Bobbin Support

[NightWinder]

I am curious....what are some materials that you guys are using between the top and bottom of the bibbin- Ie: the middle . Wheather it be for a P90, or a similiar design. I mostly use hard maple, and I have used plastic, but wood works great. I never really seen anyone mention this sooo..

[Spence]

Note quite sure what you're referring to. Wouldn't you use a pole shoe for a P90?

[NightWinder]

Between the top and bottom of a bobbin> where you put the screws. Cut off the top and bottom of a bobbin. That piece.

[Spence]

I have used maple but the plastic would be the normal thing to use.
Early P90's were made with black perspex. You can easily do this yourself if you can source black perspex.

[Possum]

huh??????

are you talking about the coil former part or bucker spacers? Are you making your own bobbins? When I made my own P90s I used plastic that Lollar recommends in his book, I forgot the name, its not plexiglass, plexi shatters when you tap it. That stuf works but you have to run the tap through it multiple times to get a clean thread. Maple would be ok but probably over time if you mess with your screws alot would strip out.......

[NightWinder]

Yeah, the maple does strip, but not fast. I've been using the same bobbin for protos for 2 yrs and the screws are still tight. Minor adjustments for screw heights are fine. Also finding the start of the thread and not jamming shit together is always a plus.
So, noone is useing perspex??? I'm looking for some alternative choices. I am aware of some plastics, and am ready to try some new ideas. I wonder....CPVC come in black. That stuff fusses together, and would never come apart..any Ideas, or supplyers out there for the perspex? Is there a better alternative for perspex?

[David Schwab]

So, noone is useing perspex???

I think Perspex is what we call Lucite (acrylic) here in the States? That should work fine. I know you can put screws in it, because I made a guitar out of the stuff!

Lexan would probably be good too. Plexiglas is too brittle. I don't think they make that stuff anymore. Rickenbacker use to make their pickguards from plexi.

What are P-90 bobbins made from? Butyrate?

[Zhangliqun]

I think the plastic Lollar recommends is lexan. I bought some to make some humbucker-spaced P90's with slightly taller bobbins. It works very well.

[Possum]

lollar.....

the generic term I think is polycarbonate. I hate that stuff, you run a tap through it then you have to run it through again twice to clean it out, you spend hours tapping the stuff, it doesn't crack and is real durable though. Its also extremely dangerous to use on a table saw. Its real grabby and cutting small pieces frequently turn into plastic bullets. At Tap Plastics they have alot of horror stories, one employee had her eye shot out. I bought a tiny mini-table saw and it shot holes through some real tough stuff I put up as a barrier. They do cut it on a table saw at Tap but they won't cut small pieces because of the dangers.

A side question, whats a good source for 1/8" thick maple to make spacers from? I've been using basswood from the hobby stores, its just the right thickness and easy to cut......

[NightWinder]

Pm for you about the maple.

[David Schwab]

the generic term I think is polycarbonate.

Yeah, that's Lexan.

I hate that stuff, you run a tap through it then you have to run it through again twice to clean it out, you spend hours tapping the stuff, it doesn't crack and is real durable though.

Makes that gummy mess that melts back in the hole? I hate drilling plastics because of that. I have heard that there are drill bits made for drilling plastic, but I've never seen any.

Its also extremely dangerous to use on a table saw. Its real grabby and cutting small pieces frequently turn into plastic bullets. At Tap Plastics they have alot of horror stories, one employee had her eye shot out.

Ouch! I always wear a full face shield when routing and sawing stuff....

A side question, whats a good source for 1/8" thick maple to make spacers from? I've been using basswood from the hobby stores, its just the right thickness and easy to cut......

How's this?

Constantines:Hardwoods/Lumber > 1/8" Thin Maple

I used to buy a lot of veneer from these people.

[Zhangliqun]

I cut it with a mini-bandsaw with a miter. No trouble with flying shrapnel so far...

[NightWinder]

thats too expensive!

[jonson]

Hi Guys. Poke my nose in here as you guys are walking right up my alley at the moment. so maybe some info. David is correct in the fact of Perspex and Lucite being the same product and both are Acrylic. Cold cast and and extruded are the 2 methods of manufacture and the one to go for is cold cast. Easier to machine and leaves a far better finish and easier to polish as well. As to how to cut it then you are looking at Solid Carbide Helix Spiral cutters. ordinary Straight flute Tungstan Carbide cutters are fine for Partical board such as MDF and High speed steel cutters are good for Timber (softwood or hardwood) but a spiral cutter is the requirement for Plastics.
Perspex routs well providing you cut the material down to size and only remove 1/16 to an1/8 of an inch with the router allthough you can go through in steps, an 1/8" deep at a time. the stuff thread taps clean if you use a good quality high speed steel tap as carbon steel taps do not carry the edge needed. Make sure your tapping drill size is correct as too small and you will just make the hole bigger and two big leaves a weak thread. Drilling plastics is down to the angle of the drill point. Standard Twist drills are ground at about 60degrees and this is what causes the snatch as you come through the other side, unless you have the material locked down tight to a backing board and you are feeding very slowly. The game is to grind the drill back to 30degrees almost a needle point as the drill will then feed through slowly and you do not get the snatch etc. Ideal point on a drill also if you want to enlarge an existing hole as the drill will follow the origional and not recut off centre. I've been through a lot of cutters over the years and have now found the best of the lot over in the USA.http://www.plasticrouting.com/
Guys in England can buy from Router House Midlands LTD. 0116 232 1111. and these beasts are not expensive but far sharper than anything else on the market. David you will will find your plastic drills here as well. I normally rout Perspex and forbon with a downcut spiral cutter with the work held down with double sided tape and never had throw out and still have 10 fingers after 60years so as long as you go by the rules with the right tools for the job you will be ok. Nightwinder not forgotten you but since I paid for the items they have now become out of stock(never were in stock) Typical UK company and have given me 6 to 8 weeks delivery so as soon as they arrive they will be in the post to you. Sorry this is so long guys but even this only covers a bit of the subject. Jonson.

[Joe Gwinn]

the generic term I think is polycarbonate. I hate that stuff, you run a tap through it then you have to run it through again twice to clean it out, you spend hours tapping the stuff, it doesn't crack and is real durable though.

Yes, Lexan is a brand of polycarbonate.

It does not take hours to tap lexan, if one is using sharp high-speed steel taps, cooled with ordinary tap water. Taps bought in hardware stores will not do.

More generally, if something that common and simple takes hours versus minutes, it's time to start asking questions.

Its also extremely dangerous to use on a table saw. It's real grabby and cutting small pieces frequently turn into plastic bullets. At Tap Plastics they have alot of horror stories, one employee had her eye shot out. I bought a tiny mini-table saw and it shot holes through some real tough stuff I put up as a barrier. They do cut it on a table saw at Tap but they won't cut small pieces because of the dangers.

I don't know why they use a table saw at all. Bandsaw works very well, won't throw things, and is far less likely to trim someone's fingers off.