Contra Rotating Propeller Drive for f3a 2m Pattern Planes
#1026
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RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Jim, I think that Brenner is going to adjust the recommended use of grease based on the current versions sealing. I honestly think that you could go 150 flights, then I would disassemble, clean, lube and assemble. I really don't think the current units need to inject more grease every 50 flights.
#1027
RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
For what it's worth I'm not a fan of greasing through the shaft. The drive takes so little time to strip and there is great piece of mind in checking that all is OK. I also like to wipe out some of the old grease before adding the three balls of new stuff in the planet/ring gear spaces.
Malcolm
Malcolm
#1028
Thread Starter
RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Hey Jim,
4cc is probably a little too much grease to add if you're injecting it through the shaft.
I inject about 3cc in my Drive, and this is our current recommendation. 4cc is probably okay if you disassemble the Drive and wipe off the old grease, but after only fifty flights, it's probably safe to assume that there is at least 1cc of grease remaining in the Drive.
Brenner ...
4cc is probably a little too much grease to add if you're injecting it through the shaft.
I inject about 3cc in my Drive, and this is our current recommendation. 4cc is probably okay if you disassemble the Drive and wipe off the old grease, but after only fifty flights, it's probably safe to assume that there is at least 1cc of grease remaining in the Drive.
Brenner ...
#1030
RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Thanks for the comments guys. Next time I'll pull it apart to grease it and I can inspect it at the same time. I can then probably determine if it needs it every 50 or if it needs to be greased less often.
Jim O
Jim O
#1031
RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Just wondered what Contra operators are doing with their throttle curve?
With a 10.15:1 gearset and the 22 x 20/22 x 18 mixed prop setup the drive gives a pretty constant airspeed over much of the throttle range and I find I have a tendency to open the throttle rather more than is needed at some points in the pattern. Back in the single prop days I often used to flatten the centre part of the curve to give a "cruise" setting but found the steeply rising part of the curve after the plateau made the throttle very jumpy towards the top end.
I would like to be able to find the cruise point easily but still have a smooth transition to the higher power settings.
Any help greatly appreciated.
Malcolm
With a 10.15:1 gearset and the 22 x 20/22 x 18 mixed prop setup the drive gives a pretty constant airspeed over much of the throttle range and I find I have a tendency to open the throttle rather more than is needed at some points in the pattern. Back in the single prop days I often used to flatten the centre part of the curve to give a "cruise" setting but found the steeply rising part of the curve after the plateau made the throttle very jumpy towards the top end.
I would like to be able to find the cruise point easily but still have a smooth transition to the higher power settings.
Any help greatly appreciated.
Malcolm
#1032
Join Date: Jan 2004
Location: Galway, IRELAND
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RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
hi Malcolm, I have found recently that my Episode model is running faster in general than my Nuance was, so i have brought my throttle curve back by 5% at the mid point setting. So when at idle my throttle curve starts at approx 7%, at the mid point it is at 66% and at full throttle it is at 100%. I was running at 71% at the mid point. It means that for the same throttle stick movement the model is a little slower in the first half of the curve so I can keep up better.I have expo set also.
I am finding that it comes down lines a little quick so I am considering setting a brake for this. I have never used a brake before so I will have to experiment.
Has anyone set a brake using a JR radio and a YGE 90 speed controller?
I am finding that it comes down lines a little quick so I am considering setting a brake for this. I have never used a brake before so I will have to experiment.
Has anyone set a brake using a JR radio and a YGE 90 speed controller?
#1033
Thread Starter
RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Hey Paul,
The Contra works very well with an ESC Brake. I use about 30% with a soft start, and it's very effective. I turn it off with a high idle switch.
I like it for maneuvers that have downlines, and I like to use it for the square loop on a corner with half rolls. It lets me fly the last leg at the same speed as the other three legs. However, for maneuvers that have 45 degree downlines I use my high idle switch.
With a maneuver like the figure M you will find that you have to add throttle sooner as you start to push into the half loop or the brake will slow you down way too much.
The nice thing about using an ESC brake with a Contra Drive is that the reaction torque from each prop cancels the other, so the only negative torque that goes into the fuselage is the torque from the motor, which is reduced by the gear ratio of the gearbox, whereas with a single prop setup you get the full negative reaction torque from the prop going into the fuselage.
Negative torque is in the reverse direction from the reaction torque when the motor is under load.
Brenner ...
The Contra works very well with an ESC Brake. I use about 30% with a soft start, and it's very effective. I turn it off with a high idle switch.
I like it for maneuvers that have downlines, and I like to use it for the square loop on a corner with half rolls. It lets me fly the last leg at the same speed as the other three legs. However, for maneuvers that have 45 degree downlines I use my high idle switch.
With a maneuver like the figure M you will find that you have to add throttle sooner as you start to push into the half loop or the brake will slow you down way too much.
