Jeremy Maso
New member
Hi! I'm working with Open Source Ecology in developing a homemade "open source" dimensional sawmill. I've got most of the design drawn up but am stuck on some parts that I need more information on. You can read about the basics on our blog here and see the development page here.
So far we've decided on a design similar to the Mobile Dimension Sawmill, with a space frame (for stability) on two "I" beams for x and y axis movements, a chassis surrounding the space frame with bearings to grip it on all sides, a vertical plate or beams on the chassis with another plate attached with bearings and adjusted vertically with a pulley for the z axis, the saws are mounted on the vertically moving plate and powered with hydraulic motors. We are using the hydraulic pump on the open source LifeTrac tractor to power the motors.
My questions are:
1. Will the current design of the rollers/bearings work? Will they have trouble going over sawdust that gets on the track? Are they strong enough to hold the saws and everything(250-300 pounds)? Is it going to be too hard to build the cage to get them to fit on the space frame tightly so it doesn't wobble around and make bad cuts? Here's a picture of the current roller/bearing design. The bearings are these ones. They are flat rollers on a bolt with spacers in a kind of U-channel bolted to the cage. They have 3 bearings on each set in the picture, but we're thinking of using just 2 on each set. They roll on the flat sides of square tubes that are the edges of a space frame. All sets are the same on top, bottom, and sides.
2. How are the rollers/bearings on other sawmills with moving saws designed? I would guess that many CNC machines would also have rollers that would be similar. Are there any pictures or online patents or design details on how other rollers work? I've heard that there are some that have a V shapped bearing in a groove to work like a track, is that what we're going to have to do? Are there any pictures of anything that uses that method? I have also seen some bearings with springs on the shafts that pull them tight against the surface they roll on.
Thanks for any help!
So far we've decided on a design similar to the Mobile Dimension Sawmill, with a space frame (for stability) on two "I" beams for x and y axis movements, a chassis surrounding the space frame with bearings to grip it on all sides, a vertical plate or beams on the chassis with another plate attached with bearings and adjusted vertically with a pulley for the z axis, the saws are mounted on the vertically moving plate and powered with hydraulic motors. We are using the hydraulic pump on the open source LifeTrac tractor to power the motors.
My questions are:
1. Will the current design of the rollers/bearings work? Will they have trouble going over sawdust that gets on the track? Are they strong enough to hold the saws and everything(250-300 pounds)? Is it going to be too hard to build the cage to get them to fit on the space frame tightly so it doesn't wobble around and make bad cuts? Here's a picture of the current roller/bearing design. The bearings are these ones. They are flat rollers on a bolt with spacers in a kind of U-channel bolted to the cage. They have 3 bearings on each set in the picture, but we're thinking of using just 2 on each set. They roll on the flat sides of square tubes that are the edges of a space frame. All sets are the same on top, bottom, and sides.
2. How are the rollers/bearings on other sawmills with moving saws designed? I would guess that many CNC machines would also have rollers that would be similar. Are there any pictures or online patents or design details on how other rollers work? I've heard that there are some that have a V shapped bearing in a groove to work like a track, is that what we're going to have to do? Are there any pictures of anything that uses that method? I have also seen some bearings with springs on the shafts that pull them tight against the surface they roll on.
Thanks for any help!
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