Extreme Speed Prop Planes Discuss the need for speed with fast prop planes (Screamin Demon, Diamond Dust, Shrikes or any REAL sound breakin'''' plane)

Questions about modding an Enforcer...

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Old 06-08-2012, 07:15 PM
  #1
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Default Questions about modding an Enforcer...

Hi all,

I have wanted to build a Balsa USA Enforcer for some time now. I have seen the enforcers that have been converted to ducted and turbines. Mods on these include extending the nose by 6 inches and moving the CG 1 to 1.5 inches forward. I have also seen some of them with canards. I really like the look of the Enforcer with the longer nose and canards. i would like to do this to my Enforcer build but I do not plan on using a ducted fan or turbine, but an OS 75ax with a pusher prop. If I were to use the 75ax and extended the nose 6 inches and add canards, do I need to still move the CG 1 to 1.5 inches forward? I do not know if the CG is moved forward because of the weight of the ducted fan in the back or if it is do to aerodynamic forces and increased surface area (more lifting body) due to the six additional inches of fuselage and canards? I would greatly appreciate any suggestions,comments, tips or guidance on this.

Happy flying and soft landings!
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Old 06-08-2012, 07:36 PM
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Default RE: Questions about modding an Enforcer...

The best forum for advice about these planes is the Sea Plane forum.
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Old 06-08-2012, 08:03 PM
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Default RE: Questions about modding an Enforcer...

Doesn't the Enforcer have a thick chord to be a real speedster? Looking at it, I'm thinkin 100-110 mph?
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Old 06-08-2012, 09:25 PM
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Default RE: Questions about modding an Enforcer...

The problem besides being too thick is the weight of the plane must cause it to fly with more AoA than the same sized deltas that are designed for max speed.
Before the Diamond Dust came out, this style delta was all I used to see at the field and they were all much slower than you would expect. If they were built within weight limits they flew OK.
I imagine it would take a turbine to get one of these planes to really move out.
For all the work that is involved, I'd rather base the design on a Screamin' Demon then go from there with a custom center section to accomodate a rear engine.
I would tuck the engine into the aft end as far forward as possible
I got tired of dealing with engine heat issues and gave up on pushers as possible speed projects.

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Old 06-09-2012, 07:58 AM
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Default RE: Questions about modding an Enforcer...


The Enforcer is not a seaplane, the Northstar is...


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The best forum for advice about these planes is the Sea Plane forum.
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Old 07-10-2012, 06:37 PM
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Default RE: Questions about modding an Enforcer...

I know that on my enforcer, I was running an OS.91, and it flew kinda doggy, for a lack of better words.. I do believe however, that the OS engine I was using was pretty old and tired..  I then put on an Evolution 1.0, and the plane came to life..  flew great, had that awesome sound that these planes with the prop swinging through the slot in the fuse produces, very Unique, and cool sounding.. 

Basically, I think you would be better off going with an engine of larger displacement than  the .75, I think you would be a bit disappointed in its flight characteristics with an engine of that displacement..  Just my opinion tho!! 

Have a great day!

Craig.
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Old 07-10-2012, 08:34 PM
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Default RE: Questions about modding an Enforcer...

i would go with a OS 120 AX and a 15x10 prop if it will fit.

Or run a 75 in the back and a 75 in the front.....
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Old 07-11-2012, 06:43 PM
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Default RE: Questions about modding an Enforcer...

I agree with Airraptor, the AX 120 would be an excellent choice..  it wouldn't overpower the airframe, would have excellent flight characteristics.. 

Now the other thought about the tractor/pusher twin engine design, now that's something I would have never even thought of, How Unique would a Twin engine enforcer be!!  I would love to see that one!!

Craig.
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Old 07-11-2012, 07:53 PM
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Default RE: Questions about modding an Enforcer...

Once in awhile, jumbo jets fly over my house on their way to Paine Field. Even though they are flying over 500 mph, they look like they are doing about 50.
Same holds true with huge models.
Why invest so much time and money into stuff that looks slow unless it's actually doing 200...?
It's like beating your head against a wall.
Those Balsa USA deltas are "dogs" [a waste of time] if you are really interested in going fast.
With the same power you can go as fast or faster with a Tower Hobbies trainer.
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Old 07-12-2012, 11:54 AM
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Default RE: Questions about modding an Enforcer...

