Turbine Enforcer
04-10-2005, 10:47 AM
#52
RE: Turbine Enforcer
Shok,
It wasn't hard to extend the nose. I cut narrow V shaped pieces out of plywood and epoxied them to the inside of the fuse side pieces. Then I used balsa pieces on the out side as filler to blend it in. The top of the nose was finished with balsa strips, then sanded to shape. If you look carefully at the pictures in post #1 you can see it. I also moved the nose gear forward to just in front of the cockpit, which required a new former and some reinforcing.
Widening the fuse was a little more involved. I had to make all new formers. Also had to shorten the front of the wing about an inch so that its width was the same as the fuse where they join together. Since I made a pocket in the wing for the tank and equipment the fuse rear section needed to line up with the ribs. See pictures in posts #37 & 40. I also lowered the height of the fuse enough that the supplied canopy would just fit. Otherwise I would have had to find another one that would look right.
Joe
It wasn't hard to extend the nose. I cut narrow V shaped pieces out of plywood and epoxied them to the inside of the fuse side pieces. Then I used balsa pieces on the out side as filler to blend it in. The top of the nose was finished with balsa strips, then sanded to shape. If you look carefully at the pictures in post #1 you can see it. I also moved the nose gear forward to just in front of the cockpit, which required a new former and some reinforcing.
Widening the fuse was a little more involved. I had to make all new formers. Also had to shorten the front of the wing about an inch so that its width was the same as the fuse where they join together. Since I made a pocket in the wing for the tank and equipment the fuse rear section needed to line up with the ribs. See pictures in posts #37 & 40. I also lowered the height of the fuse enough that the supplied canopy would just fit. Otherwise I would have had to find another one that would look right.
Joe
04-18-2005, 07:38 PM
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RE: Turbine Enforcer
Here are a couple more pix. This is a VERY tired plane, still flies OK. A great job finishing it by the builder Duane Vander Molen.
I had to remove the nose gear door as flying fom grass rips it off.
Enjoy,
Bart
I had to remove the nose gear door as flying fom grass rips it off.
Enjoy,
Bart
04-18-2005, 07:42 PM
#55
RE: Turbine Enforcer
Man, I still love the looks of that plane! Definitely my favorite Enforcer! I think you need another one for turbine now! 
Or maybe I could have your buddy build one for me in that style!
Is that Monokoted or did he glass and paint?
Myles
Or maybe I could have your buddy build one for me in that style!Is that Monokoted or did he glass and paint?
Myles
04-18-2005, 08:03 PM
#56
RE: Turbine Enforcer
Bart wrote ...
I had to remove the nose gear door as flying fom grass rips it off.
I had to remove the nose gear door as flying fom grass rips it off.
Seriously, that's a nice variant. But with the LEX's and extended nose, compared to a normal Enforcer planform, where's the happiest CG?Mike
04-18-2005, 10:08 PM
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RE: Turbine Enforcer
Myles, I'm pretty sure it is glassed...Bart let me fly it a couple of years ago, it is a surprisingly gentle flyer.. I had a dead stick on my first flight about 100 feet up over the end of the runway....no problem at all getting it down and stopped right in front of me. It would be nice to replace that tired ol' .60 with a mw 44 or something...but there is a lot of flammable stuff in the vacinity of the engine bay - stuff like wings, elevator, fins, etc......
04-18-2005, 10:19 PM
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RE: Turbine Enforcer
Mike, here is a pix. and I have marked the CofG with green tape and a line. As Nony says it is a real gentle flyer, once taking off during summber the engine was overheating and sagging, NO airflow virtually with the prop behind the engine, and it was staggering down the field, I pulled up and it waggled like a drunk and my spotter figured it was game over, but I just waited and speed came up, once no ground drag, and it picked up speed and was fine. It drops in the corners but is very light and no problems. Looks VERY COOL coming in nose high and the airbrake open, then after landing you drop the brake and you turn around and taxi home.
Bart
Bart
04-18-2005, 10:37 PM
#59
RE: Turbine Enforcer
Bart replied ...
It drops in the corners but is very light and no problems.
It drops in the corners but is very light and no problems.
Thanks for sharing the info.
