Rotary: Screwdriver

[SteveNelson46]

I'm having a real problem designing a screwdriver handle with the rotary software. Everything comes out as planned except for the diameter of the end for the ferrule. The project is 6" long by 1.75" in diameter and the depth of the carve region (shown by the red arrows) is .375". If I pass the mouse over the region, the status bar in the lower left corner indicates a diameter of 1". That's exactly what is needed for the ferrule. However, it only measures 29/32" after it is cut. The really frustrating part is the diameter does not change with incremental changes of the depth of the carve region until at least a .005" change is made. Then the diameter jumps to 1.027". So I'm down to experimental carves that take 2 hours each. I have also tried to design the ferrule end as part of the extrude instead of a separate carve region with even worse results. Anyway, if someone can come up with a different approach I am open to all suggestions.

I'm a little reluctant to post the mpc. If I can get this perfected I was thinking of putting it in the pattern depot as a project.

[fwharris]

Steve,

Nice design! Does the rest of the handle dimensions come out good? Is this done with separate elements or a pattern?

[SteveNelson46]

Steve,

Nice design! Does the rest of the handle dimensions come out good? Is this done with separate elements or a pattern?

The design has just 3 elements. An extruded section, the carve region in question and the "bumps" pattern. If this was just for me I could mount the finished carve in the lathe and size the end for the ferrule (which has to fit "hammer on" tight). But, if I put it in the pattern depot it has to be perfect.

EDIT: Yes, everything else seems to come out good. Although, the sizes are not as critical as the end for the ferrule.

[SteveNelson46]

I really don't think there is a solution to this. I just thought that by bringing to light the accuracy problem it might possibly be addressed in the next release of the software.

Attached is a picture of the kit that I was planning to use

[blhutchens]

I had trouble with this same thing. I made several and never got em exact.

[James RS]

Hello,
I had a problem like this when I made spindles for my coat rack, it's been awhile since. But I believe I cured the problem with the height, I made a rectangle region in the area
and adjusted the carve height and it cured the problem. Also I have Ed Bakers Rotary jig and 1.87 software.

I'm having a real problem designing a screwdriver handle with the rotary software. Everything comes out as planned except for the diameter of the end for the ferrule. The project is 6" long by 1.75" in diameter and the depth of the carve region (shown by the red arrows) is .375". If I pass the mouse over the region, the status bar in the lower left corner indicates a diameter of 1". That's exactly what is needed for the ferrule. However, it only measures 29/32" after it is cut. The really frustrating part is the diameter does not change with incremental changes of the depth of the carve region until at least a .005" change is made. Then the diameter jumps to 1.027". So I'm down to experimental carves that take 2 hours each. I have also tried to design the ferrule end as part of the extrude instead of a separate carve region with even worse results. Anyway, if someone can come up with a different approach I am open to all suggestions.

I'm a little reluctant to post the mpc. If I can get this perfected I was thinking of putting it in the pattern depot as a project.

[bergerud]

I wonder what the problem really is here. On the new rotary jig, the bit touches on the aluminum and the center axis is accurately known to be 1.75" below. Is it a z calibration problem which needs to be tweaked in the software or is it simply that errors in radii double for diameters? I have always had plus or minus 1/64" troubles with depths of regular carvings. That would jump to 1/32" for rotary diameters.

I wonder how it would work if one milled the 1" diameter part? Carve it down close and then use, say, the 3/16" cutting bit to "pocket" it. Could be an interesting experiment.

[SteveNelson46]

Hello,
I had a problem like this when I made spindles for my coat rack, it's been awhile since. But I believe I cured the problem with the height, I made a rectangle region in the area
and adjusted the carve height and it cured the problem. Also I have Ed Bakers Rotary jig and 1.87 software.

There is no height on a flat carve region so it cannot be set. I also tried including the ferrule end as part of the extrude and then adjusting the height but, since the display on the status bar is inaccurate, that only compounded the problem and that's why I changed to a flat carve region. If the height is adjusted until the uppermost part of the extrude is at the surface of the board any higher setting will have no effect. Any setting below the designed height and you not only start to lose detail but, the display inaccuracy on the status bar remains the same. My point here is that the actual carve should be as accurate as the displayed value. If the Designer displays values in increments of .001" the carve should reflect those values and not be rounded off.

[James RS]

You are correct sir, I said it had been awhile

There is no height on a flat carve region so it cannot be set. I also tried including the ferrule end as part of the extrude and then adjusting the height but, since the display on the status bar is inaccurate, that only compounded the problem and that's why I changed to a flat carve region. If the height is adjusted until the uppermost part of the extrude is at the surface of the board any higher setting will have no effect. Any setting below the designed height and you not only start to lose detail but, the display inaccuracy on the status bar remains the same. My point here is that the actual carve should be as accurate as the displayed value. If the Designer displays values in increments of .001" the carve should reflect those values and not be rounded off.