Hello folks!  I'm writing this to request some suggestions and recommendations for converting my Brodak Legacy to electric.  It's Brodak kit ARC-0017, ws= 59-3/8", rated for .40 - .61.  My original thoughts were to mount my N.I.B. OS FL 70 four stroke but I also think it might be a good subject for conversion.  Now please understand, I have a fair amount of c/l and r/c scratch and kit building experience so that shouldn't be a problem.  However, I've been hardcore nitro and gas to this point and as such I've not put much effort into learning about electrics as they relate to conversions.  I'd appreciate any suggestions.

Jim,

Here is the set up I've used in 2 planes and it's basically the same set up used by Will D. and others, all planes in the same size ballpark.

Cobra 3520/10 KV 980
Castle Ice 50 Lite/Phoenix 60
Zippy 4S 3700-4000
Hubin timer

Good system.  Hope this helps.

James

  Thanks guys!  About an hour after I posted this a buddy suggested that I contact Brodak (don't know why I didn't think of it myself  )>  I did and got a really nice response from the folks who forwarded it to Dennis Adamisin who supplied me with his recommendation .... plus it's "one stop shopping!!     Now to sneak the checkbook away from the wife!!   

Dangit, that thought was trying to knock on my brain and I didn't listen.  Do they have a conversion kit for the Legacy?

Looks good, Denny -- batteries go in from the top?

Looks good, Denny -- batteries go in from the top?

Yup.

WARNING what follows sounds like a commercial: 

The top rails help reinforce the opening and also provide a ledge for potentially locking in the battery and top hatch. The kit will include a wing mod to build a reinforced pocket into the wing leading edge.

A lot of folks are discovering the 3515 & 3520 motors so I designed the conversion to accommodate either 35xx (3526 shown) or 28xx motors.  I would expect a quite a variety of 4S, 5s, & 6S packs will be in play.  The battery compartment is 2.25" wide x 2.375" tall (below side rails) x 8.75" long including the LE pocket.  I show the MPI arming plug up high on the outboard fuse (my preference) but it will be optional to put it pretty much anywhere the builder wants it.

The cowl is built in place, the motor is installed through the battery hatch.  You can do this with a rear mount motor if you mount the motor to the BACK of the firewall and slip the motor through.  The advantage for no cowl is that it restores a lot of the structure you lose with a top side battery hatch - comparable to a normal fuselage open to the bottom with a long cowl.   

BTW, for Jim C I recommended the Arrowind 2826, 4Sx3500 pack and the new Brodak F2B Hornet ESC.  The Arrowind 28xx motors actually have a 30mm stator like the Scorpions so they run "big" to their size.  The new 4S x 3500 packs are very high capacity for their size and weigh just under 10 oz.  The ESC is a brand new piece that I started flying late last fall.  Designed for Heli's it has a VERY smooth governor designed for Heli's.  I worked with them to revise the physical package somewhat and to enable BRAKE function while the Heli governor is active.

Jim C will be converting an ARC, I suspect Jim will best be served with a rear mount motor because that will be his best assurance of tying into solid fuselage structure.  I have not touched the Legacy ARC/ARF, but I converted a SV11 ARF using the Universal "B" set designed for 2.25" inside width fuselages.  To do that I removed the mounts and the "F1" bulkhead then installed the new firewall & battery tray.  Also set it up for a top battery hatch. 

I suggest you get those engine bearers knocked out of there ASAP.  That way there'll be no turning back!

Not yet, its on my bench. Taking awhile because it includes pieces for front mount and rear mount variations, I have to build both to include in the installation manuals.  Here's some pix so far:

hmmmm - where have I seen this setup/layout before.... 
oh yeah - on my vectors and legacy of about 5yrs ago -  totally dig it - it WORKS

Hi Jim,

I did an Electric conversion with a Legacy ARF just a while ago using Bob Hunt's Hard nose mount.  The details are in the "List your set up" section,  and I also have some pics of the mods in the video below.

Greetings Joe!  That's a really nice looking setup you have there.  I like that motor mount!  I looked over your video and find it to be very enlightening, especially considering I've no idea how to rig one of these electric jobs up.  I see you've even acquired the capability to program your setup from your laptop.  Please explain what features you are setting and if you think the laptop is necessary for initial programming.  I don't know if the items I purchased will require programming because given my skillset I may as well revert this thing back to my OS 40 !!  This morning I began removing the built-in hard wood motor mounts and made a firewall from a piece of 3/8" aircraft ply that I had left over from another project.  Hopefully I can rig everything up correctly.  Just curious, what kind of prop is that you're using?  I like it! 

The 3-blade prop I’m using is Igors 11x5C , it’s super light!  works very well on the Legacy.    I’m not too familiar with the Brodak set ups,  but I would think they come pre-programmed like the RSM ones. 

