Paul Walkers B17 going electric?? Are the rumors true?

[Paul Taylor]

I hear Paul’s B-17 is now electric??

If so what is the setup?

Retracts ?

Should be much easier to start. 😎

[Gary Dowler]

The rumors are true.  Seen it in person with my very own eyes! LOL!

[Ken Culbertson]

I had enough trouble wiring a twin even with Bob Hunt's help.  I can't wait to see how he wires a quad!

Ken

[Paul Walker]

In fact I have flown 3 different electric powered 4 motor planes.
Both original B-17's have flown electric and one smaller 720 in^2 test plane to gather data for the new bomber that is now under construction.
The new one will be 700 in^2. The plans are 95% done. Critical parts have already been built. All the info is in a spreadsheet, as in every piece of wood, control systems  landing gear motors, batteries etc. This is to check the weight and balance prior to construction..one of the critical parts is the vertical tail. 12 grams were estimated for the entire vertical and rudder. It came in at 13 grams. The HT was also close to the estimate as well. That was close enough for me to start overall construction.

There is no schedule for this one. It will fly only when fully ready. Hopefully that wil be sometime in later 2025.

[Paul Taylor]

In fact I have flown 3 different electric powered 4 motor planes.
Both original B-17's have flown electric and one smaller 720 in^2 test plane to gather data for the new bomber that is now under construction.
The new one will be 700 in^2. The plans are 95% done. Critical parts have already been built. All the info is in a spreadsheet, as in every piece of wood, control systems  landing gear motors, batteries etc. This is to check the weight and balance prior to construction..one of the critical parts is the vertical tail. 12 grams were estimated for the entire vertical and rudder. It came in at 13 grams. The HT was also close to the estimate as well. That was close enough for me to start overall construction.

There is no schedule for this one. It will fly only when fully ready. Hopefully that wil be sometime in later 2025.

Cool Beans!!!
At least show us pictures for those that enjoy B-17’s.
What plane are you going to represent.
The Memphis Belle would be a good choice. 😉

[Paul Walker]

Have not decided which to use as the basis for the paint.

Am leaning towards a natural aluminum model.

Time and weight will tell!

[Lauri Malila]

What is the target weight, Paul? L

[Matt Neumann]

Have not decided which to use as the basis for the paint.

Am leaning towards a natural aluminum model.

Time and weight will tell!

I remember us talking a bit a couple of years ago on this subject.  You were working on getting the weight down and was thinking of a C or D model to try and save weight.  So I am now curious, which model? 

[Paul Walker]

It will be an E/F version.

The target weight is 70 oz (1980g)

[Paul Walker]

I had enough trouble wiring a twin even with Bob Hunt's help.  I can't wait to see how he wires a quad!

Ken

The basics of the wiring is not the issue. The second one was wired based on the take apart "pieces"
 There are two esc's attached to the inboard wing half, two on the outboard half. The arming plug and switch are mounted on the aft section of the fuselage and the battery in the forward fuselage section. All these pieces have to come apart for transport, thus....there are a lot of connectors in that system. Also, there is a single timer that runs the motors. Several Y conne tors that also have connectors. Since this was a retrofit, space is limited.  That arrangement was a test to verify functionality and "ease" of use. The one pain with this is having to change settings in the esc's. Since they are all connected to one timer and a single on/off switch the switches on three esc's were removed and a connector in its place. The other side of the connector can be attached to an on/off switch. This is necessary for adjusting each timer. Change one, move switch to the next, change settings until all are changed. It tried it the simple way and it didn't work....

The new one will be a one piece plane so many of these connectors are not necessary, thus simplifying things

[Ken Culbertson]

The basics of the wiring is not the issue. The second one was wired based on the take apart "pieces"
 There are two esc's attached to the inboard wing half, two on the outboard half. The arming plug and switch are mounted on the aft section of the fuselage and the battery in the forward fuselage section. All these pieces have to come apart for transport, thus....there are a lot of connectors in that system. Also, there is a single timer that runs the motors. Several Y conne tors that also have connectors. Since this was a retrofit, space is limited.  That arrangement was a test to verify functionality and "ease" of use. The one pain with this is having to change settings in the esc's. Since they are all connected to one timer and a single on/off switch the switches on three esc's were removed and a connector in its place. The other side of the connector can be attached to an on/off switch. This is necessary for adjusting each timer. Change one, move switch to the next, change settings until all are changed. It tried it the simple way and it didn't work....

