Acro Wot ARTF (balsa) chat

[Brian Clamp]

Thanks for that. Will do ASAP. It is a new engine so idle is a bit high at the moment.

[stuey]

Would it be worth (with a mix) setting up the ailerons to go up a few mm each side to help slow the model down on approach? My old kit Acrowot used to float on, and my patch is not the biggest by any means!

[John Allen]

I usually set up flaps on all models, but don't use them on all models. Worth testing at high altitude to ensure you don't get tip stall as you slow down.

Or mix some down flaps with ip elevator for air brakes.

[Flanker .]

Hi. With my Acro Wot I have a flapperon set up. Both ailerons drop around 3 or 4 mm more is not very comfortable in roll. A nice low idle. With the flapperon there is an elevator compensation mix. The main thing with flaps and landing is the TRIM s you need to adjust the acro's trim on elevator from the normal fun position to a little up , the Acrowot will fly very slowly in quite a nose high attitude with flaps. You can try with the elevator stick and when you find the nice sweet slow spot adjust your trim to that. When you a trimmed for slow flight just line up and use the throttle to control the height.

This is the full size technique and works well where I fly because there is little space and NO WIND.

Works well with this floaty model. F

[Greybeard]

I finally got around to flying mine yesterday.

As I reported earlier it’s fitted with a new OS 72 4 stroke so needed running rich and smoky for the first flight. It only needed about 1mm of aileron trim to fly level on half throttle and was very docile, so much so that I have now removed the 100g of lead nose weight ready for its next outing. I was flying in very light winds but found the landing approach quite easy even with the new engine set at a fast tick over for reliability.

As an aside I was very pleasantly surprised to find not just how quiet this engine is but also how clean running it proved to be, hardly a trace of oil remaining on the model.

Unfortunately my satisfaction does not extend to the covering which is quite dire, seemingly determined to part company with the airframe with rucks and wrinkles everywhere.

[John Allen]

I've repeatedly had to iron down the covering (much more so than with the Wot4), plus my ASP FS91 spits a lot of crap out over the model, and the covering seems to stain quite easily.

[Greybeard]

I’m not into ironing, so I shall just have to be content with flying a shrivelled prune.

[Greybeard]

The OS FSa72 turns a 14x7 APC at close to 10000 rpm on the ground and provides almost unlimited vertical performance, so much so that I feel that the 56 version would provide ample performance for this model. The supplied tank provides in excess of ten minutes flying time with this engine.

Having removed the 100g of lead that I had installed to achieve the balance at the recommended point I find it quite comfortable to fly with the more rearward CoG.

Because of the models high wing loading it is difficult to slow it down for still air landings, I shall investigate aileron droop mixed with a tad of up elevator to create more drag. I shall also try using a 15x6 propeller to see if that helps reduce landing speed.

The model fish-tails, but not as badly as some earlier versions that I have owned. The covering still has the surface of a wrinkled prune.

[Brian Clamp]

Getting to grips with the landings. Slowed the tickover to 3300rpm on the Saito 82. This is improving matters. Prop is a 14x7. Getting a lot of vibration from the plastic engine mount supplied. Will be replacing it with a hangar 9 Ali version. Then may be able to slow the tickover a tad more. May be getting some foaming of the fuel. What is fish tailing that keeps being mentioned. Mine flies like on rails.

beginning to get wrinkling of covering.will have to deal with that.

[John Allen]

Well my ASP FS91 failed a couple of weeks ago (rear bearings destroyed), so I replaced it with one I had reserved for the Zlin 50l. I ran it in using high castor content 12% nitro and a Master Airscrew 14x6.

I had the first flight yesterday, and it seemed very tail heavy, so after I landed I took out a MA 14x6, and a JXF 14x8, placed one in each hand, and WOW the JXF is well heaver than the MA.

So I reamed out the JXF, and balanced it, popped in on, and took off once again. Much better, and with the new engine (still running on 17% synth, with about 8% castor), I have unlimted vertical, and the speed is just amazing. Its obvious that the old engine was having bearing problems for some time.

I can heartily recommend an ASP/SC FS91 for this model, flys beautifully, floats in for landings, balanced at 85mm without any additional weight. Only weighs 10gms more than the ASP/SC FS70.

 

Edited By John Allen on 06/05/2013 15:26:06

Edited By John Allen on 06/05/2013 15:26:33

[Steve Hargreaves - Moderator]

Thats good to know John....the ASP91 was the motor I had in mind for the Acrowot....

Interesting about the JXF props too....I use these & find them to be excellent.....I've never noticed them to be particularly heavy though....

So do you still intend to buy the Zlin too?? Thats another one on my list so if you could just test it for me & let me know what you think I'd be ever so greatful....

[John Allen]

I have the Zlin already, but now no motor for it. Will have to wait till I get some more funds or destroy the AcroWot.

[Rafael Scabora]

Agree with John, I've bought a brand new ASP.91 4 stroke for my AcroWot, still running very rich, but there is SO MUCH POWER!!!! Take off is very short and infinite verticals, 1/4 of throttle is enough to make the plane climb... Balance was spot on, no added lead... I'm loving every second of flying it!!!

[r6dan]

Its awesome that an ARTF acro has been produced, i loved mine sooo much!

i built mine really heavy with a carbon lined fus and wings and had an sc 61 up front and it would fly in any condition it was a flying brick!! Loads of times at the club I was told if i threw it around the sky like i did it would break up but it didnt!!!

