Electrifying a WOT4 Pro ARTF

[David Pearce 4]

I used to have the earlier electric balsa ARTF WOT4 and am looking at buying the WOT4 EP/GP as a replacement. But reading blogs on here I see it has the same problem as the earlier version in that it's tail heavy. Many owners report the need for substantial nose weight unless they select a heavy motor and a 5000mah lipo. (I'd prefer using my 4000mah rather than buying new 5000mah)

I was wondering if the Pro version, which is lightened, may be suitable for electric conversion. In other words, would fitting a lipo hatch to the Pro be a better solution than adding nose weight to the EP/GP version? Or are there other difficulties in fitting a electric power?

Any WOT4 Pro owners have a view?

Edited By David Pearce 4 on 19/11/2018 11:56:26

[Bruce Collinson]

David,

There's no panic to answer your question then! I know the feeling.

I can't speak for the Pro version but I'm on my third standard ARTF in two years (don't ask, pilot error) and they all flew on the Ripmax Quantum 40 motor and mostly 5A 4S LiPos. None needed noseweight. I appreciate that your LiPo will be a bit lighter than mine.

I left the standard elevator pushrod in and upgraded all the clevises to metal. If I really wanted to lighten the tail end I'd try a carbon tube pushrod and maybe risk the plastic clevises, than look carefully at the tailwheel, and finally consider some judicious lightening holes in the tail surfaces.

Last time it needed attention I dug out a slightly larger Overlander motor and was about to start drilling to fit when I realised the bullet connectors are larger and contemplating changing all 3, I lost the will to live but next MOT I'll try it. If you're buying a motor especially for it, this might all add up to a no-ballast solution with which I agree entirely.

Whatever you decide, good luck and if it's a Pro do please report back.

BTC

[David Pearce 4]

Thanks Bruce, that's interesting. Adding my own lightening holes (carefully!) to the tail and fuselage is a good idea. A friend did the carbon rod mod you suggested for the elevator which helps too.

He also added spats, no real help to balance but it really improved the appearance.

I'd still like to hear the thoughts of any Wot4 Pro owners on this.

Thanks

[Geoff S]

If it's the ARTF Wot 4 mk 2 then it's not really a problem. I put one together a few weeks ago and had no problems at all.

Geoff's Wot4 Nk2 electrification.

I get up to 10 minute flights comfortably on 4AH 4S LiPos with a decent motor on a 12x6 prop - 700 watts maximum but I do use throttle control

Geoff

Edited By Geoff Sleath on 20/11/2018 19:20:06

[David Pearce 4]

Thanks Geoff but I was specifically asking about the feasibility of electrifying the ARTF Pro version that is designed for IC:

**LINK**

In the hope that it's lighter and doesn't suffer from being tail heavy. But thanks for your response.

David

[Denis Watkins]

To help your analysis David, two of these fly at my patch, one electric, one I/C

Now, my observation is that the Foss Camp have lightened the wing, the u/c etc and the rear fuz

Overall, this has lightened the front end somewhat

The rear stabilisers are still sheet stock, but larger, for control, so they are heavier (fractionally)

My job at the patch is to test fly everything, that the model is stable, and that the failsafe operates

Both flew beautifully, can be flown lively, or sedately, with nothing of note on the day

They flew much like a Wot 4 Classic

[John Lee]

A bit late to the party but I've electrified the WOT 4 Pro. The worst part was cutting a top hatch - measure 4 times cut once and then fit magnet closures. The model was intended as a winter hack so I specifically wanted a top hatch rather than having to invert the model in the mud to change the batteries.

Mine's fitted with an AXI 2826/10, 10x8 prop, 60A ESC & 4S 2700 batteries. The battery carrier is the option one from the GP/EP version which fitted directly. CG came out spot on with no ballast (I don't know which version you flew Dennis but mine has built up tail surfaces, as does even Pro I've seen). AUW RTF is 1.88kg (about 4.1lbs) & power output is just over 700 watts.

And it flies like a WOT 4. I've had just about every variant of the standard size since it was first produced & this is up there with the best of them. Recommended.

[Bruce Collinson]

David,

How did you go on?