Mike
04-19-2005, 03:21 AM
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RE: Turbine Enforcer
Since this post started, I ordered an enforcer and have it well on its way. I have a JDE 54 turbine, springair retracts, Eurokit struts, Intairco wheels and brakes. I have operating gear doors. I extended the nose 6 inches. There is a 50oz dubro fuel tank over the CG and I will probably put in a 12 oz. header tank, should be good for 8 - 10 minutes, as I probably will fly half throttle most of the time.
I have a few concerns, which I hope I have fixed plus I need to decide on a couple of things before finishing.
Concern 1. I heard that the enforcer is prone to flutter. ( I am using elevons ) I made the elevons slightly thicker than the trailing edge, the linkage will be slop free and I am using strong servos. I will also seal the gaps plus put balancers on the elevons.
Concern 2. Since I extended the nose by 6 inches I am wondering about the CG. All of the calculating charts that I see only deal with the wing MAC.
Concern 3. I have the angle of attack pretty muck the way the kit is, but the gear are not as long. I hope this works.
Decision 1. Should I put on canards? Should they be fixed or functioning? Good idea or not?
Decision 2. Should I install a speed brake? Top mounted or belly mounted? I am looking at the thick airfoil and thinking the speed brakes may not be needed.
Decision 4. I notice a lot of variations to the fins shapes and sizes. I have not cut the rudders out as I am deciding what, if any shape to make them, or does it matter?
I am also considering making tip fins, like the Viper. Is there any advantage to this?
The problem with bashing a kit, is all of the unknowns being thrown in. This will make for a stressful maiden flight.
It sure has been fun building this model as you can install all of the mods as you build. I have no idea as what color scheme I want, but the time is approaching.
Any helpful ideas will be considered and appreciated.
Randy
I have a few concerns, which I hope I have fixed plus I need to decide on a couple of things before finishing.
Concern 1. I heard that the enforcer is prone to flutter. ( I am using elevons ) I made the elevons slightly thicker than the trailing edge, the linkage will be slop free and I am using strong servos. I will also seal the gaps plus put balancers on the elevons.
Concern 2. Since I extended the nose by 6 inches I am wondering about the CG. All of the calculating charts that I see only deal with the wing MAC.
Concern 3. I have the angle of attack pretty muck the way the kit is, but the gear are not as long. I hope this works.
Decision 1. Should I put on canards? Should they be fixed or functioning? Good idea or not?
Decision 2. Should I install a speed brake? Top mounted or belly mounted? I am looking at the thick airfoil and thinking the speed brakes may not be needed.
Decision 4. I notice a lot of variations to the fins shapes and sizes. I have not cut the rudders out as I am deciding what, if any shape to make them, or does it matter?
I am also considering making tip fins, like the Viper. Is there any advantage to this?
The problem with bashing a kit, is all of the unknowns being thrown in. This will make for a stressful maiden flight.
It sure has been fun building this model as you can install all of the mods as you build. I have no idea as what color scheme I want, but the time is approaching.
Any helpful ideas will be considered and appreciated.
Randy
04-20-2005, 07:35 PM
#62
RE: Turbine Enforcer
Randy,
Looks good. FWIW here's my two cents worth:
Concern 1: You shouldn't have any flutter problem with the elevons. I have heard of some having issues with the fins. The 3/16" stock that comes with the kit is too thin. I made fins out of 1/4" balsa on my DF and put triangle stock at the base to stiffen them up. This is a 150 mph plane and I've never had a flutter problem. For the Turbine Enforcer I made the fins out of 5/16" balsa.
Concern 2: I extended my nose by 6 inches and needed to move the CG about 1" forward of the plan location. The plane is very stable at that location. Joe Lupton had the same experience with his.
Concern 3: That will be fine, you just need a slight amount of nose up. Measure the distance from the ground to the center of the LE near the fuse. As long as that is greater than the distance of the center of the TE off of the ground you're OK.
Decision 1: Canards are really personal preference. You don't really need them unless you extend the nose a lot more than 6". If you install functional canards you will have better pitch control, but won't need it unless you're doing abrupt maneuvers.
