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PostPosted: Wed Aug 25, 2010 6:50 pm 
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spares man wrote:
I've had a question about how you would determine the right electric motor setup to use in an airplane that is originally set up for glow fuel,for example if you have a twin engine airplane that originally was intended for twin 40s how would you figure out what electric motors to use
to get the same performance that the glow fuel engines delivered say in a scale aircraft like a
pby or b-25 granted some kits are already available but still how do you arrive at a solution when there isn't any available kits?maybe this question has already been answered not sure.


Well, that question can be as simple as me recommending a motor, or as complex as asking which battery and prop you want to run.

Suppose you want to use a 5 cell battery, and you want more 4 stroke like performance (lower rpm, bigger prop) then I would look for something in the 600kv range since a 5 cell battery is 18.5v x 600 gets you 11,100 rpm.

In my opinion good 46 size performance is about 1000 watts of power (1.34HP.) If you take your 1000 watts / 18.5v then you get 55 amps.

Now your looking for the lightest motor you can that can do 55 amps, 1000 watts, 600kv.

Here are a few to look at:
http://www.subsonicplanes.com/uploads/D ... __page.pdf
http://www.e-fliterc.com/Products/Defau ... =EFLM4046A
http://www.hobbyking.com/hobbyking/stor ... oduct=2098
http://aero-model.com/Hacker-Brushless-A40-12S.aspx

Now if you want to run smaller props or a 4s battery then you might look at a 800kv motor like this:
http://www.subsonicplanes.com/uploads/D ... __page.pdf
http://www3.towerhobbies.com/cgi-bin/wt ... XLWV6&P=ML
http://aero-model.com/Hacker-Brushless-A40-10S.aspx

Please note that the hacker numbers are VERY conservative so you pretty much run them over spec or you pick a different vendor, or you run a hacker inside of their specs and I suspect they would be extremely reliable.

So to answer your question, which prop and battery do you want to run?

If it where me I would run the hacker or motrolfly on 4s, but then again I have a number of 4s packs already. If I was starting from scratch then I would go 5s since that is the best efficiency. Or if I had a number of 3s batteries around I might try to use a 500kv motor and double those up for a 6s system.

This is the great thing about electric, you can build the power system around the airplane, batteries, or prop. This is also the bad thing about electric, there are so many options it makes you head spin.

schu


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PostPosted: Thu Aug 26, 2010 8:03 am 
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Ryan at AHOH donated a sacrificial lipo battery for the clinic. At the last club meeting we decieded that the clinic could be held at my venue where we've had other clinics, but if AHOH has moved into their new building by the time we have the clinic, I have no objections to having it there. Schu, settle on a date and location and count me in. Thanks.

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PostPosted: Thu Aug 26, 2010 9:23 am 
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Date is Sept 25. I don't know if we will be at AHOH or your shop, lets wait until they move to make the call.

schu


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PostPosted: Thu Aug 26, 2010 6:26 pm 
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Can you do the workshop later in the day after 4:30 for all the working stiffs like me. I really would like to come but I have to work Saturdays. If it's possible I would really appreciate it. Give it a thought and post it please.


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PostPosted: Fri Aug 27, 2010 4:02 pm 
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schu wrote:
Date is Sept 25. I don't know if we will be at AHOH or your shop, lets wait until they move to make the call.

schu


Sounds good to me. I'm thinking about getting MotoCalc. It's a great tool for electric enthusiasts.

http://motocalc.com/

Update, I downloaded it and discovered my S.E.5a is overpropped, putting too much load on the motor and ESC, need to reduce from a 10" to a 9" Also 3S battery is inadaquate for my motor and prop I selected for my Pawnee. The 4200 ma. 3S batteries I ordered just arrived today, now I gotta get 4S or more, need to crunch more numbers befor I deciede on the batteries. May have a couple of brand new 3S 4200 mAh lipo's for sale if I don't find a project for them to go into soon.

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PostPosted: Fri Sep 17, 2010 11:03 am 
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Here's a map of the location, the main crossroads is C st. and Intl. Airport Road, we're south of there off Potter Drive. 5601 Silverado way is the address. Parking is South of the building, enter through the front office entrance, the customer service entrance in the rear of the building will be locked. See ya there 2:00 pm.


Attachments:
Map2.jpg
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PostPosted: Sat Sep 18, 2010 9:42 am 
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Thanks Kim,

Everyone: The clinic will start at 2pm and run until 5pm. There is NO FEE to attend - it is provided on a donation basis. There is around a $150 cost to provide this event so hopefully the club treasury can break even or close to it with donations. Schu will be giving away 2 door prizes for those who attend!!

Thanks Ryan :D - for the generous donation ($$ discount) from the Anchorage House of Hobbies on the club's purchase of motor and speed control unit.


