stunthanger.com
Electric Stunt => Gettin all AMP'ed up! => Topic started by: Shug Emery on August 08, 2015, 09:42:05 AM
-
I have a Top Flite Score ARF and am mulling going electric with it. It calls for an RC style motor mount for IC. Is there an electric type conversion offer thaat anyone can lead me too?
Many thanks for any intel.
Shug
(http://i928.photobucket.com/albums/ad127/Shug7secure/IMG_0009_zpselazmzmv.jpg) (http://s928.photobucket.com/user/Shug7secure/media/IMG_0009_zpselazmzmv.jpg.html)
-
The RC-style electric motor mount is a box made out of plywood or metal, and built off the firewall that locates the motor at the right spot relative to the spinner ring. I don't think this'll fit, but it's something to ponder: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXLCL4&P=ML (http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXLCL4&P=ML).
If I were you and I could find the room in the cowl, I'd make the engine front mount -- but that may require too much shoe-horning to work. If it does work the "box" will probably have to be octagonal or hexagonal to fit. It may be better to ask what motors work well rear mounted and use one of them.
Read Crist's thread on his hard-to-cool engine before you build: you want to have your air path figured out before you start cutting wood.
-
The RC-style electric motor mount is a box made out of plywood or metal, and built off the firewall that locates the motor at the right spot relative to the spinner ring. I don't think this'll fit, but it's something to ponder: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXLCL4&P=ML (http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXLCL4&P=ML).
If I were you and I could find the room in the cowl, I'd make the engine front mount -- but that may require too much shoe-horning to work. If it does work the "box" will probably have to be octagonal or hexagonal to fit. It may be better to ask what motors work well rear mounted and use one of them.
Read Crist's thread on his hard-to-cool engine before you build: you want to have your air path figured out before you start cutting wood.
These are great ideas..that mount may be the thing. Maybe kinda.
The coolong will be paramount.
I thankee.
Shug
-
Cut the fuselage in half and build a new nose.
MM
-
Cut the fuselage in half and build a new nose.
MM
Hey...I'm trying to find an easy solution)))) :##
Good idea. I will bring it to my staff.
Thankee.
Shug
-
Look at the Cobra for reference here
http://innov8tivedesigns.com/parts/brushless-motors/cobra-c-3520-14-brushless-motor-kv-700
If you notice the X mount, you could use that and rear mount the motor with 4 corner standoffs and through bolts, 6-32. Standoff length will adjust total length to put the prop adapter/spinner in the correct position. You can hole saw out the existing firewall centrally in the X for airflow, and mount to the perimeter.
For Cobra you will probably want to flip the shaft and is easily done following instructions on the Innov8tive site, or IIRC, E-Flight is sent with the shaft the other way. Cobra has 3 bearings and is better, in my opinion, for rear mount.
Is the "tank" area long enough for most batteries, or do you need the short packs?
Similar to these for reference,
http://www.hobbyking.com/hobbyking/store/__26989__ZIPPY_Compact_2700mAh_6S_25C_Lipo_Pack_USA_Warehouse_.html
or
http://www.hobbyking.com/hobbyking/store/__26989__ZIPPY_Compact_2700mAh_6S_25C_Lipo_Pack_USA_Warehouse_.html
-
Look at the Cobra for reference here
http://innov8tivedesigns.com/parts/brushless-motors/cobra-c-3520-14-brushless-motor-kv-700
If you notice the X mount, you could use that and rear mount the motor with 4 corner standoffs and through bolts, 6-32. Standoff length will adjust total length to put the prop adapter/spinner in the correct position. You can hole saw out the existing firewall centrally in the X for airflow, and mount to the perimeter.
For Cobra you will probably want to flip the shaft and is easily done following instructions on the Innov8tive site, or IIRC, E-Flight is sent with the shaft the other way. Cobra has 3 bearings and is better, in my opinion, for rear mount.
Is the "tank" area long enough for most batteries, or do you need the short packs?
