Janus77 Posted November 18, 2020 Author Share Posted November 18, 2020 (edited) External panels (24mm): Internal bracing (18mm): I'll use some of the 18mm to make the grill frames. Troels suggested to mitre a 45 degree angle on the inward facing edge, i'll also probably round the outer edge with a router. Max driver excursion on the 15" driver is 15.4mm before damage occurs, and the 8" is similar i guess (similar X max to the 15pr400's), so an 18mm height off the front baffle for the speaker cloth will be fine. I do wonder though if i need an additional cross support on the grill frames. I guess if not, i just need to ensure i stretch the cloth enough that it doesn't sag at all. Edited November 18, 2020 by Janus77 Link to comment Share on other sites More sharing options...
Janus77 Posted November 18, 2020 Author Share Posted November 18, 2020 Link to comment Share on other sites More sharing options...
Janus77 Posted November 18, 2020 Author Share Posted November 18, 2020 (edited) I think i'll go with these, good on carpet apparently, 9cm height. https://www.bunnings.com.au/move-it-50mm-70kg-black-twin-wheel-swivel-plate-castor_p0101905 Edited November 18, 2020 by Janus77 Link to comment Share on other sites More sharing options...
aris Posted November 18, 2020 Share Posted November 18, 2020 2 hours ago, Janus77 said: I think i'll go with these, good on carpet apparently, 9cm height. You may want two per speaker that lock, mind you I doubt they will move easily! These are what I ordered, you may find them in black. https://www.factoryfast.com.au/products/8-x-2-polyurethane-castor-wheels-swivel-and-4-with-brake Link to comment Share on other sites More sharing options...
unclemack Posted November 18, 2020 Share Posted November 18, 2020 Fascinating thread. Love the fact that the OP has dived into the deep end as a first try. Good luck mate. Looking forward to seeing the progress and the finished product. They will be awesome! Link to comment Share on other sites More sharing options...
Janus77 Posted November 18, 2020 Author Share Posted November 18, 2020 16 minutes ago, unclemack said: Fascinating thread. Love the fact that the OP has dived into the deep end as a first try. Good luck mate. Looking forward to seeing the progress and the finished product. They will be awesome! I have a history of my eyes being too big for my stomach, let’s see how I go. 1 Link to comment Share on other sites More sharing options...
Janus77 Posted November 18, 2020 Author Share Posted November 18, 2020 (edited) Made some bridging connects for the bass and mid/tweeter binding posts yesterday. A colleague advised they loop them, which is how i'll wire them up, so there's some spare in case they need adjusting (which is why they're so long). I realise i could have done it internally or just run a wire between, however I figured I've spent so much to this point I may as well make some fancy connectors for the back too! Edited November 18, 2020 by Janus77 Link to comment Share on other sites More sharing options...
aris Posted November 18, 2020 Share Posted November 18, 2020 1 hour ago, Janus77 said: Made some bridging connects for the bass and mid/tweeter binding posts yesterday. A colleague advised they loop them, which is how i'll wire them up, so there's some spare in case they need adjusting (which is why they're so long). I realise i could have done it internally or just run a wire between, however I figured I've spent so much to this point I may as well make some fancy connectors for the back too! That’s very cool. You need the loop as if you use wire then the banana plugs don’t seem to go all the way in on the binding posts. I’m gonna follow your example! 1 Link to comment Share on other sites More sharing options...
Janus77 Posted November 19, 2020 Author Share Posted November 19, 2020 Cost about $15 in parts, 4 packets of PT4560 gold crimp 6mm eye terminals ($2.95 each) and some speaker cable from Jaycar. pleased with the result, unfortunately my last use of the solderer seems to have blown it so i can't solder them up. The physical crimp is pretty strong though. I'll get them soldered at the workshop. Link to comment Share on other sites More sharing options...
BioBrian Posted November 19, 2020 Share Posted November 19, 2020 Hi Hugh, I'm presuming these are for the inside of the boxes? My Jantzen binding-posts (which I don't use) have 6 mm threaded shafts on the inside, but would need a 10 mm eye on the outside. Or a fork with at least 8.5 mm inner width. Maybe yours are different? Link to comment Share on other sites More sharing options...
Janus77 Posted November 19, 2020 Author Share Posted November 19, 2020 (edited) 4 minutes ago, BioBrian said: Hi Hugh, I'm presuming these are for the inside of the boxes? My Jantzen binding-posts (which I don't use) have 6 mm threaded shafts on the inside, but would need a 10 mm eye on the outside. Or a fork with at least 8.5 mm inner width. Maybe yours are different? Ouch. will have to check. I built them based on the product description of the posts being M6. Hmm, looks like they're wider on the outside. Edited November 19, 2020 by Janus77 Link to comment Share on other sites More sharing options...
