sjhanc

My Feedback: (3)

Total capacity for the pack is 6600mah.

mark IX

My Feedback: (9)

What was your throttle position? I'm assuming around 1/2 to 3/4. Was there any room left to increase your speed. I'm planning on using a 200amp ESC and it looks like that will give me adequate margin. I suspect the motor was working a little harder due to the windy conditions. Sounds like the Zinger 24x16x4 prop may be too much for this motor and especially your ESC. Any plans to try that prop?

The other thing too, if your batt pack is 6600maH and your getting 4minutes of flt time, I may consider going to the 8000mah pack even it will push my AUW to around 26 lbs. These batteries weigh an additional 2 lbs. I'm worrired about the strength of the Spitfire wing.

Mark

sjhanc

My Feedback: (3)

I used full throttle 3 times during the flight, the first time about 20 seconds into the TO climb-out to insure adequate airspeed during the turn down wind after gear up for 20 seconds. the next 2 times were each on downwind turns for a few seconds, first time for the speed run. Most of the rest of the flight throttle input varied constantly 1/2 to 3/4. I plan to get a set of 20-16 blades to try next on the Zinger hub but it will be a couple of weeks before that happens. On Top of the World is having their big-bird spring meet March 28 so I am tuning it up for that using the Varioprop set at 19 inches pitch. I only flew 4 minutes to be sure of having enough battery for go-rounds in the windy conditions. Remaining battery capacity could have easily gone my usual 5 minutes with reserve. I don't know much about your Spit but have flown other peoples Spitfires several times in the past and they were always lighter handling than any other warbird I have flown. A zero might rival it but I have only seen them fly, never at the controls. My wing area is 1245 sq. in. so if you have more than that its good to go. I have modified The TF flap hinge to make it more forgiving at TO and LND speeds. I don't land slower, it is just more solid handling and the couple of times I got it slow enough to actually start to stall adding throttle recovered it instantly. With the stock flap hinging it would have dropped and damaged the gear and wing. You probably have split flaps so need to be careful to maintain a constant approach speed. Cut the throttle before touchdown and split flaps act like air brakes. I keep some high idle throttle on all the way till tail-drop to maintain rudder steering effectiveness. I makes for long run-outs but no damage and spectators all think that's the way it should be done. The full scale P 51 C pilot did the same thing when we landed. I thought the approach speed was high but he touched wheels about 800 feet after the runway beginning, the tail wheel coming down near 1000 feet from the other end. I have also cut into my wing from the bottom to reinforce the spars and lnd. gear mounts. If you are unsure of the wing strength you should do it also. The modified wing won't weigh much more but will be able to handle light bouncing and slow ground looping.

mark IX

My Feedback: (9)

SJ, if your are going to go with another set of Zinger blades, I would ask Zinger about their "Pro Series" blade. It's their newest blade shape, perhaps its thinner. Worth asking the question. Although its not the correct shape for the P-51.

Mark

sjhanc

My Feedback: (3)

I have used Zinger Pro blades many times before, The ZDZ 80RV I have seemed to perform very well with them. The first 26-10 I used on the Rimfire 65cc motor is a Pro-Zinger. It did not have enough pitch for it and I soon found that 26x14-16 inch props worked better as this motor likes to be lugged to get the best performance. This fact led me to try almost every high pitch prop available on this motor. Unfortunately manufacturers don't have a good selection of high pitch props. Most of what is available is the sizes that work best on the chain saw motors. Gas engines work best when operated at high rpms, needing a pitch that allows the motor to turn at a speed that matches their torque and horsepower curves. The Varioprop seems to match the electric requirements much better being tunable. Unfortunately, its relatively low max rpm limit (in the size I bought) means more experimenting. I want scale appearance and size and I made the wrong choice. The 16D hub, however can utilize several blade diameters and my testing points to the smaller blades with their higher design rpm limits. Blade sets are not too expensive so this hub will soon get a set. The 50cc motor will be a better match for the smaller diameter props.
The Zinger 22-16 4 blade I have is usable but will take some adjustments in the power package. All of my testing is aimed at a power package that will fly larger and heavier warbirds. I started out with the TF GS P 51 and a Fox 2.4CI turning 20x10 props and at that time thought it was a fun package to fly. It is true that this plane handles much nicer at a 21lb. gross weight. Increasing the weight even a little demands airframe upgrades, more weight and more power. If Zinger can supply electric blades for this hub it would go a long way toward making it better suited for electric flight. Now that I have found a way to bolt it on to the 65cc motor I plan to do more experimenting with it. An option I have considered is to adapt other brand blades to the Zinger hub. The best blades I have found are APC and XOAR electric, but you need to buy 2 or 4 props to cut up for this, it can get expensive quick. I would rather buy electric blade sets than make them myself. I am not against buying a big Hacker motor for a bigger plane but it will still need electric blades for efficiency and duration. The Zinger 4 blade I have is better suited to an 80-100cc gas motor with a big fuel tank.