I'll leave the debate as to weather this would make a good speed plane or not to the others. [:'(]

To answer your question about CG, the plane flies fine in the stock configuration, at the stock CG location. The relation of the fuselage length to the wing will not change the CG location appreciably if you lengthen it, but adding canards will. It is essentially adding lifting surface in effect making the wing act as if the chord were longer. If you follow the established mods, follow their CG recommendations. If you roll your own, the CG will have to be re-plotted which is easy to do using the various web based calculators available.
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Old 07-12-2012, 05:15 PM
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Default RE: Questions about modding an Enforcer...

As others have noted, with the addition of canards you will have to adjust your cg forward in order for the canard to operate properly; as well as adding a bit of length to the fuselage.
Now if your looking at building this a a speed plane as well that is going to take even more work. First of all you will want to get the airplane a heck of a lot lighter than even the six pound weight they suggest as the lower limit to get it to move at all. All in all your probably better just sketching up your own design base on an enforcer and going with that given the modifications your thinking of making, plus a few others like a thinner wing as well.

Now with all of that having been said,I kinda like the idea of the twin tractor powered canard, here is a sketch that some one drew from my description awhile back.

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Old 07-13-2012, 03:10 PM
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Default RE: Questions about modding an Enforcer...

The BUSA Enforcer might not be a speed demon, but I for one really enjoy Flying my enforcer.. real fun AC to fly.. I am going to re-cover mine, and now that I am thinking about it, I think I will put some retracts on it while I have it down to the bare Fuse, that ought to get me at least another 50 - 75 MPH out of it!!!

Craig.
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Old 07-13-2012, 03:13 PM
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Default RE: Questions about modding an Enforcer...

BTW, Iron Eagle,

Love the rendering of the Twin Canard that  you have there..  It kinda reminds me of the Beechcraft Starship..  it's a Twin engine Canard in a Pusher configuration!!  Cool looking Aircraft.. I for one would have loved to own one!!

Craig.
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Old 07-13-2012, 03:33 PM
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Default RE: Questions about modding an Enforcer...


Quote:
ORIGINAL: SeaJay

The BUSA Enforcer might not be a speed demon, but I for one really enjoy Flying my enforcer.. real fun AC to fly.. I am going to re-cover mine, and now that I am thinking about it, I think I will put some retracts on it while I have it down to the bare Fuse, that ought to get me at least another 50 - 75 MPH out of it!!!

Craig.
There is a myriad of things that probably could be done to improve the speed but like CP says in the end a lot of work.
See if you can lighten it up a bit as well, adding retracts is going to add weight... It be interesting to see how much effect it will have.

I loved the Starship. So sad about Beech being sold to China.

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Old 07-13-2012, 07:38 PM
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Default RE: Questions about modding an Enforcer...

I am not worried that the Enforcer isn't a high speed Aircraft, I just love the way it flies, and the sound it makes in the air!! As far as the retracts go, I was just thinking that it would look cooler and sleeker, not really worried about an increase in speed.... I was just being silly about the 50 - 75mph speed increase, if anything, it might go 5 - 10mph faster, but I don't really care, just love looks and flight characteristics.. the plane anyway!!

had been thinking about a few different color schemes for it tho, one to make it look similar to a Space Shuttle, one that it would be nearly all chrome, to resemble a UFO in the daytime, the other almost all black with 3 or 4 small white LEDs near each leading edge, with one larger either red or white LED in the center of the plane to resemble a UFO flying at night the classic V config. Or I guess I could just leave it in the same scheme that it currenly has now, as show in the photo on my Profile page!

Craig..
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Old 07-14-2012, 07:38 AM
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Default RE: Questions about modding an Enforcer...

Night flying! You just jogged my memory. Something I always wanted to try, towing a 200' line with ultra bright LEDs every foot.
I have an Enforcer I got cheap, just siting in the corner of the garage and it needs minor repairs, wick-in glue in all joints, recovering and in wing servo upgrades. My plan was to install an OS 70 heli (the big head would help cooling) but reading this post has got me re-thinking, perhaps an OS 120 or YS 115 would be wiser. The prop slot is 18"+ wide and it looks like easy clearance for angle of departure/rotate as well with stock fixed gear so swinging the largest prop for either of those engines would no problem. This one will not be flying any time soon. Yes, this is no speed plane C.P.

