Hi, I am new to the forum, but probably about the same vintage as many here.  I will introduce a couple of airplanes, and my electric adventure.  I started flying at about 10 years old (1957-1958) with a Thimble Drome Cox 0.49 and the rubber banded Flight Trainer.  I have drifted in and out of the hobby a few times since.  I was flying a Jetco Dolphin in the late 70’s and saw the Chris Lella Sundance in a magazine.  I found that a fellow named Bob Hunt was selling skinned foam wings and that the Sundance was available, I ordered.  The Sundance was finished in 1977 and, as I recall, a Genesis wing ordered within the next year.  I flew for a while and then life got busy with family and work, and I hung the airplanes in my basement, for years.  I eventually returned to airplanes with RC pattern, sailplanes and electric park flyers.  About 8 years ago a move got the airplanes a new “hanger.”  The basement airplanes went to the next house, but there was not enough room, so they moved again.  They ended up in the attic of a friend for a few years.  About 6 years ago the Sundance emerged briefly for a few flights.  It had a bit of hanger rash, but flew reasonable well, still with an OS 35s.  It was not quite what we wanted so, we built a Magician and scratch built another profile and used the newer OS 40FP and flew for a season.  The Sundance joined the Genesis in the attic and sat until the middle of the 2012 season.

My friend, forum member Dave Denison, started up this year where we left off a few years ago and finished a scratch built foam wing Cardinal, but converted it to electric.  It was built as IC, never finished or flown.  With his encouragement, read insistence, I was pulled back in.  The Sundance was found in the attic in a bit of disrepair.  The original finish was Pactra Dope now 35 years old and well cured in the attic.  We decided that it had mostly cosmetic damage and started looking at electric conversion.  It turned out that there was some separation or delamination of the wing skin.  Actually it was mostly at the trailing edge up on to the foam, and solved by some foam safe Ca.  I will digress a bit and share a memory.  When I got the foam wing the first time, they also delaminated.  Mr. Hunt was having some difficulty with the contact glues.  I believe, if memory serves, that the red stuff failed.  Of course he replaced the wing without question or return of the product.  Hmm, I wonder if the contact cement guarantee was good for lifetime  ?  The electric conversion actually turned out to be easy.  The conversion was done and the Sundance once again is flying.  

The airplane was originally about 570 sq inches and 45 ounces without fuel, about 50 oz RTF.  It was fairly stark as I ran out of weight with the silver paint that I originally intended as a base cover coat.  

For the electric conversion I used:

3 cell 2800 pack, about 2200 ma used in 5 minutes.
Turnigy 1250Kv D3542/5
APC 11X5.5 EP
50 amp ZTW controller
KR Governor System
Weight, about 50 oz ready to fly.

I removed a OS 35s, Big Art muffler and normal flying gear and replaced it with essentially the same weight electric system, each weighing about 18.5 oz.  The electric gear is actually about 1 – 2 oz. heavier, but lighter wheels were substituted.  Balance was also fairly close, but I eventually added about 20 grams of nose weight in the electric.
Now, on to my version of the Genesis.  The RC Curare by Hanno Prettner was featured in the late 70’s and had an anhedral stab.  I liked the look, and it seemed to fit with the Genesis.

Hi Fred,
 Welcome to stunthanger!!! looks like you are off to a great start. Nice conversion on the Sundance. If I remember right, I saw Chris' original fly in the 1970,s in Flushing Meadows park here in NYC. Did you make it a top loader or is it a bottom loader? How is the power with the 3 cell system? Keep us informed on the Genisis and what system do you plan on using?
William

Wow! You received a wing from me that was covered using the infamous "red" contact cement! That was around 1975 I think! Yeah, had to "eat" a few wings over that stuff!  Today - and for the past 20 plus years - I have been using a very thin coating of epoxy finishing resin to attach the skins and have had no delamination problems.

Congrats on the conversion of the Genesis to electric. Nice weight, too!

I've posted the conversion photos here for the Genesis that I retrofitted in 2005. Actually I fist installed a rear mount system and didn't like that too much. I re-retrofitted the ship with a front mount system and that has worked wonderfully. I highly, highly recommend front mounting for outrunner electric motors!

I'll attach those photos again here for the benefit of those who might not have seen them the first time.
Note that these photos depict the use of a rear bearing support yoke. We found that the rear support was not necessary and have not used it for years. The photos also depict the mounting of a timer unit. That unit was superceded by the Hubin unit which works great.
Later - Bob   

Wow! You received a wing from me that was covered using the infamous "red" contact cement! That was around 1975 I think! Yeah, had to "eat" a few wings over that stuff!   Today - and for the past 20 plus years - I have been using a very thin coating of epoxy finishing resin to attach the skins and have had no delamination problems.

Congrats on the conversion of the Genesis to electric. Nice weight, too!

I've posted the conversion photos here for the Genesis that I retrofitted in 2005. Actually I fist installed a rear mount system and didn't like that too much. I re-retrofitted the ship with a front mount system and that has worked wonderfully. I highly, highly recommend front mounting for outrunner electric motors!

I'll attach those photos again here for the benefit of those who might not have seen them the first time.  

Bob, thanks for the comments and pictures.  I had seem some of those and worked with my friend as he converted a built, not flown, airplane from IC to E.  He did front mount and I would have preferred that, but more work than I wanted on 35 year old attic dried airframe.  Or perhaps I am a bit lazy.  Hopefully I can follow with photos that will help explain the choices.

The Sundance wing was originally red contact, replaced.  The Genesis was only about 1 year newer but had lightply landing gear ribs, foam cut flaps, and I got your foam and sheet stab/elevator.  All of the contact bugs were gone.  Great stuff then and now, and may merit a refinish in the off season.  I hope that you and others on the forum will be happy to see it and not offended by the hanger rash. 