Hi Joe!! Yep, I left the aft part of the motor mounts in place principally because I was lazy but what you've stated about using them for the battery tray and esc mount  .... well, now I'm mighty happy I did  !!  As I get closer to final setups, I'll reach out to you for info as to how to acquire a couple of those props.  I'm hoping Dennis has continued to monitor this thread because I'd like to know about the necessity/needs for computerized setup with the components I received, as listed above.  Believe me, from what you've described, it looks like all of this conversion is going to be one heck of a learning curve coated with a thick layer of frustration.

I converted a Vector & a SV11 ARFs to accept the Brodak conversion packages.  Key to that was gutting the fuselage between "F2" and the nose ring.  Here's a few pix on how it was done.  

* By carefully removing the top block I was able to re-use it as a top side battery hatch.  Plan B would have been to substitute a new hatch made form a 3/4" balsa block.

*With the top removed it was easy to get to the beams.  I drilled several holes along the beam right where it meets the doubler, then jigsaw the beam into several short (2.5"?) pieces.  I pulled these out using Channeloc pliers.  I have done this several times before and this was the first time I ever had the ply under the mount delaminate.  Not quite the disaster that it sounds, as the conversion includes a set of 1/8" x 1/14" rails that reinforce the top opening to the battery tray.

Thinking this over, the next time I try this I will simply jigsaw the mounts out close to the surface of the doubler then grind/sand them out til flush.

* F1 helps stabilize the front end - with the mounts out its the last to go.  What's left is a pretty good shell for building in the conversion bits...

BTW, getting both fuselages shown to this stage took about 1 1/2 hrs, so it is not terribly time/labor intensive. 

Also BTW; removing the IC mounting beams saves weight.  The final conversion with all the electric parts installed is 22 grams lighter than the starting point with the beams.

• It is not wise to just unplug the battery -- Bad Things can happen to the ESC if you do.
• If the timer has a button you should be able to press that and make it turn off.
• If not, you should be able to unplug the timer from the ESC
• Have you ever installed a 3-phase motor in a commercial plant?  Our motors are the same -- just plug the three wires in, give it a whirl, and if it goes backwards reverse any two wires
• Pursuant to that, you may want to tape things down right under the prop, so the wires don't get sucked up in there if it starts in reverse
• First time around you can do it with no prop

I hope this helps.

   Okeey dokee!  Thanks guys!  So, it will be all right to run it without the prop .... great!  And just to make sure I understand, I can push the red button to start the motor, per the instructions, and if need be, press it again to stop the motor at some point during the run.  Okay, I think I'm ready to experiment !  I guess the next big thing to figure out is how best to mount that big ol' potentiometer (I assume to be the RPM pot)    Of the various E-models I've seen, I don't remember seeing anyone with something like this mounted to the side of their plane!   

  Okeey dokee!  Thanks guys!  So, it will be all right to run it without the prop .... great!  And just to make sure I understand, I can push the red button to start the motor, per the instructions, and if need be, press it again to stop the motor at some point during the run.  Okay, I think I'm ready to experiment !  I guess the next big thing to figure out is how best to mount that big ol' potentiometer (I assume to be the RPM pot)    Of the various E-models I've seen, I don't remember seeing anyone with something like this mounted to the side of their plane!   

Tim & Wynn pretty well summed it up - everything has been said but not everybody has said it! 

About the stress - I know what you mean because I was EXACTLY where you are when I did my first set-up. When I first started mine - nothing happened!  The system I had used a small activating switch and there was a broken solder joint.  Fixed that, it worked, and I felt like I OWNED it!

The Brodak hardware all comes pre-wired and ready to plug & play - hopefully taking a little bit of that stress out of the equation.

Plug the 3 motor wires into the ESC - you have an exactly 50% chance of getting the correct motor rotation first try.  As noted above, if it runs backwards, shut it off and switch ANY two of 3 wires and try again.  I used to mark the connectors with tape - but I do not bother anymore.  Its less bother to just check & correct it. (yes, I have got to the flight line with a motor that ran backwards when started - twice!)

The START button is also the STOP button - unless you let it run out the flight duration time you have set.

Will Hubin makes lots of timers, I selected his manual timer with the RPM fine tuning pot because it is as close to a "needle valve" as you can get and (generally) "newbie friendly".   Will originally built timers like this for people who like the Castle "High Gov" governor mode and wanted a refined way to set the RPM. 

There are 3 pots on the timer, their functions are called out on the timer board. This timer has a pot adjustment for start-up delay, another pot for flight duration and two pots for setting the RPM. The "coarse" RPM adjustment is on the timer board and is intended to get the RPM to within 500 rpm - in reality you can usually set it right where you want it.  If you miss the RPM, then the remote pot is a fine-tune, with a range of 500 RPM.  It is suitable to - well, fine tune the setting you want.  It is also handy for those of us locked into the glow engine ritual of changing the settings every flight (you will learn to forget that habit!)