Note; pusher's usually over heat quickly on the the ground, so limit run-up, tuning time and for god's sake don't brake it in on the plane.
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Old 07-14-2012, 07:57 AM
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Default RE: Questions about modding an Enforcer...

When your doing the setup of a pusher a lot of guys use a regular prop then switch over to the pusher prop for flight.
We have night flying at our club as long as we use lights.
I kinda like the shuttle look myself.
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Old 07-14-2012, 09:36 AM
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Default RE: Questions about modding an Enforcer...


Quote:
ORIGINAL: iron eagel

When your doing the setup of a pusher a lot of guys use a regular prop then switch over to the pusher prop for flight.
Very good idea. Now I know I'm slipping, so obvious.
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Old 07-14-2012, 12:45 PM
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Default RE: Questions about modding an Enforcer...


Quote:
ORIGINAL: freakingfast


Quote:
ORIGINAL: iron eagel

When your doing the setup of a pusher a lot of guys use a regular prop then switch over to the pusher prop for flight.
Very good idea. Now I know I'm slipping, so obvious.
Of course you need to use a different method of restraint for the two props. oops!

Once you have the initial setup worked out you only need to tweak it before each flight so you really don't have to bother switching over the type of props that often.
(Wish I could claim credit for the idea but something that was thought of long before my time.)

One useful modification for an enforcer would to be to cowl the engine. Andy Lennon swore by it as a necessity to get any real performance out of a model airplane, especially a pusher. The blunt end of the fuselage isn't doing you any favors as far as the airflow reaching the prop so I would have to say in theory the idea has merit.
I'd also use something like a J-Tec in cowl muffler for the exhaust either way.

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Old 07-14-2012, 01:41 PM
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Default RE: Questions about modding an Enforcer...

120 AX or YS 115. run a 15x10 on both engines or a 14x12 on the 120AX. For the 115 and the 14x12 stay with 30% fuel or less dont want to run thru the prop.
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Old 07-14-2012, 02:01 PM
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Default RE: Questions about modding an Enforcer...

Quote:
ORIGINAL: ser00

Hi all,

I have wanted to build a Balsa USA Enforcer for some time now. I have seen the enforcers that have been converted to ducted and turbines. Mods on these include extending the nose by 6 inches and moving the CG 1 to 1.5 inches forward. I have also seen some of them with canards. I really like the look of the Enforcer with the longer nose and canards. i would like to do this to my Enforcer build but I do not plan on using a ducted fan or turbine, but an OS 75ax with a pusher prop. If I were to use the 75ax and extended the nose 6 inches and add canards, do I need to still move the CG 1 to 1.5 inches forward? I do not know if the CG is moved forward because of the weight of the ducted fan in the back or if it is do to aerodynamic forces and increased surface area (more lifting body) due to the six additional inches of fuselage and canards? I would greatly appreciate any suggestions,comments, tips or guidance on this.

Happy flying and soft landings!
Ser00

I though the same as you. However instead of modding the Enforcer like crazy there is a better airframe to start with that is just about perfect for you. It's called the Crusader II

http://www.rcmplans.com/index.php?ma...oducts_id=1845

You can get plans for it from RCM. It's a rear prop plane but it should take a fan eazy enough.
Here is the fan I'm going to use in mine.
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Old 07-14-2012, 02:47 PM
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Default RE: Questions about modding an Enforcer...

Quote:
ORIGINAL: airraptor

120 AX or YS 115. run a 15x10 on both engines or a 14x12 on the 120AX. For the 115 and the 14x12 stay with 30% fuel or less dont want to run thru the prop.
That's why you should use something like a J-Tec for the exhaust, it my understanding that they can be tuned as well. You get the exhaust stream out a lot further from the prop than a standard exhaust.
Something like this one.
http://www.jtecrc.com/incowlmufflers130-215.htm

And of course you don't have to cowl the motor to use one.
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Old 07-14-2012, 02:50 PM
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Default RE: Questions about modding an Enforcer...

