Wots Wot XL

[Bob Cotsford]

Just arrived in the post, a pair of:

One of these will take two wing halves and have a purpose designed pocket for the wing tube plus a large zip pocket that will take the aileron link rods and struts. On first look it's very well made from a heavy padded nylon outer, a separator for the two wing halves, decent zips plus velcro tabs and a decent carrying strap. The 90 x 61 x 7cm size is a good fit for the WWXL wings lengthwise with plenty of spare width so for around £35 a pair posted all four wing panels are protected and joiners/struts/link rods won't get left behind.

[Rich too]

That's a great idea, I need some of those thanks Bob

[cymaz]

I can second the HK wing bags. A flying friend has a set and is delighted.

On the matter of hardware in the Wot kits, this is the second artf Wot 4 I have had in recent years. My standard Wot was not well built at all. Luckily I found this out because I decided to do a recover. Some ribs were as thin as paper in places, which needed some doublers. I used none of the hardware on that one either...simply not good enough.

On the other hand I have had a couple of Seagull and Black Horse artfs. Didn't swap anything except to put in a Dubro one. So if they can do it why not Foss Models?

[Bob Cotsford]

Sorry Cymaz, I have a BH Macchi which was generally good - except for the wrong length wing pushrods, 2mm wire Y elevator pushrods which were (poorly) soft soldered together, rubbish retracts, oleos that weren't up to the job, hinge pins that were reported to have come out on other's models - just a few of the more memorable flaws off the top of my head!

Seagull SeaFury - pretty good except for the poor fit of the 'radiator' mouldings, weak retract mechanics, odd areas of bare wood around the cowl etc.. Oh yes, the rather odd leading edge section that suggests someone forgot to sand them to shape before covering the wings.

Not to mention a severe lack of glue and poor material choice for the retract mounts - both use laminated liteply with large reliefs cut out of them.

I think the only ARTFs I've had that I consider well finished and equipped were H9 and Worlds Models ones so some manufacturers really can do it - at a price!

PS - the BH Macchi was a £350 kit of similar size to the sub £200 AW XL.

[cymaz]

I must have got lucky

[Bob Cotsford]

Posted by cymaz on 24/08/2016 20:39:57:

I must have got lucky

Quite possibly, they can't get them all wrong all of the time , can they?

Actually, one of the all time best ARTFs I've owned is also one of the cheapest - a Durafly Hyperbipe.

Anyway - next question, has anyone ever tried hooking up a 2 stroke can to a 4 stroke? I've got a couple of JMB 30cc size canisters and I am tempted to fit one on the GF38 in the WW XL to see if I can get it under 80dBa. I just need to make up some sort of adaptor to go from M14*.75 on the manifold to the 20mm can inlet. I think I need to start a new thread for canister mounting advice.

[Tim Flyer]

Just another quick question for Wots Wot XL flyers on the hardware. I wondered if any of you are using the standard steel wing bolts. They weigh a lot and I was thinking of swapping to nylon as their strength seems unnecessary. The Wot 4 XL uses nylon bolts. Do you think swapping to nylon is ok on this model? Obviously the wing balsa is way weaker than the steel bolt. Maybe they put steel bolts in just to save cost?

Edited By Timothy Harris 1 on 25/08/2016 11:12:44

[Bob Cotsford]

That's a good point Tim. I was wondering the same, both with this model and the Acrowot, 6mm steel bolts seems overkill and potentially destructive if you catch a wingtip. Maybe 7 or 8mm nylon would be better? I don't think the weight is really an issue so much as the lack of any give.

A quick Google shows even 6mm nylon bolts are rated at 8-900N UTS, 8mm takes that to 16-1700N while 6mm HT steel are rated at 24500N - that's a lot of load capability, around 5,500lb! Even the 6mm nylon have an ultimate load in the order of 180lbs each so that's around -13G that they could withstand for a 14lb model, or -26G for a two bolt fixing - in theory. I seem to remember Peter recording G readings in excess of 20 on a sports model pulling out of a dive.

I suspect that there's a lot more to it than that though with plastic deformation coming into the equation.

I am tempted to go for a pair of 8mm bolts, if only because tightening those two 6mm steel bolts causes me some puckering!

 

Edited By Bob Cotsford on 25/08/2016 11:31:37

[Bob Cotsford]

Hmm, looking back at that last post - maybe I have too much time on my hands

[Tim Flyer]

Thanks Bob. The only reason I could possibly think of was that they used steel for stiffness. Possibly they thought the slight stretch of nylon bolts may cause problems in certain situations. Seems unlikely. I think I will swap mine for nylon as I found in test flights that it's easy to over tighten the steel ones as they are naturally looser in the threads. I think nylon ones are less likely to come loose.

