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FORA / CYCLON .15 powered speed plane

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

FORA / CYCLON .15 powered speed plane

Old 04-04-2014, 05:07 AM
  #251  
MJD
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Yes, the small engine speed bug seems to be a fun one to catch so far! And why not? There is a perverse satisfaction in a 1cc model that can whip every sport model at the club field. Of course, I'd have to show up at the club with it to do that, but speaking hypothectically.

Indeed, handling these high performance little devils seems to amount to mounting them on an airplane, fueling them up and go flying. So much for bad handling. Now, with pipes.. maybe not quite so fuel 'n' go.

I scrounged a rod for the UCTKAM 2.5, so once that shows up I will finally have the front 4" I needed for the half-built 24" SWR delta that's been lying around for a while. It was going to be a Profi .061 model but I ended up building the little low wing racer for it instead. Which, thanks to SmokinRV's nice prop nut he made for me, is now checked out and ready to go again. I'll clock it next time out if it is behaving.

Last edited by MJD; 04-04-2014 at 05:14 AM.
Old 04-04-2014, 10:37 AM
  #252  
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It's nice to have a hand full of pipe seals, o-rings, etc. I'm not sure how much heat the .15 generates but if it follows the same "rules" as other piped engines I've run.......if you are melting pipe seals often then you have a 5 or 6 item checklist to investigate.
A blown pipe seal during a speed run is like adding air to a cutting torch. I
believe it is possible to have world class performance with out smoking hot runs if you find the perfect balance of all the things that you have control of as tuning tools. The prop itself and compression being the most critical tuning tools. Once you arrive at the perfect prop, then you want to crank out several copies from the rough blanks while magic knowledge you gained is fresh in your head ..!!!
Hopefully too...there is an "off the shelf" prop blank that doesn't require much sculpture and it becomes one you can get cheaper by the dozen or else make your own.
The YuckDamn 2.5 has always been on my list for the challenge. I remember Patrick having trouble dismantling his because the slot head screws that held his together were so chinsy that they were not budging loose without ruining the slots . He got it for something like $20 with a pipe included..!
I don't know if AJC or Andy Woitkowicz ever played with one of these, but I would try to do it Andy Style and use replacement parts from similar engines that are dimensionally close to what is needed.

Last edited by combatpigg; 04-04-2014 at 10:40 AM.
Old 04-04-2014, 11:10 AM
  #253  
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I already spoke to Bill Hughes, he knows how to rework them and I am ordering a rod from him. His main points are (1) replace the rod right away, they are the big weak point, and (2) get the compression up to spec, the head volume is too high stock. And the old low volume pipe like I have is not as good as the newer one. Oh well, it's good enough for an SWR.

Eliminator has props specific to the Profis. http://eliminatorprops.com/store/ind...products_id=23

With IMC there is no need for melt down. Kill it or richen it, whatever is needed. No need to suffer through 10 laps to get an official while the engine immolates itself.

The engines run pretty hot in ukie speed apps, they run a fine line on stinger exit area to retain heat for maximum power output. More than one speed engine guy has recommended opening up the stinger area a little bit to make it a bit less critical. This is likely another key point regards longer engine runs and overall longevity.
Old 04-04-2014, 11:19 AM
  #254  
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It's nice to have great support like that.but surprising to hear that the stock rod needs immediate upgrade. It will be interesting to see the 2 rods side by side.
Some piped engines with a run away heat condition flare up real fast and you can not richen them fast enough to get them to recover. The best medicine at this point is to yank the fuel line off the thing..[.or rig a "flood off" bypass that is activated by a fusible link that is attached to the engine..]

Last edited by combatpigg; 04-04-2014 at 11:23 AM.
Old 04-04-2014, 11:20 AM
  #255  
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This is the UCTKAM that needs the rod I'm talking about - this doesn't surprise me. The Profi is out of the box ready to go fast.
Old 04-04-2014, 11:45 AM
  #256  
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This thing scares my dog. He looked at the computer screen and ran away.

I can't wait to hear how it flys.
Old 04-04-2014, 01:55 PM
  #257  
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Originally Posted by MJD
This is the UCTKAM that needs the rod I'm talking about - this doesn't surprise me. The Profi is out of the box ready to go fast.
OK.....that makes much better sense to me..!

