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Boomerang Sprint Build Thread!

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Boomerang Sprint Build Thread!

Old 09-19-2009, 10:38 PM
  #951  
crhammond
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Default RE: Boomerang Sprint Build Thread!

The Sprint is my first turbine jet. I have a Comp-Arf Spark and some other smaller e-jets too. Mostly I fly IMAC and some Scale but decided to try turbine this year after going to a couple fo jet meets with my Spark.

Mine is 18.6lbs with a PST 600R, air trap tank full and 10oz of nose weight. I am using the Beotech heavy C36/2 gear from Altecare (this is simply AWESOME gear - just fantastic.) Unfortunately I bought the PST used and the front bearing siezed after only 4 1/2 flights. Live and learn I guess The TEMS said the trubine only had 7:15 on it. The jet started losing power immediately in the air (thank goodness for the big wing area - I was able to keep it flying!!!) and I made few slow circuits to burn some fuel and nice safe landing. The front bearing was siezed once it cooled down.

This jet flies great. The recommended CG is quite too far forward for my liking when inverted on 45 or level... but great for learning I guess. I needed a -25 flap to airbrake mix for landings and 3/16" of elevator down trim for level flight. I am not using crow. It lands very easy and VERY slow with about 55 deg of flap. Takeoff is good even from grass and it only takes 200ft or so with 25 deg takeoff flap (when the turbine is working right that is.)

I don't know if my PST was ever working right but for the first 3 flights I think it was. It was certainly hitting full RPM's. The 14.5 lbs thrust is no where near enough power to have fun. You can fly around but it will barely loop and can't hold a 45 line for long for nice cubans etc. Rolls are quite axial with the recommended differential. I never felt I had enough power for KE, rollers or any of the fun stuff I hope to do with this jet. I can tell it will do them all once I have an engine in there with some power that I can trust so thats a good thing My wide open straight line speed is not fast at all... maybe 100mph? Certainly way, way, way slower than my Comp-Arf Spark which will do 170mph. I didn't get this jet for speed - its for a fun do-it-all jet with a wide speed envelope that I can fly from grass. But I want tons of vertical power so I am going to get a much bigger turbine to replace the PST.

I plan to try and get some relief on the used engine I got... worst case I get it repaired and keep it as a backup for when the main engine is getting serviced. I hope to order a new engine and get it expressed to me on Monday so I can fly the Sprint again ASAP.

This is a very smooth nice flying, super stable jet. I think the P80SE is probably the best choice of turbine thrust-wise - but I am looking at the Behotec J66 and WREN SS also... or maybe a G-booster 90. The WREN is quite light for the thrust it makes... I'd like to add as little weight as possible.

Can anyone recommend any other good turbines that are light and in the 20 - 22lb range. Good service is also a must... (Jetcat wins there again, but I hear Behotec have great service also.)
Old 09-19-2009, 10:41 PM
  #952  
Doc...
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Default RE: Boomerang Sprint Build Thread!

Hi,

Patricia and Alan will not be back until October 2. Tell us what you need or don't understand and we will help you.

Doc...
Old 09-20-2009, 06:47 AM
  #953  
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Default RE: Boomerang Sprint Build Thread!


ORIGINAL: crhammond

Can anyone recommend any other good turbines that are light and in the 20 - 22lb range. Good service is also a must... (Jetcat wins there again, but I hear Behotec have great service also.)
I have a falcon in mine and I am Very Very Happy with the performance.
Old 09-20-2009, 07:10 AM
  #954  
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Default RE: Boomerang Sprint Build Thread!

i would go with a jetcat p80se. choose the engine with the best service. jetcat hands down. for 1 to 1 power the new p80 will be a good choice.
Old 09-22-2009, 07:24 PM
  #955  
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Default RE: Boomerang Sprint Build Thread!

Hi All,

Excited to buy a Sprint witha P-80SE in it this winter (I live in Chicagolong winter ahead with no real flying) to build and I'm starting to gather needed parts - question I have is it necessary to have two remote receivers for the JR R921 2.4 receiver or is just one standard satellite fine for this application?

Thanks!
Old 09-22-2009, 07:58 PM
  #956  
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Default RE: Boomerang Sprint Build Thread!

i only use one with all my 921's
Old 09-22-2009, 08:07 PM
  #957  
seravios
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Default RE: Boomerang Sprint Build Thread!


ORIGINAL: KC36330

i only use one with all my 921's

Do u use any powerbox?
Old 09-22-2009, 08:11 PM
  #958  
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Default RE: Boomerang Sprint Build Thread!

not on any of the 921s, i do have a Powerbox on a 1221
Old 09-22-2009, 08:15 PM
  #959  
seravios
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Default RE: Boomerang Sprint Build Thread!


ORIGINAL: KC36330

not on any of the 921s, i do have a Powerbox on a 1221

How many 921s you have onboard?


Old 09-22-2009, 08:18 PM
  #960  
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Default RE: Boomerang Sprint Build Thread!

i don't use any dual rx setups.
Old 09-23-2009, 06:12 AM
  #961  
ricardinho
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Default RE: Boomerang Sprint Build Thread!

i also use one 921 with two sattelites and one duralite 4400 4cell.
Old 09-23-2009, 06:26 AM
  #962  
seravios
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Default RE: Boomerang Sprint Build Thread!

I seldom hear dual Rx setup,not seen one actually.
Old 09-23-2009, 05:30 PM
  #963  
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Default RE: Boomerang Sprint Build Thread!

