Ripmax Acro.Wot Mk2 XL

[Paul Adams]

I think the down thrust needs adjusting

Keep the post going as looking at getting one myself. Changing to two elevator servos I agree must be a a good idea.

Anyone else flown one yet, and if so any videos

[Martin Cavie]

I have mine now ready for its maiden flight which hopefully will be Friday. I used Ripmax Quartz 501 servos all round except the throttle which is a JR 591. I have an ASP 180 2 stroke up front and needed 40g on the tail to balance.

[Bob Cotsford]

Posted by ChrisB on 27/07/2015 21:34:34:

I've got the wotty Xl and I'd give it a 7 out of 10, not too bad really.

I can't understand why on earth the manufacturers choose to use a mixture of imperial and metric fittings...absolutely ridiculous!! UC Bolts and elevator pushrod metric and aileron pushrods were imperial, I don't mind which but to mix them is stupid! The instructions are a little out of date, as they show pre-installed captive nuts for the engine, although mine didn't have any, or holes, or even marks and its no wonder they don't describe the installation of the elevator pushrod.

Is the Acro Wot the same?

I replaced the aileron push rods and the pins in the clevises fell out as soon as I fitted them to the horn, so they went as well.

Cheers

Edited By ChrisB on 27/07/2015 21:35:45

I remember having problems with loose pins on the Wot XL, but I don't remember them being imperial threads.

The Acro XL appears to use metric all round, and now the bulkhead isn't drilled and the instructions cover fitting the blind nuts so it seems they are learning. Even installing the elevator pushrod is a breeze compared to the Wot XL

Mine has the batteries right back alongside the elevator and rudder servos to get the CofG at the front limit, but it needs around 3/32 (2mm or so) of up trim for level flight and a fair bit of down stick for inverted so I'm wondering about sticking a pair of servos at the back for the elevator halves. + two servos and extensions, - one 3/8 pushrod and wire ends - I reckon that would leave a balance of about 50 gms extra at the tail.

What do you think?

 

One thing I did notice compared to the original kit built Acrowot - the big boy is much easier to land, none of that horrible floating on and on that the little one is prone to.

Edited By Bob Cotsford on 11/08/2015 11:50:06

Edited By Bob Cotsford on 11/08/2015 11:50:41

[Paul Marsh]

Strangely, the marks for the engine holes lined up perfectly for the mount for the saito twin.

[Rich too]

Following thread with interest. I fancy one of these, and having done some research, I don't think my Zenoah 45 would be out of place up front, although it sounds like balance may be a problem..

[Paul Marsh]

Just finishing mine off. Ran the engine.

[Rich too]

Posted by Andrew Ray on 27/07/2015 18:47:50:

Bob, yes the wing tube on mine is tight in one wing but I have left it as is because I will leave the wing in one piece for storage and transport.

I'm interested that yours balances as it does, I have a Roto 35vi which is a similar weight to the NGH GF38 and my balance point is well forward, I can shave off some weight at the front but not enough to avoid lead in the tail. As a rough calculation mine is currently 6.7kg which includes about 300g at the tail to get it to balance. The Roto uses a beam mount but requires additional spacing of something like 50mm to put the engine in the correct place. I have made an alloy mount from bar stock and as a guess if I used stand offs I would be able to reduce the weight at the front by approximately 200g but that would result in less than 100g reduction at the tail due to the moment arm. I'm sure the model will carry the weight but lead in the tail doesn't seem right.

I too think this kit is good value. I found that the clevises were quite loose on the supplied rods and I had a nut that would not tighten against the clevis, the problem being the supplied threaded rod in my example being slightly undersize.

That's quite hefty, is that a usual weight for these? I think at that weight anything from 25-50 cc should be fine up front.

[Paul Marsh]

I varied from the plan, and put two servos in the tail, driving each elevator half. Much better, no slop and redundancy should a servo fail in the air. Also, two lower powered servos can be used and mixed on the 8ch rx as dual elevator.

Vid of engine running:

Edited By Paul Marsh on 11/08/2015 15:38:12

[Paul Marsh]

Finished. Might fly it later...

[Bob Cotsford]

Paul, what servos did you use for elevators? Did you stack them one above the other, and what did you find when you cut into the tail? Is it there enough space to bury standard size units to a respectable depth?

 

Edited By Bob Cotsford on 11/08/2015 17:26:10

[iqon]

once you have flown yours please let me know if a Zenoah G26 magneto would fly this....looking for a new home for engine...thanks...

( not looking for 3d, but want a bit more than scale flying... )

Edited By iqon on 11/08/2015 20:28:40

[Paul Marsh]

Mine flew perfect. Had 3 flights and that engine is so gorgeous.

On the first take off, I put it into a set or rolls, loop, wing over on the first circuit. No trim adjustments at all. Just floats on, suppose like the Kit Extra Wot.

I used a Hitec 7966HB Digital Coreless on the rudder, and two 5495BH HV on the elevators and two on the aileron and a Hitec HV 430BH on the throttle.

As for the elevator servos, I staggered them one each side and just so they miss each other.

These servos make the plane so locked in, and Chris said how precise it seemed to fly. Decent engine, good quality servos, and two on the elevator is much better than one with a floppy forked pushrod.

 

Edited By Paul Marsh on 11/08/2015 21:18:46

[Robert Welford]

I'm tempted to 'build' an Acro Wot XL and was thinking of installing a 3W 28i petrol engine that I own.The 3W 28i is less powerful than an OS 33 petrol, but nevertheless do you think this would be a good combination?

Robert.