So am building my 3rd old time quaker only this ones a "flash 65 span, am guessing the AUW will be under 2lbs
thought about going with a small F/S then again geared electric might be the way to go, so am curious what suggestions would be for that power source.

I built a Quaker 54 with an eFlite Park 450. That is WAY overpowered. I reduced the throttle to limit it to 200 Watts and it flies fine. Weighs about 1.8lbs with a 3s 1300mA battery. It makes the perfect small field flyer.

First off if you go electric forget about gears. Needless drag to fight when there are so many outrunner brushless options that would work just fine and be easier to mount and don't have the power lost to the friction of the extra bearings and gears. Not to mention no gear noise.

Now unless you want it to fly like a modern jet fighter you really only need around 60 to 70 watts per lb. And for casual flying that might even be a little strong. And if you can keep it down to around 2 lbs this suggest that you only need a motor that is capable of around 150 watts and prop it for a bit less so it's not straining. An E-Flite or Turnigy Park 450 would certainly be one such option since they are roughly a 200 watt motor.

A model I'm playing around with trimming at the moment is running a motor that I tested at 165 to 170 watts. And that puts it roughly in the Park 450 power range. The model is 41oz or 2.56lb. So that works out to 65'ish watts per lb. And it still can easily climb at around 45° with good speed at full throttle and easily takes off and climbs out in a fairly scale like manner at only half throttle or likely somewhere around 40 watts/lb.

The motor that was in it previously was putting out just over 250 watts. So around 100 watts per lb. When I tried it at full throttle on a couple of flights it would pretty much instantly nose up and climb nearly vertical at a pretty fair turn of speed. Hardly scale like for a Stinson.....

So it all depends on what you want. But my suggestion would be to look for somewhat lower Kv value motors so you can turn a fairly larger sort of prop to stay in keeping with the style of model. Pick a motor that is OK with up to around 180 to 200 watts and prop it to run around 150. And on a 3S pack that means you're only looking at around 13 to 14 amps even for takeoff. A walk in the park for even fairly small capacity packs which would further aid with holding down the weight. You'd likely want to run something around a 1300 to 1500mah to get a good flight time of up around 10 minutes? But those are really light these days. And there would be lots available to run just the radio if you can find a thermal or two.

Yep. 300 Watts into my Park 450 sent my Quaker 54 vertical. 200 Watts climbs nicely. 250 to 300 will be plenty for a 65” Quaker.

So am taking a turnigy 3536/8T 420 W off a 50 span lectric Zephyr and going with that for power, gonna have to build a box extending out from the firewall to fit the motor so think were on track, gonna start off with a 10x6 1500 3S and hope it balances.

The model itself weights in @ 24 oz , so am assuming will come up with around a 32 oz. AUW

I supposed that if you have it you might as well use it. But the motor itself is up around 3.7 oz. to hit your 32oz goal you only have 8oz of "room" for the radio gear, flight battery, the motor and the ESC, Given that 180 to 200 watts at full power would be easily enough why not use a lighter 2oz motor? Or does it need the nose weight anyway?

Originally Posted by BMatthews

I supposed that if you have it you might as well use it. But the motor itself is up around 3.7 oz. to hit your 32oz goal you only have 8oz of "room" for the radio gear, flight battery, the motor and the ESC, Given that 180 to 200 watts at full power would be easily enough why not use a lighter 2oz motor? Or does it need the nose weight anyway?

haven't mounted the motor or bat so that will be the deciding factor but can always play around to get the CG right, servos/ESC weigh practically nothing

am using that motor cuzz I had it and it fits the bill besides I like to fly upwind a lot so that will be plenty power from a "bench flight perspective

Spec.
Battery: 2~4 Cell /7.4~14.8V
RPM: 1000kv
Max current: 30A
No load current: 1.7A
Max power: 430W
Internal resistance: 0.052 ohm
Weight: 102g (including connectors)
Diameter of shaft: 5mm
Dimensions: 35x36m
Prop size: 7.4V/11x5 14.8V/10x6
Max thrust: 1160g
 

I'd suggest that you end up proping it to hold the max power at more like 200. Why? Well, I recently went through flying a model that was "generously" over powered at around 130 watts/lb. I found that I could not use more than the first 1/3 power without making it look like a jet fighter. And since it's a Stinson Voyager that would have been a little out of character.... But the real issue wasn't that it was over powered. Instead it was how it compressed the usable portion of the throttle stick travel into a small range of travel. This made it quite hard to make small cruise power changes because it was always wanting to try to sit on top of one of the "clicks" of the lever.