As for the size of the pot, I am installing one now and plan to cut down the length of the shaft.  Looks like I could remove about 1/2 of it and never miss it.

By the way, lots of folks settle on Will Hubin's FM-9 timer SYSTEM which incudes a box for programming the timer.  It is more expensive to start out with but generally a good idea if you plan on building a lot of electric birds.  Write to Will directly to get his prices and lead time.

Functionally the timers will all drive the ESC the same way, it boils down to which methods do you feel comfortable with and how much do you want to invest.

Well, just to make sure I wasn’t losing my mind I opened up all the electric motor setups stuff I had ordered from Brodak’s a while ago for the LOCKHEED NEPTUNE (that I never finished   ) and rigged a set to test.  Well, to my joy, it worked exactly as advertised.  Using the 11.1V battery the ESC beeped when the battery was plugged in and the little motor spun up shortly after the button was pushed and even shut off when the button was pressed the second time.  I’m pleased!  Well, I went back and checked the LEGACY setup again, step by step.  The battery checked good but when plugged into the ESC there was no initializing beep.  Any suggestions??

Okee dokee!  The GT Charger is functioning as designed.  During this interim I put the larger battery back on the charger and all four green lights ans showed 100.  As for the Venom Pro, I have been very pleased and impressed with its performance and capabilities across multiple battery chemistries, many of which I'll never need to access.

As you suggested, swapped the timer with the smaller timer for the LOCKHEED NEPTUNE, which I did, and the test setup didn’t work.  Again, I went into my box of “goodies" and found a BH-1683, 35A Aerowind ESC that I had ordered quite a while back but never used.  I opened the package and substituted it for the LEGACY's F2B Hornet ESC and everything functioned as expected using either battery or timer set.
 
I’m pleased.  It looks like the F2B Hornet ESC is faulty.  I wonder if I can return it for an exchange/replacement?  Any suggestions?

Okee dokee!  The GT Charger is functioning as designed.  During this interim I put the larger battery back on the charger and all four green lights ans showed 100.  As for the Venom Pro, I have been very pleased and impressed with its performance and capabilities across multiple battery chemistries, many of which I'll never need to access.

As you suggested, swapped the timer with the smaller timer for the LOCKHEED NEPTUNE, which I did, and the test setup didn’t work.  Again, I went into my box of “goodies" and found a BH-1683, 35A Aerowind ESC that I had ordered quite a while back but never used.  I opened the package and substituted it for the LEGACY's F2B Hornet ESC and everything functioned as expected using either battery or timer set.
 
I’m pleased.  It looks like the F2B Hornet ESC is faulty.  I wonder if I can return it for an exchange/replacement?  Any suggestions?

DEFINITELY return for replacement.  Sorry for the inconvenience.

OK, now THAT is a problem I have encountered.

The T- Plugs (Dean's Ultra) main power plugs have spring tabs on them that are supposed to keep the contact snug and usually it works fine.  HOWEVER it is possible to plug it in with the spring tab missing the slot and going outside the plug.  When you do this there is nothing holding the contact, and you get something like you described - jiggling it to get (& intermittently lose) contact.  I had this problem on a profile - the spring tab is very flexible and its amazing how easy it was to plug it in incorrectly.

I am pretty sure that is your issue.  BTW, I got your first ESC in the mail.  Tried it out this morning and it initialized & started up just like it was supposed to - I am guessing the same thing was happening for you on it.

I STRONGLY recommend using the Max Products arming plug system.  You can take your time and take care in plugging the battery in, even inspect the connection to make sure it is right, then arm for flight using the arming plug.

Happy Easter.

 http://www.maxxprod.com/mpi/mpi-21.html

Now before I go, what is "Max Products arming plug system"??  What is it used for?  I do not understand the setup .... I thought it was sufficient to use just what I have .... just install the components, mount the battery, press the red button and fly !!  I take it this is incorrect  .

You need to read the pertinent rules.  The digest (and you should read the rules!) is that if it's an electric plane, and you leave it unrestrained with the battery connected to the ESC, then you'll be disqualified.  It's a safety measure to prevent airplanes in the pits or whatnot from starting up unattended.

For a profile you can get away with unplugging the battery.  In theory you could do that with a full-fuselage stunter, but most people prefer to use an arming plug -- the routine is to put the battery in at your leisure in the pits, while swapping lies with all the slime-powered guys who are fueling up.  Then you walk the plane to the circle and plug in the arming plug, after which either someone holds on to the airplane or you hold onto the handle.

