speedbrake

I'm going to build a Bruce Tharpe Delta Vortex using a turbine for power. It has been done before. Mine will have a canard configuration and use a PST-600 turbine. No retracts and pretty much a standard Vortex build except for those changes necessary to accomodate a turbine. The standard Vortex has an engine box structure for a .91 size engine...mine will eliminate the engine box and replace it with a forward fuselage section that extends 22 inches beyond the wing LE. The fuselage portion is already complete...now working on the wing.

warbird51

My Feedback: (12)

Cool! Keep the pics coming.

speedbrake

More work on the wing; added the main spars and LE cap. I took the wing off the board to begin installing the tanks. Two 24oz tanks centered on the CG...just inside the leading edge area. The CG is located 26 inches from the TE. Normally the Vortex is eight pounds ready to fly. I will double that weight..perhaps more. I added another spar, running span wise, to handle the additional weight. An additional wire was added to the LG to strenthen it. Normally only the center section of the wing is sheeted....I will sheet the entire wing. I will add lite-ply to those areas I feel need to be strengthened.

Jim Patrick

Did you check out this thread on the Turbine Enforcer ?
I fly the ARF version of the Tharpe Delta with an OS 91
A fun plane to fly, does 120 with the OS on a 13/10 APC

Veritech

Ha, I have a Delta vortex ARF in the basement that is halfway through a turbine conversion. I was going to use an SWB Mamba (10# thrust) but once I got it all together I had a serious CG issue and would have required about 1.5 to 2 pounds of lead to the nose. I guess the custom ply motor mount is too far back. One of these days I will get back around to it and see if I cant move the motor farther forward to get it to balance better... It should be a real hoot with 10# of thrust...

speedbrake

I built a regular Vortex with an OS .91. It flies very well..not sure how fast it is. However, I've seen a turbine powered Vortex fly and it was clocked at 180mph. Not sure if mine will be as fast. My motive to start this thread was how well the turbine powered Vortex flew. It had the same characteristics as the .91 powered Vortex. Landings are about the same...nice and easy and slow. That big wing produces lots of lift.

Got ahead of myself and put the pieces together to see what it will look like. The long fuselage should make the CG easy to obtain even with the turbine installed on the TE.

joeflyer

My Feedback: (48)

Looks good. Reminds me a lot of my Turbine Enforcer. That airfoil is rather thick, so I doubt one could do 180 mph without grossly overpowering it, i.e. 30# thrust or so. My suspicion is that there was something wrong with the radar, he was in a very steep dive, or he was stretching the truth.

The landing gear and mounting doesn't look strong enough, especially if you'll be flying off of grass. I suggest making plywood doublers for the center 4 ribs that extend as far fore and aft as the spars. Also make the wood piece the wire rests in wider. Make a new gear out of 3/16" music wire, or better yet install retracts with knee action struts. My 3/16" wire struts will bend every time I go off the runway.

You'll need more than 48 oz. of fuel if you want to fly longer than 5 minutes. I have a 64 oz. juice bottle for a tank and can fly for 7 minutes with reserve using a Wren 54.

joeflyer

My Feedback: (48)

WOW! Not sure why the pictures came out so large.

speedbrake

Added the shear webs to both spars and the TE sheeting. The wing is very stiff and light.

Joeflyer: Yeah you are right. The LG is pretty weak. My original thought was to add a sheet metal gear....shown in picture. Then I got thinking about that extra weight behind the CG and decided to go with the MW LG I guess I'll rethink the LG...nothing is glued yet. The gear shown is not long enough...not enough height to allow rotation on TO and LDG without striking the underside of the wing. It does add six inches to the LDG span...which I do like.
As for the fuel tanks, I need to go with what will fit inside the wing. 32oz. tanks will not fit. I do have room inside the fuselage for a hopper tank plus the UAT. There is room under the canard for a 10 or 12 oz tank...once the airframe is complete I can put everything in and see what will work.

speedbrake

Joeflyer,
I like your jet. I'll bet it flies great.

As for the 180mph Vortex....I don't know. I watched the first two flights. I was emailed about the speed run. That Vortex has the turbine installed close to the CG and has no LG. The PST600 is rated at 14 pounds...I'll guess the weight of the model ready to fly is 16 or 17 pounds. TOs and landings are done on grass...and yes the rudder control is solid while on the ground. It takes about 70 feet to TO. Landings are slow and it slides to a stop in 20 feet or so. Obviously not having wheels limits where it can be flown. The owner built it to go fast...that is what he likes.

i3dm

My Feedback: (51)

Nice work - cant wait to see the finished product.

BruceTharpe

My Feedback: (1)

I like it too! I've always said the Delta Vortex is a good starting point for creative types to build upon and it's always fun to see what guys come up with when they decide to do something different. Keep plugging away speedbrake!

speedbrake

Added the servo mounts and engine mount. Also added a lite-ply doubler to the inner ribs to make them stronger for the fuselage addition. These doublers will be used to mount the fuel tanks. Once the tanks are installed the leading edge sheeting can be glued on. Then....the fuselage can be mated to the wing. Not too many bits and pieces remaining in the kit box. Amazing how many little things go into building a kit. I'm going to add STOL tips...these add a nice touch and won't take much effort to carve. I decided to use a sheet metal LDG. The existing MW is fine for an eight pound model but not for 16 or 17 pounds.