The new one will be a one piece plane so many of these connectors are not necessary, thus simplifying things

Thanks for the explanation.  I have resorted to toggle switching the ESC2/Timer port on the Fiorotti and it took the better part of a day to get all of it right without any smoke on a twin.  I can only imagine how long it took to figure all that out on a quad.  Sometimes I miss the simplicity of setting the needle valve.....but not for long.

Ken

[Doug Moon]

The basics of the wiring is not the issue. The second one was wired based on the take apart "pieces"
 There are two esc's attached to the inboard wing half, two on the outboard half. The arming plug and switch are mounted on the aft section of the fuselage and the battery in the forward fuselage section. All these pieces have to come apart for transport, thus....there are a lot of connectors in that system. Also, there is a single timer that runs the motors. Several Y conne tors that also have connectors. Since this was a retrofit, space is limited.  That arrangement was a test to verify functionality and "ease" of use. The one pain with this is having to change settings in the esc's. Since they are all connected to one timer and a single on/off switch the switches on three esc's were removed and a connector in its place. The other side of the connector can be attached to an on/off switch. This is necessary for adjusting each timer. Change one, move switch to the next, change settings until all are changed. It tried it the simple way and it didn't work....

The new one will be a one piece plane so many of these connectors are not necessary, thus simplifying things

This will be most excellent! Hopefully pics will be available along the way.  Cant wait to see it.

[Dan McEntee]

It will be an E/F version.

The target weight is 70 oz (1980g)

  The B-17 has been modeled a lot through the years, mostly R/C but I would hazard a guess that you have the record for C/L  variants!! When ever I think of the B-17 I always think of the earlier versions, the prototype 299 through the D with what some call the Shark Rudder with no dorsal fin. I think almost all of those were natural aluminum polished out with colorful red, white and blue national markings. I guess I fell in love with that by watching the movie "Air Force" that follows a crew delivering one of the B-17s that flew into Hawaii and Peral Harbor in the middle of the attack. Great cast and great shots in it. The subject plane was an early B-17C I think, and was in olive drab but typical prewar national markings. I loved the part where they invented the tail gunner position by sawing off the tail cone and installing a single .30 caliber machine gun I think. When I first saw the article on the Mathis Excalibur and saw that rudder, the Boeing 299 was the first thing I thought of!!  Their isn't much structure back there, and very little side area which raises some plus and minus questions on building that version. But I'll give my vote for a polished aluminum E/F model!
  Type at you later,
  Dan McEntee

[dave siegler]

What direction are the motors turning?  All the same way? 

all the same speed?  Do the inboards run a little faster? 

[Walter Hicks]

Pat Johnston has a profile B-17 electric !

[Paul Walker]

What direction are the motors turning?  All the same way? 

all the same speed?  Do the inboards run a little faster?

Every test I have run so far had them all turning the same way. This new one will do the same to start.

As far as motor speed, I would not do what you suggested. It is about the last thing it would need. If anything motors 2 and 3 might be the same speed in level flight but power up more in maneuvers than 1 and 4 will.

[dave siegler]

Every test I have run so far had them all turning the same way. This new one will do the same to start.

As far as motor speed, I would not do what you suggested. It is about the last thing it would need. If anything motors 2 and 3 might be the same speed in level flight but power up more in maneuvers than 1 and 4 will.

OK great.  I am developing a timer/ controller with a MEMS sensor.  iIt adds power in maneuvers and turns off the power if you nose over or crash.    I may try a multi-engine this winter. 

[Paul Walker]

OK great.  I am developing a timer/ controller with a MEMS sensor.  iIt adds power in maneuvers and turns off the power if you nose over or crash.    I may try a multi-engine this winter.

Multi motors are fun to work with. Hope you have as much fun as I have have!