Similar to these for reference,
http://www.hobbyking.com/hobbyking/store/__26989__ZIPPY_Compact_2700mAh_6S_25C_Lipo_Pack_USA_Warehouse_.html
or
http://www.hobbyking.com/hobbyking/store/__26989__ZIPPY_Compact_2700mAh_6S_25C_Lipo_Pack_USA_Warehouse_.html
Thanks for all this. Need to read it a few times to suss it out then mull it over.
Shug
-
The X is made to mount to the motor and screws sent. The outer holes on the X then mount to the firewall/standoffs. 4 small pieces of maple adjusted to thickness/length will then fit the whole motor and X assembly lengthwise. You could get fancy with lathe and threading for real standoff, but not as simple. With a bit of tedium, the 2 outer blocks can be shortened a little, and the firewall end of the X shifted toward the inside of the circle a little to center the spinner to the cowl. Similar shift and offset would have been done for IC to have motor offset of 1 - 2 degrees and hit the cowl.
Perhaps someone will suggest simpler, or explain better, but I think it works and is similar to how I am mounting a scratch built design currently under construction. I am not using the standoff blocks because I could choose my firewall location leaving more room for battery behind the firewall.
-
Hey Fred -- picture of your mount, please?
Shug -- if you decide to do it Fred's way, you can get standoffs at electronics places like DigiKey.
-
I have a Score that I have considered converting to electric, like my Legacy. I believe the tank compartment is too short to accept most batteries other than the pricey square-ish ones from Thunder Power and maybe some other makers. I would remove the existing motor mount bulkhead and rebuild the nose using ply doublers, and place the new motor mount appropriately to make the whole works balance right. It is a good flying model and will serve you well. Would need to design air flow ducting for cooling, as you mention.
BTW I replaced the entire control system, used CF pushrods with ball joints, new BC and leadouts. Also engineered (if that is the word) an alloy joiner plate to tie the front of the wing to the fuse at the wing saddle. Unless you really want it to be take-apart, a better idea is to glue the wing in place and forget about the take apart feature.
-
What is the leading edge to firewall length, and what is the leading edge to spinner space? If too short, balance can become a problem. I would find a friend with a motor and battery to approximate balance, or figure a 7 oz motor in the motor space (1/2 lb wt to allow for prop/spinner) and about 12 oz of battery + add 2 - 3 oz for electronics in the battery compartment (1 lb weight centered in the battery compartment).
The HobbyKing info approximates various battery lengths and configurations.
Tim, wood block "standoffs" are easy and can be glued to the firewall. Last I knew, Fry's had standoffs in electronics so those are easily available. I didn't need standoffs, so just have a standard X to the firewall used as a rear mount. Not photo worthy, but, if needed..
-
Tim, wood block "standoffs" are easy and can be glued to the firewall. Last I knew, Fry's had standoffs in electronics so those are easily available. I didn't need standoffs, so just have a standard X to the firewall used as a rear mount. Not photo worthy, but, if needed..
I'm too much of an electronics geek. You said "standoff", my brain immediately jumped to "PC board standoff, aluminum", like this one.
(http://media.digikey.com/photos/Keystone%20Elect%20Photos/3438.JPG)
-
And those could work with the X at one and a through bolts bolting all to the firewall. The surface area would be small so one would have to avoid sinking the standoff into the wood firewall, so back to simple, wood. I saw long stand offs like those used with the motor front mounted to an X on a plane at a contest in Salem.
Similar here, with a variety of pictures worth a thousand words
https://www.google.com/search?q=electric+rc+airplane+motor+standoffs&safe=active&biw=1620&bih=1001&tbm=isch&tbo=u&source=univ&sa=X&ved=0CE4QsARqFQoTCO7l6NvonMcCFcakiAodiBsCsQ
-
Did you ever get this Score working? Do you like it?
-
Did you ever get this Score working? Do you like it?
Not gotten around to it as of yet......
hug