sjhanc

My Feedback: (3)

mark IX
Note that I corrected the Brand name of the prop adapter nut I modified above. While looking through old packaging materials I found the correct information. These nuts are available from Tower Hobbies too.

mark IX

My Feedback: (9)

Thx for that update, sj. I was looking around in the internet last night and it seems that there are not a lot of 4 blade props in the diamerter that we are talking about with a pitch greater than 16. The Vario prop has an advantage of having an adjustable pitch. I may have missed this in your write up above, but did you request a special thread for the R65 thread, from Vario? I did not see a M10x1.25mm nut on their website.

Mark

sjhanc

My Feedback: (3)

I just gave the motor info to the hobby dealer and he ordered the correct parts, you need the nut, washer and a spacer sleeve. The R 65 is 10mm and the Varioprop is 12mm.

spitfire66

My painting a couple weeks ago was a success. It couldn't have been any easier. I'm just waiting a couple weeks for the paint to dry and my schedule to allow me to paint the white invasion stripes and the nose of the cowling and spinner. I now have the graphics from Callie Graphics. I have some custom nose art that a friend and I came up with.

fujiman

My Feedback: (133)

Very nice work!!!!!!!!!

CRJDriver

My Feedback: (57)

She's looking great spitfire!

mark IX

My Feedback: (9)

SJ, any new data with any new props and the R65 setup? I am thinking about buying the Biela prop as you did. There is not a lot of choice out there for adj pitch props, unfortunately.

Mark

sjhanc

My Feedback: (3)

I set the pitch back to 18 inches and flew at On top of the world Saturday. I got 3 good flights in but the last landing didn't go well. Trying to get it down in the strong, gusty crosswinds that came up as I was on the downwind approach ended with a bounce, noseover and 3 broken blades. No damage to the wings or gear but embarrassing. 18 inches is the best for my combination. Will post performance data later.

mark IX

My Feedback: (9)

Sorry to hear that SJ. It happens to all of us.

Mark

sjhanc

My Feedback: (3)

According to data downloaded from the Castle 160HVF;
Highest current draw-115amps, 4842watts on one of the take-offs.
top rpm-6645 full throttle= 120mph at 18inch pitch.
average cruise current draw=70amps.
TF GS P 51B at 29.5lbs, 12s 2p 6400mah, 6-4 cell 3200mah 35c LIPO batteries.
Varioprop 22.6 4 blade set at 18 inch pitch, last landing nose-over broke 3 blades, 1 blade ok. Hub ok. Break just 1 blade on the Biela and you need the whole thing.
Duration=5-6 minutes using 1600-1900mah per 3200mah capacity cell.
Battery temps after flight-barely warm. Could be recharged immediately.
Motor temp-115-120f, ambient temp 65-70 degrees F. Winds NW 10-30mph runway to the west. Gusty and turbulent at times although most flights ended well.
Most pilots headed into the wind for to and ldg.
In defense of the Carbon Biela, they usually don't break, they bend the crankshaft. Somethin's got to give. My ZDZ 80 has a screw-in prop-bolt that is replaceable- I changed a few. My Fox had to have a new crank and the DA 50 had to have a new crank and prop bolt. Wood or carbon reinforced plastic blades give first and no crank damage.
Maneuvers were rolls, low passes, Victory rolls and a big loop, no hard climbs.

sjhanc

My Feedback: (3)

mark IX,
Information I just got from another pilot convinces me that the E-Flite Power 360 is a better choice of motor at a similar price. This motor has a large rear bearing to carry the rear of the out-runner case. I have had a lot of vibration issues with the RF 65cc that I can reduce but not eliminate, it needs another bearing in it.

sjhanc

My Feedback: (3)

Another issue with the P-360 is its 4 bolt hub may not be compatible with the Varioprop.

mark IX

My Feedback: (9)

SJ, yes, I read that about the EFlite 360 as well. More learning, that's good. How are the bearings in your R65? Maybe they are causing the vibe issues. I just bought a new R65, however, and I still plan to use it with the props we have been discussing. Did the thread say what Vario prop size he was using with the P-360, I may have missed it.

