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There are extruding companies that will make a die based on your design. It would be a large up-front cost, but imagine if you were the only guy selling extrusions that were designed to carry the cheap skate bearings. I guess this is still not good, because it would be the stainless bearing riding on an aluminum extrusion. We still want a hard rubber wheel.

When you get to the length I need for the Z lift belt, the sizes start going in 8"-10" steps. It is tough to find the size you need. I really want to try Econobelt because the price is almost a 1/3 of Stock Drive. The Z lift lead screws don't need to go at the ends of the table, so I am going to move them closer together. This might cause an issue with the X axis motor. I thought about moving the motor to the top side of gantry. This does not change much at all and gains some usable XY range.

I am going to try this method and show the results.

I measured the belt length using a piece of wrapping paper ribbon. It measured about 113" which is right about what the CAD model said. The ribbon actually worked. . The tricky one to thread is the one with the motor. I may move that to the front. I am sure it will be easier with a real belt that has some stiffness.

Econobelt has a 103" and a 122". I think it will be easier to to move the lead screws together, so I will go with the 103" I ordered three belts.

I wonder how they make these belts. I can't imagine they have a mold for each one.

Here are the mods to the gantry. The putting the motor above gives maximum clearance of the table. My previous design had to allow clearance for the motor along the left side. Now you get about 2" inches of travel. The assembly is actually easier to assembly and uses less parts. The belt is tensioned by moving the motor to the left as it is tightened.
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Looks great! I like the way your new belt clamp supports the belt; it also appears stronger than previous designs. Does the new clamp attach the same way as previous clamps?

It attaches from the bottom with two screws. You mount it lightly, then slide the belt ends in from the side. Tighten the clamp. Then tension the belt.

I hope to post the drawings tonight. This affects a lot of drawing, some only visually.

I want to post everything at once, so there is no period where old and new are on at the same time.

The new versions of the drawings have been posted on the drawings page. This includes all the new Z lift drawings and mods to the gantry to get the motor above the extrusion. I am going to work towards the part kits next. The assembly drawings need a lot of clean up, but that should be usable anyway.

My laser will be down for at least a week while I wait for for the belt. I should be ready to start cutting after that.

I would use four v bearings on the y for stability.

Put me at top of the list of kit purchase.
Robert
[quote="bdring"]The new versions of the drawings have been posted on the [url=http://www.buildlog.net/cnc_laser/drawings.html]drawings page[/url]. This includes all the new Z lift drawings and mods to the gantry to get the motor above the extrusion. I am going to work towards the part kits next. The assembly drawings need a lot of clean up, but that should be usable anyway.

My laser will be down for at least a week while I wait for for the belt. I should be ready to start cutting after that.[/quote]

What timing belts and pulleys are you using? I'm guessing the MXL belts from econobelt? Do you have a complete list of parts for both x/y/z axis belts and pulleys used? I'm looking to buy all the belts and pulleys from econobelt in the next day or so. Thanks!