Balsa USA enforcer
07-04-2004, 11:28 AM
#176
My Feedback: (48)
RE: Balsa USA enforcer
Great thread. I'm just seeing this for the first time.
I've been flying my DF Enforcer for a year now (60 flights) and still love it. If you want a fast Enforcer a Byron conversion is the way to go. It's easily a 150+ mph plane. I've had mine at a couple of jet meets and keeps up with some of the turbine powered models. I've had some of the seasoned jet pilots make comments that they were amazed at its speed and would never have believed that anything with a Byron fan could be that fast.
For the guys trying to do a tractor fan conversion you won't get the speed unless you can design an efficient set of inlet ducts and a proper thrust tube. A tractor fan sitting out in the open is not very efficient. The other concern is engine overheating; without ductwork you will not have sufficient air flow over the head to keep it cool enough. That's why Byron and other pusher DF's use a large heat sink head. A pusher configuration is much more tolerant of less than perfect inlet airflow. The Byron fan has a nice "bellmouth" shape to the fan inlet which helps direct the airflow properly to the fan. Build the engine/fan pod according to the conversion plans and it will work fine.
Here's a thread I posted a while back that lists some of the mods I made plus some pictures.
http://www.rcuniverse.com/forum/m_80...rs_801604/mpag
Joe
I've been flying my DF Enforcer for a year now (60 flights) and still love it. If you want a fast Enforcer a Byron conversion is the way to go. It's easily a 150+ mph plane. I've had mine at a couple of jet meets and keeps up with some of the turbine powered models. I've had some of the seasoned jet pilots make comments that they were amazed at its speed and would never have believed that anything with a Byron fan could be that fast.
For the guys trying to do a tractor fan conversion you won't get the speed unless you can design an efficient set of inlet ducts and a proper thrust tube. A tractor fan sitting out in the open is not very efficient. The other concern is engine overheating; without ductwork you will not have sufficient air flow over the head to keep it cool enough. That's why Byron and other pusher DF's use a large heat sink head. A pusher configuration is much more tolerant of less than perfect inlet airflow. The Byron fan has a nice "bellmouth" shape to the fan inlet which helps direct the airflow properly to the fan. Build the engine/fan pod according to the conversion plans and it will work fine.
Here's a thread I posted a while back that lists some of the mods I made plus some pictures.
http://www.rcuniverse.com/forum/m_80...rs_801604/mpag
Joe
07-09-2004, 12:55 AM
#181
RE: Link
Here are some pictures of my progress on the Enforcer, last weekend was a total no building weekend [&o] do to my sis. visiting 
and a horrible toothache (ouch) [:@].
Some of the pictures show the engine mount glued to the ribs and the engine mount spars I will probably add more to the mounts to get them stiffer.
CARS II
and a horrible toothache (ouch) [:@].Some of the pictures show the engine mount glued to the ribs and the engine mount spars I will probably add more to the mounts to get them stiffer.
CARS II
07-09-2004, 02:21 PM
#184
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RE: Link
Hi Cars,
I would be surprised if you saw much of a difference due to the wing slot. However, I think you really need to consider making a bell mouth for the fan intake.
Much has been written on the subject. Strange as it seems, the sharp lip on the fan inlet does not create a smooth flow to the fan just inside of the lip. The Byron fan has a lip molded into the duct, since most applications for the Byron fan does not involve an intake with a smooth flow into the fan. Ducted fan models such as BVM's take great care to insure a smooth flow in the ductwork into the fan.
The Enforcer fan modification using the Byron fan has the lip of the fan nacelle a smoothly rounded inlet with about a half inch radius.
Joe
I would be surprised if you saw much of a difference due to the wing slot. However, I think you really need to consider making a bell mouth for the fan intake.
Much has been written on the subject. Strange as it seems, the sharp lip on the fan inlet does not create a smooth flow to the fan just inside of the lip. The Byron fan has a lip molded into the duct, since most applications for the Byron fan does not involve an intake with a smooth flow into the fan. Ducted fan models such as BVM's take great care to insure a smooth flow in the ductwork into the fan.
The Enforcer fan modification using the Byron fan has the lip of the fan nacelle a smoothly rounded inlet with about a half inch radius.
Joe
07-10-2004, 11:59 PM
#185
RE: Link
I totally agree with you, a thought that I have is after it is flying I will add an intake duct, I think Larry has a very efficient one that I can play with.
I know that you can loose as much as 25% trust without the intake duct [:'(].
So lets keep experimenting just for the fun of it
.
I know that you can loose as much as 25% trust without the intake duct [:'(].
So lets keep experimenting just for the fun of it
.
07-12-2004, 05:36 AM
#187
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RE: Link
Good morning Cars II,
I know it's very easy to be critical of someone else's work, but I do have a few thoughts about what you have done to the fuselage top. You can take them or leave them. I'm only trying to offer some suggestions which might save you some grief later.
Since you don't plan to put an intake on your fan mouth to start with, I think you should try to keep the airflow into the fan as smooth as possible. The triangular former right in front of the fan would appear to me to do just the opposite, creating a lot of turbulance just where you want it to be smooth. I would recommend that you try to smoothly bring the top of the fuselage deck down flush with the wing just in front of the fan. This would also have the advantage of allowing you to start it without having to put your starter wand through the fuseage. This might require your tank to be a little lower than optimum, but with pipe pressure, it shouldn't be a problem.