[Paul Taylor]

Some of us are still waiting on pictures. 😉


Or a video. 👍🏼

[Paul Walker]

Some of us are still waiting on pictures. 😉


Or a video. 👍🏼

Not much to see currently. Just a VT, HT and ribs cut.

[Paul Taylor]

Not much to see currently. Just a VT, HT and ribs cut.

👍🏼

Getter-Dunn 🤣

[Matt Neumann]

Not much to see currently. Just a VT, HT and ribs cut.

I personally would be interested to see how you make the fuselage and then your alignment jigs.  Normal people have to only align one engine.  You get to align 4 on the same plane.  Be interested to see that jig.  I am going to assume molded fuselage but there seems to be many different ways to molding these days.  The fuselage is not really standard shape.

[M Spencer]

Pictures'd be good .

[Paul Walker]

Update. Wing done. Next step, add the four nacelles.
Not hard, just a bit tedious.

Big hole in front will be the ESC bay.

[Paul Taylor]

Memphis Belle is looking good. 🤣😂🤣😎

[Ken Culbertson]

Paul, what motors are you using and do you have tunnels built into the wing for motor wires.  I am guessing you have nearly 10' of wire in that wing.  What gauge?

Ken

[Paul Walker]

Paul, what motors are you using and do you have tunnels built into the wing for motor wires.  I am guessing you have nearly 10' of wire in that wing.  What gauge?

Ken

The motors will be BA 2310-1220.

There are aluminum tubes from the LE cutout to each nacelle. They can be seen on the photo where they exit the LE sheeting.
The wire will be either 16 or 18 gage. I am not home right now or I would go look at the test plane.
 

[M Spencer]

" The wire will be either 16 or 18 gage. "

Some P & T wire used for a rear mounted battery , in the mighty Cortina ! was ALUMINIUM .
The Thought Occured , Aluminium Wire Would Be Lighter . and as theres a bit of it there ,
it could be appreciable . Might have to alumn. Braze the fittings . Low Temp rods .

This'd keep the cows out ! ( theres other stuff on the picture thing .) https://www.amazon.com.au/GearIT-Gauge-Wire-100ft-Each/dp/B095C3GJ3H?th=1


Now , If you used it for LINES , the plane'd be a lot lighter .     

[Matt Neumann]

The motors will be BA 2310-1220.

1220 kV?  Wow seems high from what I normally see.  What props are you using and how big is the battery and how many cells?

[Paul Walker]

The motors will be BA 2310-1220.

1220 kV?  Wow seems high from what I normally see.  What props are you using and how big is the battery and how many cells?

There are limitations in this. The first one is the Jeti Pro 22 ESC's. They can only tolerate 17 volts. This limits the battery to a 4S.
With the need to power up in maneuvers, the KV needed is arou f 1200, thus the ones I have selected.
In the new B-17-3, I will use at 4S4500 45 amp battery. I have test flown a test plane and verified that this will work.  The old big bomber likely will require motors of at least 1500 KV as the weight will require more rpm in maneuvers.

As far as props, the new one should use APC E 8*6. They too have been tested. That test plane weighed 85 ounces, flew at 5.9 laps and still did maneuvers!  The big bomber uses APC E 9*6 props. They both sound really cool as they are so balanced in level flight.

More fun to come!

[Steve Thompson]

It may be trade-secret information, but curious how the RPM is set for 4 engines.

Faster on the inside wing?  All the same?  All close but intentionally slightly different?

Is resonance significantly less of a concern with electric vs reciprocating and disregarded?

If I am peaking behind Oz's curtain, an entertaining answer is fine.

[Dan McEntee]

There are limitations in this. The first one is the Jeti Pro 22 ESC's. They can only tolerate 17 volts. This limits the battery to a 4S.
With the need to power up in maneuvers, the KV needed is arou f 1200, thus the ones I have selected.
In the new B-17-3, I will use at 4S4500 45 amp battery. I have test flown a test plane and verified that this will work.  The old big bomber likely will require motors of at least 1500 KV as the weight will require more rpm in maneuvers.

