C-ARF Ultra Flash build Thread + Video
11-20-2017, 03:11 PM
#5926
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Want to know if you guys know the answer to this one. Some Flashes, my classic made a really cool, reverberating sounds past half throttle. Almost like a standing wave resonance in the airframe(no not flutter).
The plane has gone through changes, new engine, new pipe and paint job and no longer makes the sound... although maybe faintly heard at full throttle now. I never knew what caused it. surely other flashes did this?
Some said you could hollow out the back of the tip tanks to get a sound but I never did that. That might make a whistle sound?
Darren
The plane has gone through changes, new engine, new pipe and paint job and no longer makes the sound... although maybe faintly heard at full throttle now. I never knew what caused it. surely other flashes did this?
Some said you could hollow out the back of the tip tanks to get a sound but I never did that. That might make a whistle sound?
Darren
11-20-2017, 10:05 PM
#5929
Thread Starter
Depends on the turbines mass flow, bigger turbines will do it or the turbines that have a high exhaust speed to generate the thrust. What did you have in and what now?
11-20-2017, 10:21 PM
#5930
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P120 SX in both cases but the original P120 SX was extraordinarily good. Seemed to be more powerful that this one till it finally gave up and seized.
Both had a Tam's pipe with a taper that decreased towards the exhaust like is done in EDF(not sure the standard in turbine pipes as I know some actually expand towards the exhaust.. those are the augment type)
Both had a Tam's pipe with a taper that decreased towards the exhaust like is done in EDF(not sure the standard in turbine pipes as I know some actually expand towards the exhaust.. those are the augment type)
11-21-2017, 12:32 AM
#5931
Thread Starter
OK, not normal with a P-120SX! The tapered pipe will cause a pressure wave and I don't think it adds any speed to the model.
You sure the tail cone to tail pipe gap is the same on both installs? It makes a huge difference to performance
You sure the tail cone to tail pipe gap is the same on both installs? It makes a huge difference to performance
11-21-2017, 06:47 AM
#5932
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I will need to check that. I still have the old pipe and could possibly even try it.
I think you are right, the engine and pipe combination is probably the source of this sound. I remember when I switched to diesel from kero the sound changed a bit, and that was the only thing I changed at the time.
I think you are right, the engine and pipe combination is probably the source of this sound. I remember when I switched to diesel from kero the sound changed a bit, and that was the only thing I changed at the time.
Last edited by dbsonic; 11-21-2017 at 08:19 AM.
11-25-2017, 06:01 AM
#5933
Thread Starter
Winter is approaching here, so we are back to flying 'heaters' at the local club field, couple of Xcalibur's and Stevie with his 110 hour P-120 Swiss UF.
11-30-2017, 07:06 AM
#5936
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Maiden flight - completed.
We did the Maiden flight on 28th November with my UF/Cheetah combo, all was good, didn't max it out but still got 313 KMH, and the best part, she makes that wonderful howling sound, fully bypassed.
Magnificent performance, hoping many more fun flights to go.
Here in Thailand were just going into winter which is the busiest most popular time of the year to fly, cool days, fresh mornings & pleasant BBQ evenings at the RC club.
Happy flying everyone.
Magnificent performance, hoping many more fun flights to go.
Here in Thailand were just going into winter which is the busiest most popular time of the year to fly, cool days, fresh mornings & pleasant BBQ evenings at the RC club.
Happy flying everyone.
12-04-2017, 03:27 AM
#5937
We did the Maiden flight on 28th November with my UF/Cheetah combo, all was good, didn't max it out but still got 313 KMH, and the best part, she makes that wonderful howling sound, fully bypassed.
Magnificent performance, hoping many more fun flights to go.
Here in Thailand were just going into winter which is the busiest most popular time of the year to fly, cool days, fresh mornings & pleasant BBQ evenings at the RC club.
Happy flying everyone.
Magnificent performance, hoping many more fun flights to go.
Here in Thailand were just going into winter which is the busiest most popular time of the year to fly, cool days, fresh mornings & pleasant BBQ evenings at the RC club.
Happy flying everyone.
01-18-2018, 04:53 PM
#5938
Any chance someone out there has a set of the “ULTRA FLASH” decals in Silver that they want to part with(sell)? My McLaren scheme UF didn’t come them and I’ve not had any luck through Carf. Let me know!
01-18-2018, 05:27 PM
#5940
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I have a set from my Mclaren Ultra Flash that I could part with. If you are interested send me a PM.
01-22-2018, 11:13 AM
#5944
With a Jetsmunt M200XBL I have clocked on one single run 250 and 287 mph.... I'm sure if I leave it open for a full lap over 300 can be reached. I'm using MKS HBL599 servos with 580 oz of torque...
David
David
01-22-2018, 12:06 PM
#5947
