rrudytoo

My Feedback: (27)

Les,

Thanks for the info. I really appreciate it.

Al

DUFLID

I have done some further measurements using the RCGF-20 dimensions because I can find any dimensions for RCGF-15 or the RCS/SV-17 the engine would eat up too much of the cowling. I was really leaning to RCV/SV-17 because the cost of the engine at $179.00. And I’ve heard the RCGF-15 will be around $240.00. So that being said I have a RCV-91cd I was going to use for another plane, I will have to find another good used or new RCV for the Bronco. Will keep you posted on the progress.

Les, yes that Super Tiger would work but the price is more that I want too pay.

Al, Good Luck with your Bronco keep us posted with some more pictures.

Now this gas idea was not too try and out do the Jones with a bigger is better more expensive plane. It was an attempt to an inexpensive alterative to glow engines. As for bigger is better I wonder why Rich decided to do a 107� Bronco.

Thanks all for your info, I really appreciated it.

DUFLID

gsmith6879

My Feedback: (37)

Very good suggestions on the cooling air. We had some minor cooling problems with the GMS glow engines until we opened up the back of the cowl. Two other things I might add.

We put a full time glow system on ours. This is just a simple 1500 or so single cell nicad in each nacelle with a switch and charge jack. We get 4 flights on a charge and this really helps the reliability of the glow engines. My friends Yellow Bronco has never had an engine out with this setup. The other thing is a simple check of the needle setting by holding the Bronco vertical for a few seconds to see if one or both engines sag. I can't tell you how many times this has saved the Broncos. You have to make yourself do this every time before you fly. I crashed my Bronco because of an engine out (and dumb thumbs). Guess what I didn't do before that flight? I had just finished a great flight and just got lazy and didn't do the vertical check before taxiing out and got bit.

gsmith6879

My Feedback: (37)

I've been working on building a new 81" Uravitch Bronco since I wadded up my first one in July. I liked the way the Bronco flew and wanted to keep all of the good characteristics but I wanted to also make it a bit more scale. I replaced the 3/8" square stock on the corners of the nacelle and fuselage with 3/4" triangle stock so that I could round over the corners more and "soften" the edges. I reshaped the fuselage nose section cone. It is now the correct outline and will allow the nose gear to retract forward. I reshaped the tail cone to allow the rounder fuselage corners. I also reshaped the cowlings for the rounder nacelle and the make them more scale in appearance. I had planned on just making temporary molds for the new parts but 3 of my fellow club members wanted to build the Bronco and wanted to make the same changes. So I made permanent molds and pulled fiberglass parts for them. We ordered plans and canopies from Rich and we should have at least 3 new Uravitch Broncos flying by early spring 2010.

I was going to use the GMS engines from the first Bronco but changed my mind when RCGF released the new 15cc gassers. I just finished mounting the RCGF 15cc gas engines rotating one of the cylinders and pistons to allow both engines to face in board. I have the custom muffler mock-ups ready to go to Bisson to have them fabricate a muffler that will fit inside the cowling and exhaust near the scale location. I machined new landing gear struts and will be using Robart actuators. I plan to paint it with Behr house paint with the VAL4 Navy markings. It should weigh between 22 and 23 pounds ready to fly. My first one weighed 22 pounds and flew like a heavy trainer. It weighs 18 pounds as pictured. The only gear left to add are 6 servos and the battery packs. Cockpit detail will be minimal.

FliteMetal

After reading the above references to the scale cowl openings I decided to post a few photos to permit anyone desiring to do so to replicate the cowl vents and scale openings in the face of the cowls. The top cowl opening opens and closes with rise and fall of the engine temperature. You could have it open wider when engine rpm is low and closed further when in the air.

Many people open a slit at the bottom of the cowl where it intersects the firewall. It does not have to be wide to work well because it is the overall area of openings you have in the cowl to permit the face openings to work well. Building in a path for air to exit the scale exhaust manifold surround will help as well.

JimO

My Feedback: (7)

Does anyone have a materials list for the 81 inch. I have the short kit and about to start.


JimO

FliteMetal

Considering Rich is really close to you....order the plans and you will received the ML.

JimO

My Feedback: (7)

Got the plans and a material list is not included.

JimO

CanDo

I ordered the balsa and misc materials by studying the plans. If you don't already have them, you can order the plastic parts from Rich. Note, the plans call out for a lot of lite ply to keep the cost down, but the ARF has substituted balsa sheets for much of the fuselage and nacelles. It's possible to build this plane under 19 lb RTF, but wood selection is very important. This plane tends to come out tail heavy, so any extra weight behind the CG is going to work against you.

JimO

My Feedback: (7)

Got all the above and getting the material is not a problem. I work for Hobbytown here in Tallahassee so picking out "light balsa is not going to be any problem. I am planning on lighting holes in the booms to save some weight.

Plans are laid out so time for pencil and paper to make the list.

