stevie

I'd like to point out a couple of minor niggles with the kit. First, the CNC machine forgot to rebate the back panel to take the input panel. The idea of the rebate is that it allows you to push the input panel into the rebate and simply glue it in. Fortunately, it's not a dealbreaker and here's what I suggest you do. Place the input panel over the cutout and mark each edge with a pencil. Then mark the other two edges. That will leave you with a pencilled square showing the outline of the input panel. Apply glue and stick it down. I've enclosed a couple of small pieces of poplar plywood with each kit that you can glue to the top and bottom of the input panel to bring the total glue area back to what it would be with the rebate. Apologies for the loss of focus in the photos, but my flash just whited everything out. The second niggle is the hole spacing for the top handle. I think this is because the handle manufacturer chose a weird hole spacing and we assumed the spacing was regular. It'll be fixed next time. In the meantime, you'll need to insert some of the screws at a slight angle to move the holes over a bit. The hole size is 3mm and the recommended screws are 5mm - so it can be done. Just screw in a few turns - then bring the screw to a vertical position and carry on screwing in.

I'm very curious to hear whether the others agree with you, Pete.

There is a trick that allows you to paint the whole cab in one go. I did mention it in the parallel thread, I think. You drill the holes for the feet and just screw the screws in (without the feet) leaving them protruding, say, 15 - 20mm. Paint the bottom panel first. Then turn the cabinet over, stand it on the screws and continue to paint the rest of the cab.

The reason I recommended sandpaper is because most people don't have a router, and sandpaper works surprisingly well. But you're quite right, Luke, a roundover bit and a router is the way to go if you know what you're doing.

Of course, I remember you mentioning that. Fascinating project! Still, it could be an idea for other builders. I sprayed my input panel matt black to contrast with the much rougher dark grey Tuff Cab elsewhere. Unfortunately, I had already glued the input panel on, which made it a lot trickier.

You might like to consider spraying the input panel with that paint before gluing it in.

Thanks for pointing it out @ChienmortbbHopefully, it will stop others making the same mistake. The glue will have filled the gaps - so I don't think there'll be a problem in practice.

The specification calls for 15.2mm rebates and 15mm plywood. That's not a huge amount of leeway. On the sample I received from the very first CNC company I used (not the current one), the rebates were slightly undersized and I had to take a Stanley knife to open them up. Not funny. Although I haven't assembled any of the current batch, I expect that taking the roughness off the mating edges with some sandpaper will make things easier.

That's definitely something to watch out for. You can check the fit of the joints visually at each end, but it's difficult to know what's happening in the centre. A steel rule like that one is a good idea. Even better is a steel square. Or you can check the fit against a straight piece of wood. My number one tip would be to test the fit of the next panel before the glue sets on the piece you're gluing. Maybe even check the fit of the next two panels if you can. The interlocking design means that if one panel is slightly out, you might not be able to fit the other panels.

You're right - those cheap ones have gone. That's the problem with recommending Ebay items.

It's a good idea. If you find it does affect the sound, consider just gluing a small piece of batten near the centre instead.

Last time I looked there was an Ebay seller doing them for £12.95 delivered. That's a crazy price. The info is in the Price List at the beginning of the thread.

It looks like an extra support for the grille. I'm not sure that it needs it but it's certainly a good idea to try to support a grille somewhere close to the centre. Acoustically, it's close enough to alter the frequency response of the horn but I've no idea whether you'd actually notice it in practice.

There are now only two kits to send out and I'm hoping to get those out tomorrow. It depends on how quickly I get through my (paid) work. Thanks very much to Tony and John for dropping off the cardboard boxes and bubblewrap - they've been a godsend. Apologies to the final two - you know who you are - but your patience will soon be rewarded.🙂

Lovely photo, Luke.

Here's an article on wood joint strength:https://woodgears.ca/joint_strength/glue_methods.html What I took away from this is that you should not apply excessive force to a joint when gluing but you should apply glue to all mating surfaces.

It's REALLY important that you do a dry fit before you do anything else. That way, you can be sure that you have all the parts and that they fit. The rebates on this batch seem to be a bit tighter than on funkle's first one. However, I've measured them and they aren't undersized. If you feel that any of the panels are a bit tight in the rebates, take a piece of 40-grit sandpaper (which you'll need later to round off the corners of the cab) and rub it along the edges of the rebate a few times - then round off the corners of the mating panel slightly.

RichardH, who produced the fantastic drawings and diagrams on page 1 of this thread, has stepped forward and produced a really neat pictorial wiring diagram that will make wiring up very easy. I'll get it onto page 1 eventually, but here it is for reference. I just love the community spirit here.

Personally, I'd glue it with some Copydex and treat myself to a few beers with the money I'd saved. Seriously, unless there's a piece of cone missing, just glue it back together.

Nice job, Stub.

I have to wonder what progress has actually been made in bass guitar cab design since the 1960s. A modern design might split the drive units into two separate cabs - not that that will necessarily make much difference - but apart from that, this is typical of what's on the market today - a fifteen and two tens in an undamped ported cab. At least the Marshall has a bit of bracing.😀

I have a few things to point out before people start building, but then it will be up to the builders to ask questions as they go. One thing I do remember is that you asked for a pictorial wiring diagram, Pete, which I'll post before everyone starts wiring their cabs up. One cab kit has been collected so far, and I hope to send two out today.

pm'd

Maybe we should just keep it all in this thread in that case. When Pete was building his cab, we were in touch regularly by pm; we reached page seven in the end. Quite a lot of the information that was exchanged will be useful to other builders.

My experience with Plastikote goes back to a time when I was involved in speaker cab manufacturing. Grilles for all the models were normally powder coated. However, when we needed to produce a small batch of grilles in a hurry, we used to paint them with Hammerite or Plastikote black spray paint, which at the time were pretty much the same. Their formulations may have changed since then, and the Hammerite spray is now a lot more expensive, but the end result was indistinguishable from powder coating. That was painting straight onto bare mild steel. When I tried the Baufix spray on the Tuff Cab coating as I described earlier, it initially softened the paint, but then hardened up after a day or two. So I reckon that the Plastikote clear acrylic matt spray would be ideal but haven't tried it myself.