LD....I'd like to maiden it over 4 foot tall grass in July instead of cold, swampy fields, but I don't want to wait that long. 4 foot tall grass WILL save crappy launches with planes this small. I've lost count of the times I've retrieved 1/2 A planes that landed on the tall grass with the engine still running.
Before tossing this one for the first time, I might work out a plan to start out with increased fin area, then gradually subtract area until I [hopefully] work my way back to the original outline.
I'm pretty sure this will involve machining different weight spinner nuts out of brass, or aluminum to compensate.

Last edited by combatpigg; 04-04-2014 at 01:59 PM.
Old 04-04-2014, 04:50 PM
  #258  
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Yeah sorry, I've been flipping back and forth between UCTKAM .15 SWR and Profi talk. The cheapie motor goes on the 24" SWR delta, the Profi goes on an composite pylon racer conversion. Both are threatening to take root on the bench soon. This weekend is finishing a HET ME-163 lekkie, tonight I'm glassing the wing root to the fuse, sand and touch up paint tomorrow, hope to get the rest of the gear in for test flight Sunday. And the other task is now that I finished and mounted the profile plate on the Profi .049 cowl pattern, it's time to finish prepping for the first side layup. Gotta build some dams from plasticine to finish the form before that, touchit all up and then realease coat. With spring threatening the ol' workshop is trying to catch up after a lazy winter.
Old 04-05-2014, 06:15 AM
  #259  
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mb 40 engines use the ball on crank scheme as well..IIRC
Old 04-05-2014, 07:59 AM
  #260  
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Originally Posted by lfinney
mb 40 engines use the ball on crank scheme as well..IIRC
The limiting factor with our model engines has been the size of the tunnel going through the crank, so it makes sense to go this route.
I don't know what the pitfalls are during manufacturing to get the heat treating just right.
An ambitious engine man could see if the OPS speed engines could be retrofitted with this same idea and cram an extra large crankshaft into one of those. OPS has that modular case design, so it seems like the biggest chore would be producing the larger shafts. Some German speed freaks are probably already working at this.
Old 04-07-2014, 12:35 PM
  #261  
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Today was too nice a day to not fly, so I flew.
Haven't flown anything for 2 years, I'll bet. Still a little bit numb from dental work earlier in the morning, too [possibly an advantage to be on lidocaine and coffee for the first flight].
The first launch didn't go well. The plane did a half roll, 180 half spin and pancaked in on the short grass. That cut down 7x3 really was pulling like a SOB and it really shot the model out of my hand...too bad the prop didn't make it.
Back to the drawing board. I brought some manila file folder paper, tape, ruler, scissors, brake cleaner, rags....and built a bigger fin right there at the field. I made it extra big and dorky looking. CG check last night showed that the CG is at 17%, so I knew I had some leeway for adding weight in back.
I un-flooded the engine and put on a 6.5 x 5.5 prop [size .10 pylon prop].
The engine sounds kind of maxxed out with this much prop. Would not want to try any larger, but with zero nitro fuel and the full stack of shims the engine was OK with it.
Next launch was perfect. It flew absolutely beautiful. The model kept accelerating and accelerating with that prop getting up to pitch speed. I won't even guess how fast it was going, after 2 years of no flying my senses are out of tune. I didn't dare move my eyes from the plane to find the elevator trim until it was gliding home. All it needed was some up trim, everything else was perfect.
For the next flight I lopped off some excess fin to a better looking profile and the model flew just as well. I called it a day after this flight, not knowing when the taped on fin was going to fail and to cycle the new batteries.
So, it's a very stable little model [considering how tiny it is] but I don't have my "RC Eyes" dialed in after such a long layoff. Even though this thing has the same span as the .40 sized deltas, it's so thin that it will take some time to get used to watching it fly. I expect after a dozen flights things will seem to slow down. This is like the first trip to the batting cages after spending all winter staring out the window.
The speed props came in from Steve Wilk, so for the next session I will have the video cam going and hopefully get some good footage and some good clockings.The engine turns 24,700 with this prop, so maybee 26,700 in the air. If so, it confirms my visual impression that the model was hitting the 130 mph range.
I'm pretty sure that dropping down to 5.5 x 5.5 or 6 x 5.... will be an improvement.
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Last edited by combatpigg; 04-07-2014 at 01:38 PM.
Old 04-07-2014, 01:34 PM
  #262  
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Well at least the question about the fin area was resolved without any major damage, I guess it was a case of being a bit to minimalist, but it had to be close. It looks like you about doubled the fin area, on the plus side it probably makes it a bit easier to see.
The thin wing really does present a challenge as far as visibility, there are times that the plane does sort of disappear. I had the same problem with the Stingray, that why the orange on the winglets.
Still sounds like it was hauling.
Old 04-07-2014, 01:53 PM
  #263  
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The challenge now will be to make the alteration to the fin come out no heavier than the one made out of cardboard and tape.
Today was also a bright day and it has been a very gloomy year up to now. A good pair of sunglasses could have really helped.
Old 04-07-2014, 04:43 PM
  #264  
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Seeing as you need a bit of up trim you may be able to get away with just a bit more weight. Although I bet there was a fair amount of weight with all the tape and cardboard, sounds like your going to be grinding off some paint and laminating some 1/32 balsa to build up the fin. (I would try 3 layers extending two if them back onto the existing fin and then sanding them to give you a nice airfoil shape for the fin.)
From both the weather and news sounds like it been pretty gray and wet out there for awhile now, must have been nice to see some sun.
Feel a bit like a gremlin going bright light, bright light, did ya?
Old 04-07-2014, 05:40 PM
  #265  
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I didn't think about using 1/32" balsa. Yes, I'll need to sand a relief into the existing surface so that grafting on an extension ends up flush.
I'm not real happy with the looks of this fin. It's almost as ugly as the latest generation of Camaro that Chevy came back with.
The 1/32" would make the lightest base for a layer of 1 oz cloth. This file folder paper isn't too bad, though...
Yes, on about the 100th day of the year, it is a relief to get some sun and a reading of 65 degrees..
Old 04-07-2014, 06:23 PM
  #266  
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Yeehah! It flies! Zalptism by Fire.

