BillFitzmaurice.info

Hi Folks
No sooner had the dust settled and DuraTek dried on my wonderful DR250s and I was back in the shed making more sawdust with the T39s

I got the sides and panels 1 & 2 for both boxes completed. I might be speaking too soon but these are a walk in the park compared to the DRs . I recon I'll have them finished by the end of the week (If I get more timber in time). The only thing I think it is worth commenting on is that I didn't bother with marking out both side panels as once the second side is ready to go on it should just be a case of putting it in position. I have not used many fastenings so far because I have sufficient clamps to hold everything in place while it cures, thus eliminating the need for markings for fasteners.





You will notice that there are four extra guide blocks around the driver anchor. These are used to position the anchor in place with the speaker firmly attached to it with ALL the mounting bolts fastened. Once it is perfectly aligned, the speaker is then removed and the anchor plate glued in position, aligned by the blocks.



I bought myself a little bit more security by putting a self tapping flat head screw next to each T-nut. The drama of trying to extract a cap head screw from a T-nut that has come adrift does not bear thinking about

Looking good so far!
I've used many screws to hold everything in to place.
the advantage of using screws was that I could go on building as there ware no clamps that bothered me.

How wide is your cap?

The cabs are 24 inches wide, overall.

A friend of mine has also got some T39's.
I've heard them play during a gig, they are extremely loud!

The tab blocks are a very good idea.

Full steam ahead, no issues with the build so far

Both cabinets are only missing the 4 inch corner cover plate and the sides can go on.









There is not much room under the top rear corner cover plate so I went with just a single Speakon mounted on a 1/4 inch backing plate, I'll route the other two handle slots out next. The slots provide enough room to access the back of the Speakon if I need to.





A few handle and caster routes, finishing and DuraTek and we are done.

I'll burn the drivers in tonight. So far this build has only taken two full days and I was also held up by timber delivery. I recon one more full day for finishing then on to the next build, 6 x Wedgehorn 10s. I think I'm becoming addicted

Corner plates are in and speaker cable installed.



Handles and Speakon done



I'm currently making a template for the wheel cutouts that is proving to be tricky. I finally managed to find a patern following adapter for the big router that is making it a bit easier. The problem I've found with the patern following bits with the bearing is that you have to raise the jig off the job to adjust the depth of the cut.

Simple template for routing the castor holes



1/4 round dowels attached inside the handles







The horn mouth braces are radiused to 32 inches





Second side is finally on
I nearly had a disaster, after the second side was secured I realised that I had not removed the tempoarry clamps that I had installed to hold the top corner plates in place (you can see them in the first picture of the previous post). With the help of my wife's vanity mirror and a poking stick (techical term) I managed to dislodge them and get them out



Access panels are complete, I just need to install the T-nuts and they are ready for dressing and paint.

That's a very good looking cab!

Thanks Kevin, I can't wait to fire them up with the DR250s

Good looking build but it looks like you only have a single brace at the beginning of the horn path.

Nice looking build I must say. Totally loving the curved brace, however. . . . .

11 1/4 Inches between the Mouth Brace and outside panels is too large. Braces can be a P.I.T.A. royally, but they are imperative for the design to function optimally. Sure your cab will work and probably sound good, yet the T39's are 'The Best' don't want to cut yourself short on ultimate output and reliability.

My 2 cents. Enjoy either way

Hi Folks, Thanks for pointing that out , I was working with a combination of the plans and the 21" Sketchup model that has a single brace. I realise that the length difference is only 1.5" but I suppose the resulting area is significantly increased. If Bill could please offer an opinion it would be appreciated!.
The fix is simple, I’ll just drill a few holes in panel 3 and stick some dowels through to panel 5, same goes for panels 6 to 4

Something like this but on both sides.



What do you think?

There is no 21" T39 model, there is a 23" panel width model. It shows single braces on some panels but only where there's two braces on the opposite side of that panel.

Thanks Bill, I seem to have saved a section of the drawing and labled it 21" for some reason
Either way, what do you think of my fix?

Worst case scenarion is routing a slot in panel 6 and putting the brace through from the front, no problem really

Panel 3 to 5 bracing will have to suffice with a few dowels.