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RE: RCG 20cc question...
ORIGINAL: Bob Paris Hi Guys, I have a RCGF 15cc gas engine...but since I had two RCG 20cc engines and the physical size and weight is almost the same, decided to go with the 20cc gas engine. I believe this model will have a nice vertical presintation... : ) ... nothing like cubic inches to add climb rate to any model. I just wonder how the torque will effect the model with a 17x6 prop. When I broke in my ST G90 on a .40 size ultra stick...the vertical acceleration was outragious...but the torque was something to care for when adding power. Ugly sticks have powerful rudders and I just got used to using my rudder thumb when I had the G90 on board. <span style="color: #ff0000">Plan on putting in a fair bit of additional right thrust on the engine. With the larger prop and stronger engine you will find the model will be capable of a knife edge loop to the left without any rudder input. Once you get flying, ease in the throttle gently and see what happens. When you pull vertical you should notice a significant pull to the left and as Isaid before, it will do a knife edge loop. </span> I used plain old 4/40 wire rods (cut from 36" long rods-12" 4/40 rods are not long enough), for the tail brace wires. I went to Radio Shack and bought pre-tinned connectors, the one with no plastic covering-with the screw hole in the middle-w/a wire connetion tab, fit the wire into the slot/tab and just silver soldered the wire to them. I made the top rudder connector first-screwed into place, for flight, then moved the wire to where I wonted to place the outboard stab connection, and cut the wire. Then I marked how the tab was to be set on the wire...then just soldered the tab to the wire-after removing it from the model. You will need to bend the tabs a bit to fit the angles of the wires to the stab, from the rudder...but Its really quite simple to do...and make sure you have the proper screws and hardware on hand for the five attachment points. I've done this on my models for years and it works. It gives you something to hold on to and also beefs up the tail feathers a bit. I used 4/40 cap head screws, washers, lock washers and fiber lock nuts...double saftied. I have a good collection of hardware on hand...so I just go to the cap head screw length that works best and attach the goodies. 3/4" long cap head screw for the top of the rudder and 1/2" for the stab connections. #2 washers, lock washers and 4/40 fiber lock nuts. <span style="color: #ff0000">Thanks for the info on the hardware used, Iwill pick me up some on the weekend while Iam in Ft Lauderdale. </span> |
RE: RCG 20cc question...
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Hi Guys,
A few of my 17x6 props arrived and a nice fuel tank vent I ordered. I installed the fuel tank vent on the bottom of my model, just aft of the fuel tank and installed my new prop. I also received the metal spinner adapter (8mm x 1.25-long) and modified my spinner to fit the props. I then balanced the prop and spinner...but still waiting for my 5" tires and new tail wheel assy. The parts are due in any day...and then we will be off flying. That sure is a big prop and the largest I've ever used on any model I've built in the past. What is the operating RPM should I be looking for, for best thrust and power. I'm not looking for speed, but vertical assent. Its getting closer for me and I hope to have a first flight in the coming week. Enclosed are a few pictures of the work done to the model and you will also see the ground clearence issue I'm dealing with. I added one washer, in two places, under the left side of my engine mount, to give me some right thrust. I'll see how this works out and I may need to add more or reduce the thickness of the washers after I fly it and see how if flys. If you look you will see two eyelets on the bottom of my fuse. These are the drain holes for the fuel tank bay. If for some reason my fuel tank leaks...it should leak the fuel out of these two eyelet holes...and not all over the models insides. I've seen several models soaked in the insides by fuel tanks leaking gas and really made a mess of everything. I do pray this works as installed... : ) My garage opens to the West...and we had an awesome sunset tonight. Thanks again for all your advice, Bobby of Maui |
RE: RCG 20cc question...
ORIGINAL: w8ye More than likely is 8 X 1 metric.. DaleD <br type="_moz" /> |
RE: RCG 20cc question...