  Dennis!!  Dennis!!  Dennis!!  I don't care what anyone says ..... YOU DA' MAN!!   I did it!!  I did it!!  And it's all because of you and your expertise and patience.  THANK YOU THANK YOU THANK YOU!!  Yesterday I completed the ARC Legacy and I gave it its maiden flight this morning.  It was absolutely awesome!!  Nice, smooth, quiet, positive pull, perfectly flat and level.  I thought about posting the build log and detailed photos but I doubt anyone else would be interested in my trip from "box to landing".  Hopefully I can bring it with me to Brodak's and I can watch you or one of the expert pilots put it through its full range of paces.  I'm a builder more so than a flyer.

Jim Carter

Hey Carter! I'm always interested in your build logs... Maybe I'll learn something! Lol

Hey Bro Dane!!  Well, for about the past 20+ years or so, for nearly every model I've built, be it a plane, ship or whatever, I've been keeping a daily log of what I do.  I don't write like the magazine articles and I guess that's why I could never get any of them published back when the magazines were the predominant means of sharing new construction.  Each of my build logs is somewhat unpolished in the way it's written but it contains my thoughts, problems, corrections, modifications, joys and frustrations associated with each build and with many of the more recent build logs, I've taken a myriad of step-by-step construction / assembly photos.  For example, the build log for this project, Brodak ARC Legacy, is 24 pages long with nearly 100 photos.  Do you remember the Brodak Legacy kit I was blessed to build for Bro Colin Anderson over on the Brotherhood of the Ring site?  Well, the build log for his model was 47 pages long and included nearly 200 step-by-step construction photos to include the modification of the removable wing.  Heck, the build log for my B-29, that I recently completed, from the box to its first contest show is 136 pages long contains just over 500 photos  .  But .... if for some reason .... I should ever build another, I know where every nook and cranny, pitfall or joy is located  .  All that said, are you shur' you wanna' see it??     

CONGRATS Jim!  Glad I (and the others who commented) could help.  You showed some pretty good persistence to soldier on through the set-backs you had and bring it  "home".  As for the power and the flying, I never had any doubts about that.  By all means bring it to Carmichaels, I'd love to see it.

I think it would be beneficial to others on this site to see more of your build pictures, especially those around your electric mods.

Now that you have successfully built and flown an electric model you are now a qualified GURU for any other electric builders-in-training.   

  Greetings y'all!!  And a very special "Greetings" to you Dennis  !!  Life has kept me rather busy but since my last posting I've been able to fly the Legacy seven times and I have been really pleased.  I Guess it was on the fourth flight that I switched props to use an APC 12x6E rather than the 13x4.5E that was originally recommended.  Given the soft landing gear struts that came with the kit    and the need for a bit more ground clearance (we have to fly off somewhat unfinished grass) the smaller prop was just the ticket.  Also, it really seemed to perform (pull) better although I didn't think to compare lap times  .  Ultimately I got fed up with the soft struts  and replaced them with two replacement struts from I fabricated from some 1/8" K&S Music wire  .  No problems with the struts now !  I can't wait to find someone with the skills to truly put it through its paces   .  In the words of Clint Eastwood ".... a man has got to know his limitations"  and I've put enough planes in the dirt "to know my limitations"  .  I've been able to video a few of the flights by attaching my little "spy" camera to the inboard wing with a bit of velcro.  They're not all that great but I'll try posting the latest one on You Tube.  I've been flying it using a set of .021"x63' lines but a friend of mine suggested using a set of .018"x60' lines as they would be somewhat lighter and may increase performance a bit more.  I suppose I just may have to give it a go, eh  !!

Hi Jim,

Good to hear is coming together..  The .021 lines are definitely too heavy to use on the Legacy.  I would try .018" x 64' eyelet to eyelet, it should work much better.  and fly it at around 5.25-5.35 laps. (depends on the trim and conditions)

Thanks Joe!  I'll be getting the lines going in a day or so.

Hi Jim.  Sounds like you and the Legacy are getting along famously. 

I think the 63' lines would be the minimum, and if you work through it per Tim's suggestion the max would probably be about 67'.  I'd probably go about 65' for a nice round number...  As other have suggested .018" is all you need - both per rules and per practical need.  If you add line length and change line diameter, do not be surprised if your tip weight needs to change - but it should be a near wash.  Longer lines will give you a "bigger sky" to fly in - you will not feel so cramped to hold maneuvers to 45 degrees.  You will probably can and will want to bump the RPM up a little - which will also affect your  battery usage, so keep some tabs on it.

About the props:  Smaller diameter can help corners, you can also clip the 13x4.5 down to 12".  The lower pitch requires a few more RPM but the flatter pitch seems to help prevent wind-up in the wind.  (on the other hand the 13" disc can be your friend in the dead calm!)  BTW, I did not see if you posted it, but how much battery ARE you using?

Are you still planning on going to Carmichaels?