I dont know if i should get an artf or build another.

are they as good as a well built home build?

[Flanker .]

Hi. The ARTF is lightly built. It has built up wings and a ply frame fuse. With a .60 up front the airframe delivers a very nice ride indeed. It wont take the bashing that glass foam wings and home buld fuse would but if you don't bash your models then no worries. Ripmax say that they have spares - wings etc - I believe.

That said it will take hard landings and when you hit a pile of rocks in the middle of the field the U/C glues back on with no trouble. It is very cheap too. For the time saved in building and the excelent performance on a .60 I would say that it is a good punt.

I love mine ! Flanker

[Steve Hargreaves - Moderator]

Just finished my AcroWot......I've fitted an Evo GX10 petrol motor so it will be interesting to see how that goes....

I'm pretty impressed with the kit.....seems well built & pretty tough...probably not as tough as a kit built one but pretty good all the same. At this price point I would say its an impressive model....

[John Allen]

Overall the kit is excellent, but the crappy clevises, control horns, and control rods need replacing. Plus I hate the pull/pull rudder system, especially on a model this size. A pushrod in a snake would be fine, and easier to assemble too.

Flys like magic with my ASP .90FS though.

[Rafael Scabora]

I would recomment anyone here to replace the undercarriage metal bolts with nylon bolts... They are able to stand some not so perfect landings and when it is really messy, they will just snap and save your fuselage... Size is 4mm x 30 NYLON.

The model overall is pretty tough, I was "lucky" enough to have a mid air colision a couple of weeks ago, the plane went down spiralling form quite high up and crashed into the high grass, ASP .90FS still running when went down... The wing and U/C nylon bolts snapped, some really small damage to the fuselage and my tailplane was chopped by the other plane prop, managed to get a new tailpane for 18 quid from an online shop, all glued back in place and plane is flying perfectly again.

[The Stig]

Thanks for the advice on the bolts, will be hoping to maiden mine at the weekend. A question for the guys who have put in bigger engines - i have an asp 61 2 stroke up front, a , my exhaust seems to not want to go in the already cut crevice, will I need to cut the piece of wood on the fuselage off, so the exhaust can fit?

[Tomtom39]

My ARTF electric converted Acrowot has just completed its 300th flight (yesterday) . Still going very strong (some minor mishaps) . I have found it to be pretty sturdy. My only gripe has been the covering especially at the wing tips where its started to delaminate. Debating whether to just keep using the iron and some balsa loc or recover next winter.

The undercarriage has not been a problem. I replaced the U/C bolts with some nylon wing bolts and these work fine (fingers crossed!) I binned the rods/clevises that came with it however I have retained the push/pull system on the rudder and this works very well. This aircraft is my favourite hack! Its pretty much as good as my built up versions!

Once again well done Mr Foss and Ripmax. Brilliant value at £108 at one of the shows.

[Rafael Scabora]

You can try an extension for the exhaust, I first fitted my AcroWot with a .46 engine that needed it... Then switched to the 4-stroke that fitted well.. Du-Bro sells extensions, but you might have to import from the US, try ebay.

[The Stig]

Posted by Rafael Scabora on 17/07/2013 10:46:11:

You can try an extension for the exhaust, I first fitted my AcroWot with a .46 engine that needed it... Then switched to the 4-stroke that fitted well.. Du-Bro sells extensions, but you might have to import from the US, try ebay.

Ah yes, just been onto just engines and they do an extension, just waiting to hear back on the size and will be placing an order. Thanks

[Steve Nash]

My Acrowot had maiden flight at the weekend. It flies beautifully on an SC 52 four stroke.

it took off dead straight and only meeded one click of right aileron and two clicks of down to fly hands off.

The 52 engine is plenty for the type of aerobatics that I fly i.e. nice gentle loops, rolls, stall turns and other smooth aero's.

it doesnt have a fantastic vertical performance or prop hanging / mental performance, but if I wanted that then this wouldnt have been my choice of aircraft or engine.

it flies fantastic though. Well pleased.

Definitely worth every penny.

[Richard Putnam 1]

I have an old Acro Wot it has been stored in the loft space and the wing has been flattened! It has cracked on the centreline. Could some kind soul tell me the dihedral measurement , with one wing flat on the bench what is the dimension of the opposite wing tip from the bench?

many thanks,

kairos

[Robert Welford]

I flew my Acro Wot artf for the first time last night using Multiplex Pro 16 M-link radio - 2 flights.

It is powered by a Laser 80 which required some modifications to the front end. I used a different engine mount, replaced the side-thrust wedge with a thinner variant (in order to mount the Laser 80 further back) and needed a cutout in the rhs of the firewall for the carb. and silencer.

CofG came out just behind the recommended position with the battery (2000 Eneloop) under the front cockpit area.

The Acro Wot flew better than expected: unlimited vertical; thrustline is about right; needed some lead to balance laterally (probably because of side-winder engine installation.

There is no sign of fish tailing (as some have reported); does crisp snap rolls; only small amount of down elevator for inverted; rolls quicker to right than left even though identical movement -(so have increased left movement); pulls slightly to belly in knife edge, but doesn't roll!

It has exceeded my expectations which is to be a 'quiet' aerobatic model for flying at my club at Old Warden/Shuttleworth. BTW Laser 80 runs for 20 mins on kit supplied fuel tank.