The fillets in the previous update do not meet my spec in this area. So I had to take the model back to the point in time of creating the back panel. There is a limitation in FreeCAD that I had to find a work around for and in this case turning the back panel to 30mm from 20mm thickness did the trick. Now I can set 40mm fillets instead of 9mm. The updated pic shows the new internal fillets
Internals for the speaker sections are mostly modelled now. The following pics show how the 90 degree bend in the heatpipe is formed, how the fillets merge with the pipe and internal walls and how the active driver cutout and step recess is formed. I have chosen a 20mm rebate step instead of flush to allow some depth for excursion
No, this issue is not a flaw in the program. That's how the fillets work. When you select an edge and fillet that, a pair of lines in the model are formed at the fillet widths. The lines from another fillet cannot superimpose or pass over. One line can approach another to any decimal point but never the whole number or beyond. When I curved the cab sides using fillets, a line got set near the rear inside curve. New fillet on the inside corner got limited to 9.999999999mm as the line was 10mm away from the corner edge line. I resolved this by going back to the back panel that I had extruded through the cab. This was going to be 20mm bamboo panel. By extending the width to 30mm, I managed to extrude it over that line and swallow it up. The new inside corner edge now has moved 10mm and no longer restricted by any lines from previous fillet and I could now set my 40mm radius work out from my scantlings for this project
Now that I am aware of this limitation, I can use it better. Next one that I draw like this will have all these initial lines placed inside points of future extrusions and carves. I hope this makes sense
The FreeCAD app is very capable but very chaotic in interface. It seems to be made up of modules (workbenches) coded by different folks. The modules aren't very consistent with each other. I think I have worked out the parts design bench fairly well now but can really feel the combined weight of these limitations for prototyping. This is a program for drawing an already designed item. Have a look at the FreeCAD templates done by other members for flat panel speaker boxes. The use of spreadsheet and all that is a very mature process for FreeCAD
Unfortunately, the only progie that seems aimed at prototyping is SolidWorks. It really is worth the money they are asking, and my hobby is important enough to me to work towards this
That's it, the rear panel is complete and so is the speaker section of this cab. Onto the electronics bay now. Version two electronics bay will be fairly roomy. At the moment, I am leaning towards an FFA001 module to drive the mains and FFA002 channels for the subs DVC. Two pairs of custom banana outs for the mains. Stereo XLR ins from the mixer and a DSP based xover inside. A neat addition will be a pair of banana sets for switching the internal amp to drive a larger external passive sub
One option here is to just print this whole thing. My scantlings allow for an all printed sandwich, and v2 allows for it. The electronics bay can be printed on its own and attached. The scantlings for print is what I have worked out for my marine parts. The spec is PETG as filament done at 240 degrees Celsius (80mms on a CR6-MAX) with 30% infill and 2mm walls (5 lines at .40mm with stock CR6-MAX). There will be a lot of support material used. Forget about printing in sections and gluing together. That's not for PETG. This can be printed in PLA and glued together but not for mobile use and must be painted well to slow down breakdown over time. I have no experience printing ABS so cannot comment on that. The most effective way to build this cab is manually building the sandwich using a mix of machined and printed parts and this will the method used
After a day of headbutting with FreeCAD. This is how far back I need to cut the model back to start the electronics bay feature. This time I think it's a program bug, as the extrude to a face function does not work as expected. I have extruded to a curved face before, so didn't expect it to not work
Doing it at this stage is super easy though. What I will do is save this as a new file, create the electronics bay and then carve away the cab to end up with a two part model
Studying this further as maybe I am not using this function correctly. Made a test case curved panel and extruded to it. A regular extrusion using the dimension option works as expected. Creates a slab and the highlighted face gets carved away next. I'll use this way to create individual side, fore and aft panels for the bay
Extruding by using up to face and both checked and unchecked for the reverse box does nothing
I will explore this some more and see about sending a link to this message
Extruding by using up to face and both checked and unchecked for the reverse box does nothing
I will explore this some more and see about sending a link to this message
Now I remember reading this about 59 years ago, but don't remember why you started designing a speaker to like it..