Simple skate bearing axis
Posted by james glanville
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Simple skate bearing axis March 13, 2009 10:34PM |
Registered: 15 years ago Posts: 332 |
I've been annoyed for a while at the friction my reprap has been experiencing, because it has limited how tight I can make the chains and have the thing move. I decided to replace all the bearings with skate bearings, and remake the axis, and thought I'd share my method. I hope that with very little friction, light milling will be possible.
Anyway, for the y-axis (on my reprap this is the axis that also has to move the x-axis) I have used 16 skate bearings. This seems like a lot, but the smoothness is amazing, and at 30p each it doesn't end up being too expensive. In fact, the friction and rigidity are so good that the axis can be moved from just one side, with no twisting whatsoever. Here are some pictures:
[picasaweb.google.com]
(best picture)
[picasaweb.google.com]#
(others in here somewhere)
As you can see, the parts are very simple, and easy to assemble with very few tools. Since all the bearing are of the same direction, tensioning is really easy, I just put a couple of sprung washers on the thin threaded rods that hold the bearings to the rod.
Now a downside of this approach is that it means extra parts that cannot be reprapped. This doesn't personally bother me too much, and I've seen other people using skate bearings, so it may not matter to everyone.
I think this would be a good positioning system for repstraps or modified darwins, because it has the advantage of getting amazing precision with very little effort (the carriage in the picture took about half an hour to design and make)
Anyway, for the y-axis (on my reprap this is the axis that also has to move the x-axis) I have used 16 skate bearings. This seems like a lot, but the smoothness is amazing, and at 30p each it doesn't end up being too expensive. In fact, the friction and rigidity are so good that the axis can be moved from just one side, with no twisting whatsoever. Here are some pictures:
[picasaweb.google.com]
(best picture)
[picasaweb.google.com]#
(others in here somewhere)
As you can see, the parts are very simple, and easy to assemble with very few tools. Since all the bearing are of the same direction, tensioning is really easy, I just put a couple of sprung washers on the thin threaded rods that hold the bearings to the rod.
Now a downside of this approach is that it means extra parts that cannot be reprapped. This doesn't personally bother me too much, and I've seen other people using skate bearings, so it may not matter to everyone.
I think this would be a good positioning system for repstraps or modified darwins, because it has the advantage of getting amazing precision with very little effort (the carriage in the picture took about half an hour to design and make)
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Re: Simple skate bearing axis March 16, 2009 03:44AM |
Registered: 16 years ago Posts: 536 |
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Re: Simple skate bearing axis March 16, 2009 08:06PM |
Registered: 15 years ago Posts: 478 |
Looks realy good I will adopt your method for my DIY Darwin thank you!
.. you say Skate bearings at 30p a shot have you got a link or an address for the skate bearings please.
Bodge It [reprap.org]
=======================================
My rep strap: [repstrapbertha.blogspot.com]
Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]
.. you say Skate bearings at 30p a shot have you got a link or an address for the skate bearings please.
Bodge It [reprap.org]
=======================================
My rep strap: [repstrapbertha.blogspot.com]
Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]
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Re: Simple skate bearing axis March 17, 2009 08:22AM |
Registered: 15 years ago Posts: 332 |
There's a local shop near me, but there are loads of cheap ones on ebay.
[cgi.ebay.co.uk]|66%3A2|65%3A12|39%3A1|240%3A1318
works out at 29p each. Searching for "skate bearings" gives loads of results, for my design you need 30 (will be posting to the builders blog later today, have a look if you want to see how I've made my x and y axes.)
[cgi.ebay.co.uk]|66%3A2|65%3A12|39%3A1|240%3A1318
works out at 29p each. Searching for "skate bearings" gives loads of results, for my design you need 30 (will be posting to the builders blog later today, have a look if you want to see how I've made my x and y axes.)
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Re: Simple skate bearing axis March 17, 2009 11:56PM |
Registered: 15 years ago Posts: 478 |
Great thank you..
I stripped down an old pair of blades Last Sunday to get 16
Bodge It [reprap.org]
=======================================
My rep strap: [repstrapbertha.blogspot.com]
Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]
I stripped down an old pair of blades Last Sunday to get 16
Bodge It [reprap.org]
=======================================
My rep strap: [repstrapbertha.blogspot.com]
Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]
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