My third ARTF is just coming out of the repairers again with the Overlander motor fitted but it’s unlikely to repair next time and I might look at the Pro version next time. I have concluded that I’m unlikely ever to be without some sort of Wot 4 in the hangar.

BTC

[colin weaver]

Posted by Bruce Collinson on 20/11/2018 14:00:37:

David,

There's no panic to answer your question then! I know the feeling.

I can't speak for the Pro version but I'm on my third standard ARTF in two years (don't ask, pilot error) and they all flew on the Ripmax Quantum 40 motor and mostly 5A 4S LiPos. None needed noseweight. I appreciate that your LiPo will be a bit lighter than mine.

I left the standard elevator pushrod in and upgraded all the clevises to metal. If I really wanted to lighten the tail end I'd try a carbon tube pushrod and maybe risk the plastic clevises, than look carefully at the tailwheel, and finally consider some judicious lightening holes in the tail surfaces.

Last time it needed attention I dug out a slightly larger Overlander motor and was about to start drilling to fit when I realised the bullet connectors are larger and contemplating changing all 3, I lost the will to live but next MOT I'll try it. If you're buying a motor especially for it, this might all add up to a no-ballast solution with which I agree entirely.

Whatever you decide, good luck and if it's a Pro do please report back.

BTC

[David Pearce 4]

Thank you John for your helpful reply. It's not too late either as, as often happens, I got sidelined into something else. But I am still keen to get another Wot4, there's nothing better for sport flying, towing streamers etc.

I was also pleased that someone knew the version I was going on about! I'm encouraged by your comments and I think the Pro version is worth the conversion work. On a maximum of 4000mah lipo it must offer longer flight times than the other version.

I find it odd that Ripmax chose to offer a lightened version for ic only. An electric version seems an obvious choice.

Thanks again.

Edited By David Pearce 4 on 29/03/2019 18:31:22

[simon barr]

I have just converted the Wot4 Pro to electric.

Unlike my mate John Lee above who cut the top hatch, I decided to cut a hatch in the bottom, as I thought that if I stuffed it up, I could easily make another!

I made a battery tray from lite ply suspended between former No2 and the servo tray, and fitted a box/back-stop for the lipo to slip into to secure it once I had worked out where it should be in order to get the C of G as near as possible correct.

All up weight ready to go with a 4s 4200 lipo is just a shade under 1.9 kg.

I have propped the motor to achieve around 600 watts.

Test flew today - Brilliant! Timer set for eight minutes (activated from throttle stick), and landed after mixed throttle flying with 32% showing on the lipo checker.

I will add some pictures once I have down-loaded them.

[simon barr]

Here you go....

Lipo in position in bottom hatch.

Top view of battery tray suspended between former No2 and servo tray.

And just for good measure, glider tow release for light weight foam gliders.

[John Roberts 9]

Very neat job Simon.

I have been thinking about getting a Wot 4 Pro myself and doing an electric conversion.

It would be very helpful if you could provide specific details of the motor, ESC and prop you used please.

Thank you.

[Bruce Collinson]

Simon,

Very useful. Mine has been in the pits again and is in danger of containing more glue than balsa or ply. Whilst I find it fine with a 5A 4S Lipo via a top hatch, as and when it becomes beyond further repair then a Pro with conversion may well be the way forward for this "go to" plane.

Any chance of some more pics from a bit further back showing the hatch detailing, in addition to John's request above?

BTC

[simon barr]

Hello John and Bruce.

The motor is a Tornado Thumper V3 3548/05 900 kv mounted on a ply plate (decent ply, not lite ply), and this is then mounted to the fire wall using 4mm stud as stand-offs.

I am using a Robotbirds 60 amp ESC (because I had one), and turning an APC 11 x 5.5 electric prop. I may try an 11 x 7 prop just to see what it is like, but I don't think it needs it... The thing goes vertical with the set-up I have already and is all well within power specs for the motor and ESC.

Battery hatch cover in place.... The plastic vent is from the scrap box, and I opened up the square film covered hole just behind the U/C as an air exit.

[John Roberts 9]

Exactly the information I needed.

Thanks Simon

[Bruce Collinson]

Snap.

BTC