Hi All,

Great build thread on the sprint - for me this is the first jet plane I am planning on purchasing/building this winter and all the information posted here has been great feedback on mods or building steps to look out for. So far this thread has highlighted the following items to pay particular attention to during the build:

- Heat on rear elevator
- Rudder servo mounting bracket
- Heat on turbine area
- Mounting of fuel filter
- Tight wing tubes?
- Pull/pull wire clearance and bulkhead mods
- P-80SE mounting mods

I think there are other concerns to look out for but these are some from the past ~40 pages of replies that I can remember. Believe me I'm not bashing anything here but just trying to get my arms around the build (every ARF needs TLC to be perfect). It might be worth $$ for someone to put together a build bulletin on this plane - I would buy it for build security and perfection!

Old 09-23-2009, 06:41 PM
  #964  
ricardinho
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Default RE: Boomerang Sprint Build Thread!

they are all very minor and easy fixes. dont let these things keep you from sleeping. this is one smooth flying plane. if this is your first jet find a club member who has alot of experience with turbines to help you. also rember very important these engines put out extreme temps .
Old 09-23-2009, 07:38 PM
  #965  
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Default RE: Boomerang Sprint Build Thread!

I hear that! I'm mainly just trying to keep the build time as low as possible since I'm building another 50cc plane just ahead of the soon to be purchased Sprint. Havingtwo young childrend,wife that works and my full time job really restricts any time I have in the shop to build so its becomes a delicate balancing act. I'm sure many others here can sympathize with the desire to get home from work and continue building - for me the building can't start until late when I'm already pooped out! (and I admit I love building as much as flying - except for hinging!) I'm sure this plane will be a subject of a few arguments....looks like I'll also be buying some Coach purses LOL!
Old 09-24-2009, 12:02 AM
  #966  
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Default RE: Boomerang Sprint Build Thread!

Hi,

The Sprint was my 1st Turbine but not my 1st Jet. Don't take what I'm trying to say the wrong way but with Turbines, it's a whole new world. I spent 6 months building the Sprint and reading this thread. There are a few people we know who didn't take the time or were looking for short cuts and as a result, they have either lost the ship or have had many problems. There are no short cuts for Turbines. When you spend $7,000.00 on a ship, well, you know the rest. I admit 6 months was a little much but it was better than shoveling snow. It was my winter project. From the time the Sprint took off in May, only 2 clicks were needed on the alerons. It has been a dream to fly but understand this ship is not designed to fly at 180 mph. Your P-80SE is really perfect for the Sprint and the Elan. Once you move to the Elan, there will be more room inside the ship to work with and there is less building as well. The best suggestion I can give you is to really study this entire thread and if you do take the tips and suggestion, you will have a great flying bird.

Good Luck,

Doc...
JPO
Old 09-24-2009, 01:34 AM
  #967  
seravios
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Default RE: Boomerang Sprint Build Thread!

Doc is right. When i took up my 1st turbine, I was in hurry to get it in the air. Having flown the KingCat belonging to my friend,I was too excited. Building a jet is far different from building a prop plane in many ways. As a result, my first jet lasted less than 30s in the air. My second lasted 5 flights. Now having learned fr my 2 previous mistakes, building jet is far easier, but still takes time. Like they say,learn the hard way (....and expensive way)
Old 09-24-2009, 03:12 AM
  #968  
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Default RE: Boomerang Sprint Build Thread!

No mods necessary to fit the P80. This model goes very very well with it.
Old 09-24-2009, 06:34 AM
  #969  
seravios
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Default RE: Boomerang Sprint Build Thread!

I elevated the front mounting screws with few washers by 5mm to increase the down thrust. That solved the heat development issue under the elevator.
Old 09-24-2009, 09:07 AM
  #970  
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Default RE: Boomerang Sprint Build Thread!

Doc, take your time. A 50cc gasser is VERY simple compared to a jet and far more forgiving. I have built and assembled many large gassers in the 40%+ size and they all went together much faster than my Sprint. Before the Sprint I had a Comp-Arf Spark EDF jet (as my "trainer") I'm glad I did because it was an in-between step in complexity from a prop to a turbine and I learned a lot. Besides it is an awesome flying jet too, very, very fast

The Sprint is not hard to assemble but there are a lot of components in a jet and they all have to be installed right... you will find stuffing all the gear inside a challenge. Especially if you do it so its all neat and easily accessable for maintenance. GET HELP is the main thing.

I think I spent 80 hrs getting my Sprint how I wanted it... and after 5 flights I went back in and made some more changes.

I strongly recommend you fire-proof the rear of the hatch. I also strongly recommed you put FOD screen on the intakes (inside the fuse) and run a FOD screen on your turbine.

You will LOVE how it flies. It feels every bit as solid in the air as a 40% prop plane and is a *****cat to takeoff and land.
Old 09-25-2009, 06:59 PM
  #971  
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Default RE: Boomerang Sprint Build Thread!

I have to say that Sprint has been extremely fun to fly.

I am just wondering why mine does not look like the picture in the manual.




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Old 09-25-2009, 08:51 PM
  #972  
seravios
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Default RE: Boomerang Sprint Build Thread!


ORIGINAL: DamBo

I have to say that Sprint has been extremely fun to fly.

I am just wondering why mine does not look like the picture in the manual.

any pic ?
Old 09-25-2009, 09:30 PM
  #973  
seravios
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Default RE: Boomerang Sprint Build Thread!

Hahahaha....good one
Old 09-25-2009, 11:46 PM
  #974  
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Default RE: Boomerang Sprint Build Thread!

Which one flys better?

Doc...
Old 09-26-2009, 01:47 AM
  #975  
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Default RE: Boomerang Sprint Build Thread!

Very funny DamBo
My only worry is that you may have given Alan some ideas[X(] I feel a visit to the development field coming on
Regards Al

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