Box joint gadget.

This section is for general discussion about Gadgets
cusoak
Vectric Wizard
Posts: 486
Joined: Mon Nov 06, 2017 1:57 pm
Model of CNC Machine: Shapeoko 3D XXL

Box joint gadget.

Post by cusoak »

Can the box joint gadget be used to make a box where the only place the fingers are, are on one edge of the sides and on both ends of the bottom the lid will be removeable
I want to be able to route a grove for glass in the front and a grove in back for a piece of plywood?
Jeff

User avatar
Adrian
Vectric Archimage
Posts: 14541
Joined: Thu Nov 23, 2006 2:19 pm
Model of CNC Machine: ShopBot PRS Alpha 96x48
Location: Surrey, UK

Re: Box joint gadget.

Post by Adrian »

Doesn't the flat lid option do that? Not sure as I don't use the gadget but reading the documentation it would seem to do what you want.

cusoak
Vectric Wizard
Posts: 486
Joined: Mon Nov 06, 2017 1:57 pm
Model of CNC Machine: Shapeoko 3D XXL

Re: Box joint gadget.

Post by cusoak »

The attached file shows 2 sides and bottom ,
The ends with finger on them is where I want to cut.
Is it possible to use the box joint gadget to do this.
Jeff
Attachments
Finger joint placement.crv
(158 KiB) Downloaded 239 times

User avatar
Adrian
Vectric Archimage
Posts: 14541
Joined: Thu Nov 23, 2006 2:19 pm
Model of CNC Machine: ShopBot PRS Alpha 96x48
Location: Surrey, UK

Re: Box joint gadget.

Post by Adrian »

The finger joints are just normal vectors and toolpaths so you can remove the fingers you don't want via node editing and then recalculate the toolpaths.

Cut on the top and bottom node on the side where you don't want the fingers, select and delete the finger part that is cut out and then use the join with a straight line tool.

cusoak
Vectric Wizard
Posts: 486
Joined: Mon Nov 06, 2017 1:57 pm
Model of CNC Machine: Shapeoko 3D XXL

Re: Box joint gadget.

Post by cusoak »

Thanks Adrian after I posted the file I got to thinking and thought about node editing, but I would have thought about connecting with a straight line.
Jeff
What I wish they had was a finger or box joint gadget that was cut with the wood being held verticaly.

User avatar
Adrian
Vectric Archimage
Posts: 14541
Joined: Thu Nov 23, 2006 2:19 pm
Model of CNC Machine: ShopBot PRS Alpha 96x48
Location: Surrey, UK

Re: Box joint gadget.

Post by Adrian »

Vertical is a very easy toolpath to do by hand (as is horizontal to be fair). It's just a series of rectangular vectors with the depth of cut being the depth of fingers. Lots of people on the ShopBot forum do them. There is a program to do them as well but it's not a gadget. Once you've done one manually though it's so simple to adjust from there to any size you probably wouldn't bother with a gadget anyway.

cusoak
Vectric Wizard
Posts: 486
Joined: Mon Nov 06, 2017 1:57 pm
Model of CNC Machine: Shapeoko 3D XXL

Re: Box joint gadget.

Post by cusoak »

I will look on the ShopBot forum for more info .Will what ever shows up there going to be using vcarve pro
Any way this is what I did with the box joint gadget buy cutting the vector I did not want and connecting with a straight line
The file also shows the tool cut out tool path. Will need to add a rabbit for the back and plexiglas front.
But it was pretty easy to do
Jeff
Attachments
Finger joint bottom and 2 sides.crv
(195 KiB) Downloaded 204 times

User avatar
TReischl
Vectric Wizard
Posts: 4575
Joined: Thu Jan 18, 2007 6:04 pm
Model of CNC Machine: 8020 48X36X7 RP 2022 UCCNC Screenset
Location: Leland NC

Re: Box joint gadget.

Post by TReischl »

Here is how I do them on a vertical jig on the front of my machine:

https://www.youtube.com/watch?v=NhLkB1ZyOPo

I do that cutting in the first part of the video to prevent splintering and tearout. Essentially what it is doing is walking around the outside corners using a climb cut. Then when it passes straight thru there is no material that will splinter out. That is pine being cut in the video which will splinter very easily.
"If you see a good fight, get in it." Dr. Vernon Johns

cusoak
Vectric Wizard
Posts: 486
Joined: Mon Nov 06, 2017 1:57 pm
Model of CNC Machine: Shapeoko 3D XXL

Re: Box joint gadget.

