Drdt-2

Thing just came in the mail today. I ran some scrap pieces through. Holy cow, this sucker rocks.

I know I know...all the purists are gonna talk about how they didn't have this and that when they built THEIR Rv-blahdityblah...

Whatever...given the choice, I'd pick this over the pneumatic squeezer if you've got some extra cash laying around.

I Agree

I built my 7a using the Avery C-Frame dimpler - whackin the top with the mallet while wearing ear protection. A few times, I had the assistance of my wife - and got my hands whacked more than once.

In building my 10, I borrowed the DRDT-2 from my neighbor and it is a WORLD of difference. It's quiet, easy to use and MUCH quicker. Makes a great dimple. Highly recommended. Anyone want to buy a C-Frame in good condition ?

I wonder how many rivets there are in the fuselage compared to the wings and tail group. I am about finished with these and will order the SB fuselage soon. Is it still worth the investment to buy the new dimpler at this stage of the game?

Jim Wright RV-9A 90919 Arkansas

I'm in Houston and have the DRT2 "kit" so I need to make the frame in the next couple of weeks to get going.
I have lot's of experience welding (auto body experience in my previous business) so making the frame is no big deal for me.

So here's an offer for anyone in Houston: If you want to pay for the steel and take the time and trouble to pick up enough of the steel to make two frames, I'll build you yours at the same time I build mine at n/c for the labor (but paint it your own self).

That's worth it to me because I'm stuck at work and have a hard time getting away during the day. SSS Steel likely has the right size in stock.

This is a limited time offer because once I do manage to sneak away and pick up the steel for my own frame, then I've done all the hard work already.

I agree the DRDT-2 is the only way to fly. I bought the front end kit from Paul at ExperimentalAero and built my own C-Frame according to the supplied plans. Works perfectly. Don't cheap out on materials by buying thinner metal, you want the C-Frame as stiff as possible. Yes,it would be worth it just for the fuselage. After you use one you'll kick yourself for putting off your decision to get one. You'll want to take your airplane apart and do it over again.

Gene

I agree the DRDT-2 is the only way to fly. I bought the front end kit from Paul at ExperimentalAero and built my own C-Frame according to the supplied plans. Works perfectly. Don't cheap out on materials by buying thinner metal, you want the C-Frame as stiff as possible. Yes,it would be worth it just for the fuselage. After you use one you'll kick yourself for putting off your decision to get one. You'll want to take your airplane apart and do it over again.

Gene

Wouldn't be without my DRDT-2 either...one of those tools that's definitely worth the extra bucks.

Dave

My father-in-law and I dimpled an entire outboard main wing skin in about 10-15 minutes (max) with the DRDT2... no mistakes, no scratches, no noise. Try that with a traditional c-frame! I really like mine, so go for it is my vote. If you're already partly through your kit and don't know if it is worth it, I bet you could sell it in about 30 seconds when you are done.

Confession of a tool junkie

It should be admitted up front that I'm a tool junkie.

However, I have a limited amount of free time in which to build. Any tool that shortens the build time like the drdt-2 is well worth the $$' s for me. Buy one, and get a pneumatic squeezer too. My favorite use for the squeezer is dimpling the ribs.

FYI. I threw out the plans that came with the DRDT for the stupid dimple table. It didn't seem very useful to me....

I used 3/4 MDF for the top, and then built a little frame of 2X4's around the edge, leaveing a bit of MDF overhanging on the front so that a bent skin can kinda' fold under the platform a bit.

Then I got scrap 2X4's I had lying around, and screwed a few legs to the inside of the frame. Finally, I put little adjustable feet under the legs (the screw in kind they sell for levelling tables and chairs and things).

Now, I can dial in exactly how high I want the tables so the skins just barely skim across the top of the dimple dies.

I didn't connect the tables to each other with the 5/8" like the plans....mine are seperate. I like that better. YMMV

Incidentally, I used 3/4" roofing nails to hold down the carpet. Staples didn't work (carpet was too thick), and I was way too lazy to use glue. If you use a carpet with a deep, tight weave (you should be able to find all you need at Home Depot for about $20), the roofing nails sink right into the carpet and the skins will never touch'em.

