Wattflyer RC Network: RC Universe :: RCU Magazine :: RCU Forums :: RCU Classifieds :: RCU User Reviews :: RCU YouTube
Home Who's Online Calendar Today's Posts RealTime Post Spy Mark Forums Read
Go Back   WattFlyer RC Electric Flight Forums - Discuss radio control eflight > Electric R/C Airplanes > Combat
Register Members List Wattflyer Extras Articles Search Today's Posts Mark Forums Read Social Groups

Combat Electric combat discussion in here.

Thank you for your support (hide ads)
Reply
 
Thread Tools Display Modes
Old 06-25-2013, 10:56 PM   #1
madmickey
Member
 
Join Date: Aug 2005
Posts: 23
Thanked 0 Times in 0 Posts
iTrader: (0)
Friends: (0)
Default gremlin electric conversion

Hi
I acquired a glow powered Gremlin from a friend and I would like to convert it to electric o I can fly it without assistance. Can anyone give me some advice on a good motor/esc battery combination.

Thanks

Mike
madmickey is offline  
  Reply With Quote
Old 06-26-2013, 12:03 AM   #2
fhhuber
Super Contributor
 
fhhuber's Avatar
 
Join Date: Mar 2013
Posts: 4,786
Thanked 493 Times in 479 Posts
iTrader: (0)
Friends: (2)
Default

Its a .25 glow power (recommended) airplane...

So E-Flight Power 25 or rough equal power.
There are MANY appropriate motors that are roughly equal. Most will cost less. This one gives you some good numbers for comparisons.

Tacon 25 is a nice one... OMG power with a APC 12X6 on 4S.
It thinks its a .60 turning that prop close to the rpm I got from a OS .61 FX with a 12X6.
(yes, I have one... on a Commander 40 EP)

60 amp ESC (may as well have excess ESC rating since they are getting cheap) The Dynam (Detrum) ESCs are good and inexpensive. Just a couple bucks extra for 60 amps... do it.

Your main issue will be getting the CG correct. It has a nice opening on top for battery access but the fuselage is SHORT and expects something quite a bit heavier than the .25 equiv outrunner on the nose (about 300 watts equals a .25... the 600 watt max of the Power 25 is about equal to a mild .40!)

Power 25 handles 4S fine and 3000 mah 4S would haul that flying wing around very nicely. You'll be outrunning Gremlins with .46's because you'll be lighter.
fhhuber is offline  
  Reply With Quote
Old 06-26-2013, 02:08 AM   #3
kyleservicetech
Super Contributor
 
kyleservicetech's Avatar
 
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,951
Thanked 774 Times in 752 Posts
Club: www.racinercclub.com (I'm the newsletter editor)
Awards Showcase

4kW  Outstanding Contributor Award  3kW  2kW 
iTrader: (1)
Friends: (21)
Default

Originally Posted by madmickey View Post
Hi
I acquired a glow powered Gremlin from a friend and I would like to convert it to electric o I can fly it without assistance. Can anyone give me some advice on a good motor/esc battery combination.

Thanks

Mike

Check out one of those computer programs such as www.motocalc.com for a bit of info before spending $$$$. This program is free for 30 days, then $39.

As indicated in this thread, you can select from a very wide range of power systems, from a few dozen bucks, to a few hundred bucks. Some of the cheap stuff isn't worth installing, some of the higher $$$$ units will work well.

That Power 25 size motor has a pretty good reputation. For more $$$$, check out the similar sized Hacker series motors:
https://www.aero-model.com/8_67_889/...-10S%20V2.html

For very good performance, you need about 125 to 150 watts per pound of airplane, including the motor/ESC/battery pack. So, weigh your model without motor/ESC/battery, look around for appropriate power equipment, and see what kind of watts you are running. This is where motocalc comes into its own. It will give predictions on how your model will fly, and will warn you if you are overloading anything.