BioBrian Posted November 19, 2020 Share Posted November 19, 2020 Yep, they look the same. The other thought was whether you could use eyes at all, but, unlike on my amp, these caps do fully screw off. The other, other thought - I've seen commercial versions of these which have bananas on one end, and forks on the other. The bananas get the full depth, but the other end has to share the other post with the speaker wire. I think your idea of using eyes all round is better. Link to comment Share on other sites More sharing options...
Janus77 Posted November 19, 2020 Author Share Posted November 19, 2020 There's plenty of meat on the eyelets, they're 12mm external. I should be able to drill them out to fit, or turn them into banana plugs if that doesn't work. Link to comment Share on other sites More sharing options...
BioBrian Posted November 19, 2020 Share Posted November 19, 2020 (edited) That's confidence! You'd only have 1 mm at the edges - I would expect 'eye problems', even if using very clever clamping. And the raised part would probably prevent screwing down properly. Not quite as bling-ful but still from Jaycar are the uninsulated eyes, part PT4940 (silver*-clad copper?), in my 2019 catalogue. I'd squash the crimp part, and solder the wire into the external groove that leaves, then cover with our universal saviour, heat-shrink. But you might find something nicer. * More likely to be tin, or zinc-clad. Edited November 19, 2020 by BioBrian 1 Link to comment Share on other sites More sharing options...
BioBrian Posted November 19, 2020 Share Posted November 19, 2020 My biggest concern with this build is the glue-up sequence. I just can't picture a best-scenario. Troels doesn't make it very clear. His write-up of the previous one, the 12" Faital 3WC, tells us a bit more of the problem, but it's as if he does the whole box in one go - surely not? I don't think PVA would stay workable that long, and it's just too much to manage all at once, especially with the front and rear panels having to be flush, have all the 45 degree parts match up, and only having sight to one lot (either front or back). Using 24-hour epoxy would make this a lot easier, staying workable for an hour or so, and filling gaps really well too. (What gaps, we ask, haha). Have you decided upon the front baffle coating, and/or how to meet your side veneer material with the baffle? It would be normal to round off these corners, but I'm not sure what your plan is here. IF you are not going to make a feature of the edge ply and 45 deg corners etc, as Troels has done, it might be a lot easier to just forget all the front rebates, make the baffle 2 mm oversize all round, and just glue it on last. One pass around all 4 edges with an "edge-trim" router bit would take little time, skill, or stress, and you'd be covering the joints on the sides with your veneer anyway. Leaving your front as one material for even staining, or whatever. I don't want to interfere with your build, but I can't see that you've 'thunk' this one out, and if I don't say it today, it'll be too late! So please accept the above as just an idea. The way Troels does his saw-cut and matching lip that both locates and helps get a larger glue area is quite fiddly - I do it a simpler way. For 18 mm bracing, I rout a 2 or 3 mm deep groove with an 18 mm bit, and the brace just slots in, any gaps filled by the epoxy; this also gives a tiny bit of wriggle room in the gluing phase. But this won't work if you want to fit the bracing (eg the B brace) in after the sides are done - Troels seems to slide things in where there's no space, and I reckon I'd be leaving most of the glue behind if I tried it. I know in some of his builds, he pre-glues internal structures, like mid-boxes and some bracing. But it's difficult not to get extra glue on other panels, so you can't get them apart without damage, if that makes sense. In any case, make sure you have at least sixteen times as many clamps as you think you need . 1 Link to comment Share on other sites More sharing options...
Janus77 Posted November 19, 2020 Author Share Posted November 19, 2020 (edited) Thanks Brian, this part does still need some working out. I came up with the plan in attachment below. However i think maybe gluing the front horizontal braces into just 1 of the side panels first, also gluing the top and bottom panel, with a dry fit of the opposing side panel and front and rear baffles when clamping might be the plan. Once these are dry, i glue in the vertical B brace, again using the opposite side panel, front and rear baffles for support when gluing, then finally the rear horizontal braces. End up with 1 side, top bottom and internal braces attached, knowing the opposite side and front and rear baffles will fit. Need to make sure i don't accidentally glue any panels that aren't meant to be (chopsticks maybe inside the step down so they can't sit flush. Below needs to be amended. i appreciate you bringing it up though, i did have it on my list to work through. i figure i'm a few weeks off needing to glue anything. Regarding the front and rear baffle. Rear i plan to spray matte black. Front i want to use a red dye and polyurethane finish. The sides, top and bottom in a black wood vinyl, i plan to wrap around so that it goes half way down the step down at the front flush where the front baffle slots into if that makes sense? Heading to the first workshop class in 15 minutes, hopefully they have lots of clamps excited!! Edited November 19, 2020 by Janus77 1 Link to comment Share on other sites More sharing options...
