Ping Calvin
Calvin: I had some questions about your dipole sub design. I think I figured out the lower Fs with small box issue......your design is a velocity transducer not a pressure transducer. I still have some questions about how you calculate the space between the two face to face drivers? Thanks Moray James.
Calvin: I had some questions about your dipole sub design. I think I figured out the lower Fs with small box issue......your design is a velocity transducer not a pressure transducer. I still have some questions about how you calculate the space between the two face to face drivers? Thanks Moray James.
frank ziel said:
Hi,
Thank you very much for suggestion.I will have it in mind.Strangely , it seems that there is no price list for their products on website... I will email them when i am interested in.
For now , i have spent most of my budget for plywood frames , so i will try to complete this project.
I managed to support the wire additionally.With 4.5 cm support points , it does not flex easy.
Regards,
Lukas.
Hi,
I have a question about panel capacitance calculation.I measured ~700pF capacitance for my stators with a digital multimeter.
Online calculator at http://www.woodsbas.demon.co.uk/calcs/permtvty.htm
Predicts , that the capacitance should be ~670 pF for two plates the size of my panel.(4 mm stator - stator distance).
But panel has only ~50% open area , so why capacitance is the same as for 100% coverage ?
Regards,
Lukas.
I have a question about panel capacitance calculation.I measured ~700pF capacitance for my stators with a digital multimeter.
Online calculator at http://www.woodsbas.demon.co.uk/calcs/permtvty.htm
Predicts , that the capacitance should be ~670 pF for two plates the size of my panel.(4 mm stator - stator distance).
But panel has only ~50% open area , so why capacitance is the same as for 100% coverage ?
Regards,
Lukas.
So long as the hole dimensions are small relative to the the stator spacing, the capacitance is very close to the same as if the stators were made of solid (non-perforated) metal. If the hole sizes are much larger than the stator spacing, the capacitance depends on just the area of metal in the solid parts of the stator. (eg. wire) Vacuum tube grids and screens depend upon this phenomenon too.
Can someone tell me
again why this wire stators are used instead of perforated sheet metal? Other than the fact that it looks different, I mean...
I_F
again why this wire stators are used instead of perforated sheet metal? Other than the fact that it looks different, I mean...
I_F
I checked at the nearest big box home center and they had 2' x 4' acrylic louvers sold by Lucite for US$7.88. About US$16 for enough material for a pair of 1' x 4' ESL panels, not bad for a ready to go ESL insulator. My stacked acrylic insulators had about US$20 of material and a lot of hours of routing and glueing.
After I got home, I looked at the egg crate louvers in our laundry room. I don't know if they are the Lucite brand, but they came from the same place. They had many small pairs of sharp points about one grid width apart on a 3 x 3 grid spacing. A little sanding would take care of them. The louvers in the laundry room are safe for now. I like them where they are. 😀
BillH: In which big box store did you find the acrylic louvers? My local Home Depot and Lowes only stock polystyrene eggcrate material. I discovered that McMaster-Carr sells the right stuff, but you have to buy an entire carton (typically ten louvers). Maybe if I go into business...
Also, are most of you stacking more than one section of louver material to achieve ESL heights greater than four feet? I started imagining trying to glue two sections together to achieve one six foot long piece of louver but since I intend to try a 1 mm air gap, I don't think I'll be able to achieve the necessary precision. I suppose I could make two separate three-foot ESL panels and place one above the other but that would yield a seam at ear level. I've done that before without major problems, but I hoped I'd be able to get away without it on this project. Ideas?
Thanks,
Few
Also, are most of you stacking more than one section of louver material to achieve ESL heights greater than four feet? I started imagining trying to glue two sections together to achieve one six foot long piece of louver but since I intend to try a 1 mm air gap, I don't think I'll be able to achieve the necessary precision. I suppose I could make two separate three-foot ESL panels and place one above the other but that would yield a seam at ear level. I've done that before without major problems, but I hoped I'd be able to get away without it on this project. Ideas?
Thanks,
Few
I've been thinking about six foot panels as well, so if anyone knows of a source for six foot acrylic egg crate, let me know. Maybe a group buy of a custom length could be arranged if a source could be found?
Take care,
Doug
Take care,
Doug
6ft would be a really odd size, make 4 panels the size you want from 4ft louvers and wire together as one in a frame.
Few, it was Menards. There's no online ordering, but you can check the website to see if there's a store in your area.
Here's an online store called Replacement Lighting that has what you need.
Here's an online store called Replacement Lighting that has what you need.
Well, I want 6 foot tall panels, not 4 or 8, so I don't understand how this would work. As well, I want to avoid the "dead spot at ear level" problem with stacking multiple panels.
Take care,
Doug
Member
Joined 2003
No dead spot at ear level with three two-foot panels. Perhaps easier to handle, depending on your construction method.
Thanks, BillH, for the response. There are no Menards stores near me so I appreciate the link to Replacement Lighting.
I had thought about the three two-foot panels approach but dismissed it because I thought it might require too much tedious assembly (twelve wire grid assemblies to put together). Perhaps I tossed the idea too quickly. Thanks for the ideas.
By the way, can I get away with the 3/8" thick louvers or is the stiffness of the 1/2" louver necessary? I'd rather go with the thin stuff if it's likely to work.
Few
I had thought about the three two-foot panels approach but dismissed it because I thought it might require too much tedious assembly (twelve wire grid assemblies to put together). Perhaps I tossed the idea too quickly. Thanks for the ideas.
By the way, can I get away with the 3/8" thick louvers or is the stiffness of the 1/2" louver necessary? I'd rather go with the thin stuff if it's likely to work.
