Lennon Burns Knobs

[miamiric]

Just in case anyone missed these!

http://cgi.ebay.co.uk/Lennon-325-Burns- ... dZViewItem

[beatlefreak]

That wasn't a bad price that they sold for.

[libratune]

That wasn't a bad price that they sold for.

True enough. That's about $59 shipped, which is about $25 less than the shipped price (new) from a well-known Rick dealer.

[beatlefreak]

Never understood why those knobs should be that expensive.

[kylek350]

I just picked up some repro Burns knobs for my 325V59. In order for them to fit on the pot shafts, I'm going to have to bore out the holes on the knobs. Anybody else ever have this experience?

[beatlefreak]

The ones I got for my V59 slid right on.

[jingle_jangle]

Some of these are bored to .250. Duh. Fuh.

They need to be .252 in order to fit the shaft. This means reaming or going with an oversized drill bit. Too much hassle, apparently, so pass the hass to the customer...

[wj350]

Never tried on a V59, but have put two sets on c58s. They were tight, in fact I suddenly understood how JLs pickguard got the crack in it.

I used a little chapstick on the pots and they slid on tightly.

Bill

[jingle_jangle]

Unlikely that the current knobs were tooled the same as the originals, as they are screw machine products, not molded items.

Very likely that JL's pickguard was cracked from dropping or casing and dropping--these knobs focus pressure on the weakest area of the guards--the holes for the pot shafts, and a nice bump can get a crack started...because they're taller than Rogans, they protrude more, too.

[beatlefreak]

When I bought my 325V59, it had a cracked pickguard (I was able to negotiate the price downward because of it). I ordered a new pickguard from RIC. When it came in, I lightly beveled each of the holes top and bottom to make it less likely to crack.

[phil2]

I had the same problem. Rather than drill I used a round file to make the holes slightly larger and they now fit perfectly.

Phil

[glen_l]

Lennon's '58 had the pickguard cracked well before the burns knobs were fitted.

His previous radio knobs were a tight press fit with no grubscrew at all. Pushing these on was most likely the cause of the cracked guard.

[jingle_jangle]

The trick in drilling pickguards made of acrylic is to use a step drill:

http://www.improvementdirect.com/index. ... eId=522985

Which works very smoothly, even in a handheld drill. The trick is to first drill a 1/8" hole with a standard drill bit, then use the step bit to gradually enlarge the hole. No risk of chipping or cracking.

Bevelling the hole helps to avoid cracking, but only a little. The problem is that the knobs provide a focus for any force applied to the top of the guitar, and the open area of the control cavity under the guard is unsupported. The guards then crack soon as pressure is applied to the knobs, whether it's from fitting new ones, or closing the case or bumping the front of the instrument. Paint further weakens the molecular structure of the acrylic. It's also important to use cast, not extruded, acrylic sheet, which can often cost as much as twice as much. Cast sheet has its stresses tempered, extruded doesn't and is less stable.