Monday, April 9, 2012

Angle Madness! - The Jigs

Time for a flashback in the project... I created some jigs to accurately cut the compound angles for this diamond-shaped entertainment center; this video goes over the thinking behind the jigs and how to make them.

I used Bridge City's Angle Master Pro to mark and verify all the compound angles.  I have to say, I was thrilled that the cuts on the mock-up (both!) were so accurate as to not need any flush sanding, filling, "colorful language".

Hopefully there are some useful ideas in here for dealing with compound angles in your projects.



(For email subscribers, here's the video link: Angle Madness! - The Jigs)

6 comments:

  • Jim A said...
     

    Paul Marcel,

    You said,
    "The 1/4" MDF under the stock raises it above the fence. Otherwise the guide rail 'bridges' and you won't get a clean cut."

    Can't you just lower the fence to keep the guide rail from bridging?

    Or are you talking about not getting a clean cut on the bottom side of the board? If so, can you do the same thing by moving the fence a little to get a solid backing from the MFT (and I don't understand what you mean by "bridging")?

    Thanks,

    Jim

  • Paul-Marcel St-Onge said...
     

    The fence is the piece of aluminum in the back with the tape measure on it. That goes under the guide rail. It's about 5/8" thick so if I just put the 1/2" MDF under the guide rail, the rail would be 1/8" above the MDF near that fence; that actually gives the saw a lot of play and can make a sloppy cut.

    By putting the scrap 1/4" MDF underneath the 1/2" I was cutting, I have 3/4" stock under the guide rail and easily clear the back fence.

    I think the normal position for that fence on an MFT is under the guiderail so it isn't something particular with my modified setup. Even so, I get more utility from the taped fence going up to the cutline than to be able to cut really thin stock without an (overused!) backer.

    Hope that explains 'bridging'; it's the only name I could come up with. :)

  • ChrisHasFlair said...
     

    Dude, you're nuts. That is a ridiculous amount of calculations and planning.

    Chris

  • Anonymous said...
     

    what are you using to lock the triangles down to the jig ?

    great video, cant wait to see finished project.

    David (runningwood)

  • rmac said...
     

    I tend to agree with Chris. But I can't really say anything because, well, I do the same thing.

    I like the "shim the triangles" trick.

    -- Russ

  • Paul-Marcel St-Onge said...
     

    Sorry, Runningwood... I saw the comment on my phone and thought to reply later with a real keyboard and ultimately forgot...

    All the hold down for the triangles is a 5/16" t-bolt coming up from underneath (the T part is in a recess created with 2 shallow 5/8" Forstner bit holes to keep the bolt from spinning) and a plastic knob to tighten down. It's from a kit of jig parts from Lee Valley; they have two: one for 1/4" bolts and one for 5/16" bolts. So nice to have on hand as there are bazillions of nut and knob sizes in the kit. Well worth it.

    The hold-downs are also 5/16" T-bolts recessed underneath the same way. Goes quickly to make the recess and it keeps it from spinning and keeps the bottom of the sled flush. I dropped a few more holes for holddowns as I did more of the mockup.