DennyV
Retired and the days are just too short, busier than ever!
kyleservicetech is offline  
  Reply With Quote
Old 06-26-2013, 03:42 AM   #4
gramps2361
Community Moderator
 
gramps2361's Avatar
 
Join Date: Dec 2008
Location: oxford, MA
Posts: 7,002
View gramps2361's Gallery9
Thanked 628 Times in 623 Posts
Club: Rocky Hill Flying Circus
iTrader: (3)
Friends: (24)
Default

I did mine up with a eflite 25 60 amp esc 3c 3300 mah battery with a 11x5.5. I use this for the Gremlin combat with streamers. Real fun wing to fly WOT in combat is 4 minutes the battery comes down around 3.80 per cell. If I am just flying it I get around 7 minute flight mixed throttle.

You will have to move the gutter fuse forward and drill new mounting holes to get the CG right. Not hard to do. Once you get it setup and balanced right you will have a ball with it.
Here is a link that might help you out with more info and build directions. Should help you with the conversion.
http://www.racores.com

By the way I am doing combat against gas powered grelims, and I do all right. You can't go too fast as you start to shred your crepe paper ribbon not a good thing to do.
gramps2361 is offline  
  Reply With Quote
Old 06-26-2013, 07:27 AM   #5
fhhuber
Super Contributor
 
fhhuber's Avatar
 
Join Date: Mar 2013
Posts: 4,786
Thanked 493 Times in 479 Posts
iTrader: (0)
Friends: (2)
Default

If the crepe paper is cut cleanly (when they split the streamer in half the long way) it can handle a lot of speed.

I drug 35 ft of streamer behind a modified "Corostang" that was clocked at 95 mph.

Common party streamers cut in half with a band saw.

If the streamers your group cuts won't take it then a bit of throttle management may be in order. :p
Or lessons in how to cut them so they don't have a ragged edge. (fine tooth bandsaw and a good cutting guide)

******************

Nice to see that its been done with essentially what I was recommending... and the same CG issue I expected.

Long time since I put a Gremlin together. We were using the sliding tray for mixing the elevons.
fhhuber is offline  
  Reply With Quote
Old 06-26-2013, 12:39 PM   #6
madmickey
Member
 
Join Date: Aug 2005
Posts: 23
Thanked 0 Times in 0 Posts
iTrader: (0)
Friends: (0)
Default

Hi
Okay what is the Gutter?

Mike
madmickey is offline  
  Reply With Quote
Old 06-26-2013, 12:58 PM   #7
gramps2361
Community Moderator
 
gramps2361's Avatar
 
Join Date: Dec 2008
Location: oxford, MA
Posts: 7,002
View gramps2361's Gallery9
Thanked 628 Times in 623 Posts
Club: Rocky Hill Flying Circus
iTrader: (3)
Friends: (24)
Default

The gremlin fuselage is made from plastic gutter down spout.
In the link I posted there is a part list for the gremlin. Any idea on how old your version of the gremlin is?
Here's another link for builds on the gremlin should be a lot of help for you to convert it.

http://www.rcgroups.com/forums/showthread.php?t=1059205
gramps2361 is offline  
  Reply With Quote
Old 06-26-2013, 01:38 PM   #8
madmickey
Member
 
Join Date: Aug 2005
Posts: 23
Thanked 0 Times in 0 Posts
iTrader: (0)
Friends: (0)
Default

Hi
Thanks for the link. I am pretty well versed in electrics as I fly them in my F3A planes however I thought I would put the post on Wattflyer to see what others are doing and to take the benefit of other's peoples experience. As clever as motor calc is, it doesn't always get it spot on and some tinkering is always required, Hence my post.

I wont be flying combat with it, nobody to play with up here but as a bit of fun it looks just the job.

Mike
madmickey is offline  
  Reply With Quote
Old 07-23-2013, 04:16 PM   #9
thrawn150
Member
 
Join Date: Jun 2007
Location: Oak Lawn, IL
Posts: 76
Thanked 3 Times in 3 Posts
Club: Palos flyers
iTrader: (0)
Friends: (0)
Default

I have made 2 EP powered gremlins. Both with a monster power 46 4S 5000mah setup, spinning a 14 x 10 prop. It did well against the glow ones in my club in combat. It is a heavy setup but boy is it fast. Here is a pic of my second one.