The nice thing about using an ESC brake with a Contra Drive is that the reaction torque from each prop cancels the other, so the only negative torque that goes into the fuselage is the torque from the motor, which is reduced by the gear ratio of the gearbox, whereas with a single prop setup you get the full negative reaction torque from the prop going into the fuselage.
Negative torque is in the reverse direction from the reaction torque when the motor is under load.
Brenner ...
#1034
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RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Which batteries used with kontra roteting ? I fly with NEU a 10.15:1 gearset and the 22 x 20/22 x 18 mixed prop setup currents 90A max in static. At last season bought 6 new packs Hyperion and all of them puffed, not well balancing,did 65-75 flights each,never over dicharge,like C-rating less than the stated.Used 25C 4600ma and 5000ma. I think what better to buy batteries for this season? If take again Hyperion, I think at least 35C to buy. Advise what batteries better to use for kontra roteting with NEU Gearbox can be changed to 10.36 to reduce current and the 22 x 20/22 x 18 mixed prop setup?
#1035
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RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Thanks Brenner for the info. To get 30% brake what percentage throttle input did you use to set it. Does this mean that the high idle is higher than that input value? Is it possible to notice the brake effect on the ground or can it only be felt in the air?
#1036
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RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Andre,
I am using same set up. Max amp static I got is 77 amp. In fly 68 amps. I measure with wattsup meter. Total energy used 3453 mah. I got only 24 flights so I am wondering why so much difference in the readings. Probably I got something wrong. I fly Masters AMA.
I am using same set up. Max amp static I got is 77 amp. In fly 68 amps. I measure with wattsup meter. Total energy used 3453 mah. I got only 24 flights so I am wondering why so much difference in the readings. Probably I got something wrong. I fly Masters AMA.
#1037
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RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
I am mesure with digital clamp meter 90A and hacker prog- box also show around 80A in static.In calm wether consumption 2500-2900ma for P-13,in strong wing max 4000ma for P-13,and 4200ma max for F-13, usually less,for F-13 always use 5000ma battery.Why this Hyperion battery puffed i don't know,because some chines battery from 2011 season still ok with same set up,but they make 15-20 flights with contra,and 70-100 flights with C-50 Hacker..Hyperion work wery well till 50 cycles.One battery 4600ma start puffed after 27 cycle.I am informed Hyperion,but they never see this situation,so many battery puffed.
#1038
Thread Starter
RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Hey Paul,
I've always used a programming card to set the brake, so I can't speak with experience about using the throttle stick.
I have my system set up so that low throttle (zero rpm ..) has the brake, at high idle the prop is turning so the speed on the downlines is higher.
You should be able to feel the effect of the brake when you turn the props by hand. What you want to do is set it so that the props never stop in the air, or on your landing approach.
Brenner ...
I've always used a programming card to set the brake, so I can't speak with experience about using the throttle stick.
I have my system set up so that low throttle (zero rpm ..) has the brake, at high idle the prop is turning so the speed on the downlines is higher.
You should be able to feel the effect of the brake when you turn the props by hand. What you want to do is set it so that the props never stop in the air, or on your landing approach.
Brenner ...
#1039
RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Hi Brenner, finally was able to get out this week with the new plane and the updated contra drive, everything working great and hope to fly in the Muncie contest in a week. By that time it may have 20 flights, as you know weather has been late this year compared to last year so it’s been difficult for our guys to get out.
Here are several pictures of the plane; all wood fuse with Andrew’s Proteus wing and stab, weighs 10.8 lbs with F3AU 5100 batteries. If I ever build another one I think the weight can be reduced some with some modifications to the framing.
Hope to see you in a week.
Dave Snow
Here are several pictures of the plane; all wood fuse with Andrew’s Proteus wing and stab, weighs 10.8 lbs with F3AU 5100 batteries. If I ever build another one I think the weight can be reduced some with some modifications to the framing.
Hope to see you in a week.
Dave Snow
#1040
Thread Starter
RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Hey Dave,
Your plane looks good. I look forward to seeing it fly.
I've resurrected my Wind S Pro with the Spark Evo wings you built for me, and it's flying better than the one I had last year, if that's possible. In my view, it's got to be the best plane I have ever flown.
I'm using a 22x20 rear prop with a 22x18 front prop, and with this combination I am pulling about 3200 mah out of my packs for a typical Masters flight flown at 100% ATV on the throttle. If I back off on the throttle , I use about 2800mah per flight. I am at 4990g using Zippy Compact 5800mah packs.
By the way, my calendar shows Muncie on the 18th and 19th, which is two weeks. This is the contest you are talking about right?
Brenner ...
Your plane looks good. I look forward to seeing it fly.
I've resurrected my Wind S Pro with the Spark Evo wings you built for me, and it's flying better than the one I had last year, if that's possible. In my view, it's got to be the best plane I have ever flown.
