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Dec 31, 2019, 02:25 PM
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Goldberg Ultimate Electric Conversion (ad nauseam)

I recently snagged an Ultimate kit on eBay and will be re-engineering and building it for electric power. I currently have a scratch built one that I converted from YS 120 power (it weighed a bit more than I planned) and it flies great on an Eflite 110 and (2) 4S lipos. I want to build the new one 'on a diet' and will be powering it with an Eflite 90 and single 6S lipo, 16-8 wooden prop. The only issue I have with my current sled is how to position (and access) the battery I currently have to take the bottom wing off. I realize there is a plethora of bits and pieces on the forum(s) about this conversion a lot of it dated. Has anyone come up with a solution for accessing batteries? On this go-round, I am thinking about a removable hatch including the canopy and forward my intent is to put the battery on the CG (like my current one) and shovel stuff around to make it work. Any and all suggestions welcome! William Tucker in Stuart Florida.
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Dec 31, 2019, 11:56 PM
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I have been sitting on one of these kits for a while, and also want to go electric.

These are the best conversion pics ive found. None of them are perfect, but the yellow one is getting close.

I would be interested to see what you wind up doing. Making the whole top removable sounds pretty good , but most electric conversions need the batteries forward of the cog to balance.
Jan 01, 2020, 11:04 AM
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Thanks for the comments and the pictures. As I am building this one from the start as an electric, it might be a little easier to make the mods from the get-go rather than doing a retro-fit. I think I am going to frame a hatch on top, will have to change the mounting style of the cabanes a bit. I will post some in-progress pics as I go along. Attached are a few snaps of my current scratch built. Thanks!
Jan 01, 2020, 12:28 PM
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Here is an innovative slide out cowl/motor/battery&esc tray on a Sig Citabria, wherein the whole tray, including the motor prop, . slides out the front of the plane and is locked into the fuselage with one spring loaded latch..... would work well in an Ultimate bipe where removing the wing(s) is a big hassle and avoids carving a hatch into top of plane behind the cowl; only one link between the module and the rest of plane, the esc control wire to receiver.

I've seen one or two other such front end removeable power modules in other build threads.

Michael in Ontario, Canada
Last edited by 2michaely; Jan 01, 2020 at 12:36 PM.
Jan 03, 2020, 09:47 AM
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Not being fluent in posting is there a way to move this post to another forum, Gas to Electric Conversions? Thank you!
Jan 03, 2020, 05:57 PM
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scirocco's Avatar
Originally Posted by MrTucker30
Not being fluent in posting is there a way to move this post to another forum, Gas to Electric Conversions? Thank you!
Look at the top right of each post. There is a warning triangle Report link. Click it, choose the option the Move this thread, which will enable selection of the forum you want it moved to. presumably Glow to Electric Conversions and provide your reasons. The mods should then move it for you.

One day I'll build my Ultimate kit, one day
Jan 03, 2020, 08:40 PM
homo ludens modellisticus
Ron van Sommeren's Avatar
Originally Posted by MrTucker30
Not being fluent in posting … is there a way to move this post to another forum, Gas to Electric Conversions? Thank you!
That will probably give you cubic inch to e-motor advice. But since e-motors are more versatile than glow/gas engines those types of advice tend to be restrictive.

I suggest having your thread moved to the Power Systems subforum.
Plane type and mass are leading, not cubic inches.

Gelukkig Nieuw Jaar Ron
• Without a watt-meter you are in the dark ... until something starts to glow •
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Jan 08, 2020, 10:04 AM
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Thank you for the help, moved the thread to Gas to Electric Conversions for suggestions on battery placement and access.
Jan 08, 2020, 03:14 PM
I just want to go fly!
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i never want to remove wings to change batts so hatches somewhere are always figured out. nice work.
Jan 10, 2020, 05:44 PM
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Roughed out the fuselage this week and fabricated the battery box out of light ply, going to install it at the approximate location of the fuel tank in the plans. Also hacked out an engine box and mounted the Eflite 90 just to eyeball everything in. Going to start on the top hatch tomorrow for battery access.

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