Jonsered safety interlock - can u help?

[purple badger]

1 hour ago, adw said:

It’s not a problem, I just want to see the finished product, always had a soft spot for Jonsered/ Jonsereds.

You and me both mate. Out of interest how easy is it to get the interlock and spring in/out of the handle? I've yet to actually look at how to get in there and I don't have a service manual for this saw.

[adw]

So let’s try again.

 

[adw]

More.

 

[adw]

Spring

 

[purple badger]

@adw Absolutely perfect, thanks! Right will check tomorrow if I got those dimensions correct. I'll also try to model up a spring jig, might have wait until the weekend as it's all kicked off today.... Looked like the rest of my week is going to be more busy than is comfortable. Guess it just happens sometimes... but hope it's going better with you!

[purple badger]

OK so I couldn't resist spending an hour over lunch finishing the prototype and printing it. @adw huge thanks as I did have a couple of dimensions off between 1-2mm, but they're now all adjusted.

 

 

Anyway, I added breakaway supports to the model that are necessary to print the slot as it overhangs and otherwise my printer would be printing in thin air. Then next job was to slice it ready for printing (took 35mins and cost 13p). 

 

 

The prototype is printed in white PLA to keep things simple and quick, you'll see it's also hollow to keep things cheap (20% infill). Once fit has been checked, the final model will be printed in black PET-G at 100% infill (solid not hollow) so it's tougher and looks like the original (although you could have it in any colour or finish you wanted including wood or metallic 😁).

 

35 mins later and it's done - the breakaway supports are snapped off - with the final model you should probably really clean it up better with a knife and sandpaper but this will do for a prototype!

 

Then the final prototype is measured up to check against the original model in the photos @adw kindly supplied. Pretty much spot on from what I can see (and yup, I found my favourite callipers!)

 

Job done - I always find it mad that this is now possible with cheap modern tech - when I think what things were like when I started and now you can draw something on a a thing called 'a computer' and print it out into the real world on another thing in your workshop in half an hour - total madness, but puts a real grin on your face when you see something emerging slowly on the print bed! Anyway, I'll try a test fit at the weekend if I get time - it'll probably need a little more fettling with some dimensions but it's definitely getting there!

Edited January 25 by purple badger

[sandspider]

That's impressive! Is it hard to do the Cad work / modelling before printing?

[purple badger]

20 minutes ago, sandspider said:

That's impressive! Is it hard to do the Cad work / modelling before printing?

No, whole thing was probably a couple of hours of work and if I'd had the actual original part in my hands it would probably have been nearer an hour. If you're starting out the CAD might take half a day or more, but you learn it really quickly and rapidly speed up...and of course once you have the model it's literally seconds to click print and get another part printed.

 

However, like anything it's what you put in that you get out - you do have to learn the CAD, but any half practical person can do it easily, especially if you have lathe/milling experience as it's just cutting and extruding. For this one I just traced round the photo on the computer to get a 2d outline drawing, scaled it so it was the right dimensions (literally one click), extruded it by thickness of the part so it became a 3D block (again one click), then cut the various holes and channels in it (e.g. draw a 2D circle and then extrude it as a 'cut' to get a hole in the part etc.).

 

That's the basic process. Basically as long as you are practically minded it's simple. Slicing is literally just adjusting a few settings for the material you're using and then clicking 'slice', once that's done printing is pressing another button. OK there's a little more to the whole process that you have to think about (supports for overhangs etc.) but that's it. Simple - I honestly don't understand why more workshops don't have FDM printers, as if I can do it anyone can.

Edited January 25 by purple badger

[sandspider]

Thanks for the detail. I don't really have much need for a 3D printer, but I still kind of want one...

[purple badger]

Yeah I said that when I was given this one for xmas.... 1 month later after having fixed a thermostat bracket I'd snapped on my hot water tank at home using it (was quoted £120 for the whole replacement thermostat + bracket part and 3 months wait by local supplier as it was during Covid...) and I suddenly understood that it was going to become essential. I then moved it into the shop and haven't looked back.

 

It's one of those tools that you don't know you've always needed until you have one - it sort of requires a mind shift and then you look at the world differently if you know what I mean!