery, Radford, VA

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larry104
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Re: Bearing / Linear Motion Design?

Postby larry104 » Thu Mar 31, 2011 1:53 pm

The bearing is sitting between two nuts (nut-bearing-nut). The hole is wide enough to fasten the two nuts tightly. Where did you get the channel with full 3/4? I got mine at Lowes and it says it fits plywood.

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beermkr
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Re: Bearing / Linear Motion Design?

Postby beermkr » Thu Mar 31, 2011 2:50 pm

onlinemetals.com it is 1 inch architectural channel with 1/8 walls.

http://www.onlinemetals.com/merchant.cf ... top_cat=60

R/
Mike Pensinger
Chief Brewer, The River Company Brewery, Radford, VA

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larry104
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Re: Bearing / Linear Motion Design?

Postby larry104 » Sat Apr 02, 2011 4:16 pm

This is how I would envision one side of the x-axis given the design I suggested earlier. The construction slides right onto the table and the slots will allow for adjustment in case the table is not perfectly straight (sorry the slots are 15/16 instead of 5/16 - I was to lazy to change it; I also did not draw the MDF connectors between all wood pieces). This design allows the x-axis to be larger than the table itself so that you could route all the way to the end of the table - or even over it. Having the connection pieces to the y-axis 90deg rotated gives extra stiffness further stiffener could be added in-between - or alternatively the chain or belt could run in-between (this would need two big holes near the bottom).
xaxis1.jpg

xaxis2.jpg

xaxis3.jpg


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