Attached Thumbnails
Click image for larger version

Name:	Gremlinmk2.jpg
Views:	300
Size:	119.1 KB
ID:	169977  
thrawn150 is offline  
  Reply With Quote
Old 09-26-2017, 03:17 AM   #10
birdDog
Charging....
 
birdDog's Avatar
 
Join Date: Nov 2007
Location: Too close to Chicago.
Posts: 2,389
Thanked 187 Times in 185 Posts
Awards Showcase

1kW 
iTrader: (8)
Friends: (7)
Default

Working on a Suppo 3520/6 840kv model. 4lb 1oz minus wing tape and covering. 4000mAh 6s is a bit heavy but 1200watts should make up for it at 300 watts per pound on a 10x5. Gonna shred some poor little wet fuelers with this beast. Yeah it's a big battery but I own quite a few and those pesky little glow planes have some run time.

A friend at the club cut the cores and passed out kits for many of us to build. Most going nitro but I remain faithful to the electrons.Call me a purist.

I don't have a short temper. I just have a quick reaction to B.S.
Rob
birdDog is offline  
  Reply With Quote
Old 11-21-2017, 06:13 PM   #11
Buzzsaw
Buzzsaw
 
Join Date: Sep 2007
Location: Muncie.IN
Posts: 164
Thanked 13 Times in 12 Posts
iTrader: (0)
Friends: (0)
Default

I have been flying electric Gremlins for a couple of years now. Using a Headsup 25, 60 esc ,3300 battery. I get around 3 1/2 minutes.


Attached Images
File Type: jpg IMG_20171121_115848477.jpg (169.7 KB, 42 views)
Buzzsaw is offline  
  Reply With Quote
Old 11-22-2017, 03:59 AM   #12
birdDog
Charging....
 
birdDog's Avatar
 
Join Date: Nov 2007
Location: Too close to Chicago.
Posts: 2,389
Thanked 187 Times in 185 Posts
Awards Showcase

1kW 
iTrader: (8)
Friends: (7)
Default

Nice collection. Actually I wound up running a Leopard 4250/620kv on 6s 4000mAh with an 11x5.5 apc and getting 7 minutes maximum (to around 3.6vpc). This is at wide open throttle for essentially the entire flight. Performance is matched well to the others flying .46 and .52 nitro but plane is pretty heavy at around 4.5 pounds. It is a lot of fun for playing around with tumbles and spins since there is no threat of a deadstick.


Unfortunately, this is far too hard on the batteries for my liking so wound up burning wet fuel (11 to 12 minutes) in other Gremlins. Here is a 75% I am getting close to finishing. The fuse is made from a box/sleeve that contained TIG welding wire. Because of the magenta color of it i decided to cover with primary colors and make it look like something you would find on the floor of a daycare center.lol. The ASP .21 engine is going to have this "toy plane" screaming through the air...



Here is a shot of a motor mount i devised by sawing up a $6 24" aluminum level. Great rigidity but I suggest Fiberglassing the front of the fuse with a few layers of cloth and CA.

I don't have a short temper. I just have a quick reaction to B.S.
Rob
birdDog is offline  
  Reply With Quote
Reply

  WattFlyer RC Electric Flight Forums - Discuss radio control eflight > Electric R/C Airplanes > Combat


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Everything You Wanted To Know About Electric Powered Flight AEAJR General Electric Discussions 273 01-09-2017 03:23 AM
Glider Kits? to a conversion to electric? BrianW517 Hi-Performance and Sailplanes 18 01-03-2015 04:26 AM
General Electric Conversion Questions Wrongway-Feldman General Electric Discussions 21 05-03-2013 05:31 PM
sig Aqua-Star electric conversion question harlanB Seaplanes E-Powered 6 05-28-2012 02:02 AM
conversion of J3 cub to electric hybrid General Electric Discussions 6 01-23-2011 10:43 PM


All times are GMT +1. The time now is 09:31 PM.


Powered by: vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2005 WattfFlyer.com
RCU Eflight HQ

Charities we support Select: Yorkie Rescue  ::  Crohn's & Colitis Foundation



Page generated in 0.13644 seconds with 47 queries