Apples
09-20-2005, 03:28 AM
How to mount Bishop Wisecarver bearings.
Okay. I am now ready to upgrade my plasma table to the Bishop Wisecarver bearings.
I am going to use the size number 2 bearings and matching track. I will also be using the matching concentric and eccentric bushings.
I plan on mounting the track onto the vertical edge of a piece of angle iron. I will be running two tracks on this angle iron. One track on the top of the angle and one track on the bottom.
Then using four bearings, two on top track and two on bottom track with concentric and eccentric bushings. These bearings will be mounted on a piece of flat steel.
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Q1) For this ‘truck’ that the four bearings will be mounted on. What will be the best type of steel to use. Should I use 5mm x 100mm (¼ x 4”) flat, or 5mm x 75mm x 75mm (¼ x 3” x 3”) angle iron or box 3mm x 75mm x 75mm (3/16 x 3” x 3”). What thickness steel will I need to stop flexing and thus stop ‘racking’ and ‘skewing‘of the gantry?
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Q2) I am planning on making the ‘trucks’ 400mm long. My old set up had 1000mm trucks. I think that because I am using the Bishop Wisecarver bearings a ‘truck’ length of 400mm might be okay. Will it?
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This is my current set up of my table:
http://www.cnczone.com/forums/attachment.php?attachmentid=9413
You can see how I have use angle iron and round bar. I have used skate bearings to roll everything around on. This actually is not too bad. Problems that I have encountered with this are:
1. The small/light gauge angle iron that the bearings run on for the long axis is sagging. The angle iron is nearly touching the round bar.
2. The weight of the gantry is about 55kg (110lbs). There is flex/wobble at the other end of the gantry when it stops. I only have one motor on that axis. I will be putting another motor on the other side to stop this wobble when making fast sharp moves. I have a pen mounted in the machine, and when doing fast drawings, right angle corners come out with a wobbly line after it turns the corner. Other that this set up works good.
3. By using the angle iron going across the table as opposed to have one lager beam going across. It is hard to mount a z axis. And also hard to see where to end of the torch will be.
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Q3 Should I use aluminium or mild steel for the x axis that goes across the table? Aluminium is lighter but will flex more where as steel is heavier and won’t flex as much. What size box should I use?
-------------------------------------------------------------------------------------------------------------
Let me know what I should do.
Cheers,
Apples
Peter (Australia)
Okay. I am now ready to upgrade my plasma table to the Bishop Wisecarver bearings.
I am going to use the size number 2 bearings and matching track. I will also be using the matching concentric and eccentric bushings.
I plan on mounting the track onto the vertical edge of a piece of angle iron. I will be running two tracks on this angle iron. One track on the top of the angle and one track on the bottom.
Then using four bearings, two on top track and two on bottom track with concentric and eccentric bushings. These bearings will be mounted on a piece of flat steel.
-------------------------------------------------------------------------------------------------------------
Q1) For this ‘truck’ that the four bearings will be mounted on. What will be the best type of steel to use. Should I use 5mm x 100mm (¼ x 4”) flat, or 5mm x 75mm x 75mm (¼ x 3” x 3”) angle iron or box 3mm x 75mm x 75mm (3/16 x 3” x 3”). What thickness steel will I need to stop flexing and thus stop ‘racking’ and ‘skewing‘of the gantry?
-------------------------------------------------------------------------------------------------------------
Q2) I am planning on making the ‘trucks’ 400mm long. My old set up had 1000mm trucks. I think that because I am using the Bishop Wisecarver bearings a ‘truck’ length of 400mm might be okay. Will it?
------------------------------------------------------------------------------------------------------------
This is my current set up of my table:
http://www.cnczone.com/forums/attachment.php?attachmentid=9413
You can see how I have use angle iron and round bar. I have used skate bearings to roll everything around on. This actually is not too bad. Problems that I have encountered with this are:
1. The small/light gauge angle iron that the bearings run on for the long axis is sagging. The angle iron is nearly touching the round bar.
2. The weight of the gantry is about 55kg (110lbs). There is flex/wobble at the other end of the gantry when it stops. I only have one motor on that axis. I will be putting another motor on the other side to stop this wobble when making fast sharp moves. I have a pen mounted in the machine, and when doing fast drawings, right angle corners come out with a wobbly line after it turns the corner. Other that this set up works good.
3. By using the angle iron going across the table as opposed to have one lager beam going across. It is hard to mount a z axis. And also hard to see where to end of the torch will be.
-------------------------------------------------------------------------------------------------------------
Q3 Should I use aluminium or mild steel for the x axis that goes across the table? Aluminium is lighter but will flex more where as steel is heavier and won’t flex as much. What size box should I use?
-------------------------------------------------------------------------------------------------------------
Let me know what I should do.
Cheers,
Apples
Peter (Australia)