Acoustat factory photos

[Few]

Perhaps I'm the only one who hasn't seen these photos showing the assembly of an Acoustat panel, but I couldn't find any diyAudio references to them. I really can't figure out how they escaped my attention until just now. Anyway, those who haven't already seen them and who spend time dreaming up ESL design and construction ideas may find them of interest.

http://www.audiocircuit.com/A-HTML/A...ory_-P-A01.htm

Few

[moray james]

Few: you can make up a couple of jigs with some plywood and a some 1/4 - 20 threaded rod. One at each end of a length of louvre and you can wind 30 gage heavy build magnet wire and have 20 wires per inch rather than the poor 5-6 that Acoustat used. If you want more wires then use a 1/4 - 32 threaded rod and bingo you have 32 wires per inch. You can buy large rolls of magnet wire from motor rebuilding shops amongst other sources. Note that this method requires that you solder all of the wires together at the ends so a small solder pot would be a good investment then you can dip solder an inch worth of stator wires at a time and then connect them all together with a small iron.
Note also that the horizontal piece of threaded rod is simply a guide/spacer for the wire. You will need to fit your jig base plate with some small hooks or screws at about one per inch across the back side of the threaded rod so you can bring your wire off the threaded rod then around the hook and back to the next thread on the rod. This is simple fast and easy to tension by hand. You then need to use your imagination to decide how you want to fix the wires to the louvre. There are lots of options. Acoustat's solvent and louvre scrap is straight ahead and works with a proven track record. I think that there are simpler ways but everybody has their own ideas. Regards Moray James.

[wolf_moses]

Moray, could you post some pics or drawings of your wire stator building method?

Also, could you post your simpler ideas of glueing the wires?

Thanks.

[moray james]

Wolf this is a pretty simple jig. Lets assume that you are wanting to wind a stator the same size as an Acoustat panel to start. You will need two identical jigs one for each narrow end of the louvre panel. The jig needs to consist of a base plate (say plywood) and a block that holds a length of 1/4 - 20 theraded rod the width of the stator panel and at the same height as the louvre panel. The block holding the threaded rod needs to have a groove or slot (horizontal) in its top to act as a seat to hold the rod. The depth of the slot needs to be about half to two thirds the thickness of the rod. The rod needs to be epoxy glued into this slot. You need the block with the slot to hold the rod and keep it from deforming under the stress of all the wires that you will be winding. The block is mounted to the base plate and butts up against the end of the louvre panel. To the back side of the block (away from the louvre) you will need a horizontal row of small hooks spaced about one every inch. These need to be screwed into the base plate. That's the whole design. The purpose of this jig is to hold the section of threaded rod in a horizontal position at the end of the louvre panel at the same height as the louvre and to provide hooks to act as anchors for the stator wire. Remember that the threads of the threaded rod are only acting as guide spacers for the stator wire, simply a series of small grooves at each end of the louvre panel. To wind a stator first anchor your stator wire to the first hook at one jig and line your wire up with the first thread of the rod. Run the wire down to the opposite end of the lovre and onto the first thread groove of that jig and then off and around the first hook and then back to the second thread on the rod. This process of serpentining back and forth between jigs goes on until the stator is wound. Hope that this helps. Regards Moray James.

[wolf_moses]

Thanks, Moray. Big help.

Regards,

[SY]

How do you tension the wires? Just a good, hard pull?

[moray james]

you got it Sy remember this is only 3o gage wire and hand pressure is lots to keep it tight and firmly pressed against the stator. Regards Moray James.

[Bazukaz]

Hi,
Since i have no digital camera now , i'd like to explain the method i use.
The jig is very simple - it contains two wooden balks with threaded rods at ends. One threaded rod is fixed , while the other is made moveable.The moveable rod can be pulled with two large screws with hooks.
Two light louvers are placed on the jig , with few wooden sticks between them so that louvers would bend slightly. Then the wire is wound on both stators at once , and additionally stretched with screws.
One note : the threaded rods must be thick enough , or they must have additional steel support.The tension force becomes very high when there are so many wires.

Regards,
Lukas.

[Few]

Instead of hooks and threaded rods, I've been wondering if 40-pin headers could serve as the "comb" shown in the first of the Acoustat photos. Their dimensions (0.025" diameter with 0.10" spacing) seem just right, and they're not overly expensive. Some way would have to be devised to hold the set of pins firmly so that they could withstand the wire tension, but they could serve as both hook and wire guide at the same time. If 23 gauge double build magnet wire with an outside diameter of about 0.025" were used, you'd have a stator with 50% open area (wire insulation included) and 20 wires per inch. Seems pretty reasonable.

[Bazukaz]

Hi,
Your idea may be quite good , if you find a way to fix the pin headers , and they prove to be strong enough.
Threaded rods work well . I chosen this method because the jig is very simple to build ( construction took about half a day , including buying parts , assembling and painting). Disadvantage of this method is that each wire must be cut at the end and soldered.