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        Question Anyone know of any composite EDF jets comparable to a turbine jet?

#1 rjp0325 May 01, 2008 12:30 PM

Anyone know of any composite EDF jets comparable to a turbine jet?
 
Does anyone have or know of composite EDF jets that is comparable in speed and performance to a turbine jet?

#2 Michael Paxton May 01, 2008 01:55 PM

One that you spend a whole lot of money on? :)
(Sorry. Couldn't help it!!)
~M~

#3 skyhawk May 01, 2008 01:59 PM

There are lots out there. Try a search for large edf or 120 mm edf.

Skymaster gripen converted and the yellow kits have been converted. Even the bvm line has been converted.

Tams fan is getting better preformance in his A-4 than the turbine version.

#4 rjp0325 May 01, 2008 02:53 PM

I was looking at the Comp ARF Shark. They claim 1:1 power ratio with the recommednded 72 carbon fiber edf and motor. The two sets of lipos alone cost $1390 ($695 ea.). The entire build cost of the jet less servos and receiver is about $4000 for 5 minutes of flight time. OUCH.

#5 k_sonn May 01, 2008 03:47 PM

Kerosine, turbine oil, and propane are not included in the cost of putting together a turbine powered airframe. Likewise, batteries are not included in the cost of putting together a high powered EDF.

For the sake of discussion, let's do some cost comparisons. The batteries you refer to cost $695 per set. Batteries, if properly taken cared of, will give about 150 cycles (flights). The cost per flight is $4.63 (695 / 150). The current cost of kerosine is $36 for 5 gallons. Turbine oil cost $29 per quart so the cost of 5 gallons of kerosine is $65. I have a kero-start (no propane needed) Jetcat P-70 powered airframe that burns 74 ozs of fuel per flight. 5 gallons equals 320 ozs so for 5 gallons of fuel I get 4.3 flight (320 / 74). The cost per flight is $15.12 (65 / 4.3). So, it costs me 3.27 times more per flight to fly a P-70 powered airframe than it does to fly the Comp ARF Spark.

Not sure where you get $4000 for the total cost of the Spark. Here are the costs from the Comp ARF website:
Spark: $1070
Retracts: $190
DS-75/Lehner Motor/Jeti ESC: $1095
Total: $2355

The Comp ARF Spark airframe is a little expensive for it's size but their target market is turine pilots who are used to paying this amount for an airframe.

Kirk

#6 Fast Jets May 01, 2008 04:36 PM

I fly both electric and turbine and never count the cost of batterys, you need energy one way or anther. I agree batterys cost more up front but will last a good amount of flights.

John

#7 rjp0325 May 02, 2008 07:34 AM

Good point guys . . . I never thought of it that way. With the cost of fuel rising, the cost to run a turbine will anly get more expensive.

What I'm ultimately looking for is a screaming fast non-foamie EDF with retracts.

#8 Fast Jets May 02, 2008 07:56 AM

I have the Tams F-16 and it is a great flyer, also K&A new F-100 and both of these have retracts. I have nothing but 3 cell packs but plug them in in series, between my son and I we have models that fly on 3,6and 12s right now. I have only been flying a lot of electrics for a little over a year and am not sure if pluging that many in series is the best but it has work great for us.

John

#9 rjp0325 May 02, 2008 11:46 AM

John,

What is your best guess as far as MPH for the F-16 and F-100? Also, are the jets capable of 3-D flying as set up?

Thanks

Ralph

#10 Eddie P May 02, 2008 03:42 PM

Quote:

Originally Posted by k_sonn
For the sake of discussion, let's do some cost comparisons. The batteries you refer to cost $695 per set. Batteries, if properly taken cared of, will give about 150 cycles (flights). The cost per flight is $4.63 (695 / 150). The current cost of kerosine is $36 for 5 gallons. Turbine oil cost $29 per quart so the cost of 5 gallons of kerosine is $65. I have a kero-start (no propane needed) Jetcat P-70 powered airframe that burns 74 ozs of fuel per flight. 5 gallons equals 320 ozs so for 5 gallons of fuel I get 4.3 flight (320 / 74). The cost per flight is $15.12 (65 / 4.3). So, it costs me 3.27 times more per flight to fly a P-70 powered airframe than it does to fly the Comp ARF Spark.

Kirk

KIRK!!!

You have to shop around for your fuel and oil, you can DO MUCH, MUCH BETTER!!! I pay $2.20 per flight, for my turbine oil and kerosene. I have 80 ounce tanks and I usually use 45 -50 ounces at a time for a 10-12 minute total run time or 7 minute "wheels up" flight. I think my 18.5 pound thrust Wren Supersport will get better fuel burn rates than my Jetcat, but I have not flown it yet to compare. If I "hot fuel", or fly 2 or three flights back to back, add a couple ounces of fuel burn on the ramp to the figure.

As an aside, oil could be had for $12 bucks a quart, or less. Whoever is charging you what you are paying for your oil should not get another dime or word from you. If the FBO is where you are getting it from, find a new FBO or buy a box from the internet. Turbine oil, unopened, has a 40 year shelf life. Fuel: Buy fuel during the sales at this time of year, last year I bought 5 gallon drums for 3 dollars a gallon locally.

I pay about $130 bucks a season for my kerosene and oil. That's all my turbines cost me to run for a year. I just paid $130 after shipping and more solder and Deans plugs for two park flyer EDF batteries!!!

I guess it depends on where you buy yor fuel - batteries and "fuel" - the both of them. :)

As far as the merits of running a turbine or EDF powerplant, I think most realize the choices are good these days. Either way we're gonna spend some bucks in these areas. Both big EDF and turbine. We all have our preferences and thresholds for annoyance (sound, smell, flammability, support equipment factor, etc).

#11 Tamjets May 02, 2008 04:15 PM

You guys can chose either turbine or EDF.
Tamjets will provide conversion kit for it.
Is not cheap when get to this level. Only way is get the best out of it when you spend this much.
This my best advise.

#12 Eddie P May 02, 2008 04:19 PM

Quote:

Originally Posted by rjp0325
Good point guys . . . I never thought of it that way. With the cost of fuel rising, the cost to run a turbine will anly get more expensive.

What I'm ultimately looking for is a screaming fast non-foamie EDF with retracts.

Fuel is just not going up, our Dollar is going down. That means any energy source, batery or wet, will be pricy these days after we pay the exchange rate for our falling currency. Gotta pay to play, no shortcuts there.

#13 k_sonn May 02, 2008 04:34 PM

Eddie,

I wished I lived in your area. Right now in my area, kerosine at the pump is over $7 per gallon. Home Depot has the 5 gallon cans for $36 but all of the local stores are sold out and they are not restocking. Last year, Home Depot put the kerosine on sell for $5 per 5 gallon can and they couldn't get rid of it. It's funny because my flying thought I was crazy last year for paying for lipos and this year he started asking me about converting to EDF because of the cost of kero.

Kirk

#14 k_sonn May 02, 2008 04:36 PM

Hey Tam,

You left out you're famous sells tag line: "Everything For Sale" :D

Kirk

#15 Lynxman May 02, 2008 04:38 PM

I get fuel and turbine oil for free and would still buy a big EDF system over a turbine. :) I just hate dealing with wet fuels.


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