Great news CP. Two years off the sticks huh? Good fun. I seem to remember doing a similar thing with the Demon .65. No sense *****-footing around shooting circuits with a decrepit old Kadet. Fill the bladder and go.
Old 04-07-2014, 06:24 PM
  #267  
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Starts with a "p" and ends in "ussy" is banned on RCU, so I couldn't say "synonym-for-cat-footing"..
Old 04-07-2014, 06:52 PM
  #268  
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Originally Posted by combatpigg
I didn't think about using 1/32" balsa. Yes, I'll need to sand a relief into the existing surface so that grafting on an extension ends up flush.
I'm not real happy with the looks of this fin. It's almost as ugly as the latest generation of Camaro that Chevy came back with.
The 1/32" would make the lightest base for a layer of 1 oz cloth. This file folder paper isn't too bad, though...
Yes, on about the 100th day of the year, it is a relief to get some sun and a reading of 65 degrees..
Ugly doesn't go far enough as far as the new Camaro...
I have used several layers of 1/32 to build up parts before, using different colors of magic marker to color the surfaces before you laminate helps as a sanding guide as well.
Nice to hear you got some good weather finally, you guys are due for a break.
Old 04-07-2014, 06:55 PM
  #269  
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Originally Posted by MJD
Yeehah! It flies! Zalptism by Fire.

Great news CP. Two years off the sticks huh? Good fun. I seem to remember doing a similar thing with the Demon .65. No sense *****-footing around shooting circuits with a decrepit old Kadet. Fill the bladder and go.
Definitely no kitty cat factor here!
Old 04-07-2014, 07:30 PM
  #270  
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Funny how this 6.5 x 5.5 prop has always been just a tad bit too much for every .15 I've ever run....but it is listed as a .10 pylon prop.
My OS CVA, K&B and Super Tigers get bogged down by this prop a little, too. The 6.5 x 5 has seemed to be the best choice [of APC props]..but I have not done much "clocking" of .15 planes.
I'm hoping to see a sizable jump in power and speed with more work. A nitro head button will need to be made to explore those possibilities. With just a 2 oz tank, at least 0% nitro gives a decent flight time, no signs of heat stress. The venturi on this thing is a complex piece of work to make by hand. I'm not sure if making a larger venturi is "in the cards" for awhile, if ever.

