Been playing around with some of the spare neo magents I have got from a previous purchase for my ribbon tweeter.
So came out with a 6.5" fullrange custom built without really burning my pocket.
Sizing of the motor using Neo Magnets
AutoCAD design and sending for fabrication
The Hamburgers looking motor
So came out with a 6.5" fullrange custom built without really burning my pocket.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Sizing of the motor using Neo Magnets
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
AutoCAD design and sending for fabrication
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
The Hamburgers looking motor
An externally hosted image should be here but it was not working when we last tested it.
Initially I used GR10 phenolic for the damper... but the flexural strength just too small... end up I use LE phenolic sheets
An externally hosted image should be here but it was not working when we last tested it.
Design and fabricating the Basket
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Designing a mold and jig for the folding of the cone
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An externally hosted image should be here but it was not working when we last tested it.
Gluing up the cone and the voice coil using hemp paper
An externally hosted image should be here but it was not working when we last tested it.
Add in the whizzer cone and the overall weight (6.3grams)
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Close up on the Phenolic damper (Spider)
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Some quick measurement I made
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An externally hosted image should be here but it was not working when we last tested it.
Beautiful work! The motor parameters came our quite nicely. Are the motor and magnets held together with self magnet force or did you also bond with glue? I like the spider - I have often thought the whole speaker sans magnet and motor and VC could be 3D printed in one shot (including cone). The sound is nice - do you have any measurements in a sealed box or large baffle so we can see frequency response?
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Will do
The motor and the magnets are hold up by the magnetic force and the groves to prevent them moving to the pole piece. You can see in the CAD cross section picture below:
An externally hosted image should be here but it was not working when we last tested it.
To put in the N42 ring magnet for assembly is quite a Nightmare. You can imagine the inner ring of the magnet keep getting attracted to the pole piece.
3D printing might be handy for fabricating the speaker basket, but that's limited to plastic 3D printing at the moment.
The damper is one of the main design(I believe), as I find the damping capability is somewhat better than normal conventional speaker damper(spider). It returns to equilibrium much faster, from observation when I inject low freq music.
Another importance to the design the paper voice coil, the sound impression has more natural feel to it with a blend of fostex + lowther texture. But downside is they can get destroyed easily as seen in lowther fullrange.
I will be planning to measure up after my phase plug and binding post terminal is machined out by this week. And probably do up a tapper tube enclosure for it.
Its measured using WT3, I did a full TS measurements but since I missing the phase plug and the lead wires are still dangling outside performing the measurements might not be fully accurate. But for now the Fs, Qes, Qms and few other TS parameters are pretty accurate.
The WT3 test you see if just to help me measure the pairs up to see if there is any mismatch.
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Some of the try and error in the damper design, before I decided to use LE Phenolic sheets(below)
I did many test in cutting the cone with various circle cutter before I end up using the Jacs Circle Cutter
https://www.amazon.co.uk/Jacs-Circle-Cutter/dp/B00GMM9WEA
An externally hosted image should be here but it was not working when we last tested it.
I did many test in cutting the cone with various circle cutter before I end up using the Jacs Circle Cutter
https://www.amazon.co.uk/Jacs-Circle-Cutter/dp/B00GMM9WEA
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TS parameters measured in post 5
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TS parameters , not the complete measurements.
VC is almost same as magnet height, gap height is 6mm and vc is 7mm.
I been trying to source self bonding enamel wire which is alcohol activated. But i have to order a minimum of 5kg.
The process now is i have to coat the vc with enamel myself.
An externally hosted image should be here but it was not working when we last tested it.
This is what happens when trying to assemble the neodymium magnet on the motor.
Indeed, imagine using more powerful magnets like N48 or N52. Can't even get them close to the assembly and they snapped to the pole without warning.
Even now I still have the fear when trying to assemble them even I made a few ribbon tweeters using N52. All those pinching bruises...
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