As far as props, the new one should use APC E 8*6. They too have been tested. That test plane weighed 85 ounces, flew at 5.9 laps and still did maneuvers!  The big bomber uses APC E 9*6 props. They both sound really cool as they are so balanced in level flight.

More fun to come!

    So, it will be a single battery and single speed controller for all four motors? That's what I was curious about. I'm not sure how to ask the next question?? The number 1 and the number 4 motors are fairly far apart, and flying different distances around the circle. When doing maneuvers, the airplane will try to wind up in any wind, so how does that affect those two motors, which I think are loading and unloading at different rates? One might be close to wind milling and the other loaded and pulling, even just by a little bit? In your test flying, that didn't cause any kind of funny yawing effect/

  Type at you later,
   Dan McEntee

[Paul Walker]

Nope. Four ESC's are required. One for each motor

Each can be adjusted independently.  Will eventually learn if that will help OR NOT.

Multiple motors can NOT run on one ESC, unfortunately.

BTW, on the first IC bomber engines 1 and 4 used 1.0 ounces of fuel, engine 2 used 1.5 ounces and engine 3 used 2.0 ounces. That is a pretty significant difference. Yes, I moved the engines around to different locations to verify it was not an engine issue.

So 1 and 4 seem to do the least amount of work!

[Dan McEntee]

Nope. Four ESC's are required. One for each motor

Each can be adjusted independently.  Will eventually learn if that will help OR NOT.

Multiple motors can NOT run on one ESC, unfortunately.

BTW, on the first IC bomber engines 1 and 4 used 1.0 ounces of fuel, engine 2 used 1.5 ounces and engine 4 used 2.0 ounces. That is a pretty significant difference. Yes, I moved the engines around to different locations to verify it was not an engine issue.

So 1 and 4 seem to do the least amount of work!

      I think you have a typo. You mean that #3 used 2 ounces of fuel? That is interesting!!
 
   Type at you later,
     Dan McEntee

[Matt Neumann]

      I think you have a typo. You mean that #3 used 2 ounces of fuel? That is interesting!!
 
   Type at you later,
     Dan McEntee

I agree with the typo.  What would be interesting but a bit difficult (and a bit expensive) would be to have 4 different battery packs.  One for each motor and see what the usage is per motor location. 

[Paul Walker]

I agree with the typo.  What would be interesting but a bit difficult (and a bit expensive) would be to have 4 different battery packs.  One for each motor and see what the usage is per motor location.

Yes, and clearly heavier.  Weight is critical here, so this is not an option.

[Matt Neumann]

Yes, and clearly heavier.  Weight is critical here, so this is not an option.

One option that I did just think of is you could take the temp of each of the motors right after a flight.  It would be somewhat reasonable that the ones that use more juice would be warmer.  Might not be super accurate but at least it might give you an idea.

[Paul Walker]

One option that I did just think of is you could take the temp of each of the motors right after a flight.  It would be somewhat reasonable that the ones that use more juice would be warmer.  Might not be super accurate but at least it might give you an idea.

It really doesn't make any difference. I still need a battery big enough to run all four.

The first bomber converted to electric had four batteries, one in each nacelle. The plane flew fine. In fact it was very similar to the IC version. There was a variation in how much each motor used and it was not unlike the fueled version. The problem with this attempt was the batteries were no where big enough for a full flight.

The new smaller bomber will use Igors new timer with Jeti Spin 44's on motors 2 and 3. Motors 1 and 4 will use Jeti Pro 22's. These do not respond as fast as the Spin versions, but they are on the two motors which do less of the work. I do not need an ESC bigger that 22 amps, but the 22's are not available in the Spin versions, so I had to go to 44's to get that functionability.

But, not sure I really care who is doing the hard work. As long as it flies well, a non issue. However, if the wrong one used too much, how would I change that? They are all running the same rpm, so not sure what could be done if the rpm is to remain the same. They sound so good when four motors are in perfect sync.  It seems to quiet down when they sync like that.

On a worse case scenario, I can use two separate timers. One for 2,3  and one for 1,4. I can run agresstve settings on 2,3 and flat on 1,4. Small weight penalty for tha

[Doug Moon]

>>>
On a worse case scenario, I can use two separate timers. One for 2,3  and one for 1,4. I can run agresstve settings on 2,3 and flat on 1,4. Small weight penalty for that

That seems like the BEST case scenario.