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Hay DaleD,
I did my second run set today with the RCG 20cc on my Ugly Stick. I'm using Turnigy 17x6 prop on a 80 deg. F. day @ sea level...humidity was 60%. I found a sweet spot at around 8100~8300 rpm, with a solid bark, smooth, sweet and rock solid. Top end came to 9000 rpm and a good idle @ 2000 rpm. It pulled like a bull with his tail on fire...this sweet model is going to have some serious vertical. When I ran the engine, the wing was on the model and the vibration was considerbly less. It still vibrated, but at around 8K it got real smooth. I needed to richen up the mixture on the high end...and I turned the forward carb set screw CCW -1/2 turn (the mixture screw nearest the prop). It seemed to lean a bit at high end and the instructions gave this set screw as the one to richen up the high end. It seemed to run better at full throttle, but 90% of the run time was on the sweet spot of about 8100rpm. I managed to get 13 minutes of engine run on 240cc fuel tank. I may install a 450cc fuel tank in the near future. Right now 10 minutes of flying is fine and what I set my Tx timer on. I was surprised I only lost 900 rpm with a 2" longer prop...and I've still two other types of 17x6 props to test run. The 17" prop is considerable more massive then the 15" prop and I'm using the RPM indicator I installed on the model to get my RPM figures. Let me know if my RPM figures are good and any additional information/help would be kindly accepted. The prop shaft is a 8mm x 1.25...that is the prop adapter size that fit on this engine and holding on my alum. spinner. Soft Landings Always, Bobby of Maui |
RE: RCG 20cc question...
Bob,
Looks like all left to do now is maiden that baby. She's definitely looking like a beauty with the power of a beast, you are going to be pleased with the performance. The 17x6 has always been reported to give optimal performance on 20cc sized engines. Make sure and try Vess and Falcon props they are known to be great. Regarding the fuel tank size, I am pretty confident you will be satisfied with the 8oz tank once the engine gets broken in as these engines are nothing like glow motors, they are very frugal on gas consumption. I am running a 6oz tank on my RCGF15 and have half tank to spare after a 10 minute flight. Make sure and tune the engine properly. Start at 1.5 to 2 turns out on both needles, warm the engine. Tune the high needle for max rpm and leave it for a lil to ensure stability. Reduce to idle for a bout a half minute and allow the engine to cool a bit then increase idle to about 3000rpm. Now tune the low needle for max rpm which should result in the engine being on the lean side. Reduce to idle again and allow to cool a bit then try to transition to WOT. You will most likely need to richen the low end to achieve smooth transition. How is your prop clearance? The GP Stick has quite a bit of clearance, the one I am building with the RCGF15 is fine with the 15x7 prop. Did you needed to install larger main wheels? Keep us posted on your plan for maiden. DaleD <br type="_moz" /> |
RE: RCG 20cc question...
Hi Guys
I have been flying this RCG (Aerovate) 20cc for about a month now, over 85 flights, 16 hours running now, spins a Menz 17/6 at 8000, pulls a 9.25 lbs Seagull edge out of a hover adequately - yes a a couple of dead sticks, the carb is a Chinese copy and the jettings are not as precise, plus cooling is an issue with small gas engines inside cowls - since smaller engines are more likely to run at higher rpm than larger displacement engines, they tend to get hot after 10 or so minutes of hard 3d flying - specially at high alpha or hover and harriers where cooling becomes an issue. I have now learnt to land after about 12 minutes of fun - fabulous engine, and I am expecting it to last many more flights http://www.youtube.com/watch?v=R8kgm...hannel&list=UL |
RE: RCG 20cc question...
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Hi Guys,
Some good news and some not so good news. My transmitter came back from Airtronics...so that is back on line. I also received a package from Tower with my wheels and tail wheel assy, along with two Master AirScrew S series 16x6 and 16x8 props. I installed the smaller tail wheel and it will work just fine. I had to recut my spinner and rebalance it again, to fit the Master AirScrew props. The 5" wheels will not work and to be honest it looked rediculas...but just to wide and big to go in without some new hardware. Then I went to charge the batteries for its first flight tomorrow...and my tail wagged...yep...wagged. It was loose...!#$%& ! So I pulled the safty wires off the tail, removed the covering and found my tail was only being held on with the top fuse balsa-and four safty wires on the tail. It was cracked all aournd both sides and the bottom. Now how on earth did that happen...? Folks...I don't have a clue...I didn't bang it...and only ran the engine...honest. The blue line on the pictures is where the crack formed on this model. The balsa was a bit soft on the bottom and on one side of the fuse. As you can see, it cracked where the servo rods exit the airframe in the tail. I also saw where one servo exit was miss cut and a small piece of balsa was placed in the repair. I've never had an Ugly Stick crack in this place...not in the several dozen I've built over the past 45 years. I'm almost ready to build me a new fuse...I've the lite ply and balsa on hand...and could get one built in a week or so. I will see how this flys tomorrow and holds up, but I'm ready to build a new fuse. I CA'd the whole mess together with slow cure, then placed 1/64" ply over the damaged area's to give added strength-then covered the ply with clear urethane for protection. It took four hours for the fix and to get the model back airworthy. The tail now is rock solid and no play at all. Its ready to fly now and I plan on giving the model its first flight tomorrow morning-weather permitting. This has been an experience for sure... Soft Landings Always, Bobby of Maui |
RE: RCG 20cc question...