Does anyone else have any thoughts along these lines?
Joe
I know it's very easy to be critical of someone else's work, but I do have a few thoughts about what you have done to the fuselage top. You can take them or leave them. I'm only trying to offer some suggestions which might save you some grief later.
Since you don't plan to put an intake on your fan mouth to start with, I think you should try to keep the airflow into the fan as smooth as possible. The triangular former right in front of the fan would appear to me to do just the opposite, creating a lot of turbulance just where you want it to be smooth. I would recommend that you try to smoothly bring the top of the fuselage deck down flush with the wing just in front of the fan. This would also have the advantage of allowing you to start it without having to put your starter wand through the fuseage. This might require your tank to be a little lower than optimum, but with pipe pressure, it shouldn't be a problem.
Does anyone else have any thoughts along these lines?
Joe
07-12-2004, 05:47 PM
#188
RE: Link
Good morning Dash
Good suggestions and I totally agree with you on the turbulence, about the fuselage down to the deck I have done that before with a Nothrstart the only problem was like you suggested the fuel tank was to low and it gave me a lot of problems ( my first kit bashing ). Here are some pic. that may help you see which way I'm trying to go with this thing ( plane ).
Any comments or suggestions are well appreciated, I'm still learning how to build.
CARS II
Good suggestions and I totally agree with you on the turbulence, about the fuselage down to the deck I have done that before with a Nothrstart the only problem was like you suggested the fuel tank was to low and it gave me a lot of problems ( my first kit bashing ). Here are some pic. that may help you see which way I'm trying to go with this thing ( plane )
.Any comments or suggestions are well appreciated, I'm still learning how to build.
CARS II
07-12-2004, 07:05 PM
#190
My Feedback: (48)
RE: Link
Looks like the starting probe will go right through the canopy. Is that the plan?
It won't perform very well without proper inlet ducting and tailpipe. I'd suggest doing it right the first time. Bring the rear of the fuse down as Joe suggested, then fashion some inlets just behind the cockpit. I saw a picture of one done like this, it looked good. Also then you could insert your starting probe through the inlet.
Joe
It won't perform very well without proper inlet ducting and tailpipe. I'd suggest doing it right the first time. Bring the rear of the fuse down as Joe suggested, then fashion some inlets just behind the cockpit. I saw a picture of one done like this, it looked good. Also then you could insert your starting probe through the inlet.
Joe
07-13-2004, 12:44 AM
#192
RE: Link
Is there really a correct way to do this Joe?, I think if get ourself into doing something like this is purely for fun and the rest , well god help us with the rest of the project because even if it flys decently is a big success after all the work and time given to these projects 
.
CARS II
, well god help us with the rest of the project because even if it flys decently is a big success after all the work and time given to these projects .CARS II
07-13-2004, 09:26 AM
#193
My Feedback: (48)
RE: Link
Cars,
You're right these projects take a lot of work and time. Most who have experience with tractor ducted fans know that they are very sensitive to proper ducting, and that they're not very efficient without it.
I was refering to your plan to try the fan without ducting, then potentially add it later. It will probably fly, but not be very fast. While it's fun to experiment, I was suggesting that you go with ducting initially, as Dash suggested for less building time more flying time.
Joe
You're right these projects take a lot of work and time. Most who have experience with tractor ducted fans know that they are very sensitive to proper ducting, and that they're not very efficient without it.
I was refering to your plan to try the fan without ducting, then potentially add it later. It will probably fly, but not be very fast. While it's fun to experiment, I was suggesting that you go with ducting initially, as Dash suggested for less building time more flying time.
Joe
07-16-2004, 01:40 AM
#194
RE: Link
Joe, some part of me agreed with you, do it right the first time, after 16 years of rc fun I know that, but nooo, here I am experimenting knowing that if I build it with an intake ducting it may give me better performance.
Well, It is fun just to mess with it, I'm anticipating low performance and I have in the back of my head picture an intake ducting for it any ways I will let you know of how it flights and then we will add the intake to see the difference on performance.
Remember, it is all for fun.
CARS II
Well, It is fun just to mess with it, I'm anticipating low performance and I have in the back of my head picture an intake ducting for it any ways I will let you know of how it flights and then we will add the intake to see the difference on performance.
Remember, it is all for fun
.CARS II
07-17-2004, 04:11 PM
#199
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RE: Link
it was put in a lazer arrow n scared the pants off me n the top notch guy that tested it before me.
$341 ..to get it to the UK ..but well worth it ....an absolute Animal ....it brickwalled very quick so we now know
the limit of this plane. sorry to be off topic but i just had to say summit.
Bare in mind it has 2500 revs to go before its on song ..jeeesus
$341 ..to get it to the UK ..but well worth it ....an absolute Animal ....it brickwalled very quick so we now know
the limit of this plane. sorry to be off topic but i just had to say summit.
Bare in mind it has 2500 revs to go before its on song ..jeeesus