Slip Ring Collector

[jenkinswt]

I've had to do a couple temporary repairs to my Jacobs slip ring collector in the last year. The original I believe was supposed to have a brush material to rub against the brass rings. The "temporary" repairs usually last 6 months or so. Its usually the positive collector that it wears or probably arcs a lot of the material off. I've just been soldering pieces of copper or brass onto the tips and putting the assembly in a spindle sander to half way align all 3.

I noticed the other day I wasn't getting power again when it was windy so I shut the tail and last night I was able to climb up and take the collector off. This time I need to make a better repair as the copper bar broke. I will attach a picture of what I believe its supposed to look like, mine just didn't have the brushes on the copper bars. I believe its berryllium copper flat bar bent into a v shape with a copper carbon brush of some sort attached. The bars are 1/2" wide about 1/16" thick. I think I need to use berryllium to make it "springy". I know this is long winded but what I wanted to do was order some of this and bend the shape I need and attach a starter brush to the tips. I don't know how to attach the brush to the tips?

Can the brush be soldered or pinned in some way? I can get starter brushes locally but I doubt I can get the bars. I'm tempted to make anything temporary also as I have limited working room at the tower top and am planning a freestanding tilt tower at some point, then I could probably order a nicer slip ring setup and attach.

[Adriaan Kragten]

The whole slip ring construction can be cancelled if you use a flexible cable in between the head and the tower foot. I have used an about thirteen metre long cable with 4 * 4 mm^2 flexible copper cables and a rubber casing with an outer diameter of about 16 mm. The tower height was 12 m. This cable could be twisted about 50 revolutions without problems. If you make a loop in the cable with a connector at the lowest point, you can easily see when the cable twist is too strong and then disconnect the connector and allow the cable to twist back. If there are no slip rings, you also don't have the extra resistance of the contacts.

Three of the cables were used to guide the 3-phase current. The fourth cable was connected to the star point of the generator winding and therefore it was possible to make short-circuit in between all six coil ends of the 3-phase winding which results in the highest braking torque. The cable has worked for about fifteen years without problems but finally the rubber casing got cracks because of the ultra violet radiation and may be also because of the twisting.

[jenkinswt]

Yes, I've really considered that as well. Currently though the cable that furls the tail sideways runs through the inside of the slip rings and I would have to do the tail differently if I bypassed the slip rings and went with flexible cable. It seems most people have had good results with a flexible cord with a plug at the bottom of the tower. Another consideration if I went that route is I would probably need something like a pipe in the center of my tower to house the cord to keep it from flopping around.

When I get a different tower I would like to possibly use slip rings like the attached image but for now I just need to throw something back up there to temporarily use it again. I found these on ebay but they have to be ordered from china which I've never done, not sure how well that would work. I'm sure there's something similar in the US but I haven't found anything yet.

[Mary B]

Ebay from China take 13 weeks usually and most eBay sellers are safe. Product quality? Hit and miss... and forget returns, shipping back will cost more than the item.

Berylium copper sheet .010 thick. I have used it for spring contacts in ham radio amplifiers... https://www.amazon.com/Beryllium-Copper-Sheet-12-010/dp/B00H3KOYES