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Author Topic: Deforming Plywood  (Read 7223 times)

Offline little john

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Re: Deforming Plywood
« Reply #20 on: June 11, 2016, 04:26:02 am »
....  Unless your fence is on the other side of your board?  I'm assuming the fence is real close to the bit.  But maybe the fence is far from the bit with the board between the fence and bit?

Isn't it WONDERFUL when the veil of confusion is lifted ?  Thank you so much for flagging-up those alternative ways of running a router table.

I do indeed run the planks between the fence and router bit (rightly or wrongly).  That way the bit rotation is against the direction of plank travel - such that if I let go of the wood, it can fly back and poke me hard in the goolies - which has happened on a few occasions ...  By running the table this way, there is a constant (and stable) distance between the router fence and router bit over the FULL length of the fence.

But - when cutting a 45 degree mitre on the edge of a plank of uPVC cladding (which I'll be writing about shortly), I set the fence as close to the bit as possible (as you say) and then hold the uPVC 'plank' on top of a 45 degree jig  which is pushed up hard against the fence - and indeed does have a couple of stand-offs to keep the jig itself from hitting the router bit - which forms the same kind of gap as that which you must be referring to.

LJ
A Heretics Guide to Beekeeping - http://heretics-guide.atwebpages.com

Offline Duane

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Re: Deforming Plywood
« Reply #21 on: June 13, 2016, 08:11:15 pm »
Yes it is!  I was trying to think how you used your level with the bit and then it dawned on me that it's not like I'm used to.  This will be different thinking for me on using the router.  Can't think why it won't work.  Guess all the caution I've heard about the table saw and trying to avoid a pinching the pieces between the blade and fence.  I just tried using the suggestion of trimming your boxes to width after being built so they'll be "perfectly even".  I was being careful with both my fingers and keeping it to the fence.  At the end, it seemed to catch and then I saw the box being pulled back.  Probably all happened in a short time, but I was trying to keep everything flat and against the fence and I saw I was losing it.  I grabbed the box away as it was being flung.  Now I have a big gouge in the edge.  So much for being even.  Since I don't understand what caused it, and had evened up edges before with no problem, I think in the future I will just cut them to width and be more careful in assembly.

So a board between the router bit and fence makes me cautious.  But it should work.  If I did it with my router table and its fence, I'll have to do it from the opposite direction and left handed.  Unless I just add an additional straight edge like you do.

Offline little john

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Re: Deforming Plywood
« Reply #22 on: June 14, 2016, 06:22:24 am »
I just tried using the suggestion of trimming your boxes to width after being built so they'll be "perfectly even".

Just a bit of clarification re: trimming boxes accurately to size.

These are the very last National Brood Boxes I made from pallet wood, which was before Mann-Lake came to town, and was the only viable way from me to acquire cheap boxes. 




Now I buy Mann-Lake boxes flat-pack, and although being 2nd-grade they need some fettling, it's more cost-effective than breaking pallets apart for their wood.

Ok - so having run the planks individually across the table router to clean-up their edges, I then glued-up wide composite planks to form the box sides and ends.  These are run across a table saw to reduce them to size, plus a few millimetres extra for trimming.  Then the boxes themselves are built.  In the following shot, the end plates were obviously left very proud (can't think why, now) but would then have been cut down to remove most of the excess, but leaving enough for the next step.




The boxes are then placed on a dead-flat bed and checked for rock - which I find is a constant issue when working with pallet wood. If it is more than just a couple of millmetres (which would be ignored, as subsequent loading weight would flatten that) then spacers - bits of old credit cards, washers etc - are inserted equally at opposite corners to stop the rock, and then hot-glued in place.




Then the sides of the jig are built up, and a router sledge placed over the top.  This is run back and forth until the edges are uniformly flat, at which point the jig is dismantled, and the box secured with the flat side downwards (no need for spacers now) and the process repeated on the other edge until the desired box height is reached.




Because this router is fixed to the sledge and thus dedicated to this one task - likewise the router fixed under the router table - I've used cheap and cheerful routers (ex bring and buy sales) for these tasks.  But to make such cheap and simple plunge routers more useful, I've fitted them with a means of precise adjustment:




This very simple modification makes all the difference in the world, turning a fairly crude and simple plunge router into a precision tool with controlled variable depth.

LJ
A Heretics Guide to Beekeeping - http://heretics-guide.atwebpages.com

 

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