Finger/Box Joint Software

[scottp55]

It's only going to hold sanding accessories, mask and ear protectors, so wasn't concerned about strength, Just wanted to try out a fancier one

[srwtlc]

When did the job type error happen?

It happened when I chose to generate code and didn't select a job type. Upon first launch, there was no default job type selected and I may also have saved as default without having one selected either. Just intended to save default machine settings and not a job type.

How if I parse the comment text (normally just for general purpose text) and for every piece of text within parentheses I just paste that piece as a line at the beginning of the g-code. Then you can put any special shopbot code in that you need. Would that be useful?

Give an example of what you're thinking. Not sure I'm following.

I am not sure how that is meant with top and bottom margin the same.

I'll have to take a closer look at that. Everything I tried didn't give a mirror image of the top fingers.

[Burkhardt]

It happened when I chose to generate code and didn't select a job type. Upon first launch, there was no default job type selected and I may also have saved as default without having one selected either. Just intended to save default machine settings and not a job type.

I'll fix that. Not sure under which circumstance it will not set any of the job types but if it does it will try to close a g-code file that has not been opened. Thanks for the tip!

Give an example of what you're thinking. Not sure I'm following.

I need to try it out. I will post when that is implemented.

I'll have to take a closer look at that. Everything I tried didn't give a mirror image of the top fingers.

Have a look at the attached pics. The top and bottom are perfectly symmetrical. That what you meant?

[srwtlc]

I guess I'm getting totally confused with the relationship between fingers per pattern, total fingers, and the two finger length columns.

In your comment box, if you could 'enter' for another line, then we could just save defaults to have....

C6 or SO,1,1
PAUSE 3

They have to be on separate lines.

[Burkhardt]

I guess I'm getting totally confused with the relationship between fingers per pattern, total fingers, and the two finger length columns. .....

Sorry about that. I need to find a better way to explain the concept, maybe with a sketch. In short:

A "pattern" is a set of minimum 2 and maximum 19 fingers of identical width that may repeat in a joint. For narrow boards and many fingers in a pattern this pattern may be present only once but if you have only a few fingers in a pattern it will repeated as often as needed to cover the necessary joint width.

The "no top" and "no bottom" margins are actually also fingers, but they don't repeat and can have different width. The top margin is the very top number in the finger list and the bottom margin is the last one. There must be as many numbers in between those two as the number of "fingers per pattern". I will see if I can arrange the list to read easier and maybe even grey out the boxes that are not needed. Please keep in mind, the 2 columns don't mean anything. They are just there to save vertical space on the screen. The only thing that counts is the vertical sequence. But I can see that is confusing.

Calculation inside the software is as follows:

- the top and bottom margin are subtracted from the board width
- the remaining joint length is divided by the "fingers per pattern" times the minimum finger width. That gives the max. number of pattern repetitions that can be used.
- the actual finger width is then increased so that the joint is evenly filled with fingers

There are probably 15 or 20 additional check calculations to assure the joint is actually feasible and I still can not catch all impossibilities.

In your comment box, if you could 'enter' for another line, then we could just save defaults to have....

C6 or SO,1,1
PAUSE 3

They have to be on separate lines.

That is a possibility. Actually I thought to do it similar like that: (C6) (PAUSE3)

[srwtlc]

That could be done, as long as they are placed on separate lines and then the SB user needs to remember to open the file in an editor and take out the ( ).

One thing to keep in mind here (speaking to SB users now), is that if you rely on C6 to turn on your spindle, it may not work reliably. This is because the C6 command as opposed to SO,1,# (# being the output # your spindle is on) relies on the variable &tool to be present in SB3 memory and if it isn't, the spindle will not turn on. The way this variable gets into memory is by way of a file that has been post processed from a TC (tool change) post processor and if you haven't run such a file before running something like a file from G's fingermaker or others that you may have added a C6 to turn on the spindle, it won't work. This is why it would be best to use SO,1,1 or whatever output your spindle/router is on.

[Burkhardt]

I changed it already for the next beta version (still needs some other fixes). But it will use a comment like in the first picture to create code like in the second picture. I suppose (hope) that using the M3 command after the spindle is already turned on with SO,1,1 does not confuse the controller.

[srwtlc]

That would work fine. Also, the M3 afterwards is fine, it just passes since it's already been turned on.

I ran a simple box test late today in some scrap red oak with a 0.375" ballnose (the only straight one I had). I thought I'd try leaving the material thicker and plane it down (one side) to finished thickness of 0.625 after cutting. I figured that with a 0.375" ballnose the overcut in depth would be approximately the radius of the bit + the overcut allowance so I started with my material at 0.8125" thick. I didn't check the file to see what the max depth was and noticed that instead of it cutting to a depth of material + radius, it was cutting material + diameter. I thought, lets try fooling it and give it a negative overcut for the next piece. I then noticed, that that also limits finger length and it wasn't cutting past the finger tips far enough. So, after cutting and planing, I had to do a little chisel work, but got it together. I had a little problem due to the fact that its past time for surfacing my table. I just pressed it together without glue for the pic.

I tried to shorten that larger middle finger/space, but only half if it would shortened as in some of your other examples where you have stepped fingers.

Sorry for the low quality phone pic.

[scottp55]

Nice Scott, Thanks for fooling around with the overcut to see what happens. Would you mind posting a pic of the screen with your settings when you get a chance? Be interested to see protrusion.glue gap, and overcut #'s . 3/8" doesn't give you many options. I can see someone buying small,long CEL BN's in the near future
G. , Any licenses left after Scott W's?

[Burkhardt]

....I didn't check the file to see what the max depth was and noticed that instead of it cutting to a depth of material + radius, it was cutting material + diameter. ......

Oh my, good find. That is a really ugly bug and I am not sure when that hatched. But the maximum depth should indeed be one bit radius plus overcut under the bottom surface of the boards. I never noticed because I usually have smaller bit and use a vac pod. Got to fix that immediately but there are several places in the program affected.

I have sent out 3 free licenses so far and if Scott W. cares to have one: please PM your email and mailing address.