Strega1

My Feedback: (7)

Hi, Jeff

This is Ben Cubillos from El Paso. The fuel tank problem is a big "goof' on GP's part. I belive that I have found a suitible fuel tank for my DB. I will use the MK 450cc. the dimensions are 2 1/16" wide x 2 3/8" high x 6 3/8" long. By removing 1/8" material all around and the fuel tank will work perfectly. This is a 15.5 oz. fuel tank. I will be using a Rossi side exhaust with a "Performace Specialties" tune muffler. The Rossi has a big case but it will fit ,if I use Dave Brown 120FS radial mount. I may have to cut the mount lugs on the front so it won't hit the cowl (?). I will have to enlarge the fuel stopper hole so that I can get a sanding drum to grind the front former. I don't want to remove any formers as the engines I'm using are very powerful, especially the 5 port RE, 9mm carb Rossi that I can also use and of coarse it will have a pipe. I had it in a Warbird Racer.. I'm still not sure witch engine I will be using at this time.

Some hobby shops cary the DB arf. The last time I looked inthe internet, there, were three shops that had 2 or three in stock. Tower says that they won't have one untill the end of August. Befor that that it was the end of April. I bought mine at Hobby Proz in Albuquerque, NM. They are out of DB's. So look in the internet you may find one. I bought mine about 2 weeks ago.

I guess that I'm asking for some input on enlarging the the two formers in the glass fuse. Any and all help is welcomed.

Ben Cubillos

energyman

My Feedback: (2)

Ben,

I too run a Rossi on my DB. I solved the tank issue in a little different way that did not require grinding any of the formers. I used the tank included in the kit in the recommended location with the pick up and vent tubeexiting the bottom of the tank stopperto clear the engine mount. This was required because I mounted the Rossi upright. I then installed a Dubro 8 oz tank in series and behind the factory tank. No grinding of themount was required. Careful planning isneeded for the installation of the fuel tubing due to the holes required in the firewall in order to not interfere with thefront tankand the retract floor as well as the cowl mounting screws. I have 22 flights with this tank setup with no fuel feed problems. If you need pictures, let me know and I will see if I can figure out a way to take some that will be helpful.

The Rossi has required 4 ounces of tail weight to bring the CG to meet my requirements. The weight without the extra tank and lead was 7.75 pounds. It is now 8.25 pounds and flies very well. Let me know if you have any questions.

Danny Jackson

ChiefK

Ben,

I just popped out those two forward formers and installed a 12oz Kavan fuel tank. Works perfectly.

ChiefK

pjwright

I tried one of those Kavan tanks, and found it fit best with some whittling on the nosegear retract well. I removed the two plywood tank formers, Dremelled the nosegear retract well and plywood mount, installed a 1/8" plywood fueltank deck (full fuselage width) with FG cloth and epoxy mixed with milled fiberglass, and zip-tied the Kavan tank to the plywood deck. I also used a 5/32 DuBro nosegear wire in lieu of the provided one, since it is long enough to be supported by both holes in the engine mount - not just the bottom one. My last mod is shimming the front of the cowl 3/16" to accomodate the extra length of my Saito .82. Should be RTF this week.

PJ

Cobra1

My Feedback: (42)

I finally got around to finishing my DB. I used my old Spring Air retracts and my YS 60 engine both from the 80's. No tuned pipe in the pics as I still need to cut the header for tuning. Initial run was 12500 with a 11x9 APC prop. A little shorter pipe and I will get 13k on the ground - not bad for an old engine. The weight cane out to 8.5 lbs and with the battery as far back as I can get it, I still need 1oz of tail weight for balance. I hope to fly it this weekend - if other life issues don't get in the way.

By the way, I used a hayes 12oz tank that fits in the fuse very nice. I support it with foam rubber and the rear of the tank rests against the servo tray. I now remember why I hated these type of aircraft back in the 80's - no room in the fuse for everything that needs to go in there.

hrrcflyer

Hey Cobra1,

AWESOME job on the YS install ! ! ! ! ! How did you cut the cowl opening so small and still get it to fit over the cylinder head? If you don't mind, the next time you have the cowl off, would you take a few pics of your engine and engine mount installation as well as your throttle connection?

