Page 1 of 2

Interlocking parts

Posted: Mon Jul 13, 2015 1:12 am
by Daman691003
Hey guys I'm playing with my so3 and loving it. I'm trying to design interlocking parts like a box. With all sides interlocking. I'm using sketch up and sketchyucam. I'm having trouble getting a tight fit. What should I use as tolerance Any ideas. I keep getting loose fits. Thanks

Re: Interlocking parts

Posted: Mon Jul 13, 2015 2:58 am
by LTEPM
it depends on the material. If you are using solid wood, try .006" total tolerance and adjust from there. you don't want a super tight fit with wood, since it will move with moisture and space for glue.

Re: Interlocking parts

Posted: Mon Jul 13, 2015 5:42 am
by woodworkerbob
I found MDF required about 0.015 inches clearance. Example: a rabbet for 1/2" MDF was cut to .515 inches. This was a 9 inch wide board going into the rabbet.

Bob

Re: Interlocking parts

Posted: Mon Jul 13, 2015 9:54 am
by Daman691003
Only problem is I don't think u can get that tolerance with sketch up can u

Re: Interlocking parts

Posted: Mon Jul 13, 2015 10:01 am
by Daman691003
I'm using sketch up and sketchyucam. I can use auto cad. But I don't love cambam. Still confusing. So I have no cam solution for autocad

Re: Interlocking parts

Posted: Mon Jul 13, 2015 10:45 am
by RobCee
Don't give up with CamBam, it gets better the more you use it. Take a look at the tutorial videos - I find new things every time I watch them. CAM is a very long learning curve and CamBam is one of the more capable low-priced options.

Just don't try to draw anything in CamBam, the drawing tools can be extremely frustrating. It's often much faster to switch out to your CAD Tool of choice and re-import the geometry!

Re: Interlocking parts

Posted: Mon Jul 13, 2015 11:07 am
by WillAdams
You should be able to get arbitrary tolerance when you set up CAM, just undersize the bit diameter by half the desired amount, and you should get that in clearance.

Re: Interlocking parts

Posted: Mon Jul 13, 2015 11:10 am
by WillAdams
Added a section for this on the wiki: http://www.shapeoko.com/wiki/index.php/ ... _tolerance

Re: Interlocking parts

Posted: Mon Jul 13, 2015 12:14 pm
by Woodworker
I second Will's solution, I use it all the time. I am in the process of learning CamBam at the moment and it takes some learning. I did draw a complex part yesterday but not needing any specific size it was not difficult. You do need to read the user guide and view the tutorials but it is a small investment for the capabilities it brings to the table.

Re: Interlocking parts

Posted: Mon Jul 13, 2015 12:15 pm
by DanMc
Actually with CamBam I would leave the bit sizes alone, even check them with a micrometer if you have one. You can over/undersize using the roughing clearance parameter. Although better still would be to deal with that in CAD so the rest of the part is not effected.