New speaker baffle board for the Integra

[Radio Fixer]

Some may remember I had started on a restoration of this French radio from 1935 ...

Anyway, I started making a back for it but then had to make a new baffle board for it. Its an odd design as the chassis is forced to the front of the Bakelite cabinet by two sprung wires, secured to bosses in the side, with a 'U' that presses against the chassis. The chassis then jams the baffle against the front. So the baffle thickness is important. It impacts on the back and where that sits on its bosses.

The original back was of hardboard, 7mm thick, that was coming apart probably from damp over the years. Nearest to it was 6mm MDF.

Now I could have simply and quickly cut the speaker hole out free hand with a jig saw (I dont have a Fly Cutter nor a drill press with back gear). But Hey! on this Forum we dont do whats quickest but try to do whats best.

The problem with free hand is getting a perfectly round hole (Yes! I know no one sees it but I do .)

So as the jig saw had tapped holes in its foot plate I made up the attachment shown in the picture.

   

The bearing that the saw is going to rotate around is just a 6mm bolt. It worked perfectly but it has to be fed slowly as the thin saw blade has a tendancy to curve inwards. An improvement maybe to make the hole for the bolt on the centre line of the blade rather than the teeth as I did.

   

Not seen this before: it could be an original bit of inspiration: WOW

Gary

[Retired]

Hi,

Nice job Gary with a good method/technique of producing the big hole that just about anyone could copy. as you say there are a number of ways of doing this kind of job; the one giving the cleanest cut would be a router set up in a similar manner to your jigsaw with a central fixed pivot point.

I fully agree with you that it will be mostly unseen but applaud your attitude as second best isn't good enough for you; second best wouldn't be good enough for me either and it's good to give encouragement to others showing that even hidden parts deserve respect. Well done.

As you know Gary I have some decent kit but for these small jobs I still enjoy a bit of hand work and for cutting a hole such as this the humble fretsaw would do the job very well as long as a steady hand was employed then the cut sanded to finish.

Thanks Gary for sharing your technique it is useful.

Kind regards, Col.

[Radio Fixer]

The jig saw with a fine blade and 'fed' slowly produced a totally clean cut Colin. Where the router would be better is in not needing a hole to insert the jig blade into. It left half a hole behind . Now I'm really getting picky!!

G

[Yorkie]

A much neater job than could be achieved by using the jigsaw freehand, trying to follow a pencilled guideline.

You're right about jigsaw blades flexing Gary, especially on thicker material. Most half decent jigsaws these days have 'pendulum action' where on the down stroke the blade backs off then comes into play on the up stroke which seems to counteract the tendancy for the blade to run off, provided of course that the right blade for the job is selected. Electronic speed control is good too, to give better control of the cut. I think that where people get in a taffle with jigsaws is in pushing them too hard instead of letting the saw and material tell you what the rate of progress should be. (Same with a bandsaw, a router or planer for that matter - more haste, less speed).

As to not doing things for quickness but doing things to the right standard, every time I pick a tool up I can hear the words of the first chap I was apprenticed to on my first day of work with him echoing down the years: "Good enough is not good enough - it's either right, or its wrong". In the end, doing it right is usually the quickest way, and certainly the most satisfying.