I've since re-motored it to a combo that not only corrected a bad nose heavy situation but also reduced the power to more like 60 watts/lb. It still takes off and climbs in a nice scale like manner at something like 5/8 throttle. But setting the throttle for cruise and making small adjustments is now far more pleasant.

Anyway I suspect you'll run into this same thing if you're at all near the full 430 watts on a 2 point something lb model. Just something to keep in mind.

As purely a side note for general interest a 65 inch span Quaker would likely have been equipped with something like an Ohlsson and Rice .29 sparkie back in the day. I've seen a bunch of similar size model and engine combinations fly over my time in free flight and thanks to flying with the SAM 8 guys out of Seattle. Now SAM rules specified a flying weight that provides a minimum of 8oz/sq-ft for free flight. So the model weight would be more like 2.5 lbs. And from how I've seen such models fly I'd say that an equivalent power level in electric would be in the 60 to 65 watts/lb range.

Examples of later old timers such as a Playboy running with a Super Cyke (a later and more powerful engine) would be more in the 80 to 100 watts /lb range. As in they COULD go dead vertical but it was clawing its way uphill at a crawl. Typically a better trim is to go uphill at around a 70° angle in a spiral climb at a little over the gliding speed.

Originally Posted by BMatthews

I'd suggest that you end up proping it to hold the max power at more like 200. Why? Well, I recently went through flying a model that was "generously" over powered at around 130 watts/lb. I found that I could not use more than the first 1/3 power without making it look like a jet fighter. And since it's a Stinson Voyager that would have been a little out of character.... But the real issue wasn't that it was over powered. Instead it was how it compressed the usable portion of the throttle stick travel into a small range of travel. This made it quite hard to make small cruise power changes because it was always wanting to try to sit on top of one of the "clicks" of the lever.

I've since re-motored it to a combo that not only corrected a bad nose heavy situation but also reduced the power to more like 60 watts/lb. It still takes off and climbs in a nice scale like manner at something like 5/8 throttle. But setting the throttle for cruise and making small adjustments is now far more pleasant.

Anyway I suspect you'll run into this same thing if you're at all near the full 430 watts on a 2 point something lb model. Just something to keep in mind.

As purely a side note for general interest a 65 inch span Quaker would likely have been equipped with something like an Ohlsson and Rice .29 sparkie back in the day. I've seen a bunch of similar size model and engine combinations fly over my time in free flight and thanks to flying with the SAM 8 guys out of Seattle. Now SAM rules specified a flying weight that provides a minimum of 8oz/sq-ft for free flight. So the model weight would be more like 2.5 lbs. And from how I've seen such models fly I'd say that an equivalent power level in electric would be in the 60 to 65 watts/lb range.

Examples of later old timers such as a Playboy running with a Super Cyke (a later and more powerful engine) would be more in the 80 to 100 watts /lb range. As in they COULD go dead vertical but it was clawing its way uphill at a crawl. Typically a better trim is to go uphill at around a 70° angle in a spiral climb at a little over the gliding speed.

thnx for the suggestion and from yrs of experience is always better to be over powered than under powered " just saying........... I'm an aggressive flyer and want the power to be their when needed, that's why I'm over powering the model

Have had 2 full size quakers that used that had saito 30s that were compatible for general flying around however due to my aggressive "wind flying" were under powered........will be back with flight results

We all have our ways. None are right or wrong, just different. I will say that there's not doubt that the results will be highly entertaining ! ! ! ! If we happen to share the same field I'd love to see it.

A full size Quaker on a Saito .30 four stroke would have been pretty darn under powered by even MY standards. You're talking "uphill glide angle" when at full throttle or pretty close to it I suspect.

My 84" full size Quaker has a OS 48 on it and flies great.

Originally Posted by BMatthews

We all have our ways. None are right or wrong, just different. I will say that there's not doubt that the results will be highly entertaining ! ! ! ! If we happen to share the same field I'd love to see it.

A full size Quaker on a Saito .30 four stroke would have been pretty darn under powered by even MY standards. You're talking "uphill glide angle" when at full throttle or pretty close to it I suspect.

Last time I was in BC was for UC speed meet in the 80s rice mill road with chris sacket and the bunch havent been that way since, maybe will see ya around

Chris hung up the speed models and is now a central figure in our small but dedicated local free flight group.

Just back from the field with success only problem was using a 3s 2200 so got about 15 min flite time at 2/3 throttle, other than that everything went well as expected.

The CG was a bit aft from where its spose to be but a bigger bat will fix that
would still like to have another full size just for kix

Congratulations!!