@OLEGsan
Hi. You used 9mm thickness magnets, and 6mm thick by 15mm wide
iron pole pieces correct ?
Did you have any bending towards each other of the horseshoe assemblies,
narrowing of your 3.3mm gap ?
Hi. You used 9mm thickness magnets, and 6mm thick by 15mm wide
iron pole pieces correct ?
Did you have any bending towards each other of the horseshoe assemblies,
narrowing of your 3.3mm gap ?
Hi ppap64
Yes, the magnets ordered Ali 10x10x50 mm, the real dimensions are 9x9x49 mm.
Plates 15x6x250mm, it took 3 weeks, did not bend, a gap of 3.3 mm
Yes, the magnets ordered Ali 10x10x50 mm, the real dimensions are 9x9x49 mm.
Plates 15x6x250mm, it took 3 weeks, did not bend, a gap of 3.3 mm
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New rubanoid project
Hello Guys,
I’m following your thread for 2years. I decided to make a ruba. This winter I finally started the project.
- 40 pcs Chinese ali magnets 40x20x10 (39x19x9.6) with holes fixed with screws
- S235 45cmx10mm steel bars
For coil I’d like to use 30um alu tape cutted with vinyl cutter knife on DIY cnc. My friend is playing with his machine try to cut the alu tape (knife from ali too).
I can’t wait longer and I make a coil with 0.28 mm diameter copper wire. 14 turns x 2 coils connected serial. Resistance 7.8 ohm. Glued with epoxy to Canson paper. Weights 48 gramm. (1 empty sheet 125g/m 15.6g calculated, measured 16g). So it became heavy. At least I heard ruba playing today.,
No surprise, there is no highs. Low freq response is quite flat. (it has more bass then my 4” fullrange closed box)
I have big resonances at 115Hz and above. (double, 3rd etc.)It is visible, audible and the distortion chart shows them.
Do you have idea why I have this huge vibration/distortion, how to avoid?
Hello Guys,
I’m following your thread for 2years. I decided to make a ruba. This winter I finally started the project.
- 40 pcs Chinese ali magnets 40x20x10 (39x19x9.6) with holes fixed with screws
- S235 45cmx10mm steel bars
For coil I’d like to use 30um alu tape cutted with vinyl cutter knife on DIY cnc. My friend is playing with his machine try to cut the alu tape (knife from ali too).
I can’t wait longer and I make a coil with 0.28 mm diameter copper wire. 14 turns x 2 coils connected serial. Resistance 7.8 ohm. Glued with epoxy to Canson paper. Weights 48 gramm. (1 empty sheet 125g/m 15.6g calculated, measured 16g). So it became heavy. At least I heard ruba playing today.,
No surprise, there is no highs. Low freq response is quite flat. (it has more bass then my 4” fullrange closed box)
I have big resonances at 115Hz and above. (double, 3rd etc.)It is visible, audible and the distortion chart shows them.
Do you have idea why I have this huge vibration/distortion, how to avoid?
Attachments
Hi Borzi and congrats for the project. It really does look nice and very promicing. 😉
The huge vibrations may come from the wires comming from outside the coil to the fixing rods (or where you solder the fat wires from the amp) due to the huge magnetic fields generated by the motor. Keep them as far as possible from the plates and magnets.
If you are talking about vibrations and distorsion then check the coil because it may be rubbing on some particles accumulated in the gap or its rubbing by the plates because it may be uncentered well or it has bended because of the humidity. The canson is very absorbant thats why i treated it for antyhumidity. ( it may bend at the center even if you centered it well)... This is another reason for wich i recommend the cuts (other than hight frecvency improvements), because you can very easy detect faults, bends or metal particles...
The huge vibrations may come from the wires comming from outside the coil to the fixing rods (or where you solder the fat wires from the amp) due to the huge magnetic fields generated by the motor. Keep them as far as possible from the plates and magnets.
If you are talking about vibrations and distorsion then check the coil because it may be rubbing on some particles accumulated in the gap or its rubbing by the plates because it may be uncentered well or it has bended because of the humidity. The canson is very absorbant thats why i treated it for antyhumidity. ( it may bend at the center even if you centered it well)... This is another reason for wich i recommend the cuts (other than hight frecvency improvements), because you can very easy detect faults, bends or metal particles...
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nice dude ! might be rubbing ? but at the same time paper starts to act weird down low where the thing acts more like a piston (or at least tries to) maybe some dampening? some heavy pieces of foam tape or anything. only the center plays high freq, you can do whatever with the rest of the thing in terms of adding stuff/weight.
greetings from the netherlands !
oh yeah serg forgot about that, the wires can make loads of noise 🙂 try finding that frequency in REW put it on and start hunting it down.
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Good point my friend Wrine, Borzi you cannot go fullrange with this size... The membrane will be blown outside the gap like cannons do (tried this). 😀
If i think twice, now, the first 1 foot ruban from the 1927 year with classic "o"shape neodim magnet and thick cardboard should kick in some serious open baffle bass, and if two magnets per speaker are used you will deffinetly gain 3dB in bass..😉
Its quite a nice and slim bass compared to a bigger than washing machine IB box.