I have a few more Sundance pictures that may help explain the conversion and install.  The following photo shows the aluminum mount.  It uses the back two holes of the OS35s mount and two addition holes with woodscrews into the original maple mounts.  The OS mount holes had blind nuts, so easy to use.  I am not in favor of rear mounts, but it seemed natural in this case.  Version 2 of the mount will go into the Genesis.  Those photos will be up coming in a few days hopefully.  The KR system is mounted with Velcro which helps to insulate it from any heat “sinked” to the mount.  The ESC is mounted to the L side as shown.  A large exit hole serves as the air outlet and the battery pack will easily insert there.  The battery is attached with Velcro to the outboard side.  There is only room for 3 cells this way.  The ESC could move to the top of the canopy, bottom below the motor mounts as shown, and make room for another cell.  That may require another air exit to get air to move around the ESC.  At the back end of the exit hole, the horizontal “remains” touched by the red lead is the tank floor remnant.  The IC version had a 1/32 ply layer between the motor bearers and another at the tank bottom, the remnant line and the tank sandwiched snuggly.  That compartment had been coated with thin epoxy resin, and the innards were amazing clean and dry.

Finally, the Genesis conversion.  Please pardon the slightly crooked spinner tip, set on for the picture. 

Next a portion of the top tank cover is removed, between the motor mount bearers.  The remaining support between the bearers is for battery support as it is inserted from the front of bottom through the air exit.  The portion removed is to allow the battery an entry or exit angle/arc.

Genesis Motor Mount

The Sundance version worked reasonably well, but a version 2 was attempted for improvement.  Both were started from the same extruded 1/8” aluminum rectangular tube.  A piece of tubing was cut off dimensioned to fuselage width.  This was then split to 2 U-channels, and one of the U-channels, then further divided.  The larger plate fits the motor mount and again used the rear IC engine mounting holes that already had blind nuts.  2 additional holes were drilled in the plate and mounts.  The smaller plate was fitted to go between the motor bearers and then mated to the larger plate.  They were screwed together to allow alignment and work, and then eventually screwed and glued after metal work was completed.

The + or cross motor mount shown above was only used as a guide clamped to the aluminum mount for drilling motor mounting holes.  The central clearance was done with a 1/2" end mill, if I recall correctly.

I've  made similar type mounts for profiles and agree. It should work very well. I was doing some reading on your motor and see that they are now made with 5mm shafts. Do you have that version? I also noticed that you have a prop adapter with a set screw. I had some issues with those as some slipped till i put a flat spot on the shaft. I now use only the compression type and have had no problems.

yes i meant the collet type.sorry.

I like that metal mount.  Looks a good place for a heat sink to attach the parts that need it.

The cowl was plugged, opened to accommodate the wiring and cooling, and fitted.

The weather somewhat cooperated.  A morning break from the rain, and almost no wind.  Flying weight with fuel was about 51 oz and after conversion to a 3 cell pack, about 51 -52 oz.  I saved about 20 gms on wheels from old style to new.  I have added about 15 gms of that back as tail weight, added 7.5 gms x2.  I also added about 7.5 gms of tip weight.

Turnigy motor 1250kv
9750 - 9800 RPM
5.2 second laps
60 ft lines eyelet to eyelet
2300 mah for about 5 minutes on a 2850 mah pack, so just at 80 -81% used and the times would be to short to compete.  I am far from that need.
11x5.5 EP prop

I am at the limits of my 3 cell system.  It ran up to 10500 rpm on the tach using the Governor to max and then back down to about 9800.

Sorry for the finish, or lack there of, but about 35 years of storage, and conversion.

If you use a motor with a lower K/v (in the 900's) you could use a 4 cell battery that has the same dimensions as your 3 cell and you would use less Mah, therefore you could extend the times ok.

If you use a motor with a lower K/v (in the 900's) you could use a 4 cell battery that has the same dimensions as your 3 cell and you would use less Mah, therefore you could extend the times ok.

I actually thought of this before.  Watts power the plane more than volts or amps, so more volts and less amps.  The best 4 cell equivalent battery is actually 241 gms instead of 248 gms, but only a 2200 mah pack.  I would have a similar issue based on the data I have seen for 4 cell amp usage.  My friend uses 4 cells and gets about 1700 -1800 ma usage in the same time frame, 5 minutes, and that is getting upper usage for a 2200 mah pack.  My pack is 113x35x30mm and the 4 cell 104x34x31mm.  I am already nose heavy on the Genesis and had to add tail weight, so I do not really want to add weight.  In addition I have a 129 - 130 gm motor and have not seen that light a 4 cell motor, especially if 5mm shaft.  If I allow about 2 to 1 weight ratio nose to tail, the weight gain adds up quickly.  Better weights may be available on CL tested equipment equipment and I would be happy to have that information.

Battery pack configuration is part of the difficulty; 2 large dimensions on that one.  The motor is small and fairly low amps/watts.  Most of the proper watt motors are in a larger heavier package.  Most of the 500+ watt motors are 1.5 - 2 oz heavier, in the nose.  As it is, I fly more maneuvers and less circles, but I am getting timing back and have a ways to go.  Hopefully by then, a solution, or a new electric airplane.  I can probably fit 4 cells and more weight if necessary, but that will almost be another conversion, similar to what Bob Hunt has done above.  I am at about 635 -640 squares and 52 oz, but also a 35 year old design, airfoil, and airframe.  I will keep flying and looking, thanks for the suggestions.

I have enjoyed a few outings over the last 3 weeks and have reasonable trim.  I flew my first entire pattern instead of just pieces.  The whole is much more than the sum of the parts as others have noted.  Genesis flies better than I, so practice is in order as weather allows.  I have learned a lot from the forum, great building and trim ideas.