[Matt Neumann]

It really doesn't make any difference. I still need a battery big enough to run all four.

The first bomber converted to electric had four batteries, one in each nacelle. The plane flew fine. In fact it was very similar to the IC version. There was a variation in how much each motor used and it was not unlike the fueled version. The problem with this attempt was the batteries were no where big enough for a full flight.

The new smaller bomber will use Igors new timer with Jeti Spin 44's on motors 2 and 3. Motors 1 and 4 will use Jeti Pro 22's. These do not respond as fast as the Spin versions, but they are on the two motors which do less of the work. I do not need an ESC bigger that 22 amps, but the 22's are not available in the Spin versions, so I had to go to 44's to get that functionability.

But, not sure I really care who is doing the hard work. As long as it flies well, a non issue. However, if the wrong one used too much, how would I change that? They are all running the same rpm, so not sure what could be done if the rpm is to remain the same. They sound so good when four motors are in perfect sync.  It seems to quiet down when they sync like that.

On a worse case scenario, I can use two separate timers. One for 2,3  and one for 1,4. I can run agresstve settings on 2,3 and flat on 1,4. Small weight penalty for tha

Out of curiosity, is the Spin versions a specially made version for this application or an off the shelf version?  I know they are faster than the non spin version.

[Paul Walker]

Yes, the Spin version is special and ONLY available through Igor.
It makes his timer sing!

[M Spencer]

Just fast forwarded ,to check out the ( what looked like ) Alligator in a swamp , on Kaz Minato's
Control line 2000 Landres in France , video .onyouuu tuuubbe .
His handle there is " revive001 ".
As thisis a clockworkcompuputer, it wont copy & paste . New spring Fitted ! 


Alligator is at 42'00 odd (engine run up ). Flight around 1- 32 -00.
The B 17 .
Sorry.No Alligators . THIS is a lot clearer than the other one on there offitt . As Kaz has used a camera , once or twice , before .

ALSO his tape of your 88  Nats . on his playlist there . = " Control line 1988 US NATS "

[M Spencer]

, If you use six foot aluminum tubes for motor mounts , and cu t em to the correct length AFTER youve nailed them on ,
The alignment will be superior .something like that. Anyway .

[Paul Walker]

Don't need aluminum for motor mounts. The BA 2310's weigh 1.3 ounces. They will attach to a ply/balsa/ply bulkhead. I will build a jig for the motor allignment.

[M Spencer]

The motors will be BA 2310-1220.

There are aluminum tubes from the LE cutout to each nacelle. They can be seen on the photo where they exit the LE sheeting.
The wire will be either 16 or 18 gage. I am not home right now or I would go look at the test plane.

  sorry  .  id read this as the nacelles were aluminum tube ,and dithered on fromthat.
Ths Electric ,you me ntion a ' silver finish ' , obviously with nooil ,plainsilver basecoat
gets it airborne .So the ' finish / can be done at liesure.

[Paul Walker]

Update.
All 4 nacelles made. Next step is to make the fuselage.

Just that simple......

[Crist Rigotti]

Nice!

[M Spencer]

Way to go . A big step forward , getting past that .

[Paul Taylor]

Update.
All 4 nacelles made. Next step is to make the fuselage.

Just that simple......

Oh Wow!!!

[Ken Culbertson]

I just read through this thread again since I am building my first multi esc ship and want to learn as much as I can.  One thing I passed over earlier was the Spin 22 Esc.  It tops out at a 4s battery.  The Spin 44 will take a 6s.  What battery are you using.  I find it hard to believe a single 4s can deliver enough power for a full pattern but the ability of electrics to deliver needed power never ceases to amaze me.  I like the idea of using the Spin vs the Spin Pro for the motor sets. That would seem to give boost and brake that is smoother.
But why not a Spin Pro 44?  It seems that the weight differential between a larger 4s battery and a smaller 6s would be about the same. 

I am also dying to see how you got 4 ESC's crammed into that hole in the wing LE.

Ken