And by the way, I object to the woodworking 101 nomenclature! This now at least the intermediate class
I had thought to make my speakers out of MDF rather the muller some decent wood! So I think I'll practice on some scrap bits I have in the shed on Saturday just in case the mood takes me to do them by hand (aka, can't get the effing jog to work!).
Jogging to work is commendable, it's an excellent idea.
Persevere with the dovetails but only for as long as you're having fun, for there are other ways of constructing speaker cabinets of this size which are just as serviceable.
Redrobin suggested lap joints on page one or you could opt for a mitre joint at each corner. Mitre joints appear straightforward but require discipline like any other joint. The discrepancies tend to add up against you rather than cancelling each other out so precision is king.
You'll be needing a mitre saw, a Festool Kapex is my weapon of choice but other saws are available.
And some glue. And then when everything has set and gone off you can use your Japanese saw to cut kerfs in the mitres and key them with veneer for extra strength.
Yes all this talk of festool stuff is just getting silly! I do have a doweling jig I could use to dowel butt joints! But, now I have the idea, It's dovetails or nothing!
Mind you, I do have a mitre saw, so that might work. That's what the plans have!
Not had any time this weekend to do any more, but I have found someone who has an identical jig to mine and who successfully makes half blind dovetails.
After quite a bit of head scratching it turns out that his cutter is a 15mm one. Mine is a 1/2" one that measures 12.6mm. On the model I have drawn and used schoolboy geometry I calculated that 15.74mm was the right size. I have a 5/8" one on order - from china(!) too much of a cheapskate to buy from Axminster Tools when I was clutching at straws.
Ok, cringe quality time. I received my new cheap 5/8 cutter from China and it certainly was cheap. I used it with my jig and essentially the tails and pins now fit. Now as you can see, fit isn't very good. The bit was really blunt and I think (as well as burning it's way rather than cutting) it pulled itself out of the router 'chuck' as it went which is why the joint looks so shite. Anyway, now I have two routes - machine (with a proper sharp bit) and by hand for doing my speaker cabs. Need to organise wood and saw to cut the pieces with. And find some time!
Had another go today with a much nicer and sharp bit. Also worked out that the jig in essence is quite flimsy so quite a lot of care is needed to hold the router firmly but lightly not pushing down too much. I had a couple of goes bracketing the right depth of cut. This one is too tight as can be seen. Getting closer now.
I always use Cascamite for gluing up dovetails (excellent gap filling properties. ) and with a little judicious clamping that joint would look perfect.
Are you planning to make the speaker boxes in MDF now ?
Last edited by mycar on Sat May 23, 2020 6:13 pm, edited 1 time in total.
Thanks Mike. Yes the plans for speakers have them made from MDF. Felt good to me as making cockups wouldn't waste proper wood. The plywood I used was just what I had lying around to practice on.
I'd forgotten about Cascamite - I must have used that in my past sometime. Probably when I was a teenager whiling the holidays away in my Dad's garage!
MDf isn't the best stuff for dovetails, you can see the material is starting to delaminate at the bottom of the tails.
Moisture resistant MDF, usually green, is a more substantial material than bog standard MDF but still not a great choice for the dovetail joint.
Have you considered making your speaker boxes from a species of tree wood ? I know different timbers have assorted sonic characteristics but with smaller boxes this tendency to resonate shouldn't concern you too much.
Oak, Walnut ? Not Beech, its a pig, Cherry, Cedar of Lebanon !
In a dusty folder in an old filing cabinet drawer I have blueprints ( remember them) and crossover diagrams of Radford speakers ( remember them) from my father. When clearing the family home found bunch of components drivers crossovers etc canibslized from the largest multidirectional Radford set that he once had but disassembled ...probably too large cabinet given the required off wall placement for practical family home ... an addicted audiophile a step too far even for my understanding mother I suppose.
One day maybe I should build some using these parts and blueprints ... probably sound pretty respectable ... there are various sizes of cabinet in papers using the components iirc
I have a minimalist home and have space but would need to up my game on carpentry skilled to be allowed to bring them into house. Keep up the good work.
2020-05-19_10-38-02 by graham Ridgway, on Flickr
IMG_20200522_162354 by graham Ridgway, on Flickr
) and with a little judicious clamping that joint would look perfect.