Decision 2: My DF Enforcer slows down just fine with a little bit of nose up AOA. I started building my Turbine without one, but later added a speed brake to the bottom based on advise I got earlier in this thread. The rationale is that the higher idle thrust of the turbine may make the plane harder to slow down. I'll see how much good it does once I start flying this bird.
Decision 4 (What happened to 3?): Fin shape doesn't matter much. Whatever looks best. The bigger they are and the farther apart they are the more stability they add. The size of the movable rudders doesn't matter much either (within reason) unless you are planning on doing some knife edge flying.
On this model I think fin tips are mainly for appearance. I'm planning on putting them on my turbine version and extending them down to double as wing skids to protect the linkages.
Don't worry about flight characteristics. A lot of Enforcers have been the victim of major kit bashing and they all fly well. It's a very forgiving airframe. The important thing is to get your CG right (err on the side of slightly nose heavy for your first flight), and make sure you have the right amount of reflex in your control surfaces, as shown on the plans.
A good source for color scheme ideas is to search pictures of recent jet meets and check out all of the sport deltas: Kangaroo, Hot Spot, Rookie, Blade, Stingray, etc.
I strongly recommend that you do something about the former just in front of your turbine. Angle it forward and lower it if you can. A flat surface like that moving through the air will create a vacuum right at your turbine inlet affecting the engine operation. Check out my pictures in posts 38, 40, and 1 (DF) to see how I did it. Also if you notice the other turbines in this thread they have all made modifications to insure adequate airflow the the engine. Moving your turbine a bit aft would also help.
Good luck,
Joe
Looks good. FWIW here's my two cents worth:
Concern 1: You shouldn't have any flutter problem with the elevons. I have heard of some having issues with the fins. The 3/16" stock that comes with the kit is too thin. I made fins out of 1/4" balsa on my DF and put triangle stock at the base to stiffen them up. This is a 150 mph plane and I've never had a flutter problem. For the Turbine Enforcer I made the fins out of 5/16" balsa.
Concern 2: I extended my nose by 6 inches and needed to move the CG about 1" forward of the plan location. The plane is very stable at that location. Joe Lupton had the same experience with his.
Concern 3: That will be fine, you just need a slight amount of nose up. Measure the distance from the ground to the center of the LE near the fuse. As long as that is greater than the distance of the center of the TE off of the ground you're OK.
Decision 1: Canards are really personal preference. You don't really need them unless you extend the nose a lot more than 6". If you install functional canards you will have better pitch control, but won't need it unless you're doing abrupt maneuvers.
Decision 2: My DF Enforcer slows down just fine with a little bit of nose up AOA. I started building my Turbine without one, but later added a speed brake to the bottom based on advise I got earlier in this thread. The rationale is that the higher idle thrust of the turbine may make the plane harder to slow down. I'll see how much good it does once I start flying this bird.
Decision 4 (What happened to 3?): Fin shape doesn't matter much. Whatever looks best. The bigger they are and the farther apart they are the more stability they add. The size of the movable rudders doesn't matter much either (within reason) unless you are planning on doing some knife edge flying.
On this model I think fin tips are mainly for appearance. I'm planning on putting them on my turbine version and extending them down to double as wing skids to protect the linkages.
Don't worry about flight characteristics. A lot of Enforcers have been the victim of major kit bashing and they all fly well. It's a very forgiving airframe. The important thing is to get your CG right (err on the side of slightly nose heavy for your first flight), and make sure you have the right amount of reflex in your control surfaces, as shown on the plans.
A good source for color scheme ideas is to search pictures of recent jet meets and check out all of the sport deltas: Kangaroo, Hot Spot, Rookie, Blade, Stingray, etc.
I strongly recommend that you do something about the former just in front of your turbine. Angle it forward and lower it if you can. A flat surface like that moving through the air will create a vacuum right at your turbine inlet affecting the engine operation. Check out my pictures in posts 38, 40, and 1 (DF) to see how I did it. Also if you notice the other turbines in this thread they have all made modifications to insure adequate airflow the the engine. Moving your turbine a bit aft would also help.
Good luck,
Joe
04-21-2005, 03:49 AM
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RE: Turbine Enforcer
Joe
You were very helpful. I did make thicker fins, they are laminated 3/16!QUOT! balsa center with 3/32!QUOT! balsa sheeted in different directions on both sides. The fins will be glued in permanently, and I can beef up a fillet around the base as well.