Quote:
ORIGINAL: AmishWarlord

Quote:
ORIGINAL: ser00

Hi all,

I have wanted to build a Balsa USA Enforcer for some time now. I have seen the enforcers that have been converted to ducted and turbines. Mods on these include extending the nose by 6 inches and moving the CG 1 to 1.5 inches forward. I have also seen some of them with canards. I really like the look of the Enforcer with the longer nose and canards. i would like to do this to my Enforcer build but I do not plan on using a ducted fan or turbine, but an OS 75ax with a pusher prop. If I were to use the 75ax and extended the nose 6 inches and add canards, do I need to still move the CG 1 to 1.5 inches forward? I do not know if the CG is moved forward because of the weight of the ducted fan in the back or if it is do to aerodynamic forces and increased surface area (more lifting body) due to the six additional inches of fuselage and canards? I would greatly appreciate any suggestions,comments, tips or guidance on this.

Happy flying and soft landings!
Ser00

I though the same as you. However instead of modding the Enforcer like crazy there is a better airframe to start with that is just about perfect for you. It's called the Crusader II

http://www.rcmplans.com/index.php?ma...oducts_id=1845

You can get plans for it from RCM. It's a rear prop plane but it should take a fan eazy enough.
Here is the fan I'm going to use in mine.
Yep that would work.
Great plane to start, with your a lot closer to start with without having to re-invent the wheel, then trick it out...

If your using an electric fan you can really shed some excess baggage.

Even a propped version would be a lot closer to start with rather than adding canards to a Enforcer and then trying to figure out where the COG needs to be.
Stretching out an enforcer and adding canards is really going to change the cog requirements, your mean aerodynamic center is going to be a lot different.
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Old 07-15-2012, 05:37 AM
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Default RE: Questions about modding an Enforcer...

Quote:
ORIGINAL: ser00

Hi all,

I have wanted to build a Balsa USA Enforcer for some time now. I have seen the enforcers that have been converted to ducted and turbines. Mods on these include extending the nose by 6 inches and moving the CG 1 to 1.5 inches forward. I have also seen some of them with canards. I really like the look of the Enforcer with the longer nose and canards. i would like to do this to my Enforcer build but I do not plan on using a ducted fan or turbine, but an OS 75ax with a pusher prop. If I were to use the 75ax and extended the nose 6 inches and add canards, do I need to still move the CG 1 to 1.5 inches forward? I do not know if the CG is moved forward because of the weight of the ducted fan in the back or if it is do to aerodynamic forces and increased surface area (more lifting body) due to the six additional inches of fuselage and canards? I would greatly appreciate any suggestions,comments, tips or guidance on this.

Happy flying and soft landings!
Going that far forward may be a mistake! It may not flare properly and land very hot.

I once had the "Quickie" arf. The factory CG mark was over 3" to far forward and not enough throw, maxed out on the elevators.
It dropped like a stone with the power off and would not flare, very hard landing!

I added canrads to a Kangaroo Jet with NO change in CG. And it flew great. Landings were easy and no hop!
The canards came from a 1/9 Rafalle not a lot of area but very effictive with +/- 20mm throw on its TE slave to the high rate elevator.

Then I added canards to my friends Rookie Jet from Comp-ARF after he flew my Roo and like the way it flew. Slight change in CG, 1/4" forward.

Note the Comp-ARF Rookie II has a longer fuse canards AND uses same CG as the stock Rookie and Kangaroo.

I know since I had a Rookie II after my Roo with canards was retired.


bob
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Old 07-15-2012, 10:20 AM
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Default RE: Questions about modding an Enforcer...


Quote:
ORIGINAL: iron eagel

Quote:
ORIGINAL: airraptor

120 AX or YS 115. run a 15x10 on both engines or a 14x12 on the 120AX. For the 115 and the 14x12 stay with 30% fuel or less dont want to run thru the prop.
That's why you should use something like a J-Tec for the exhaust, it my understanding that they can be tuned as well. You get the exhaust stream out a lot further from the prop than a standard exhaust.
Something like this one.
http://www.jtecrc.com/incowlmufflers130-215.htm

And of course you don't have to cowl the motor to use one.
what are you talking about? What you said isnt relevant to what i was saying.
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