Don't foget to re-check the center of gravity after that fix....
Good luck on the maiden, AV8TOR |
RE: RCG 20cc question...
Hay av8tor1977,
Yes I did rebalance the model and it was a bit nose heavy before...now its dead on. Thanks for the input, Bob |
RE: RCG 20cc question...
<span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; border-spacing: 0px; font-size: medium; "><span style="font-family: Arial, Verdana, sans-serif; font-size: 12px; ">Well done with the repair Bob. I would suggest that you forward the pictures of that crack/break to the manufacturer, at the very least they should be aware that the area could be a potential weak point on the model. Thanks for sharing, I will be sure to properly check the one I am building for any cracks or weaknesses.</span><br style="font-family: Arial, Verdana, sans-serif; font-size: 12px; " /><br style="font-family: Arial, Verdana, sans-serif; font-size: 12px; " /><span style="font-family: Arial, Verdana, sans-serif; font-size: 12px; ">I hope the weather with be kind enough to allow for a ,aiden this weekend. Did you ever consider a spinner prop nut as opposed to he spinner? For my UltraStick with RCGF15cc I installed a spinner prop nut from Tru Turn in order to reduce weight on the nose, work out great and looks better that the spinner in my opinion.</span><br style="font-family: Arial, Verdana, sans-serif; font-size: 12px; " /><br style="font-family: Arial, Verdana, sans-serif; font-size: 12px; " /><span style="font-family: Arial, Verdana, sans-serif; font-size: 12px; ">DaleD</span></span><br type="_moz" />
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RE: RCG 20cc question...
DaleD,
I did forward pictures and my fix to Tower Hobbies. I've done business with these folks for over 25 years and never a problem. I did not ask for a replacement, just sent them the pictures and the problem I found with my model. I am not sure if running the engine with out the wing caused the crack on the aft fuselage...or just a fluke with this airframe. I also modified the model and placed the rudder and elevator servo's aft in the model and also added my stab support wires. I'm not sure if this help create the problem or just a build issue with the guys who built the airframe for Tower. Either way, I'm still happy with the model and plan on flying it tomorrow. I was going to go fly this morning, but the winds were up and over 10kts (Maui R/C weather station). This Sping and Summer has been windy and not much flying due to the weather. Winters are best here on island for flying R/C and when we usually have our airshow. Soft Landings Always, Bobby of Maui |
RE: RCG 20cc question...
ORIGINAL: Bob Paris Hi Guys, Some good news and some not so good news. My transmitter came back from Airtronics...so that is back on line. I also received a package from Tower with my wheels and tail wheel assy, along with two Master AirScrew S series 16x6 and 16x8 props. I installed the smaller tail wheel and it will work just fine. I had to recut my spinner and rebalance it again, to fit the Master AirScrew props. The 5'' wheels will not work and to be honest it looked rediculas...but just to wide and big to go in without some new hardware. Then I went to charge the batteries for its first flight tomorrow...and my tail wagged...yep...wagged. It was loose...!#$%& ! So I pulled the safty wires off the tail, removed the covering and found my tail was only being held on with the top fuse balsa-and four safty wires on the tail. It was cracked all aournd both sides and the bottom. Now how on earth did that happen...? Folks...I don't have a clue...I didn't bang it...and only ran the engine...honest. The blue line on the pictures is where the crack formed on this model. The balsa was a bit soft on the bottom and on one side of the fuse. As you can see, it cracked where the servo rods exit the airframe in the tail. I also saw where one servo exit was miss cut and a small piece of balsa was placed in the repair. I've never had an Ugly Stick crack in this place...not in the several dozen I've built over the past 45 years. I'm almost ready to build me a new fuse...I've the lite ply and balsa on hand...and could get one built in a week or so. I will see how this flys tomorrow and holds up, but I'm ready to build a new fuse. I CA'd the whole mess together with slow cure, then placed 1/64'' ply over the damaged area's to give added strength-then covered the ply with clear urethane for protection. It took four hours for the fix and to get the model back airworthy. The tail now is rock solid and no play at all. Its ready to fly now and I plan on giving the model its first flight tomorrow morning-weather permitting. This has been an experience for sure... Soft Landings Always, Bobby of Maui Just a wild guess,glad you caught it before you took off. BCCHI |
RE: RCG 20cc question...
ORIGINAL: bcchi What is that big ding in the leading edge of the stab in second picture.This is probably what broke the tail loose.Must be pretty weak in the tail section. Just a wild guess,glad you caught it before you took off. BCCHI DaleD <br type="_moz" /> |
RE: RCG 20cc question...