I do plan on shaping the rear of the fuse into sort of an intake with maybe some air scoops, still designing that part. I was even thinking of enclosing the engine at one time, but did not see any advantage to it. I am wondering about some sort of cushioning between the engine and fuel tank which is just 3 inches in front of the engine, I am thinking fire prevention here, in case of a crash. So once I figure this out I will also finish the air flow for the engine as well. Moving the engine is still possible, I am waiting until I do a balance check so I can use batteries and the engine to get the CG right.
I was, just today, thinking of how light this plane will be and had the same thought you did about the residual thrust. So I think a speed brake may be a good idea. If it is not needed, it can always be removed. I can just imagine a calm day with the engine at idle and it just sails right on by the runway.
The wing tip fins I had in mind, would also be extended below for skids in case of belly landing, as my elevon servos are on the bottom.
I have searched for all of the various mods of this model and that is the reason I decided to try one myself. So far I am having a blast building this. I have some ARFs, ie Kangaroo and MB 339, but I still like kit building better.
I can send some more pics when I get farther along with this project.
I guess I did not have a decision #3 ????
Any other tips are appreciated.
Randy
You were very helpful. I did make thicker fins, they are laminated 3/16!QUOT! balsa center with 3/32!QUOT! balsa sheeted in different directions on both sides. The fins will be glued in permanently, and I can beef up a fillet around the base as well.
I do plan on shaping the rear of the fuse into sort of an intake with maybe some air scoops, still designing that part. I was even thinking of enclosing the engine at one time, but did not see any advantage to it. I am wondering about some sort of cushioning between the engine and fuel tank which is just 3 inches in front of the engine, I am thinking fire prevention here, in case of a crash. So once I figure this out I will also finish the air flow for the engine as well. Moving the engine is still possible, I am waiting until I do a balance check so I can use batteries and the engine to get the CG right.
I was, just today, thinking of how light this plane will be and had the same thought you did about the residual thrust. So I think a speed brake may be a good idea. If it is not needed, it can always be removed. I can just imagine a calm day with the engine at idle and it just sails right on by the runway.
The wing tip fins I had in mind, would also be extended below for skids in case of belly landing, as my elevon servos are on the bottom.
I have searched for all of the various mods of this model and that is the reason I decided to try one myself. So far I am having a blast building this. I have some ARFs, ie Kangaroo and MB 339, but I still like kit building better.
I can send some more pics when I get farther along with this project.
I guess I did not have a decision #3 ????
Any other tips are appreciated.
Randy
04-21-2005, 12:11 PM
#64
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RE: Turbine Enforcer
Randy,
I had my RAM 500 almost at the tail end and the ECU battery aft of the canopy. All other electronics were in the cockpit with nothing forward of the nose wheel and I still had to add 3 ozs of lead to the very back. I did have the stock vertical stabs though. I did find the speed brake helpful though maybe not necessary depending on your field conditions. With the speed brake the landings required very little elevator input as the nose would raise up with the SB deployed. I imagine having the engine at the very aft also helps.
All,
I really enjoy seeing all your different Enforcers. What a great airframe it is to be able to modify and still fly great.
Larry
I had my RAM 500 almost at the tail end and the ECU battery aft of the canopy. All other electronics were in the cockpit with nothing forward of the nose wheel and I still had to add 3 ozs of lead to the very back. I did have the stock vertical stabs though. I did find the speed brake helpful though maybe not necessary depending on your field conditions. With the speed brake the landings required very little elevator input as the nose would raise up with the SB deployed. I imagine having the engine at the very aft also helps.
All,
I really enjoy seeing all your different Enforcers. What a great airframe it is to be able to modify and still fly great.
Larry
05-31-2005, 08:29 PM
#65
RE: Turbine Enforcer
ALMOST READY !!!
The plane is essentially ready to go. I've got a couple more Ferrari decals on order to finish her off. That' not what is holding me up though. Only need two more notorized signatures on my turbine waiver application, then I can send it in. Hope to have the maiden flight in about two weeks.