I can't wait to see pics or even a video of your DB hauling a__ down the runway. Good luck with your maiden......

David

Cobra1

My Feedback: (42)

Thanks for the kind words. I am looking forward to a 110+mph low pass down the runway. After I tune the pipe this weekend I will take a few more pics. Concerning the cowl, it is split behind the engine so it goes on easy but covers up the gap behind the engine. I will get a pic of that also along with the tank install.

Cobra1

My Feedback: (42)

Here are a couple of pics with the cowl removed. The throttle uses a ball joint to take up mis-alignment. No shot of the inards as of yet.

pitstop000

My Feedback: (26)

Has anyone lightened up the aluminum wing joiner with some holes or is everyone just assembling it as in the manual.<o></o>

<o></o>

I just think its overkill as is and some weight could be saved, just wondering any thoughts on the matter.

Cobra1

My Feedback: (42)

Yes I believe that you could lighten it up some with the holes as you state, maybe save an ounce or two. I did not and the airplane came out to 8.5 lbs. with balance weight added so I am happy with the weight as built - - but lighter does fly better...

PatternPilot

My Feedback: (58)

Why are these planes so heavy.... Is the glass work that bad and heavy ? I have been watching this thread on and off .. And just can't believe these weights... servos, hardware, rx battery. looks like a diet is needed.

s.

ChiefK

Pitstop,

I also thought that the aluminum dihedral brace/wing-half joiner was overkill. I drilled lots of holes in mine before gluing it in, but haven't got a way to accurately weigh the plane.

Scott,

The airplane is not particularly heavy. The glass work is actually quite good and very light. In fact, I'm really careful about how I pick up the airplane to avoid splitting a seam. I doubt that this airplane would survive a ground loop. The LG mount is also a concern. At the SPA contest last weekend in Asheville, I pulled loose one of the LG legs in the wing when landing (and it was a good landing). Two of the screws in that leg pulled out, stripping the threads in the ply mount. I'm planning to drill out the stripped holes and glue in a piece of hardwood dowel, then redrill (both wing gear mounts).

The good news is that these airplanes are very competitive. One of them won Senior Expert. I won the first two rounds with mine (the gear broke on that second round landing) in the Novice class (finished the last 3 rounds with my backup Intruder), and a couple more DB's were also impressive.

ChiefK

hrrcflyer

Cobra1,

Thanks for the pics. Did you use the motor mount that was supplied with the ARF?

David

Cobra1

My Feedback: (42)

I did use the supplied mount, it is just wide enough when fully adjusted to its widest position.

As far as the weight, as stated the fuse is built very light but the wing could be lighter. It is sheeted foam and I am sure the foam is solid.

pitstop000

My Feedback: (26)

Chief,

<o></o>

I decided to lighten it up a little, saved me another 1.5 oz., now to do the second wing.

Back to the shop.

PatternPilot

My Feedback: (58)

nice work Paul...... Why not do like we did with LA1 and do a hard balsa and carbon fiber and hard balsa sandwich... did have a small peice of ply also in middle where we cut out for pipe... super strong and super light..plus great bonding surface... never a proplems with snaps and spins..

well back to my shop also...

s

ChiefK

Very neat job Paul. I was a bit more "willy-nilly" with my drilling. My goal was to get the same number of holes on each side of the centerline.

Scott, sounds like a great high-tech solution to the problem, but I bought this airplane because I needed something to fly without a prolonged build, while rebuilding my Deception. Didn't think about it beyond drilling some holes.

Repaired the LG and it's ready to fly again.

