E-cab luvin

[chunkstyle]

To follow up on the dropped tenon shoulder cuts I think it's solved. Big thanks to Kenneth.
My .25" M.C. compression was set up as .253" in diameter. Changing the bit diameter to .25" allowed the cut to be made. Why it didn't throw up a tooling error I have no idea. The tooling tolerance setting is set to .01", also.
Spoke to the Thermwood shop and the owner mentioned that the pocket cut for the tenon shoulder has a boundary and perhaps it is becouse the boundary is at .25" and not .253"? That would make me wonder, though.

Why no tooling errors?
Is a .375" diam. bit not able to mill out a shoulder for a .25" long tenon? I would like to think it could.
Does the code not get written from the data in the tooling? Why would it skip the pocket altogether if the tolerance is set to .01" and my tooling is only over by .003"?

I'll drop a line to TW and let them know the results.

Tim


P.S: Email from TW just arrived as follows:


Tim,

Try changing your tool diameter from .253" to .25" or less. This should
take care of the tenon problem.

If it doesn't, let me know.

Thanks,

[Gary Campbell]

Tim...
I was going to have you send me a cab file, as I was sure what your problem was. I guess it is obvious now, but the tenon cannot be shorter than the diameter of the cutting bit.

Since parts are nested an outline bit diameter and a few thousandths apart, cutting geometry with a larger bit wont work. It would be nice, but is not available as a feature at this time.

In case you are wondering, the reason the parts were able to be cut on the TWD machine and not yours is simple..... The TWD operator was not trying to trick the software by adding erroneous bit diameters.

I am VERY happy to see Kenneth help you solve these problems. (he knows why) Send him an email and ask him how much easier life is when you decide to live it within the realm of supported features in a software package rather than trying to force your own wishes, methods and logic into something that was written not for you persoanlly. You have the makings of a very good combo with eCabs, the SB Link and your ShopBot. Those that have traveled this path before you would advise you... "Don't fight the software"

As a side note, if you need the tooling set to .253 to get accurate dado widths, set your tenons to that number, those 3 thou. will be absorbed by the depth clearance easier than gaining 6 thou. on the width

[chunkstyle]

Thanks for the help Gary,

Actually, I did not think that it would matter what the bit diameter for setting the tenon lengths. It is all X,Y direction. Now getting a .253 to cut a .25 inch dado is another matter. Without evidence to the contrary, i would assume that the software would no where to put the tool path to account for the extra .003". The tolerance setting could also be construed to allow for this, no?

I am not trying to get the software to conform to my thinking. Rather the other way around. I have been up against this problem for about 3-4 weeks now and have talked to TW about it and sent the associated files to be looked at. All of which is appreciated.

Question is- Why no tooling error? Again, not fighting it (been there done that ) merely trying to figure out what has been going wrong. There was no feedback from the system to give an indication where to find the problem, correct?

I have been wondering all day about those shelves mentioned earlier that had this same operation skipped on the front edge. Here we have a .253" bit cutting out 55% of .72. I will look into this some more, given the time, to see what could have been wrong there. I'll isolate the part in the link nest and run it again. See if I can replicate this problem.

Not fighting it brudder. Learned along time ago how resistant software is to outside considerations. It's not my first time to a rodeo where technology, in the form of chips and code, had replaced earlier modes and methods of doing things. All of it in film and graphics, from personal experience. Adapt, improvise and overcome right?

In this case, there was no obvious feedback for what was going wrong. At least to me anyways. Sometimes things do get set up for failure, not realized until it's happened. Guessing we've all been there. Is it the failure of the user or is there something in the design of the user interface?

Glad to find this one. Hopefully, the other one will get sorted out as well. Trust me, this isn't the first time a file of mine has blown up on the launch pad and I've had to figure out why. Thermwood has the patience of Noah helping me out over the years. I hope they will continue to help me. I love trying stuff in E-cabs. So much so that I bought a SB. So much that I'll be critical of it, if that makes sense.

Thank again for your insights and inputs. It's always appreciated and helpful.

Tim

[ken_rychlik]

Tim,

It will let you use a .25 bit for a back rabbet/dado that is only .2 deep. i apply some cabient backs this way and they changed the programming to allow it on an outside of a cabient side. The dado overhangs the part before it is cut out.

Maybe the same thing could be done for a tenon?? If you tell them you would like to be able to use a 3/8 bit to cut the tenon and let the bit hang off of the part, they may work it into the next release.

I am thinking you were telling it you had the wrongs size bit to make your parts fit together.

Use the correct bit size and make your fit adjustments within ecabinets settings. "construction settings"

Once you get it dialed in, life is good.

I have been through about 10 reports with thermwood and 3 of them turned out to be bugs. The other 7 were operator error.

[Gary Campbell]

Tim....
"Actually, I did not think that it would matter what the bit diameter for setting the tenon lengths. It is all X,Y direction. Now getting a .253 to cut a .25 inch dado is another matter. Without evidence to the contrary, i would assume that the software would no where to put the tool path to account for the extra .003". The tolerance setting could also be construed to allow for this, no?"

In short NO. As we spoke of before, the tenon has no clearance etc applied to it. It will be the programmed width and thickness set in eCabs. You need to remember dados are pure rectangles. They will NOT go off the edge of a part, due to close nesting tolerances. They cannot encroach on the interior of the part. If you select .25 as the tenon depth an exact .25 rectangle is placed on the edge of the part. Period. Your selected bit must be equal or smaller. Period. It is this way with every CAM software that I have looked at. You cannot cut the interior of a .250 rectangle with a .253 bit with any one of them. How or IF they report an error, varies with the App.

The software does not know where to put any extra amount, even .001. Your extraordinary ( .010) high tolerance number may have supressed the error. Set this from 10/1000 to a realistic number under 5/1000. You have agonized over .006 variation in a dado width, (which is .003 X 2 sides) why accept .010 in your tooling?

As a side note, I would prefer to cut my tenon dados with a .375 dado as Kenneth desribes, so would a good number of guys on the TWD 3 axis forum. If we add this to our wish list as they have.... never know.. we might get it.

I have a 5mm compression bit mounted as my "dummy" bit. In other words, if the designer was a dummy, the ATC can compensate for him. I prefer not to say how many times it gets pulled from the rack!

[chunkstyle]

Gary,

To recap what you said and gut check my thinking on this, the tenon length set up in E-cabs construction settings will determine the size of the boundary box for the tenon shoulder cuts?
The bit diameter is not factored into the boundary box, only the tenon length Dado depth in construction settings). Correct?

What are you referring to regarding the .375" tenon dado's? It's e-cab easy, just multiply your material thickness by a tenon percentage thickness to get to .375". What could be more simpler? Less of course you change the thickness of the material at the twd. Your dado's will be .375" plus any fit clearance added right? Or are you referring to the boundary box to create the pocket operation for your tenon shoulder cuts? Cutting a shoulder on a .25" long tenon with a .375" bit?

It was a long way to the well but I think I got there. Thanks for the help and patience,

Tim

[kerry_fullington]

Tim,

Here is a link to a thread on the Thermwood forum discussing the larger bit situation. It is a little confusing also but the gist is that at this time you can't use a larger bit .375 to cut a .25 tenon on blind dado. They are hoping to get this ability implemented.

http://www.thermwood.com/forums/view...hp?f=7&t=11752