Deburring/Dimpling Question

[Rick6a]

I took away from the handbook that you don't deburr at all for dimples...is this wrong?

why the diconnect between the Handbook and the way we do it?

I would never dimple a hole without deburring.

Why the double deburr? It seems counter productive to do all this twice.

I get the sense we may be skewing ourselves towards overanalyzing this whole issue. Think of it this way. What do fluting and deburring have in common? The answer of course is that both tedious procedures need only be accomplished AS REQUIRED. It is a counterproductive waste of time to arbitrarily debur each and every hole whether it needs to be deburred or not. To verify holes are sufficiently deburred, highly practiced production inspectors will commonly and quite simply lightly run their finger tips across the hole pattern. Any wayward burrs will quickly be descerned. I believe the intent of the designer is to merely underscore the necessity to verify that the holes are burr free.
On to a far more delicate issue.....as far as the "handbook" is concerned. I found occasional variances...a disconnect...between what was printed in the instructions and what was ultimately expected. In the case of my slowbuild kit, it was mostly due to upgrades in the quality of the parts, yet such improvements were rarely noted and duly updated in the manual. Large production environments can have whole departments of technical writers to constantly update documents. I doubt Van has that resource. Also, we must remember that individual members of Van's staff may not necessarily be focused on the same sentence of the same page at the same time. Similar to the makeup of our diverse forum, Van's staff, while unquestioningly RV enthusiasts across the board, are still individuals and can and often will have varying opinions on any number of topics subject to our well-intentioned queries.

[tomcostanza]

AAAAHHHhhhh. The voice of reason. Thanks Rick. I found that when deburring after using a sharp drill or a reamer, especially on thin material, that I created more burrs than I removed. I have learned to deburr only the burrs.

I previously raised the question about dimpling before or after drilling, since I have read (in 2 places), that dimpling should be done BEFORE drilling. What the authors may have meant is that you should drill undersized holes, dimple, and finally drill to final size. Anybody read similar advice?

Tom Costanza
Langhorne PA
RV-7A Fuse

[markerthebarker]

After studing several other builder's websites, I've noticed several builders have set up their C-Frame Dimpler, whacked it with their hammer, and put a dimple in the wrong place. My question is two-fold, first off, can you not put the male die in the bottom holder and the female in the top, thus using gravity and the bottom die to hold the skin in place while you whack with your hammer (inside of skin facing up of course)? Secondly, has anyone ever tried to add a handle to their C-Frame Dimpler and use it to squeeze in your dimples (sort of like the DRDT-2)?

GeorgeH
Tooling Up

[Brian130]

Originally Posted by markerthebarker

After studing several other builder's websites, I've noticed several builders have set up their C-Frame Dimpler, whacked it with their hammer, and put a dimple in the wrong place. My question is two-fold, first off, can you not put the male die in the bottom holder and the female in the top, thus using gravity and the bottom die to hold the skin in place while you whack with your hammer (inside of skin facing up of course)?

My male die is on the bottom (standard Avery C-frame dimpler). The skin still tends to want to jump off and I suspect that's what you're seeing rather than reverse setups. My wife has gotten pretty good at holding skins still while I dimple.

[AntiGravity]

I had the male in the bottom when I tried to single-handedly do my HS skin and made an extra hole. It still jumped off. Now when I do large skins I have my wife help. Oh, and I have a DRDT-2 now as well, which is much much easier!

[TShort]

Some of the skins (like LE skins, folded control surfaces) cannot be dimpled with the male die on the bottom - there is no easy way to hit the c-frame with it set up that way. Flat skins like the wings could easily be done this way.

Thomas

[AntiGravity]

Originally Posted by TShort

Some of the skins (like LE skins, folded control surfaces) cannot be dimpled with the male die on the bottom - there is no easy way to hit the c-frame with it set up that way. Flat skins like the wings could easily be done this way.

Yes they can, but it is very difficult, even with two people. It has to be done before the skin is bent to final shape, and it is very hard to keep the skin away from the C-frame. Most definitely a two-person job, and sometimes the dimples aren't 'square' with the work.

Do yourself a big favour and mount your C-frame (or DRDT) close to the edge of the table and do the skin the other way round with the male at the top (on the Avery C-frame you might need to cut an angle on the bottom of the frame to accomodate the skin; not sure, never tried it that way and now have a DRDT).

[jcoloccia]

I definately have the male die on top when I'm using my DRDT. It's so easy and controllable that it works out fine, plus I can slide the skins around without worrying about scratches from the male die on the bottom.

When I was using the C-Frame, I finally just took the stupid spring off. It seemed to make dimpling about 10 times easier, especially if you were doing it without help. WAY too much *SpROinGA SpROinGA* action if you leave the spring in.

[Rick S.]

Most folks get a little over zealous with the deburring part anyway, only remove the burr, don't put in a mini countersink.

As to the dimpling with the C-frame, I use the male on the bottom and I surround the C-Frame with two 2' X 2' X 2" sheets of styrofoam insulation from Home Depot. You can move the foam and C-frame around to fit any spot on the metal that it is capable of reaching. The sheets lay flat on the foam and I can position the female die right on the male and hold the shaft and give it a double whack. I never trusted the tool to travel true and straight right onto the male die positioned from above. FWIW I would get the DRT-2 if I had it to do all over again.