CarveOne's Solsylva 25x37 Router Build

[Mr.Chips]

Originally Posted by CarveOne Here's a shot of the assembled inertial damper. I don't know if the spring tension is enough to tune it for best slippage/performance on the 425 oz/in stepper motors. It may need a spring with a larger gauge spring wire. When the machine is running again I'll post some subjective results here. For this photo I used the original axle bolt. I'll drill and tap the hex head bolts tomorrow and post a photo of one installed on a stepper motor. CarveOne

Uhhhh what does a inertial damper do? Haven't seen them on motors.

[CarveOne]

They dampen resonance vibrations that cause the steppers to miss steps or have complete stalling if it is severe enough. Dampening out the resonances allows running at higher IPMs (that's the theory anyway). The spring tension or caster size can be adjusted to tune for best operation.

There are commercial neoprene, silica jell filled, and ferrofluid filled versions available but the Solsylva mechanical version is cheap to make at home.

They basically allow the inertial mass (the caster wheel) to slip a little with each step to resist the step vibrations. If they don't work, one set screw will easily remove them. I'll at least have three casters available for use on some other project.

CarveOne

[CarveOne]

Mr.Chips,

Thanks for the pics. That looks simple enough to implement easily. I think I already have the angle stock on hand.

CarveOne

[CarveOne]

My repaired Xylotex controller arrived today. I mailed it on 1/31/2008. Less than two weeks turnaround from the east coast to the west coast (USA). I'm impressed with both Xylotex and USPS. It must have cycled through Xylotex in one day.

I'll set the driver voltages again tomorrow and see if I can be somewhat less of a klutz around the cables this time.

edit/update - I found some time to reinstall the board and it's working fine again.

pumelloman,

I'll do some more tuning without the inertial dampers and then see if installing the dampers allow improving the speed without resonances. I won't get a chance to do it until Wednesday at the earliest. As soon as I know something positive or negative I'll post the results here. If it's really positive, I'll let you know in your build log also.

CarveOne

[CarveOne]

I mounted four of the limit switches today. Not knowing for sure that what I'm doing is correct, I arbitrarily set the switches to trip 1" from the physical collision point. 1/2" would probably be more than enough stopping distance, as this thing traverses slowly enough that it doesn't skid to a stop at all. The switches can be rotated a little and the ramps can be bent a little to give any adjustments needed.

The ramp is 1/16" aluminum and seems plenty stiff enough to not flex under normal roller pressure. The ramp will pass by the switch without switch damage if the software doesn't see the switch closure and crashes the gantry into the physical collision point.

I epoxied the limit switches to a 1/16" alumimum plate that is roughly 1" square. I roughed up the limit switch surface and the plate's surface with 80 grit sandpaper to give better adhesion of the epoxy.

The Z axis switches may be a bit more tricky to mount than the X and Y.

CarveOne

[pumelloman]

Wow, that was actually pretty smart (or at least I thought so). I hadn't thought about what could happen if the software doesn't recognize the switch. I especially like how the gantry doesn't smash into the limit switch to stop, it gradually pushes it down. Very nice!

[CarveOne]

I have run my gantry into the side rails on purpose to see what hits first and what happens. The collision is not violent at the speeds that we will be running these at. The steppers just stall like they do during resonance. I don't care if the switch arm gets bent a little but I would rather not have to replace broken switches. Not recognizing the switches can happen during power glitches if everything is not on a UPS backup supply or during Windoze lockups. I have not seen any lockups in Ubuntu Linux and EMC since I've been using it. It's still worth installing your switches to save you effort later.

I'm also trying to keep most of the switch wiring on one side of the machine as much as possible for ease of wire routing.

I'm still not sure how I will fit the switches into the Z axis yet. Doesn't look like it will be as easy as the X and Y. I'll have to study on that a while. I don't think they will be so elegant when finished.

CarveOne

[Khalid]

I am reading reading reading your design and work u posted here... and i am really happy with your neat work on wood... I wish to see this machine working... I will post details when i read all these interesting pages...

Wish you best of luck..
Regards
KFK

[CarveOne]

Kahlid,

Since deciding to build this machine with red oak I have found that it seems to be in more use than I had first thought. When I glued the 1x4 oak boards together to form the 2x4 side and end rails I oriented the annular rings in the boards so that they oppose each other and will, hopefully, produce very little warping and more stiffness. So far, it has been inside my house and everything has remained stable. The wood parts all have five coats of satin polyurethane sprayed on them and I don't expect to have moisture problems. It's not steel, but it's as close as I can reasonably get with wood. (I hope)

Thanks for taking a look at my humble efforts.

CarveOne

[Nitroghost]

I like the way they look. did you cut them by hand? i have some 1/4 inch laying around and would love to make a set. If you cut them on another cnc do you have the files used so i can make a couple for myself? Thanks and congrats on a sweet looking setup.

Jim

[CarveOne]

Thanks Jim,

I don't have the CAD files or gcode for these parts. Even if I did I doubt that David Steele would be happy that I gave them away. I'm sure that he prefers that you buy the plans from him if you don't already have them. These were easy enough to mark out and cut.

The 1/4" Lexan that I used came from Lowes. As this stuff melts at low temperatures you will need to use a coarse tooth bandsaw blade to cut it. The holes were cut with a hand held coping saw. A power scroll or jig saw will melt the plastic and it will fuse back together behind the blade.

The Lexan seems to be holding up pretty well so far. I was going to make them from 3/16" aluminum plate until I found the Lexan sheet I had left over from another project was large enough to make these plates.

CarveOne

[Nitroghost]

Originally Posted by CarveOne Thanks Jim, I don't have the CAD files or gcode for these parts. Even if I did I doubt that David Steele would be happy that I gave them away. CarveOne

Yea. I have the book. I will attempt to cut them on a veriable speed scroll saw. I have enough to test and see if it will work. Thanks for the info.

Jim