Mark

sjhanc

My Feedback: (3)

I have just put the second set of bearings and a new shaft in the R 65. The bearing wear is the result of the outrunner bell hitting the steel plate stack for the motor windings and ringing. It is not as bad as when it was new but seems to be impossible to completely eliminate. I have passed on my mods. to other pilots having this issue but don't have any feedback on success. It doesn't do a lot of damage, it is just annoying and it shouldn't have this problem. Eventually, if the bell is rung often enough, the magnets are going to loosen and destroy the motor. My planes have a lot of value to me so if a part doesn't measure up and I can't work it out I switch brands. It is a shame because it is a powerhouse motor at a good price. Maybe there are only a small percentage of faulty motors but I won't buy another one for the next plane. I had this issue with the R50 motor but was able to fix it and have about 80 flights on it since. The R50 has a shorter length outrunner bell so the vibration harmonic is high enough that the vibration does not occur now. I have run the R 50 up to 10,000 rpm with out a hint of vibration or noise(no prop). The R65 does its thing at low rpm during take off then is quiet for the flight. And prop selection or balance makes no difference.

sjhanc

My Feedback: (3)

I am going to order a set of 20 inch blades for the Varioprop hub and switch back to the R 50 motor for the TF P 51 B. I have found that by eliminating a couple of the more power demanding maneuvers I can safely stretch duration out a couple of minutes. This gives me 7 minutes with 2 landing approaches.

sjhanc

My Feedback: (3)

On the other pilot's H 9 with P 360, he is using the same varioprop and blades I am but modified the P 360 prop hub. He posted the description in today's thread on the H 9 60cc build thread. He says that the larger 32i Varioprop can be fitted with an optional 4 bolt hub adapter that Varioprop supplies.

mark IX

My Feedback: (9)

That's good info SJ. I haven't run my R65 yet. I thought it already had 3 bearings in it according to the manufacturer. For now I am going to try the R65 when I'm ready, but will keep an eye out on the experience with the P360. I really don't want to reduce the prop to 20" diameter. If I can get 80-90mph speed with 5-6 min flt time, I'll be happy. I think this may be possible since my model is 3-4 lbs lighter than your P-51. I'm still considering the 8000maH batt packs. Right now I'm finishing the Spit build but I'm anxious to start some bench testing with these motors and props

BTW, were you able to use the stock R65 prop nut and washer to mount the Vario prop to the R65 motor, or did you need a special nut there as well. Any pics?

Thanx, Mark

sjhanc

My Feedback: (3)

The R 65 does have 3 bearings- 2 small bearings behind the prop driver and a slightly larger bearing at the back of the prop shaft. The magnet bell (rotor) is unsupported at the back where it has tight clearance between it and the steel plate stack (stator) the windings are wrapped around. The slightest disturbance causes that end to bounce off the stator and ring. If the interference is as bad as mine was when new, the resulting noise and vibration can be heard when the plane is 800 feet away. The vibration always occurred at 1/4-1/3 throttle and wears out the bearings quickly. If yours makes this noise I recommend you return it for another. I have tried replacing parts but it (the noise) always comes back. If nothing is done about the problem the magnets may get knocked loose destroying the motor and maybe the plane. Other motors I have looked at (Hacker, AXI, P 360 all have a large concentric bearing seated on the rear motor case and the rotor is pressed over this bearing. The rear shaft bearing is smaller and fits inside the stator case that is bolted to the rear motor case. The actual mounting plate is bolted to the rear motor case. So there could be as many as 4 bearings in the more expensive motors. This noise-vibration is exaggerated when the motor is used for 3D maneuvers.

mark IX

My Feedback: (9)

SJ, Do you think it is possible to open that clearance up?

Mark

sjhanc

My Feedback: (3)

The only way is to grind the steel stator or the magnets themselves. Opening the clearance could reduce power. Grinding the magnets will change the rotor balance. The real fix is another bearing to support the open end of the rotor. This is not something that the average modeler could do (bearing).