Few
options
You could also consider a four foot and a two foot set of panels. I have never found there to be a problem with two panels vertically stacked as long as you are not right on axis when seated. Two three foot panels mounted about a foot up off of the floor places the dead spot above your ear when seated in a chair or sitting on the floor anyway. The 3/8 inch louvre makes an excellent panel which i prefer to the 1/2 inch thick material. Regards Moray James.
You could also consider a four foot and a two foot set of panels. I have never found there to be a problem with two panels vertically stacked as long as you are not right on axis when seated. Two three foot panels mounted about a foot up off of the floor places the dead spot above your ear when seated in a chair or sitting on the floor anyway. The 3/8 inch louvre makes an excellent panel which i prefer to the 1/2 inch thick material. Regards Moray James.
Hi,
For some time i was thinking about the right glue to bond wires to plastic louvers. I have found a few types of glue in advertising material shop.
The first type is Cosmofen PLUS HV http://www.oracal.md/oracal-eng/materials/index.php?p=p171
The second type is Acrifix 116
http://www.roehm.de/en/plexiglas/_d...p/391-21%20ACRIFIX%AE%20116_d+e+f+nl+i+sp.pdf
What do you thing about these glues ? Which (if any) is suitable
to bond PVC insulated wires to light louvers ?
Regards,
Lukas.
For some time i was thinking about the right glue to bond wires to plastic louvers. I have found a few types of glue in advertising material shop.
The first type is Cosmofen PLUS HV http://www.oracal.md/oracal-eng/materials/index.php?p=p171
The second type is Acrifix 116
http://www.roehm.de/en/plexiglas/_d...p/391-21%20ACRIFIX%AE%20116_d+e+f+nl+i+sp.pdf
What do you thing about these glues ? Which (if any) is suitable
to bond PVC insulated wires to light louvers ?
Regards,
Lukas.
Hi Bazukaz,
be carefull ! Most acrylic glues utilize solvents in order to make styrene or acrylic glueable. The solvent might attack the PVC, although its chemically very robust.
Capaciti
be carefull ! Most acrylic glues utilize solvents in order to make styrene or acrylic glueable. The solvent might attack the PVC, although its chemically very robust.
Capaciti
Hi,
Yes , i know this. I want to archieve a reliable bond to PVC wires.I have experimented with Epoxy diluted with acetone , but even this didn't give strong enough bond between styrene and PVC.
I have also made some experiments with super glue , but this is too toxic to work with , and still is not so good glue as it may seem.
For example , it would crack easily if cooled below 0 degrees celsius.
I would even use the method used by acoustat(styrene dissolved in dichlormethane) , but in my country it is restricted to buy this chemical without a special permission. Funnily , most of paint removers available in any shop contain dichlormethane , but i fear it may have some unknown additives.
I already wasted one light louver and a hundred of metters of wire because was not patient enought
Now i am trying to build a jig by using threaded steel rods , but still have to test how it works.
regards,
Lukas.
Yes , i know this. I want to archieve a reliable bond to PVC wires.I have experimented with Epoxy diluted with acetone , but even this didn't give strong enough bond between styrene and PVC.
I have also made some experiments with super glue , but this is too toxic to work with , and still is not so good glue as it may seem.
For example , it would crack easily if cooled below 0 degrees celsius.
I would even use the method used by acoustat(styrene dissolved in dichlormethane) , but in my country it is restricted to buy this chemical without a special permission. Funnily , most of paint removers available in any shop contain dichlormethane , but i fear it may have some unknown additives.
I already wasted one light louver and a hundred of metters of wire because was not patient enought
Now i am trying to build a jig by using threaded steel rods , but still have to test how it works.
regards,
Lukas.
Choose a solvent based adhesive for the substrate...
you are not going to find an adhesive that will bond to either styrene or acrylic and also to pvc. An adhesive that bonds to your louvre substrate that is a heavy syrup consistancy will encapsulate the wires onto the substrate (your louvre) and firmly hold the wires in place for a good 25 to 30 years at least. If you go to this address you will find just about all the useful information that I have been able to collect on stators of this kind. http://www.diyhifi.org/forums/viewtopic.php?t=300 Best regards Moray James.
you are not going to find an adhesive that will bond to either styrene or acrylic and also to pvc. An adhesive that bonds to your louvre substrate that is a heavy syrup consistancy will encapsulate the wires onto the substrate (your louvre) and firmly hold the wires in place for a good 25 to 30 years at least. If you go to this address you will find just about all the useful information that I have been able to collect on stators of this kind. http://www.diyhifi.org/forums/viewtopic.php?t=300 Best regards Moray James.
Hi,
I have bought Acrifix 116 glue.It is quite expensive( ~ 6.5 Euros for 100 ml ). After some tests , it revealed quite good adhession to louver material. The glue hardens in a few hours.
I found it being problematic to bond each spot where wire and louver cross. Some very few wires seem to glue between each other and not plastic louver.I think this is because glue is a little too viscous.
Regards,
Lukas.
I have bought Acrifix 116 glue.It is quite expensive( ~ 6.5 Euros for 100 ml ). After some tests , it revealed quite good adhession to louver material. The glue hardens in a few hours.
I found it being problematic to bond each spot where wire and louver cross. Some very few wires seem to glue between each other and not plastic louver.I think this is because glue is a little too viscous.
Regards,
Lukas.
I couldn't help but to bring this up. Please correct me if i'm wrong
Much has been said using verious glue including epoxy; will polyester rasin for fiberglass making be suitable? this can be diluted with aceton to good flowing viscousity.
It's cheaper the epoxy and easily available...
Cheers
Much has been said using verious glue including epoxy; will polyester rasin for fiberglass making be suitable? this can be diluted with aceton to good flowing viscousity.
It's cheaper the epoxy and easily available...
Cheers
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