No, you do not have to have a 1 inch throat - that was just my back of the envelope estimate of what the throat width is. As I recall, the full scale Cornu (27.6 in) has a throat of 1.2 in and scaled x 22/27.6=0.96 in. If you can get the driver to fit in the chamber then build it as is, no trimming of spiral needed.
Hi Cal,
Unfortunately the only foam board that I've come across is the 'deluxe' type with the heavier smoother/plasticky facing
The only other option would be Depron, which is XPS foam used for RC model building.
The thicker faced paper can work just fine. I have used it and it just requires more pressure with a knife when scoring the lines for the bends. It makes a very sturdy baffle though - feels much more solid than the cheap dollar store stuff. Go for it!
The thicker faced paper can work just fine. I have used it and it just requires more pressure with a knife when scoring the lines for the bends. It makes a very sturdy baffle though - feels much more solid than the cheap dollar store stuff. Go for it!
Thanks for the reply. Good to hear that the stiffer foamboard will still work.
The TC9FD's are on the way from Germany
Now I just need to source a glue gun and get the foam board.
Out of interest how many glue sticks did it take you guys to build your spirals?
Toolstation do 100 sticks for £4.50.. a REALLY nice glue gun for £22 http://www.toolstation.com/shop/Professional+Glue+Gun/p29000
and a craft knife hobby kit for £11
51 pieces ..http://www.toolstation.com/shop/Hobby+Knife+Set/p58235
.. I'm in Chelmsford .. Hobbycraft do 3 A1 sheets for £8 too..
They also do this glue gun http://www.toolstation.com/shop/Hot+Melt+Glue+Gun/p24076
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Toolstation do 100 sticks for £4.50.. a REALLY nice glue gun for £22 Toolstation > Hand Tools > Carpenters Tools > Professional Glue Gun
and a craft knife hobby kit for £11
Toolstation > Hand Tools > Knives & Blades > Hobby Knife Set
.. I'm in Chelmsford .. Hobbycraft do 3 A1 sheets for £8 too..
They also do this glue gun Toolstation > Hand Tools > Carpenters Tools > Hot Melt Glue Gun
Thanks for the info, I've sourced a gun and glue courtesy of Amazon. Much as the tool station gun is nice I can't justify £22 on a tool for a budget build. Maybe if the foam core addiction kicks off I'll upgrade
As I mentioned earlier the local art shop does ~A0 sheets of foam core for £6.50. So I'm going to source it there as I can pick and choose the sheets to get the best edges and it saves on delivery charges or a car journey to the nearest Hobbycraft.
I've also sourced a local printing company who can print out the 20" spiral templates for a few quid to save me having to stitch several print outs together.
Speaking of the templates, my next question is how was everyone transferring the design to their foam board? I think I saw it mentioned earlier in the thread that Cal was using a pin to put marks on the board from his template.
I was thinking of gluing the printed templates directly to the board and then working on top of them.
I just printet the scaled pdf in 1:1, tapet it in position and ran a knife along the spirals, this scored a easily traceable line on the surface
Thanks for the reply. You've given me an idea of using a serrated tracing wheel to transfer my spiral to the foam board.
An externally hosted image should be here but it was not working when we last tested it.
The TC9FD's arrived today
Got the templates printed and trimmed to size. The foam board is in the spare room. Just waiting impatiently for the glue gun and glue to arrive, it's taken Amazon 4 days to dispatch items that were in stock
Looking at the driver dimensions and the template, I was wondering do you need to remove some of the first part of the inner spirals to allow room for the driver?
Got the templates printed and trimmed to size. The foam board is in the spare room. Just waiting impatiently for the glue gun and glue to arrive, it's taken Amazon 4 days to dispatch items that were in stock
Looking at the driver dimensions and the template, I was wondering do you need to remove some of the first part of the inner spirals to allow room for the driver?