Here's the stats:
Ram 500
JR 811 servos
JR 955 receiver
64 oz. main tank
homemade UAT
Spring Air retracts
BVM wheels & brakes
12 lbs. dry
The plane is essentially ready to go. I've got a couple more Ferrari decals on order to finish her off. That' not what is holding me up though. Only need two more notorized signatures on my turbine waiver application, then I can send it in. Hope to have the maiden flight in about two weeks.
Here's the stats:
Ram 500
JR 811 servos
JR 955 receiver
64 oz. main tank
homemade UAT
Spring Air retracts
BVM wheels & brakes
12 lbs. dry
06-16-2005, 07:41 PM
#68
RE: Turbine Enforcer
Finally got my Turbine Waiver in the mail today!!!
My ECU and fuel pump are on their way back from Bob Price. Bob fixed an rpm oscillation problem I was having. The weather forecast looks good for the weekend. So as long as the ECU shows up I should do the maiden flight this weekend. Also I'm planning on going to Winamac next week.
Randy,
I was talking to Dennis Fuentes the other day and he mentioned your Enforcer with the JDE 54. How is it coming along? Any recent pictures?
Joe
My ECU and fuel pump are on their way back from Bob Price. Bob fixed an rpm oscillation problem I was having. The weather forecast looks good for the weekend. So as long as the ECU shows up I should do the maiden flight this weekend. Also I'm planning on going to Winamac next week.
Randy,
I was talking to Dennis Fuentes the other day and he mentioned your Enforcer with the JDE 54. How is it coming along? Any recent pictures?
Joe
06-17-2005, 04:52 PM
#69
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RE: Turbine Enforcer
Hi Joe
I hoping to get back to finishing the enforcer. It is ready to cover and final radio install and cg balance. I'll send more photos when I get more finished.
Randy
I hoping to get back to finishing the enforcer. It is ready to cover and final radio install and cg balance. I'll send more photos when I get more finished.
Randy
07-02-2005, 08:56 PM
#70
RE: Turbine Enforcer
Finally Did It !
I put the maiden flight and the first few flights on my Turbine Enforcer last weekend in Winamac. Just returned from my club field where I put a couple more flights on it today. I've got to say that this is one sweet flying plane.
After first flying my DF Enforcer I told people that it was the best first flight I ever had. The Turbo Enforcer was a repeat performance. It has no bad habits, very stable and controllable, and lands easy. It flies a lot like my DF one only faster. Top speed is in the 160 - 170 mph range. Since this is my first turbine plane I couldn't be more pleased.
I highly recommend the Enforcer if someone wants an inexpensive great flying delta.
Joe
I put the maiden flight and the first few flights on my Turbine Enforcer last weekend in Winamac. Just returned from my club field where I put a couple more flights on it today. I've got to say that this is one sweet flying plane.
After first flying my DF Enforcer I told people that it was the best first flight I ever had. The Turbo Enforcer was a repeat performance. It has no bad habits, very stable and controllable, and lands easy. It flies a lot like my DF one only faster. Top speed is in the 160 - 170 mph range. Since this is my first turbine plane I couldn't be more pleased.
I highly recommend the Enforcer if someone wants an inexpensive great flying delta.
Joe
09-28-2005, 03:41 AM
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RE: Turbine Enforcer
I am finally finishing my turbine Enforcer. I measured the CG on the plans and come up with 16 inches from the very end of the trailing edge. I noticed some of you have suggested moving the CG forward. I did a balance check with the above CG and found that I have to mount the engine way back. All of my batteries, ECU and fuel pump are way back as well. I did extend the front of the fuse 6 inches, mainly to accommodate the nose retract.
I installed spring air retracts, with Eurokit struts and Intairco wheels and brakes. I have a 50oz. main fuel tank and a 12oz, header tank. I have 3 JDE engines one is 12 lb thrust, one is 14lbs and the other one is around 16lbs ( JDE 55 ) I will probably go with the 12 lb. I have not weighed it yet but I know it will weigh less that 12 lbs dry.