Yes, I gave some thought to pulling out a trainer to get warmed up before flying this.. but then I kicked the little ***** demon that was talking that nonsense in the nads and left for the field with just this plane.
Old 04-07-2014, 08:15 PM
  #271  
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The Graupner Speed 6x5.5 might be one to try if you're curious about their props. The OPS .15 - which is just a perky .21 case size .15 but no monster - turned it about 24k in the air.

Not the CAM props. There are three of these that I know of: 6x5.5, 6.5x6.5, 7x7. For club 20 racing?
Old 04-07-2014, 08:42 PM
  #272  
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CP I think with a bit of downhill you may be able to get the APC 6 X 6.5 to unload, I think the plane is clean enough. I would even try a 5.25X 6.25 stock apc as well it almost worked on a 58 oz plane. Figuring your plane weighing in just a little over a pound, and half the wing area of the stingray, it should be an interesting as far as speed on your plane. That prop would only load the motor enough to draw 635 watts at 26,700 rpm (.84 hp) so it might be an option to try.
As far as nitro I think I would try reducing the thickness of the head gasket first after reading about them wanting a 13:1 compression ratio for no nitro.
From what I read is they use thin oil and a syringe to measure the volume of the head at TDC and then calculate the compression after having measure the actual bore and stroke to determine the actual compression ratio so they have a real idea of what it is.

A couple caveats: these guys were really into fine tuning the engines, and they were not worried too much about the idle.

Last edited by iron eagel; 04-07-2014 at 08:48 PM.
Old 04-07-2014, 08:52 PM
  #273  
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Where do you get them..? Graupner's regular line of sport props that were carried at local hobby stores were always more expensive and I almost never bought them just for that reason.
I'm fairly certain this plane and engine will respond to props with less than 6 inches of diameter. I'd like to see 5.5 pitch multiplied by 30,000 as a workable goal.
With the big crank threads / big spinner nut it limits the possibilities just a little. Some of the carbon props that showed up might not have enough meat at the hub..but I'm not sure yet.
Old 04-07-2014, 09:26 PM
  #274  
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Originally Posted by iron eagel
CP I think with a bit of downhill you may be able to get the APC 6 X 6.5 to unload, I think the plane is clean enough. I would even try a 5.25X 6.25 stock apc as well it almost worked on a 58 oz plane. Figuring your plane weighing in just a little over a pound, and half the wing area of the stingray, it should be an interesting as far as speed on your plane. That prop would only load the motor enough to draw 635 watts at 26,700 rpm (.84 hp) so it might be an option to try.
As far as nitro I think I would try reducing the thickness of the head gasket first after reading about them wanting a 13:1 compression ratio for no nitro.
From what I read is they use thin oil and a syringe to measure the volume of the head at TDC and then calculate the compression after having measure the actual bore and stroke to determine the actual compression ratio so they have a real idea of what it is.

A couple caveats: these guys were really into fine tuning the engines, and they were not worried too much about the idle.
This engine ought to be run at 30,000 [I think].
I need to see what size prop "off the shelf" it can rev to 30,000....then use a HP / Thrust calculator to generate alternative sizes that take similar amount of HP to turn as my "control prop" used.
For example today..6.5 x 5.5 @26,500 requires 1.315 HP..so then I know I've got 1.3 HP to play with and the next move would be to see what it can do at 30,000 with 1.3 HP or slightly less.
So I plug in 5.5 x 6 @ 30,000 and find that it requires 1.067 HP. The resulting speed would be 170 mph and I would have a hard time believing that there is another 30+ MPH waiting to be had beyond what I witnessed today..but this is the approach I take with engines.
With electric motors that have perfectly flat torque curves you don't have this to consider. The engine has a peak "metabolism" almost like a living thing that has to operate at a certain pulse rate and blood pressure to be at it's best..
If I plug in 5.5 x 6.5 it requires 1.15 HP but now the over squareness is beyond what I've ever seen work in real life.
I have a feeling that the 5.25 x 6.25 needs to operate much faster than 30,000 and that if it's an E prop can it be drilled out to 5/16"..?

Last edited by combatpigg; 04-07-2014 at 09:38 PM.
Old 04-08-2014, 06:11 AM
  #275  
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Congrats on the successful flight!

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