JimO

gsmith6879

My Feedback: (37)

PM me your email address and I will email the Excel spread sheet that lists all of the material I bought for the 3 Broncos we are building. The list defines where the material goes so you should be able to delete the stuff that came with the short kit.

JimO

My Feedback: (7)

Got the wood and ready to build, any good building tips other than what is in this thread.

JimO

gsmith6879

My Feedback: (37)

The Bronco builds fairly easy. Uravitch did a good job with the design. I've built 2 of them now and didn't find anything to complain about. Rich uses a lot of light ply in the design and light ply likes to warp. Just make sure you keep everything straight and aligned during the assembly.

Good luck.

fancman

My Feedback: (16)

It's strange that the Uravitch kit built OV 10 uses light ply for the sides and the Hobby Hangar ARF Bronco based on the Uravitch design uses only balsa for fuse and nacelle siding. The balsa is sufficient and if I were going to build another Uravitch Bronco I would use balsa instead of the light ply. I've had both and the balsa was definately lighter. I would also skip the linkage to the elevator in favor of using the small metal gear Hitec servo's in the tail surface. I built in the long servo leads when assembling the tail and install hard points in the tail fin to screw the servo mounts to with great success. It's way easier to do and works great.

JimO

My Feedback: (7)

Fancman, I had thought about the servo in the tail and happy to hear someone has done it. I had also thought about using twin micro servos, one on each side, your thoughts on this.

DId you mount the rudder servos in the back or did you run push-rod's?

I hear the build comes out tail heavy, so want to be careful of location of electronics.

Going to use Thunder Tiger 91 FS for power and know this will help offset some weight. I also have some Hayes aluminum mounts to help with the CG location.

JimO

fancman

My Feedback: (16)

I positioned the rudder servo's as per the plans but used one micro servo for each side of the elevator. My first bronco was way heavy because I glassed and painted the whole thing. Almost 24 lbs and it flew great with both engines running. Landed like a butterfly but with one engine out the extra weight showed and I lost it finally. There are pictures of my bronco in this thread near the beginning I believe.

JimO

My Feedback: (7)

Did you use micro servo's or the thin wing servos?

fancman

My Feedback: (16)

I used two Hitec 85mg servo's. I cut down the leads to two inches and redid the connectors to attach to the long servo lead built into the tail. They provide plenty torque and operated fine. See post #448

gsmith6879

My Feedback: (37)

Here is the update on my Uravitch Bronco completion. With the exception of the cockpit and canopy all finish work is done. I have installed and made operational all radio and retract gear. The new RCGF 15cc gassers are installed and waiting on the Bisson Custom mufflers. The finish is 1/2 ounce glass cloth applied with West Systems epoxy, primed with automotive acrylic lacquer primer and painted with Behr exterior house paint. The all up weight with the pilots in the cockpit is a bit over 24 pounds. This a pound over my target. My first Bronco weighed 22 pounds with GMS glow engines and Monokote. The 2 RCGF engines added a full pound over the glow engines and I added an extra flight battery for redundancy. This and the extra wing sheeting (no cap strips) for the paint brought the weight up. I looks like it will balance without extra lead so the 24 pounds is it. I don't like the extra weight but that's the price you pay for gas and paint. I'll report on the test flights when they are completed.

Fili

She's georgous gsmith!

Destroyer of Airplanes

My Feedback: (25)

gsmith,

Very very nice. Are you using decals or masking and painted graphics. Who did them I would like to have them do mine as well.

Thanks
Paul

gsmith6879

My Feedback: (37)

Paul,

The black lettering was done with vinyl paint mask painted with the same Behr exterior house paint that I use for the original paint. The stars and bars and other red and white markings are print on vinyl. My local sign shop has been doing my graphics for about 5 years and is great to work with. I do everything in cad and then print it out for him to scan and send to his cutter. The print on vinyl is a new technology in the sign business and he has the latest equipment. He can print high def photos on vinyl (I'm thinking nose art!).

The downside to the print on vinyl is that you can't clearcoat it with just any paint. Solvent based paint will lift the vinyl. I clear coat with water based Behr Matte clear to get a good even sheen.

My sign guys name is Greg Vanderveer, Signs for the Times, Muskogee, OK. His phone number is 918 682-8849. I just talked to Greg and he can duplicate what he did for for me and mail it to you. If you don't want to paint he can do the black letters in vinyl and you can just stick them on like the print on vinyl.

I can also email the cad file if you want to look for someone in your area to do this work for you.

Gaines

Destroyer of Airplanes

My Feedback: (25)

Gains,

That is good information. I will call Greg this afternoon. Here is a picture of the airplane I'm doing and another of how far along I am.

Thanks again

Paul

gsmith6879

My Feedback: (37)

Paul,

Funny. Here is a photo of my first Uravitch Bronco. Seem familiar?

aeroscale

Here's my 1st 52" version. My 1st 80" was the same. Popular scheme...........