Janus77 Posted November 19, 2020 Author Share Posted November 19, 2020 (edited) Actually on rethink, maybe only glue the top or bottom panel initially, that way i'm not sliding the B vertical brace in and rubbing all the glue off in the process. 1. Front horizontal braces, top and side panel glued together, using bottom panel, opposite side panel, and front and rear baffles when clamping to ensure parts are glued straight for everything to fit together. 2. Vertical brace and rear horizontal braces glued in, again using same panels without glue for support till dry. 3. Apply felt, drill holes for speaker wire, install wire, and seal holes. 4. Glue rear baffle after installing binding posts and felt. I think i can install the crossovers after the rear baffle is glued in - the holes in B brace should be large enough. That will have me with a semi finished box with no front baffle. 5. Polish up the front baffle, and apply vinyl to sides, top and bottom before gluing in front baffle. Sound ok? Will it be difficult to use the panels not being glued as supports when clamping together? bit of a jigsaw puzzle. I'll keep thinking it through until i have a clear game plan. Hopefully @aris chimes in on this as he's already built them. Itching to get to the workshop! Edited November 19, 2020 by Janus77 Link to comment Share on other sites More sharing options...
aris Posted November 19, 2020 Share Posted November 19, 2020 I found that I glued the main brace to a side (to create a T) then glued the remaining side (to create a H). You can use the front and back baffle to keep square. Then I glued the remaining bracing, bit by bit. Small clamps were useful here. The hardest was the top and bottom, which had to fit exactly, involve the 45deg mitre etc. Given I had already put in the bracing (minus front/back baffle) I could use small clamps for the top/bottom. See attached photos! Aris 3 1 Link to comment Share on other sites More sharing options...
PKay Posted November 19, 2020 Share Posted November 19, 2020 2 minutes ago, aris said: I found that I glued the main brace to a side (to create a T) then glued the remaining side (to create a H). You can use the front and back baffle to keep square. Then I glued the remaining bracing, bit by bit. Small clamps were useful here. The hardest was the top and bottom, which had to fit exactly, involve the 45deg mitre etc. Given I had already put in the bracing (minus front/back baffle) I could use small clamps for the top/bottom. See attached photos! Aris That looks like a great effort. Well done. Link to comment Share on other sites More sharing options...
aris Posted November 19, 2020 Share Posted November 19, 2020 My first attempt to “do it all at once” ended with me scraping glue before it had set and redoing. Slowly slowly works better sometimes. Aris 1 Link to comment Share on other sites More sharing options...
BioBrian Posted November 19, 2020 Share Posted November 19, 2020 (edited) Wow, that's very fine work there, @aris. Wish we'd seen more of that as it emerged. Hope you don't mind me using your pic as an illustration - in an early post here, I said I'd prefer more meat on (eg) the lower vertical struts of Brace B. Making the 4 lower holes 5 mm less in radius would give those struts another 10 mm width and attendant mass increase. With rounding of all hole edges I reckon it'd be just right. Wonder if I'm alone here? Edited November 19, 2020 by BioBrian Link to comment Share on other sites More sharing options...
Janus77 Posted November 19, 2020 Author Share Posted November 19, 2020 First class was mostly machine inductions. Had a little time to cut and got 1 piece of ply broken down into manageable sizes. 1 Link to comment Share on other sites More sharing options...
BioBrian Posted November 19, 2020 Share Posted November 19, 2020 7 minutes ago, Janus77 said: time to cut You're a lucky man! Awesome machines. Wanted to say - don't cut your front and back panels until you've dry-clamped up the sides and ends. The furry edges on 45 degree cuts are not easy to measure for length, and the rebate depths are not perfectly predictable either. And the 45 or 46 degree thing - even with these amazing tools, I wouldn't trust that they cut the exact angle it 'says on the tin'. They need test cuts and fit-ups. This is hotting up! 2 Link to comment Share on other sites More sharing options...
Janus77 Posted November 19, 2020 Author Share Posted November 19, 2020 Only 3 of us in the class, so plenty of time with the instructor when needed. Might only be 2 in the class, seemed like 1 person was slightly unsure if they were going ahead with it. After the course, I can use the facilities for a fee going forward. Looking forward to getting stuck in properly next week! 2 Link to comment Share on other sites More sharing options...
aris Posted November 19, 2020 Share Posted November 19, 2020 (edited) 13 hours ago, BioBrian said: Wow, that's very fine work there, @aris. Wish we'd seen more of that as it emerged. Hope you don't mind me using your pic as an illustration - in an early post here, I said I'd prefer more meat on (eg) the lower vertical struts of Brace B. Making the 4 lower holes 5 mm less in radius would give those struts another 10 mm width and attendant mass increase. With rounding of all hole edges I reckon it'd be just right. Wonder if I'm alone here? Don’t mind at all. I should have chamfered the brace holes just forgot! Also I did adjust the diameter and placing as I was using 24mm (and had created grooves/slots). It’s my first build so there are some things I would do differently next time I am of half mind to do them again at some point as the plywood cost is minimal cf. the overall. Part of the fun is learning! Edited November 19, 2020 by aris 2 Link to comment Share on other sites More sharing options...
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