TG "The Loudspeaker" Build (Sort of)

[Max N]

And I think I was a lot less brave than you with the feed and step

[MistyBlue]

Patience was never really my strong suit.

[MistyBlue]

While I’ve got the rotary table set up, I thought it would be a good idea to get the port rings and plugs made. Last time I did this, I remember it left a film of fine dust over everything and gave me a bit of trouble on my chest but seeing as I’ve had a bout of that already I dug out the industrial extractor I had put to one side for the surface grinder. I got it cheap second hand locally from someone who runs a woodworking shop but was upgrading it because the regulations had changed over the filters and now a 1 micron filter was required for commercial use. It came with one of those socks for wood chips and dust which could filter down to 5 microns, so I set it up outside and ducted it into the workshop on the mill through a 3d printed reducer adapter down to about 40mm diameter for a standard domestic vacuum hose. I wish I could of used this with the router but it would have made it even more of a nightmare with the circular hole cutting. It worked a treat and with the right filter should be great for the surface grinder. I wore a standard FFP3 mask but removing it to check if I could detect any wood dust proved that it managed to extract even the fine wood dust. There was no dust film left on the mill either. I just used the usual vacuum cleaner to suck up the chips as I went.

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[MistyBlue]

Done...

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[MistyBlue]

Ok, so 5 hours and just one more dead router cutter later we have the front baffles. I was dreading this part, but it turned out fine. Going much slower with the feed and with a reduced step down to ensure there is no chance of the cutter slipping in the collet takes its toll. Just got to sort out the driver mount threaded inserts and any relief on the rear side for the midrange.

This woodwork is starting to hurt a bit too much. My back is killing. Luckily there is finally light at the end of the tunnel.

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[MistyBlue]

I agonised a little bit over how far I could go with this, but Troels makes a convincing argument for chamfering a relief on the rear of the baffle especially for midrange drivers.

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I probably could go further with it but I don’t want to go mad and take too much material off. I like using the T nuts as it gives a secure type of compression mounting to the drivers without using plain woodscrews and gives a strong steel thread for a stainless steel cap head (hex socket) bolt that can be machined back on the face to give a nice decorative “jewel” type feature around the drivers. It’s a trick I learned from the other member of the household’s interest in motorbikes etc. I figured that just giving it a once over with a radius cutter and then use an angle grinder to grind back the T nuts flush with the radius and then take a view on whether I could go further with it later before final assembly. The rain was also closing in and forced my hand to call it a day at that point anyway.

[Max N]

If you do want to take it further you could remove some more material in 8 segments between the fixings, if that makes sense.

[Greg]

If you do want to take it further you could remove some more material in 8 segments between the fixings, if that makes sense.

…………and you could replace those cut down T nuts with threaded inserts.

[Ray P]

…………and you could replace those cut down T nuts with threaded inserts.

Yea, it's what I would have used, drilled slightly loose and then foxed with some epoxy to stablise the plywood. Probably not very clear from the photo below, but I inserted the threaded inserts from the back as a further aid to them not pulling through, and the rounding is as Max suggested, with more between the fixings.

[MistyBlue]

Thanks for the suggestions guys.

I think I will take some more material off between those T nuts. It’s not exactly something that can be done retrospectively!

I did actually consider those threaded inserts (ones with the hex socket for insertion) and previously used some on the 2A3SE amp and was impressed by them. Those were the M4 version. I was concerned that the birch ply is not as robust as most materials I’m used to and was worried that the ply could get “mashed” if something went wrong when turning the bolts either due to misalignment, or when removing them. Maybe I’m just being silly or suffering past thread based trauma (LOL – but yeah, really), especially given the number of times I’m likely to take the drivers out. It would indeed be a more elegant solution for sure. I will have a think and may reconsider.

[MistyBlue]

Just seen that Ray...Looks good especially with the epoxy idea - now that could put me at more ease over the material issue. I'll have a think about that.

[MistyBlue]

Nice salad bowl speakers BTW!!!

[Ray P]

Nice salad bowl speakers BTW!!!

Thanks, they turned out OK. I also added the following to my previous post, which may be helpful to overcoming your phobia, "Probably not very clear from the photo below, but I inserted the threaded inserts from the back as a further aid to them not pulling through, and the rounding is as Max suggested, with more between the fixings."

[Ray P]

Oh, and, as the fixings were deliberately slightly loose, I used a 3D printed jig and some waxed bolts to ensure everything would line up for the the speaker units, and i used a slow cure epoxy to ensure it got into all the little nooks and crannies.

[MistyBlue]

Speaking of that sort of idea (epoxy), I may have something of interest in due course.....