Dust foot woes...

[harryball]

I'm trying to figure out how to attach my dust foot so I can accomodate the Z in the highest position for the project I'm cutting. It occured to me if I turned the foot 180 degrees it would solve a lot of issues. However, I can't figure out how to attach to the front of the spindle. Short of some kind of clamp I can only think of tapping small holes on each said of the spindle face over the corner air channels and attach brackets.

Here is the idea mocked up...


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I'd need to mount something to extend out between the brackets but that'd be the simple part.

I'm not keen on drilling holes in the spindle nor will I do so if I find out it'd void the warranty.

Does anyone have any other ideas or are you doing something similar?

Thanks,
Robert

[evan]

How about using some 3M double stick tape the type car manufactures use attach logos on the body of cars? There shouldn't be that much torque or sheer force. Or if that doesn't work; epoxy?

[harryball]

After close inspection and a quick call to shopbot...I drilled and tapped two screw holes into the air flow chamber on the side of the spindle. With a custom aluminum bracket and some aluminum screws here it is...


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It works much better to remove the foot and do a bit change from behind Z axis side of the gantry which is where I stand. The Z axis can now raise all the way up without striking the dust foot bracket.

In future I may work in some kind of elbow and bring the hose up through the gantry. I know it will be a complete rework if I ever get a second Z axis... but who knows when that'll happen.

You may also notice that I have removed the metal under pan and short flat hose as the foot was originally configured. This more than doubled the inlet area on the hose. I've been using the dust foot with this hose adjustment for a few weeks and it works much better. My next task is to swap the skirt with either stiffer plastic skirt or go with a brush.

Robert

[harryball]

This arrangement is SO MUCH BETTER! I can leave the head parked at 0,0 and casually remove the dust foot, replace the bit and reinstall the foot. This has cut the bit replacement time in half.

Though drilling holes in your $2800.00 spindle housing requires a certain amount of something I either have too much of or not enough of... it has been well worth it. As I'd hoped the all aluminum bracket and screws expand and contract close to the same rate as the spindle housing does as it heats up and cools off. After 2 good days of use I've checked the bracket while hot and cold, always tight.

Robert

[Brady Watson]

Robert,
You know you could have moved the entire Z axis to the center of the bay and essentially do the same thing but retain the t-rail mounting configuration, right?

-B


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[harryball]

I thought about that but I was concerned about additional flex from the extra leverage. When I'm running my roost grooves at 12 ips even cornering at lower speeds it makes for really sloppy curves as I found out.

See the holes all the way to the left that have been used? This bot had twin Z's at the IWF so the table was centered up in an attempt for both spindles to reach each end of the table. I was about 1" short of this spindle reaching the far end of the table when I got the machine.

In my original attempt to reach the far side of the table I moved my Z over to the otherside thinking bit changes might be easier etc... not only did it not improve handling but my curves looked horrid. Even after tightening everything and using the slower cornering at 12 ips I had really rough turns. Remembering that I decided not to opt for center holes to solve this problem.

Robert