Aloha DaleD,
I did take a look at that spot to on the stab and didn't think that was the cause. When I test ran the engines, I used a bungy cord around the rudder, then went under the forward part of the stab, aft to a pick into the ground. The bungy rubbed on that very spot and I saw it at the time. I believe the bungy cord may have created this part of the stab, but I really do not know for sure. I do know when I ran the engine the first time...with out the wing...the model shuck like crazy. I'm very surprised at the out put of this engine with a 17x6 prop...it does streach that bungy cord...a bunch more then I expected. But what ever the cause...it was noted and fixed prior to the first flight. I just hope the fix will do the job and I will check it out after the first flight and each flight there after. I received my Tx back from Airtronics and went to the flying field this morning...with the Ugly Stick. When I hooked up the wings...only one aileron worked. I left the Tx manual at home...and I was not able to fix the glitch, untill I got home at noon. It took a while, but I managed to get it all worked out (and I was about ready to shoot the flippen Tx by then), but by then my day was slowing down. I will fly this beast on Tuesday...if the wind gods are kind to us. I tried to buy a Spinner Prop Nut on line at Tower...but they are out of stock for the 8x1.25's I need. That was my first idea, but just wasn't able to find one anywhere to buy. Do you know who sells one I can buy ? I put on a Master AirScrew Symitar S-Series 16x8 prop. I've flown these props with my .60 and .90 glow engines and they are as good as APC and I think better...more robust in construction, with the same performance. I'll keep you posted on the first flight. Soft Landings Always, Bobby of Maui |
RE: RCG 20cc question...
ORIGINAL: Bob Paris Aloha DaleD, I did take a look at that spot to on the stab and didn't think that was the cause. When I test ran the engines, I used a bungy cord around the rudder, then went under the forward part of the stab, aft to a pick into the ground. The bungy rubbed on that very spot and I saw it at the time. I believe the bungy cord may have created this part of the stab, but I really do not know for sure. I do know when I ran the engine the first time...with out the wing...the model shuck like crazy. I'm very surprised at the out put of this engine with a 17x6 prop...it does streach that bungy cord...a bunch more then I expected. But what ever the cause...it was noted and fixed prior to the first flight. I just hope the fix will do the job and I will check it out after the first flight and each flight there after. I received my Tx back from Airtronics and went to the flying field this morning...with the Ugly Stick. When I hooked up the wings...only one aileron worked. I left the Tx manual at home...and I was not able to fix the glitch, untill I got home at noon. It took a while, but I managed to get it all worked out (and I was about ready to shoot the flippen Tx by then), but by then my day was slowing down. I will fly this beast on Tuesday...if the wind gods are kind to us. I tried to buy a Spinner Prop Nut on line at Tower...but they are out of stock for the 8x1.25's I need. That was my first idea, but just wasn't able to find one anywhere to buy. Do you know who sells one I can buy ? I put on a Master AirScrew Symitar S-Series 16x8 prop. I've flown these props with my .60 and .90 glow engines and they are as good as APC and I think better...more robust in construction, with the same performance. I'll keep you posted on the first flight. Soft Landings Always, Bobby of Maui DaleD <br type="_moz" /> |
RE: RCG 20cc question...
We are all so eagerly awaiting hearing from you re your maiden flight that I do hope the winds Gods smile on you favourably soon.
Karol |
RE: RCG 20cc question...
Hay DaleD,
Thanks for the information and I did order two 8mm x .125 prop nuts from True Turn this morning. I'm bitten at the bit to fly this model and tomorrow is the day. Thanks for everything, Bob |
RE: RCG 20cc question...
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Hi Guys,
The wind was up to 18kts, gusting to 27kts by noon. I will atempt to fly tomorrow, but not if its over 15kts. Just to much wind for a first flight and although this model has lots of power...I need to see how she flies, before I do so in higher winds. I received my landing gear from Tower...the landing gear came from the larger gas ugly stick ARF. The gear is a bit wider...but not to wide and I was able to change it out this afternoon. I have over 4" of prop clearence and this landing gear is a good bit stronger. I also reversed the aileron push rods, so the kwik link/spring is on the control horn...not the servo. This gave me more travel, without binding and 25% more flaps. There is little I can do to the model now, but fly her. Soft Landings Always, Bobby of Maui |
RE: RCG 20cc question...