I was planning on building a simple turbine model but I ended up adding gear doors that sequence ( main doors are closed with gear up or down). I added a speed brake under the wing. I was going to finish it with Black Baron Presto to give it that aluminum look. This stuff really looks good, but you need to lay it on in panels. I tried to heat shrink big sheets on the surface and the heat really leaves blemishes, so I opted not to tackle the aluminum look at this time. If I used the presto then I would be tempted to also do rivet details. So I covered the top with Chrome monocote with orange and blue trim. The bottom is flat blue. It looks cool but to shiny to look like aluminum. But it isn't a scale model anyway. Once you start bashing a kit, you just keep bashing and bashing, it is fun though. But will it fly?
I had to redo the aft end of the fuse in order to move the equipment back. I'll post some photos when I get it more presentable.
My big concern is that I have the correct CG. If I move it forward an inch as stated before, that means I could be tail heavy if this is wrong.
Any more feed back on CG would be appreciated. Does adding 6 inches to the front of the fuse change the CG? I haven't calculated the CG mathematically yet, but I probably will just to see if the plans are in the ballpark.
Randy
I installed spring air retracts, with Eurokit struts and Intairco wheels and brakes. I have a 50oz. main fuel tank and a 12oz, header tank. I have 3 JDE engines one is 12 lb thrust, one is 14lbs and the other one is around 16lbs ( JDE 55 ) I will probably go with the 12 lb. I have not weighed it yet but I know it will weigh less that 12 lbs dry.
I was planning on building a simple turbine model but I ended up adding gear doors that sequence ( main doors are closed with gear up or down). I added a speed brake under the wing. I was going to finish it with Black Baron Presto to give it that aluminum look. This stuff really looks good, but you need to lay it on in panels. I tried to heat shrink big sheets on the surface and the heat really leaves blemishes, so I opted not to tackle the aluminum look at this time. If I used the presto then I would be tempted to also do rivet details. So I covered the top with Chrome monocote with orange and blue trim. The bottom is flat blue. It looks cool but to shiny to look like aluminum. But it isn't a scale model anyway. Once you start bashing a kit, you just keep bashing and bashing, it is fun though. But will it fly?
I had to redo the aft end of the fuse in order to move the equipment back. I'll post some photos when I get it more presentable.
My big concern is that I have the correct CG. If I move it forward an inch as stated before, that means I could be tail heavy if this is wrong.
Any more feed back on CG would be appreciated. Does adding 6 inches to the front of the fuse change the CG? I haven't calculated the CG mathematically yet, but I probably will just to see if the plans are in the ballpark.
Randy
09-28-2005, 09:28 AM
#75
RE: Turbine Enforcer
Randy,
Extending the nose will affect the CG because you have added more lifting surface to the front of the plane. Moving the CG forward makes it more nose heavy, moving it aft makes it more tail heavy.
I just checked the CG on my Enforcers. Both have the nose extended 6". The DF one is 16 1/4" from the TE of the wing (not counting the control surfaces). The turbine one is 16 3/4". On the DF I extended just the nose in front of the cockpit, on the turbine one I also made the fuse wider; so the turbine has a little more area up front. I prefer the flight characteristics of the turbine, which is more stable.
If the CG is too far back the plane will be overly sensitive to control inputs and difficult to fly. As you move the CG forward the plane becomes more stable. Part of it is personal preference depending of how you fly. For a first flight it is better to err on the side of nose heavy. I'd recommend that you start with 16 3/4 to 17". If it tends to drop the nose on turns then move it back slightly.
Post some pictures when you get a chance.
Joe
Extending the nose will affect the CG because you have added more lifting surface to the front of the plane. Moving the CG forward makes it more nose heavy, moving it aft makes it more tail heavy.
I just checked the CG on my Enforcers. Both have the nose extended 6". The DF one is 16 1/4" from the TE of the wing (not counting the control surfaces). The turbine one is 16 3/4". On the DF I extended just the nose in front of the cockpit, on the turbine one I also made the fuse wider; so the turbine has a little more area up front. I prefer the flight characteristics of the turbine, which is more stable.
If the CG is too far back the plane will be overly sensitive to control inputs and difficult to fly. As you move the CG forward the plane becomes more stable. Part of it is personal preference depending of how you fly. For a first flight it is better to err on the side of nose heavy. I'd recommend that you start with 16 3/4 to 17". If it tends to drop the nose on turns then move it back slightly.
Post some pictures when you get a chance.
Joe
