A tip on atty rebuilds and a request for help on 901

[tonyorion]

After a few false starts and getting a feel for dismanteling and reassembly, I have my 510 rebuilds down to less than a half hour. Done 6 good ones in a row now, after a few botched attempts-mostly due to shorts caused by the mesh touching something. I got a little lazy and tested only for continuity, not the actual resistance.

One thing that really helps is having a pencil torch like the Bernzomatic. It does make soldering a bit easier because of its compact size and high heat. It makes soldering to the base really easy, although I use a regular soldering iron for the nichrome to magnet wire.

The real help, however, is using the flame to clean out the ceramic cup. I was going nuts trying to open up the holes: I think the factories must use some sort of compound to seal and insulate the wires. Just take the cup in a tweezer and heat until it glows. Whatever solder or gunk is left in there disappears like magic. Any residue will clean out easily with a sewing needle in a pin vise. You only need a few seconds.

Be careful to let it cool long enough (about a minute) since it holds heat.

My attempts at rebuilding 901's have been a failure. I have been able to separate the inner assembly from the tube easily enough on the 510, but no luck with the 901.

Using a 8x.75 steel bolt (about 35mm which is all I had) as outlined by vaporer just does not seem to work. He suggests a tap which might give me a bigger lever because it would be longer.

Regardless, these little buggers just do not slide out as easily as on the 510.

 

[perlionsmitnick]

All I rebuild is 901s.

To separate new ones get something like a bolt to go in the threaded end and press the guts out with a vice. you may have to use a similar sized tube on the other end to give the atty assm somewhere to go. It's the glue on the atty and battery that is holding you up. The knurling doesn't help either.

You're idea on the insulation in the cups is a good one. I have been drilling them out with a #76 drill bit.

After separation I normally replace both wires with some new enamelled 32 ga wire and make them 1.5 inches long so that I can just cut the coil off and re-stripe them next time. I don't separate the batt connector, just wet it a little just enough to absorb the heat while soldering. Also you may want to file or dremel some of the knurling off of the battery connector to make it easier to get apart next time.

Throw away the bridge and the mesh on the upper part. All you need here is silica rope

For a coil I will take a sewing needle with silica rope against it and start wrapping 32 ga nichrome or kanthal around it. I usually shoot for a 2 mm coil diameter with about 7 or 8 wraps (2.5 to 3 ohms).

Slide the needle off and make the silica rope about 1.5 inches long. Take needle nose and bend U hooks on each of the nichrome leads. Do the same u hooks on the enamelled wire leads.

Doing one at the time, hook the u hooks together and crimp with needle nose pliers. Apply some acid flux to the connection and solder that joint then do the next one. Magnifying glasses helps here for us older farts.

Re-assemble the atty as you took it apart. The chrome atty cover I normally break the washer type top part off to make for more room for the silica.

Rotate the atty to put a twist on the wires as you lower it towards the batt connector. This is when I check resistance
to make sure no wires broke. Slip the external cover back on then push the two strands of silica sticking up down into the tube with a twisting wrapping motion.

When I rebuild them a second time I will do 6 or so at a time and can do them in about 30 minutes. I normally use about 1 or 2 a week before they start building up the atty with crud. I like those flavors that are not atty friendly. (caramel vanilla etc)

I hope this helps you with your 901's.