Hi Guys,
I had my first through third flight this morning. I flew with a Xoar 17x6...rpm hit 8600 and it pulled hard, with a vertical that was trully impressive. Wow...flew great and the model handled so well, I did at least 20 touch and goes, in 10~18 kt. winds. With a 20.6 oz./sq. ft wing loading...it didn't have good penitration in the winds...but keeping a little power on, made simple work of the landing. DaleD, Thanks for your advice on tuning my engine. It purred and I did exactly what you told me to do... : ) It would idle so low...the wind blew the model backwards. I'm a little rich on the high end and plan to keep it so until I get a couple of gals of gas threw the engine. But with that Xoar prop...Wow...unbelievable. I never had a model that went up...like this one does...never...and I stuck G90's on .40 powered ugly sticks in my day. This engine starts so easily its amazing and its great on gas. I flew three 11 minute flights...and had better then 20% of the fuel left in my 240cc fuel tank. I believe after this engine breaks in properly...it may do better...but its really sweet. Again...thank you guys for all your advice and help, Bob |
RE: RCG 20cc question...
Now, apart from flying my own models, this is what I enjoy about the hobby. Following the progress of someone who is undertaking a new experiencing, in your case gas engines, right through to when they have a success maiden. I am happy for you Bob, congrats on a successfull build and maiden.
DaleD<br type="_moz" /> |
RE: RCG 20cc question...
Where might I find the rpm readout the bob of maui has on the top of the hatch?<br type="_moz" />
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RE: RCG 20cc question...
Hay plaurence,
There are several outlets that stock them and I got mine from Troy Built Models, but Tower sells it too. Bob |
RE: RCG 20cc question...
ORIGINAL: plaurence Where might I find the rpm readout the bob of maui has on the top of the hatch?<br type=''_moz'' /> |
RE: RCG 20cc question...
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Hi Guys,
I've now more then 20 flights on my Ugly Stick and I'm very impressed with the engine/airframe combination. It has more excess power then I had ever dreamed of and the model has great vertical. I did run into a couple of problems with the model, and one that got my attention yesterday was the wings forward hold down plywood. The wing is held down with two plastic screws on the rear of the wing and plywood on the leading edge of the wing, to hold the wing on to the fuse. As I stated the engine does vibrate a bit, and all the vibration has caused the forward wing plywood hold down, to ware a notch into that plywood piece. The fix for me will be thin brass sheet over and around the plywood notch and wing seating tape, placed on the first 1/3 of the wing seat forward part. I've yet to do the fix, but it will get done before I fly. The fus. plywood forward bulkhead seems to be ok and I plan on installing a nice aircraft grade plywood doubler here. I've got the engine purring and its quite strong. The 17 x 6 prop is an excellent choice, even though several men in our club are running 16 x 6 props on their DLE 20's. But I'm getting 8600 rpm with a Xoar 17 x 6 and I do want to keep the prop under 9K, I'll keep with the 17 x 6 props. I changed out my 6 oz. fuel tank to an 14 oz. RotoFlow tank. No reason to do so...the 6 oz. tank worked just fine but now I can fly for 20 minutes if needed, with reserve. My next scale bird wil be the 7F7 and I'll run two 20cc engines and these tanks. The bracing wires have come loose from the little clips I soldered on the tail feathers...I must have cold soldered them, but now hold firm. Great model...great help from all of you. Soft Landings Always, Bobby of Maui |
RE: RCG 20cc question...
Hay Guys,
50+ flights on the model now and the RGC 20 is purring. Solid idle...the idle is so low...the model will stand still with no wind. Good power and working on my 4th gallon of gas...now 32/1 Royal Purple mix. No further airframe issues and the fire wall is still solid, with no mods to the fire wall. I had a bunch of dead sticks learning how to tune the carb...but I managed to find the sweet spot... : ) Very happy with the engine and fuel system. I modified the fuel system a bit, buy adding a new fuel tank and a more direct plumbing feed to the carb now. I've needed to replace a few wood props but now use a 16/8 S Series Master Air Screw-2 blade. I found if you change prop brands and size...you will need to retune the carb...but once re-adjusted...its rock solid. I'm lucky the Ugly Stick is so easy to land dead stick...I managed to get at least 20 before I figured it out. But now it has a very solid idle and transition to full throttle. I just need to set up my throttle curve on my transmitter...it seems I go from a high idle to full power with 1/3 throttle stick movement. From 1/3 to 2/3 movement of the stick gets 80% of your power. Its livable and easy to deal with. Best two blade wood prop so far is a xzore 17x6. Best pull and vertical. I'm pulling the engine and installing my second RCG 20...to brake it in...then its on to a Top Flight P-47... .60~.90 size, w/RCG 20 cc. I've the kit, retracts and getting ready for a new project. Soft Landings Always, Bobby of Maui |
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