A different hold down approach
 

Today I visited a customer of the CNC machines I sell, besides this machine he has a medium size router he uses to cut airplane models.
He uses 2mm boards, and his main problem when he started was keeping the board flat, so he came with a solution, take a look:

This is the view from the top, the hole in the middle is where the spindle passes thru this gizmo, the side tube its for the vacuum attachment, and the holes on the sides are guiding holes, thru them ride two guides that are attached to the spindle. You can leave this head floating, meaning that it touches the material to be cut, or it can be fixed at some height.
http://peu.net/mods/prensachapa_v1_01

this is the view from the bottom, the radial holes are there to prevent the vacuum lifting the board and to catch the produced debris, the delrin center is raised a little so only the plastic touches the wooden board to be cut
http://peu.net/mods/prensachapa_v1_02

another view of the bottom side
http://peu.net/mods/prensachapa_v1_03

and a straight view from the top.
http://peu.net/mods/prensachapa_v1_04

He also designed a version 2 of this gizmo, inspired mostly by how the sewing machines hold the clothes where they need to be, he does not built it because version one works dandy, here are the drawings:

http://peu.net/mods/prensachapa_v2_01
http://peu.net/mods/prensachapa_v2_02
http://peu.net/mods/prensachapa_v2_03
http://peu.net/mods/prensachapa_v2_04
http://peu.net/mods/prensachapa_v2_05
http://peu.net/mods/prensachapa_v2_06

What do you guys think?


Pablo

What a beauty!
Love the 1st version, simplicity at its best! Easy to construct & simple to use. Especially admire the use of the radial holes to relief excess suction pover while providing a vacuum curtain around the cutting point.
AND it floats too!
Wonder if making the chamber out of acrylic would be practical, or maybe glass for its any scratch property.
I just decided to go with this design for my build.... later...
Like Ver 2 is a bit, but more tricky to build.

Thanks for sharing.

I cannot see the pictures on this idea...all other pictures show up OK.
Normally this happens from work with the firewalls and rubbish there, but from home I never had this problem. Anybody else that cannot see the pictures, then I can start to look for my problem.

No pictures visible from 2 different PC locations/types.

www.peu.net has crashed

its up now!, sorry guys, just in case it crashes again, here are the photos at an alternate location: http://www.dropbox.com/gallery/36245...ddown?h=cc2944 in the same order presented here.