ChiefK

energyman

My Feedback: (2)

Scott,

With an EVO 60, Jett muffler, extra 8 ounce Dubro tank, 7 servos (5 digital) and Hobbico retracts, the all up dry weight was 7 lbs 10 ounces. With the Rossi 60, Mac pipe, 4 ounces of tail weight, and the same equipment as above, the weight was 8 lbs 4 ounces. I will echo what Chief said about the fuse. It is light and thin in the area between the wing saddle and tail. The wingis where weight can be saved by lightingor replacing the dihedral brace as some have done.

The Rossi setupis bulletproof as faras reliability is concerned.Thespeed, and power are also very good. The prop on the Rossiis an APC 11x9 at approximately 13,000 rpm. Iwas curiousso I installed the EVO to fly the plane at a lighter weight. The enginehas never beenas reliable. It will turn an APC 10x8 over 15,000 making for a fast and loudflight. The firstflight with the EVO was without aproblem.On the second flight, the engine diedon the downline ofthe second leg of a Figure M. Wind was about 20 mph. There was no way to circle and land upwind. The downwind landing was one of the fastest I have experienced and was on a rough grass field. The plane hopped the runway, and flipped after crossing the runway. The only failure was a broken nose gear strut. The nose gear and main gear unitsdid not fail or pull out of the plane. There are two areas in the top of the fuse in thethin area that flexed enough to damage the paint. I will repair with epoxy.

I willaccept the weight of the Rossi considering all the positive attributes as mentioned. I have 31 flights on the plane and am very pleased with the performance.

Energyman

pitstop000

My Feedback: (26)

Thanks Guys!

<o></o>

I had thought about doing a carbon fiber sandwich Scott but like Chief I just need them ready ASAP.

<o></o>

The most time has been spent just getting the NovaRossi RE shoehorned in!

The O.S. was a piece of cake to install.

<o></o>

If all goes well I’ll be breaking in the engines tomorrow, now back to the shop assembling these two birds.

Strega1

My Feedback: (7)

Hello, Paul

I see that you are using the Rossi (Nova) reat exhaust. I'm in the prosces of using the standard Rossi 3 port with a tune muffler from Performance Specialties. So far everything is kosher but I'm using the Bob Brown 120sf composite radial mount and it will fit the firewall. I rather use the 5port RE Rossi as it has a lot more power and I can use a pipe.
How bad or how musch did you have to grind or cut the firewall in order to make the header fit. Your help is appriciated. Thanks in advance to you and everyone that has written to me with advice.

Ben Cubillos
El Paso, Texas

AllTheGoodNamesAreTaken

My Feedback: (180)

Paul,
Are you going to have to remove any material on the side of the fuse to get the NovaRossi header to fit? I tried to fit my NovaRossi and the header wont clear...
Jeff

pitstop000

My Feedback: (26)

Ben,

Jeff,

<o></o>

Yes to get the header to fit with clearance you’ll have to go into the side of the fuse. I’m not concerned about the repair work because I’m shooting all the white on this fuse with yellow and doing a black canopy.

<o></o>

Here is a pic of the mods I made to the mount just to get the motor back enough before getting into the fuse work.

pitstop000

My Feedback: (26)

Hey Ben,
Here are some pics of how much I ended up grinding and cutting to get the header to fit, I've also had to rebend the header.
All worth it for me to get this powerhouse into the Dirty Birdy!

Ralph White

Paul, How did you go about re-bending the header? I was afraid the header might kink if I tried re-bending it.
Ralph White

Strega1

My Feedback: (7)

Hey Paul

Thanks for the pics and the info on the DB and Rossi. I'm at a loss on the header. Why did you have to bend it? Was there an obstruction? Does all this grinding weaken the firewal? How are you going to reinforce it and with what? When you are done with this project, please furnish more pics and a blow by blow on how you did this particular cut to the firewall. I'll be doing the same with my project, either the side exhaust w/ Performance Specialties tune muffler, or the RE Rossi and modifications. I'll furnish plenty of photos

Thanks for all the info and the photos.

Ben Cubillos
El Paso, Texas