CafeenMan

I have a Hacker Tiger Moth kit that I picked up in Germany. It is designed for Rubber or CO2 power. I was thinking about putting a .03 Diesel on it, but now I'm more inclined to go with electric.

I would like this airplane to actually fly with plenty of power - not a desperate struggle to stay airborne. A buddy of mine recommends using Lithium batteries which seems good to me, but I have no idea what size motor to use or anything about electrics actually.

How do I determine the proper size motor, batteries BEC to use?

The plan is to use full-house controls. The plane has a 23" wingspan - not sure of the area.

I have three different type micro servos and will also get a feather type receiver. Based on my experience with glow, I would expect the plane to come in at about 10 oz. with a .02 glow. I have no idea what the batteries will weigh, but remove the engine, add the electric motor and batteries and that's what it will weigh about. Sorry for being so cryptic.

All advice from you electric experts is much appreciated.

Thanks

- Paul

Greg Covey

Hi Paul,

Today, there are many solutions available to power your Tiger Moth for electric flight. These range from inexpensive GWS geared Speed 300 power systems to more pricey brushless motors. Additionally, the battery cost will vary with different technology cells from NiCd, to NiMH, to Lithium Polymer cells.

I would recommend a complete motor, gearbox, ESC system like the Astro Flight 010 at [link=http://www.aeromicro.com/Catalog/astro_flight_010_brushless_motor__14t__with_micro_ gearbox__3_3_1__and__variable__2787498.htm]Aero Micro[/link]. This can be used with 8-cells of 720mAh NiMH or 3-cell LiPo packs like the Kokam 1500HC. This type of pre-assembled system will cause you the least worries. This is not an extensive list and many other possibilities exist but the AF 010 will power the plane very well.

As for a receiver, I would recommend a "full strength" micro receiver instead of the single conversion Hitec Feather. FMA Direct makes the M5 receiver and Hitec makes the 555 or Electron 6 receivers. Others also exist like Berg, etc.

Good luck!

CafeenMan

Thanks for the Reply, Greg. I have several Hitec 555's. I love them, but they're too big for this project. I'm going to need something smaller.

I appreciate the information. I'll look in to the power package you recommend. Thanks.

CafeenMan

Greg - That is one expensive little motor! Yikes! The reason I was stearing away from Diesel is that the .03 is about $90. That motor is $50 more than that.

Have any more economical suggestions?

Greg Covey

Paul,

You can always remove the case on the 555 receiver to drop some weight. If the FMA M5 receiver is too expensive for you then I would just go with a GWS R4-P single conversion receiver. Often, our budget helps to limit our choices.

Try to determine what size prop you would like to swing and the maximum size prop for safe ground clearance. This will determine which gear ratio is best to use. Check out these GWS EPS-300C power systems at [link=http://www.aeromicro.com/Catalog/electric_rc_power_systems_107407_products.htm]Aero Micro[/link]. For $17.45 you get a Speed 300 motor and a nice ball-bearing gearbox. You'll then need a 10amp ESC and a prop.

CafeenMan

Greg - I still don't think that receiver will fit even with the case removed unless I don't use any servos in which case a receiver is unnecessary. What is the best feather receiver going?

As far as cost goes, the real issue to me is putting a $150 power plant in a $20 kit. Doesn't make a whole lot of sense. I'll get the $80 deisel before I do that. I was thinking I'd be able to find a decent electric motor for this size plane for around $30 plus speed control/bec. That Speed 300 looks like a winner. I have no idea what size prop to use. Again, this is a 23" biplane.

Greg Covey

Paul,

Perhaps I misinterpreted your initial post.

The cost of the receiver will be the same however you decide to power it. The M5 is the best dual conversion receiver at 0.3oz. There are many good single conversion receivers available like the Hitec Feather, GWS R4-P or Berg.

Your 23" Bipe may simply be suitable for a typical GWS Lite Stik power system. This is a DX-A geared motor, 2amp ESC, and 10x4.7 prop. This will work fine on a very light 2-cell Kokam 340SCH LiPo pack.

Optionally, you can spin the prop faster, if needed, with a higher gear reduction ratio using the same prop on a 3-cell Kokam 340SCH pack. Use a DX-C geared motor...same motor, different gear ratio.

First, determine if a 10" prop will work for you. If not, what is the biggest size?

CafeenMan

Greg - I'm thinking the only way to launch this plane is by hand. It's just too small for any place I fly to attempt an ROG. The plans show a 7" prop on the CO2 motor and that only gives about 1/4" of ground clearance.

When I said I want plenty of power, all I mean is that I want to be able to fly the plane at about 1/2 throttle and not be struggling to stay airborne. This is a Tiger Moth, so it doesn't need to go fast and would look silly doing so.

The real problem is that all I've ever used is gas. I'm aware of many of the items used with electrics, but don't know how to size a motor to the airframe. If it's gas, then no problem.

I plan to cover the plane with tissue and dope and expect it to be very light. The kit is very nice. All the outlines are pre-laminated and ready-to-use. The ribs are die-cut, but the manufacturer has already removed them from the sheets and bagged them.

What's the difference between the 03 and Lite Stik system power wise? What would you say is the maximum weight that both of these engines could fly?