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PostPosted: Fri Sep 24, 2010 9:17 am 
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Schu,
I see that there's an item on the agenda to talk about soldering Dean's connectors. I wonder if you've looked into the Anderson Power Poles as an alternative. The way I see it, they have a couple of significant advantages over the Deans connectors. The biggest and most obvous is that they are much easier (and safer) to get apart, a close second is that they can be crimped or soldered, and don't require heat shrink after you're done. There's a really good article at the following link that talks about them for RC use, might be worth talking about at the clinic, even if just briefly. I switched over to them after some frustration with the Dean's and don't ever plan to go back. I think Daryl uses them also. I came across them when they came on the ends of my West Mountain Radio battery analyzer. They use them exclusively for the same reasons I have already stated.
http://www.flyrc.com/articles/using_powerpole_1.html
Thanks
Dave W.

PS Following is a post from WattFlyer about this topic:

"I've been using Anderson Power Pole connectors exclusively for about twenty years. I've put currents of well over 100 Amps through them. They are reliable, fool-proof, easy to connect and disconnect, easy to make with the crimping tool and very versatile.

Every time I look at a new connector I see no reason to even consider them. Most are unsafe and not built for constant abuse. The Anderson connectors are actually designed for real industrial applications, so they are rugged as can be. I've had crashes where just about the only thing that survived where the connectors!

I do use bullet connectors for the ESC-to-brushless-motor connection. the criteria here is that they are smaller and they will not be repeatedly plugged/unplugged. There is no real danger from accidentally crossing wires either. So, Anderson for power input and bullet for ESC-to-motor is my recommenation.

-Martin"

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PostPosted: Sat Sep 25, 2010 7:36 am 
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I've read some posts from others that did some testing on all of the modern connector types and they found that deans where as good as the power poles and better than most. Since I already have a lot of deans connectors, I decided to standardize on them.

Deans connectors are easy to pull apart as long as you use real deans connectors. The cheap knock offs are the ones that are hard to pull apart.

Anyway, it doesn't matter what connector people use, the ability to solder correctly is important to modelers so I wanted to demonstrate how to get a good quality solder joint.

Feel free to bring up alternative connectors at the clinic, as I'm sure that others will want to see them.

Thanks,
schu


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PostPosted: Sat Sep 25, 2010 7:38 am 
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Members,

Here is the presentation for those that are going to miss the clinic.

Yes, I know it's long and exhaustive, but that's my style. :) I want to provide as much information as I can.

Thanks,
schu


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electric clinic.pdf [106.26 KiB]
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PostPosted: Sat Sep 25, 2010 5:08 pm 
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Thanks Schu for the clinic. I can probably speak for 100% of the people... We all learned from you on atleast 1 or more things.

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PostPosted: Sat Sep 25, 2010 5:45 pm 
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Thanks Schu, it was a very concise and informitave clinic, well presented. Kip A. got the ball rolling early as Schu was running a bit late but then left for some reason. Kip, hope you're feeling okay!

There was a good turnout with about 15 in all. Doc won the Castle Creations Ice 75 amp. ESC. and Daryl won the Hacker motor. Thanks FFF and AHOH.


Attachments:
File comment: Part 1 of the crowd.
056.jpg
056.jpg [ 72.39 KiB | Viewed 2203 times ]
File comment: Part 2 of the crowd.
057.jpg
057.jpg [ 72.09 KiB | Viewed 2203 times ]
File comment: Hacker motor at full song, you didn't want to get near it!!
062.jpg
062.jpg [ 50.55 KiB | Viewed 2203 times ]

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PostPosted: Sat Sep 25, 2010 6:01 pm 
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Location: The Shop
Good to hear it went well. Congrats to Doc and Daryl. Thank you Matt, for all the effort you've put into this, and I hope it can be done again. Thank you to Kim, also, for the location. And thanks to all the Fun Flyers who attended.

For those interested in the alternative, we have carried Power Poles for at least twenty years. Though, as Schu points out, as long as you can make a solid joint, either is a fine choice.

Ryan


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PostPosted: Sat Sep 25, 2010 7:40 pm 
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Congrats Shu on a very professional seminar. I have been reading a lot about electric power over the years but have never seen the subject better explained. I learned that its past time to retire my 30 watt radio shack soldering iron for one thing.
Thanks to Kip for getting the crowd warmed up.
And thanks to Ryan for supporting this seminar. I am sure we will all remember that support when its time for that next purchase!
Hope Shu does it again....I will be there....

Bob S


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PostPosted: Mon Sep 27, 2010 6:45 am 
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Location: Wasilla, Alaska
I would like to add my thanks to Shu. That was a very good program and I will also sign up for your next class.

Now that I have the Hacker I guess I will need to put all that information together to pick a plane, esc, and battery pack to go with it. When I told my wife that I had won a new motor she said "O great, now you will probably need a new plane to go with it." I think she is learning how all this works. :mrgreen: :mrgreen: :mrgreen:

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