I'm using a 22x20 rear prop with a 22x18 front prop, and with this combination I am pulling about 3200 mah out of my packs for a typical Masters flight flown at 100% ATV on the throttle. If I back off on the throttle , I use about 2800mah per flight. I am at 4990g using Zippy Compact 5800mah packs.
By the way, my calendar shows Muncie on the 18th and 19th, which is two weeks. This is the contest you are talking about right?
Brenner ...
#1041
RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Great, 2 weeks I may have 30 flights then depending on the weather.
I have the 10.33 gear set in with the 22x22 back and 22x20 front for the initial flights, great power and speed in the air we have now but I have the ATV turned down to control the speed. My current setup is using 3700+mah for 8 min flights of P13 plus several F13 maneuvers, I'm going to try the other prop combos soon now that I have more time.
Dave Snow
I have the 10.33 gear set in with the 22x22 back and 22x20 front for the initial flights, great power and speed in the air we have now but I have the ATV turned down to control the speed. My current setup is using 3700+mah for 8 min flights of P13 plus several F13 maneuvers, I'm going to try the other prop combos soon now that I have more time.
Dave Snow
#1042
Thread Starter
RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Hey Dave,
The 22x22 rear with the 22x20 front is fast setup. If you want to back off on the speed, the 22x20 rear with the 22x18 front might be a better combinations for you. I actually think this combination is a better match with the Proteus wing you are using, because it looks very similar to my Spark Evo wing.
Brenner ...
The 22x22 rear with the 22x20 front is fast setup. If you want to back off on the speed, the 22x20 rear with the 22x18 front might be a better combinations for you. I actually think this combination is a better match with the Proteus wing you are using, because it looks very similar to my Spark Evo wing.
Brenner ...
#1043
My Feedback: (2)
RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Here is mine. This is the Gadious. Neu motor. 22x20 and 22x18. 10.15 gear ratio. I like prop combination and works well in windy conditions. This spring has been crazy and I still need to try in very calm conditions. I think is going to be OK. I got around 40 flights already. I finished installing the stab fences. I tried the rudder strips and liked more the stab fences.
#1044
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RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Hey Brenner, Dave,
Your planes are very light, all the more so as your packs have great capacity.
Here are some pictures of mine with Dave's wings and stab. I'm very happy with this configuration because spin, roll and snaps are way better.
It's more pleasant than with the stock integral, especially with wind.
I use 10.15:1 gear set and APC props for the moment 20.5X20.5 front and 20X22.5 rear. Consumption is between 2800 and 3500 for about 8 mn flight with 100% ATV with Neu F3A.
I wish you very good flights.
Your planes are very light, all the more so as your packs have great capacity.
Here are some pictures of mine with Dave's wings and stab. I'm very happy with this configuration because spin, roll and snaps are way better.
It's more pleasant than with the stock integral, especially with wind.
I use 10.15:1 gear set and APC props for the moment 20.5X20.5 front and 20X22.5 rear. Consumption is between 2800 and 3500 for about 8 mn flight with 100% ATV with Neu F3A.
I wish you very good flights.
#1045
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RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Hi Brenner
How does one go about getting one of the contra rotating drive systems? Are they sold through hobby shops or bought directly from you?
If the answer is contained in the 40 pages posted to date, my apologies in advance.
Regards
Burt
How does one go about getting one of the contra rotating drive systems? Are they sold through hobby shops or bought directly from you?
If the answer is contained in the 40 pages posted to date, my apologies in advance.
Regards
Burt
#1047
Thread Starter
RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Hey Burt,
I know that it's not totally clear how to get a Contra Drive, but you can get Drives directly from us. Just send me an email or PM through RCU. (email preferred because then I can respond with attachments ..)
Up until now we haven't done a lot in the way of promotion, primarily because we get more than enough business for us to handle just through word of mouth, but we are working to change this.
For instance, we are going to subcontract out making props, and also replace me as the the guy who assembles Drives with someone who should be a little more reliable. This will free up Mike and myself to focus on the stuff we do better, like product and process development.
Brenner ...
I know that it's not totally clear how to get a Contra Drive, but you can get Drives directly from us. Just send me an email or PM through RCU. (email preferred because then I can respond with attachments ..)
Up until now we haven't done a lot in the way of promotion, primarily because we get more than enough business for us to handle just through word of mouth, but we are working to change this.
For instance, we are going to subcontract out making props, and also replace me as the the guy who assembles Drives with someone who should be a little more reliable. This will free up Mike and myself to focus on the stuff we do better, like product and process development.
Brenner ...
#1049
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RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Hey claude,
I really don't feel like going back to YS with my Addiction for now. The Contra Drive is fabulous.
Vincent ...
I really don't feel like going back to YS with my Addiction for now. The Contra Drive is fabulous.
Vincent ...
#1050
RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Hello Vincent
Thank you for your answer. I like the design and the look of your new Integral. Do you know the weight of these scratch built wings
Claude
Thank you for your answer. I like the design and the look of your new Integral. Do you know the weight of these scratch built wings
Claude