HB-4 Narrow-5 conversion

[bassdude]

Background:
Long ago I had an unrealised fetish for Steinberger "cricket bat" headless guitars, which led me to discover the narrow-5 option whereby the 4-string neck & body was converted to accommodate 5 strings. Hence the narrow-5 (model XT2-5).

So:
Being a recent recipient by gift of an HB-4 kit, I began wondering if a narrow-5 conversion could be achieved. There appears to be enough room on the headstock to accommodate a 5th machine head; nut could be easily enough replaced; the floating bridge for arch top could be readily either replaced or modified to work for 5 strings. There may even need to be some additional bracing installed inside the hollow body for strengthening due to the extra string tension.

The main obstacle seems to be the string mount block for the tail piece. The standard tail piece supplied has 45mm span across the strings (15mm spacing). I envisage a replacement string mount block with a 48mm span (12mm string spacing) as the final puzzle piece to solve the HB-4-to-Narrow-5 conversion. Question is, how could such a replacement part be sourced?



Peter

[Simon Barden]

I doubt it, at least not from a stock part. Which is where a lot of new kit ideas fall down. The Chinese guitar kit makers buy in the hardware from other factories, so unless one already makes a suitable bridge and tailpiece, it probably isn’t going to happen. A new kit that requires variations from a standard body shape normally require a minimum run of 100 guitars IIRC, and anything requiring brand new hardware will probably need an order of 500-1000. Far more than someone like Pit Bull could afford to order at once, especially for a relatively niche model.

It could be done, but the economics weigh against it.

[bassdude]

Thanks Simon. I think I'll try the fabrication route. Overall dimensions of the string mounting block are 18x11x82mm approx. I've ordered a length of 19mm (3/4") square brass rod x300mm long, which will be ample for at least a couple of retries if I mess up the first couple of attempts. The curve of the top of the standard 4-string block looks pretty close to the same 12" radius as the supplied fretboard sanding block, so arriving at a rough finished shape before polishing shouldn't be too difficult. I have a drill press somewhere, so drilling the various orifices should be quite achievable. If I'm happy with the result, I'll look for a local business who can do some chrome plating for me.

Peter

[Simon Barden]

That’s certainly the way I’d go. A simple drilled block with smaller diameter holes for the strings and bigger ones for the ball ends should be easy to make, and can simply replace the existing block on the trapeze.

[bassdude]

That’s certainly the way I’d go. A simple drilled block with smaller diameter holes for the strings and bigger ones for the ball ends should be easy to make, and can simply replace the existing block on the trapeze.

The proximity of the trapeze lacework to the block would be a hindrance to threading the strings through the block. I'll be replicating the underside slotting which extends forward from larger pockets that contain the ball ends, as in the standard 4-string block pictured. And I'm happy to say the brass rod has already shipped from Perth today & will hopefully arrive on the east coast by end of next week

Peter