Thanks Bruce! I hope this project doesn't butcher your fine kit too much.

speedbrake

Added the mount for the canard and steering servos. The steering servo will be mounted upside down so the servo arm will be the same height as the steering arm. The canard is 1/3 the size of the wing...with same LE sweep. The carard TE is one inch forward of the wing LE. The UAT will be just behind the servos. The fuel lines from the main tanks will enter this portion of the fuselage...just behind the servos. I plan to have the vent line exit the bottom of this compartment. The header tank will be in the next forward compartment, under the canard. Receiver and batteries will be forward of the header tank (under the forward hatch).

speedbrake

Added the TE, LDG mount, and tanks. I need to make the LE sheeting which made from three 3/32 balsa sheets X 4. Once the sheeting is on and the LE sanded to shape, the fuselage can be installed. Project will go rapidly once the fuselage is joined. Much of the upper fuselage and wing center section will be open... four hatches for access. Waiting for fuel tubing, tip blocks, LGR, wheels and covering to finish. Also might need more 3/32 balsa sheets for wing. Tower orders take about four days to arrive.

speedbrake

The bottom LE sheeting is on. Now I have to wait for the fuel tubing before the top sheeting can be put on. My plan was to have the header tank under the canard but decided it would be better behind the canard and steering servos. It would be almost on the CG. The UAT will go under the canard...but will need to be mounted horizontally instead of the recommended 45 degrees. The pictures show just how long the fuselage is. The fuselage is 59 1/2 inches long....the nose is 22 inches from the wing LE. The engine is mounted 18 inches behind the CG. The CG is located just behind the main spar.

joeflyer

My Feedback: (48)

Looking good, speedbrake. You should put some additional support (maybe plywood) under the front of the tanks. You would hate to have them crack your wing sheeting if you bounce a landing. Don't forget to safety wire all of your fuel connections, including inside the tanks.

Will your tanks be accessible once the sheeting is on?

Joe

speedbrake

Really need the parts now....things are slowing down. I was able to finish the holes for the fuel lines going through the fuselage and the holes for the various tubes and wires going through the front bulkhead. I started sheeting the bottom of the wing. The bottom of the fuselage is parallel to the long axis, as is the canard and engine mount. By placing a level on the canard and engine mount I can safely ensure the fuselage and wing mate correctly. I will use a hook to pull the fuel lines through the fuselage once the top LE sheeting has been glued on, at least that is the plan.

Joe: No the tanks will not be accessible. I'll ensure all the fuel lines are secure. BOUNCE A LANDING?[sm=frown.gif] I hope not...especially that hard. I noticed on your plane the tips appear to be metal. Is that to prevent the under side from scaping the ground?

Cheers,
Keith

joeflyer

My Feedback: (48)

It happens eventually even to the best pilots. A delta can get into a kangaroo hop if you land too fast at the wrong angle.

My wing tip skids are made out of aluminum to protect the control horns and linkages, which are on the bottom. They have come in handy on some high alfa and gear up landings.

Joe

speedbrake

Fuel tubing finally came in....was able to sheet the top LE. Once done the LE was glued and sanded then the fuselage was mated to the wing. One of the pictures shows the thickness of the wing....awesome wing for those of you who haven't flown this plane. UAT is plumbed. Need to finish the aft fuselage so the top of the wing can be sheeted. Plane stilll feels light.

speedbrake

This is a small airframe as jets go......span is 54 inches, total length is 59 1/2 inches. I guess the weight will be about 17 pounds. My turbine is rated at 14 pounds...so will have adequate performance.

speedbrake

The top hatches are done. Need to sheet the bottom of the wing and then the top. Notice the photo with the yellow arrows; the left arrow points to the standard front CG point for the Vortex. The right arrow shows the forward shift of the CG caused by the canard.

speedbrake

The basic structure is done. Some filling and sanding are the immediate jobs. The wing tips will be last because I don't want to damage them during handling of the structure for sanding.. The landing gear has arrived, need to rebend it so the proper height is obtained. I will start covering the canard so I can install the canard elevator. According to the wife's scale, the structure weighs five pounds. My target has been fifteen pounds. So it looks promising that can be acheived. I'll keep pictures coming as it progresses. I live in Germany so the plane needs to be shipped to the states this summer. I plan to fly it in August or September, will keep this thread posted with flight photos.

speedbrake

The LDG was installed. Gives the model sufficient height to allow rotation without shriking the TE. Carved the tips. This is easy to do and gives a good look to the wing tips. Will start covering soon, need one more sanding and cleaning.

speedbrake

This is the slow part for me....covering takes forever! I'll be at this for a week at least. Over all color is yellow with red and white trim. A little bit of gray for panel lines.