Edited By Timothy Harris 1 on 25/08/2016 11:40:41

[Bob Cotsford]

Yes, that's another point that was niggling at me - the possibility of the steel bolts unscewing themselves, though I have to say that the ones on the AW XL haven't slackened off - yet.

[Rich too]

Yes Bob, a few of my models came with steel bolts, H9 uses them for instance. I've never had any issues, the only bolts I ever thought of replacing with plastic were the u/c bolts on some models. However I now tend to use c/f u/c which I find more forgiving.

I finally got some time on my WWXL today. Building in loft has its limitations and aligning and gluing the tail was not going to be possible so I waited until I had time. It was mostly without issue, how have you guys found the wing alignment out of the box? I mean there's not really any adjustment. Ironically, my top wing is good, but the bottom is 5mm out of square at the rear of the fuse (third photo). I will try a washer on the dowel where the front of the wing mounts.

Is it really necessary to glue the top wing mount? It's bolted after all?

The tail did not require any trimming to get it square, just a tooth pick to hold whilst gluing. By the way, I love the use of a soldering iron to cut the covering for gluing! You never stop learning!

There were a couple more issues with the "kit". No indication of what hardware should be used for wing mounting etc. So I just guessed, and I couldn't find any penny washers for the main wing bolts.

Finally, the bolts, nuts and washers used for mounting the wings are far too small, and I will lose them. I am going to replace most with clevices and R clips.

 

 

 

 

 

Edited By Rich2 on 27/08/2016 19:21:35

[Rich too]

[Rich too]

[Rich too]

[Rich too]

[Rich too]

Tbh I am itching to start my next build so I am trying to crack in with this. Finished the tail today so if should be downhill from now, hook up surfaces, install tank, batteries and throttle...oh, and pilot and canopy.

[Rich too]

[Rich too]

I didn't have any Vaseline and instead I used plumbers silicon grease - I can now highly recommend it for lubricating hinges prior to gluing. 

Edited By Rich2 on 28/08/2016 18:17:06

[Rich too]

Posted by Rich2 on 24/08/2016 09:15:31:

I appreciate that Percy, but they have his name on them.

Email - unfortunately all of us in business have to deal with them - I would go back to snail mail in my business tomorrow.

The Wots Wot XL has a rrp of £300 so is not a budget model. If the quality is not up to standard (you simply cannot use the clevises) then do not include them.

I have sent him a fax. If he does not respond I simply won't buy another of his designs.

Well, I am impressed. Chris called me, twice! I wasn't available the first time so he called back! He explained that it is out of his control but he will bring it up with Ripmax. He also jested that it would be better not to include substandard items - I agree.

Anyway, that was very good of him to take the time to make the call, well done Chris, thank you.

[Rich too]

A little more done today, swapped the wheels and u/c.

[Rich too]

No problem with prop clearance!

[Tim Flyer]

Looks Good Rich! Nice to hear Chris Replied. I have certainly had lots of fun from his models he is a great guy. The clevices on this model are beyond awful ....just amazing they can make them that bad. I used new properly made ones, and nice allen head set screws on the wings from model fixings,co.uk all in stainless steel that look good and are easy to fit.

Regarding your question on the upper wing brace and gluing. The instructions suggest cyano and a bit of medium cyano isn't a bad idea. I hardened up the wing brace before fitting with thin "rocket penetrating cyano." The wing brace is a weak point. The bolts make it very strong in terms of vertical load but laterally its quite weak. I.E if you touch a wing down or hit it with a side load there is not much support. A bit of glue at the top helps brace it. It is not worth over doing it as it will make replacement difficult after a crash. With no glue it is likely to start wobbling from side to side after a while, as the balsa wedging it in place will not stand many knocks. A bit of cyano will harden it up,

Regarding plastic wing bolts, i prefer them because they also cause much less damage in a crash as well as saving a bit of weight(not that much i admit...about 16-20g on this model). I am leaving the steel undercarriage bolts as our strip is sometimes quite rough and I have found plastic ones sometimes get stretched and loose.

[Rich too]

Thanks Tim. I hadn't thought about the lateral forces, and it's a shame, as unglued it would be much easier to replace.

I'm fitting the tank, throttle cable, and batteries next, the tank and batteries will be a challenge!

[Bob Cotsford]

The AW XL review in the latest RCM&E made me chuckle with the comment that 'the included hardware was all useable as supplied'! As the hardware supplied with the Wot4XL, AW XL and WW XL that I've had has all been to the same standard the reviewer obviously needs to start buying lottery tickets if his pushrods and clevises were OK.

Incidentally, speaking of my AW XL, the foam tyres on the supplied wheels are starting to break up and that's flying exclusively from grass. time to fit some decent rubber ones.

I really must get my mods exhaust finished and the WW flown.