Bones1

Hello,
I saw a few Big Lift topics here but none were finished.
I recently re acquired an original Big Lift I owned for many years but had sold to a friend 10 years or so ago. I had bought it the 90s from a hobby shop as a consignment plane. I am guessing it was built in the 80s some time.
Anyway, while I owned it I had run several different glow engines on it including OS 120 FS, Webra 120, OS 1.08, and a OS 160 Gemini twin. It flew about the same with all of these engines and total weight was between 10 and 11 pounds. Launched many gliders etc..I tried to rig it for a Cross Country event but I couldn't get it to fly more than about 60 miles per hour no matter the engine. Just too much drag I guess.
I would like to bring it back as an Electric but have little to no learned experience so I am asking for advice on motor, speed control, and batteries. I will need to purchase support equipment as well. I would like to run a 16/8 or 15/10 prop. I am not interested in the geared motors and hoping for direction toward brushless out runners. I just want this plane to fly like the big trainer it is but with more than enough power for piggy backing gliders or towing if needed. The fire wall is ready for something and there is plenty of room in the fuselage for batteries etc. A little extra weight although not wanted will not hamper the way this plane flies. I saw that Seagull Models sells a plane called the Maxilift that looks identical to the Big Lift, same wing span of about 88 inches and 1080 square inches At 10.5 pounds this comes out to about 22 Oz per square Ft of wing loading
Thanks
Bones

blvdbuzzard

Well not sure of the weight of your plane. But a Tacon 110 with a 17x10 prop will put out about 15 pounds of thrust at 65 amps or 1900 plus watts.

Motor
http://www.hobbypartz.com/96m607-big...325-295kv.html

ESC
http://www.hobbypartz.com/07e-flyfun-100a-hv.html

Battery (2) 4s for an 8s setup
http://www.hobbypartz.com/98p-30c-5300-4s1p.html


This is a starting point.


Buzz.

Bones1

Thank you. Ready to fly should be 10 to 11 pounds. A 17 inch prop would be at the limit for prop clearance. I have been flying glow/gas for thirty years and these engines perform better with specific diameter .and pitch combinations. I am guessing that electric motors develop their power and efficiency differently. So would an electric motor care if you ran a smaller diameter and lower pitch prop as long as the rpm limits were kept in mind? I guess what I am asking, should I choose a combination such as the one you have supplied above and be able to run lesser props with out penalty besides weight and expense? I was going to say that a ten pitch prop usually means a faster approach speed at idle but I guess that doesn't apply here. I do like the bigger props with lower pitch because they respond so quickly from low rpm.
Thanks for taking the time to answer my question as I will have to forget a lot of what I think I know. You know how arrogant those darn glow fuel guys are!
Bones

blvdbuzzard

E power has a ton of torque so they tend to spin larger more pitched props slower RPM's. You can always go with a 3 or 4 blade prop.

if you drop to a 15x10 4 blade you are about the same as you have with the 17 inch prop.

Now if you upped the battery to a 10s, 16x10 prop you would have about the same thrust at 55 amps.

Here is a calculator you can try different motors, props, batteries before you let the magic smoke out of any thing.

http://www.ecalc.ch/motorcalc.php

Buzz.