Post by cusoak »

TReischl Your video shows just what I want to be able to do.
My shapeoko will travel beyond the front of my machine far enough to be able to cut the thickness of wood I want to use.
I like the tool path you came up with to do the cuts around the back and front first. To keep the tear out from happening.
Did you create that in vcarve. Would you mind sharing how you did that tool path.
Thanks Jeff

User avatar
TReischl
Vectric Wizard
Posts: 4575
Joined: Thu Jan 18, 2007 6:04 pm
Model of CNC Machine: 8020 48X36X7 RP 2022 UCCNC Screenset
Location: Leland NC

Re: Box joint gadget.

Post by TReischl »

Cusoak:

Here is what the tool path vector looks like:
Capture.JPG
I usually climb mill around it rather than what is shown in the picture. I also normally move the two end lines (vertical) out a bit from the stock size so that if I need to adjust the bit size to get a good fit I don't start cutting into the edges of the boards.

There is also another variety that I showed in the video, just split the vector up and have it do a loop on one side of the board at a time. These days I generally do it the way I showed it in the attachment, it is faster because it is not cutting air so much.
"If you see a good fight, get in it." Dr. Vernon Johns

cusoak
Vectric Wizard
Posts: 486
Joined: Mon Nov 06, 2017 1:57 pm
Model of CNC Machine: Shapeoko 3D XXL

Re: Box joint gadget.

Post by cusoak »

So is that vector just the cut on the outside.
Jeff

User avatar
TReischl
Vectric Wizard
Posts: 4575
Joined: Thu Jan 18, 2007 6:04 pm
Model of CNC Machine: 8020 48X36X7 RP 2022 UCCNC Screenset
Location: Leland NC

Re: Box joint gadget.

Post by TReischl »

cusoak wrote:So is that vector just the cut on the outside.
Jeff
Yup, that is all it is. The climb cut is important, btw. What is happening as you can see is the tool is walking around the corner when it enters the material, when it gets to the opposite corner it is pushing the wood into the stock. So, the result is no chip out. It takes longer than just cutting straight across, but finger joints go fast anyhow. You can cut a lot deeper in one pass because you are side milling.
"If you see a good fight, get in it." Dr. Vernon Johns

cusoak
Vectric Wizard
Posts: 486
Joined: Mon Nov 06, 2017 1:57 pm
Model of CNC Machine: Shapeoko 3D XXL

Re: Box joint gadget.

Post by cusoak »

Well I ran the box joint gadget yesterday and cut out a box. And of course it did not fit together. joints to tight.
So I was using .25 material and an .125 end mil in plywood.
I did not put anything in the allowance box.
So my question is this.
IS the allowance bases on anything other than just a guess
If that is correct what might be a good starting point for an allowance.
Jeff

User avatar
TReischl
Vectric Wizard
Posts: 4575
Joined: Thu Jan 18, 2007 6:04 pm
Model of CNC Machine: 8020 48X36X7 RP 2022 UCCNC Screenset
Location: Leland NC

Re: Box joint gadget.

Post by TReischl »

cusoak wrote:Well I ran the box joint gadget yesterday and cut out a box. And of course it did not fit together. joints to tight.
So I was using .25 material and an .125 end mil in plywood.
I did not put anything in the allowance box.
So my question is this.
IS the allowance bases on anything other than just a guess

Of course it is. And no it is not. End mills often cut something other than their stated size. They could be undersize or oversize and they may not run true in a collet. Wood is different in that it has fibers and those fibers can be springy, push down, pop back up.

If that is correct what might be a good starting point for an allowance.

Hard to say actually. But keep in mind that when you adjust size you should always recut both pieces. That said remember that any size adjustment you make is actually quadrupled. Each side of the slot on both pieces. So it is advisable to make very small changes, like a thou at a time unless you can see that it is REALLY off.
Jeff
"If you see a good fight, get in it." Dr. Vernon Johns

User avatar
WNC_Ed
Vectric Craftsman
Posts: 296
Joined: Fri Dec 07, 2018 5:56 pm
Model of CNC Machine: Shark HD4 AXYZ 4010
Location: Western North Carolina - Heart of the Smokies

Re: Box joint gadget.

Post by WNC_Ed »

Ted, great point and worth repeating ... so here it is:
That said remember that any size adjustment you make is actually quadrupled.
Maker of sawdust

Post Reply