laser cutting slots and tabs offset issue

[paul j campbell]

HI everyone i am new to lasers
and i have found a real probelm for myself
i have a 3d puzzle i want to cut that has Slots and tabs
i want to cut this from 3mm thick plywood.

so i thought i would run some tests to get the fit right
what i found is this (which i should of thought of but i did not)

the laser beam cuts along the vector meaning it places the vector in the center of the beam
so when it cuts a slot the slot is too large by the amount of half the beams thickness lets say .02
now along it comes to the tab and because the tab is opposite to a slot the beam now makes to tab too small by the same amount ...end product is a slot and tab that is .04 out and does not fit together much too loose.

ok so the guy thinks just adjust the scale of the overall puzzle to compensate for beam thickness but this does not work because you just increase the problem by the amount you rescale the puzzle ...so we think a solution would be to be able to offset the beam from the vector in the software to compensate so that the beam outside is actually cutting along the outside of the vector...like it would using a CNC router...but on my Morntech laser i can not see any option for offsetting the beam from the vector....it would be crazy if i have to go an adjust all my tabs to compensate for this issue as the puzzle has hundreds of them so my question and i am sure you have all asked in your newbie days how do i solve this problem easily so i can cut 3d puzzles.

thanks in advance...and i hope i made sense

[Matt Turner (physics)]

What vector graphics software are you using? There may be a way to "grow" all of the outlines by the proper amount, which will do what you want.

[Rodne Gold]

The morntech uses laserworks/Rdcam.. there is an offset command , called sew width compensation.
Double click on the listed items where it shows the colour , cut , speed etc At the bottom of the dialog box that comes up , click advanced , you will see another dialog box called other cutting parameters , click enable sew width compensation and then enter the amount of offset and either inwards or outwards.
You might have to use 2 layers or colours , one for inwards , the other for outwards.

[Joe Hillmann]

One problem I see with what you want to do is, what is the outside of the part if there are tabs on the inside of the parts the only way that off setting the cut would work is if for all of the slots you did a back minus front rather than just putting the slots on top otherwise of setting everything to the outside will cause the slots to actually get bigger rather than smaller.

You may want to set your step to.002, start selecting nodes or groups of nodes and moving every tab one step larger on each side.

[Guy Hilliard]

Piece of cake.

CorelDRAW -

join all of the outline to form a single object
make the outline 2X as thick as the offset you need.
convert outline to object
break apart
delete the inside line of outside details and the outside line of inside details

Most CAD programs -

join the outline so that it becomes a single object
offset the outline to the outside (for outside details) or the inside (for inside details) by the amount of offset you need
delete the original outline

Bob's yer uncle.

[Matt Turner (physics)]

CorelDRAW -

join all of the outline to form a single object
make the outline 2X as thick as the offset you need.
convert outline to object
break apart
delete the inside line of outside details and the outside line of inside details

You can also use the Contour tool in CorelDRAW.

[Peter Meacham]

Paul

You could use this program: http://www.oberonplace.com/products/jigsaw/index.htm
as described in this A&E Magazine article about Corel Draw: http://a-e-mag.com/article/creating-...h-puzzle-laser

Pete

[paul j campbell]

The morntech uses laserworks/Rdcam.. there is an offset command , called sew width compensation.
Double click on the listed items where it shows the colour , cut , speed etc At the bottom of the dialog box that comes up , click advanced , you will see another dialog box called other cutting parameters , click enable sew width compensation and then enter the amount of offset and either inwards or outwards.
You might have to use 2 layers or colours , one for inwards , the other for outwards.

Thanks to everyone for your input and help it is all very much appreciated
special thanks to Rodne looks the the solution to me

[Guy Hilliard]

Matt;

Sometimes Contour does freaky things with sharp points that thick lines does not.

[Matt Turner (physics)]

Matt;

Sometimes Contour does freaky things with sharp points that thick lines does not.

Good to know. Thanks!