If i think twice, now, the first 1 foot ruban from the 1927 year with classic "o"shape neodim magnet and thick cardboard should kick in some serious open baffle bass, and if two magnets per speaker are used you will deffinetly gain 3dB in bass..😉
Its quite a nice and slim bass compared to a bigger than washing machine IB box.
Borzi try a single coil of about 0.18mm copper wire. It should give you lower mass and about 40w sinus power wich i think its more than enought..
0.22mm will give you 100w and so on. These dims are with enamel taken into account so 0.22mm is enameled copper not the actual almost 0.2mm stripped copper.
0.22mm will give you 100w and so on. These dims are with enamel taken into account so 0.22mm is enameled copper not the actual almost 0.2mm stripped copper.
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i can hook you up with aluminium wire to, got some 0.15 0.17 rather easy to create a coil. thinest after is getting big again 🙁 0.310
Thanks for the comments.
Yesterday I try to find the root cause of resonance.
Without success.
Modified rubber band, change foam dumping on side to more softer.
Modify the width. (more butterfly or more round)
I think the problem is: I not perfectly glued the coils and the to half to each other.
I have 0.2 mm copper wire maybe I will make a trial before the alu foil coils will be ready.
My friend told me seems he is able to cut them whit his machine with the Chinese vinyl knife. He fixed the alu tape with 2 sided tape, and the cutting works.
He just convert the latest wire design what I draw in Inkscape to his machine.
I have Xeros never tear 95 um 125g/m2 I'd like to try this as well. Not necesarry to impregnate.
This material feels 50% thinner then similar weight Canson paper.
Yesterday I try to find the root cause of resonance.
Without success.
Modified rubber band, change foam dumping on side to more softer.
Modify the width. (more butterfly or more round)
I think the problem is: I not perfectly glued the coils and the to half to each other.
I have 0.2 mm copper wire maybe I will make a trial before the alu foil coils will be ready.
My friend told me seems he is able to cut them whit his machine with the Chinese vinyl knife. He fixed the alu tape with 2 sided tape, and the cutting works.
He just convert the latest wire design what I draw in Inkscape to his machine.
I have Xeros never tear 95 um 125g/m2 I'd like to try this as well. Not necesarry to impregnate.
This material feels 50% thinner then similar weight Canson paper.
Hello Borzi1024
Screws fixing magnets from non-magnetic material?
I think the idea of using magnets with holes is unsuccessful.
Here is my reel, with a device for winding.
Wire is 0.14mm, weight is 1.6 gr.
[/url][/IMG]
Screws fixing magnets from non-magnetic material?
I think the idea of using magnets with holes is unsuccessful.
Here is my reel, with a device for winding.
Wire is 0.14mm, weight is 1.6 gr.
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Hello Olegsan,
Of course the screws are non magnetic. (stainless steel)
The motor feels enough powerful with screws.
I get magnets with holes, because I found them cheapest. (40 pcs N50 40x20x10 magnets 87 USD)
The sound pressure with 8 ohm ruba and my 4 ohm closed box with same volume settings sounds approximately same.
So I do not think I loose too much magnetic force due to the screws and holes.
I will make later calibrated sound pressure measurement to see the real sensitivity of rubanoid. I can borrow a calibrated sound pressure meter.
Thanks for your jig picture I made similar one.
Of course the screws are non magnetic. (stainless steel)
The motor feels enough powerful with screws.
I get magnets with holes, because I found them cheapest. (40 pcs N50 40x20x10 magnets 87 USD)
The sound pressure with 8 ohm ruba and my 4 ohm closed box with same volume settings sounds approximately same.
So I do not think I loose too much magnetic force due to the screws and holes.
I will make later calibrated sound pressure measurement to see the real sensitivity of rubanoid. I can borrow a calibrated sound pressure meter.
Thanks for your jig picture I made similar one.
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Hello Borzi1024
Screws fixing magnets from non-magnetic material?
I think the idea of using magnets with holes is unsuccessful.
Here is my reel, with a device for winding.
Wire is 0.14mm, weight is 1.6 gr.
[/url][/IMG]
He nice bobine!! Looks beter theb my atemps !!!
Wel, if none of the issues that Wrine and i posted works than this is for shure your issue. After reading that you used epoxy i thought that the coil shoudnt have bonding issues.. I thought that this should happend only when using super glue, because of the fast drying..
I'm glad that you found out whats causing the prob.
Borzi and Oleg, please dont forget to post some pics with your attempts and work as we did. It should help others that are willing to try.
I used the wire 0.14.
17 turns of 8 ohm. For me, the width of the winding of the coil is critical.
Plates 6mm mean the width of the winding should be less than 6mm.
It turns out 17 turns should be packed in 6 mm.
For this reason, I can not use a foil spool.
Although I have 2 side-foil fiberglass 0.55 mm.
17 turns of 8 ohm. For me, the width of the winding of the coil is critical.
Plates 6mm mean the width of the winding should be less than 6mm.
It turns out 17 turns should be packed in 6 mm.
For this reason, I can not use a foil spool.
Although I have 2 side-foil fiberglass 0.55 mm.
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