I built my own table too... for those thinking of doing the same, I have a few additional comments.

John touched on this... build it so that the the angle of the legs matches the angle of the lower arm of the DRDT-2. At first I couldn't figure out why the bottom of the DRDT-2 is sloped they way it is, but then it hit me... duh!


Another thing... Make sure you anchor the DRDT-2 to the table during dimpling. This will allow you to apply more pressure and get better dimples without everything moving around. I use bolts, fender washers and wing nuts to temporarily attach it...


My last comment would be to make sure the lower die is even with or above the surface of the table (carpet). If you are using thick squishy carpet, this isn't such a big deal, but with thin industrial stuff it is. Why? If the die is lower than the surrounding surface, when you dimple, you may end up deforming (denting) a larger area around the hole because the upper ram will want to press the entire area down to meet the lower die. To adjust the height of the lower die, I use washers, and it seems to work fine.

Here is the full shot of my table. It isn't attached to the DRDT-2 in any way, it just sits on top once the DRDT-2 is anchored to the table.


Just my $.02... Good luck!

Brad's got a good point about keeping the die higher than the surroundng table. It doesn't need to be exact by any means, I've found, but a little bit higher is definitely better than a little low.

Also, anchoring down is good. My simpler way allowing for a much quicker set up/take down when you're only doing a few holes: just take a speed clamp and clamp the back of the frame to the table. You don't even need to clamp the front as the downward force of the dimplying will take care of that.

As someone else noted doing, I did not connect both sides of my table (i thus have two small tables). I allow them to float wherever necessary to support the skins. This has made dimpling everything except the main wings skins a one person job.

Washers under the dimple dies to adjust the height? Why use a nice elegant solution like that when you can waste all sorts of time messing around with table legs, adjustable feet, levelling things.....

john <==== having a "why didn't I think of that" moment

Oh well....I'll rebuild the tables for my next plane.

jcoloccia said:

john <==== having a "why didn't I think of that" moment

Click to expand...

LOL! Like the time I drove the hardware store to buy a 3/8" bit to drill the hole in the bottom of the rudder when my unibits were sitting in the tool chest?!?!

Drdt-2 Pluss

Yes I love my DRDT-2 also. Bought one as soon as AVERY listed it. I am doing most of my work by myself so I went one step farther. I removed the handle, machined an adapter, added an air cylinder on top controlled by a foot valve. Now I can slide large sheets across by myself. Bought all extra hardware from W.W. Grainger.


RV7A Working on tanks.

Now that has me curious - is the air cylinder/foot valve to run the dimpler ram, or have you got an air table to slide the sheets around without touching the table? Either way, can you post pictures, or an explanation of how to fabricate this, please?

Drdt-2 automation

I used a double acting air cylinder with 6 inch stroke to move the ram up and down. It is 1 1/2 inch in dia. I used in-line adjustable restrictions to control the speed of advancement and retraction. Everything was purchased off the shelf and bolted on. The only thing I had to make was an atachment bracket on the ram lever. I did not change the Drdt except to drill and tap four holes in the top beam. The adapter I made bolts on using the same two holes that the handle bolts use. I will make some photos and a parts list a little later. I am starting with Pro-Seal today and will try to get it together later tonight if possible.

Lower die removal

Nice job on the air powered bit. I'm sure you will enjoy the ease of use.

If I was to do a simple modification to the DRDT-2, during assembly, it would be to drill a slightly oversized (like .219) hole in the base frame directly underneath the hole in the bolt-on block that holds the lower die.

Some of my dies are a little tighter than others and are tough to get out of the hole without using a wood chisel to get them started or a pair of pliers on the OD. Neither of which I like. A drive punch from the bottom would be great. Just like removing them from the "c" on a squeezer.

It not that big of a deal really. If it was, I would have already drilled the hole, which I have not. I guess I'm too busy building..........