Max Thrust Riot - Upgrades

[Peter Beeney]

Ok Keith, just a couple of comments in reply then. I do agree you have a problem and I’m sure a comparison with a normal Riot will easily prove this. If the ESC really is shoving the full battery voltage at the motor at full throttle then it might well be a motor kV discrepancy. I would certainly have to consider that it should fly better than you describe. Just a thought, did you ask Century for any ideas they may have?

I simply assemble the model with full control throws right from the start and thus never have to tinker with inadequate surface movements. Beginners have to start as they mean to go on…

That 12 x 6 prop. Maybe Century had simply found a shed load of the props as a cheap job lot; and now they’ve come across a barn full of 11 x 5.5s. This does lead to an interesting little situation though. If their prop statement “flies better” is at all accurate then the watts per lb figure has actually gone down and yet the performance has improved. What’s going on? How does that work? Precisely the reason for my little - ‘Lots of different aspects to consider re. motors etc.’ - suggestion at 02/01/2020 14:06:09 above. And they may well be right, too, that’s definitely the direction I would be going…

Please post with any new info. or any results you get, neg or pos…

I’ll get me coat……

PB

[Keith Miles 2]

Peter,

One could certainly speculate regarding the prop change and I was thinking along similar lines to you!

I think, as you suggest, that it might, in fairness to Century, and before making a final judgement, to drop another line to them to report my more recent findings and, indeed, to see if the motor performance figures I’m getting are, at least, what they would expect.

I think I might, therefore, put a temporary hold on buying any 4S batteries especially as, after considerable research, only an Overlander 2900 currently seems to meet all of my requirements without too much further fuselage modification and these cost between 36 and 40 quid each! It would be more financially sensible to replace the motor and ESC, if that is where the problem lies.

Unfortunately, in view of the weather outlook I am unlikely to get a chance to check out any other Riots for a while!

No need to get your coat yet.

This week, I are mostly staying indoors because it’s more a case of “freezio” than “brilliant!”.

[Keith Miles 2]

Peter,

Just been watching BBC2.

What a strange coincidence!

Nice.

😊

[Shaun Walsh]

Posted by Keith Miles 2 on 02/01/2020 21:53:59:

Peter,

One could certainly speculate regarding the prop change and I was thinking along similar lines to you!

I think, as you suggest, that it might, in fairness to Century, and before making a final judgement, to drop another line to them to report my more recent findings and, indeed, to see if the motor performance figures I’m getting are, at least, what they would expect.

I think I might, therefore, put a temporary hold on buying any 4S batteries especially as, after considerable research, only an Overlander 2900 currently seems to meet all of my requirements without too much further fuselage modification and these cost between 36 and 40 quid each! It would be more financially sensible to replace the motor and ESC, if that is where the problem lies.

Unfortunately, in view of the weather outlook I am unlikely to get a chance to check out any other Riots for a while!

No need to get your coat yet.

This week, I are mostly staying indoors because it’s more a case of “freezio” than “brilliant!”.

The PO-3541-1070 motor from 4-Max is a straight swap for the standard Riot motor, even uses the same mounting plate. On a 12x6 epc prop it draws almost 40 amps from a 3S Lipo and gives a very noticeable increase in power. I upgraded the ESC to 50 amps to be on the safe side.

[Jeffrey Cottrell 2]

Hi Guys

Peter and Keith, thanks for your contributions to the discussion.

Couple of minor points

First of all, Peter. When I started this thread I called it Riot Upgrades. Seems to me that talk of changing props and cell count is entirely in keeping with this, and not off topic as you suggest.

Keith. When I flew my Riot I found the same as you. Although it flew adequately it lacked 'sparkle' which is was I like in a model.
My benchmark is to be able to fly on half throttle or thereabouts, with full chat for those 'hooligan' moments.
My Riot certainly did not do that, requiring almost full throttle for the whole flight.
Have to agree with Peter, the standard flight performance would be ok for practising and taking your 'B' test, but not a lot in reserve for those brown trouser moments.

Anyway, back to the plot.

Dug my Riot out of its winter induced hibernation, and did some bench tests. Results were interesting, to say the least.

First was a baseline run. This is its original flying form, 3s and 12 x 6 prop. Note this was not the Century supplied prop, but a 'bone' prop from HK.
Results were 30.5a current and 7500 rpm.
These are very much in keeping with the figures Keith posted. Certainly close enough to doubt there is anything wrong with his model. If there is then I must have the same issue.
Next swapped to a 11 x 5.5, also bone prop, and came the first surprise.
Current dropped to 21a, and rpm up to 8150.
Smaller prop accounts for the increase in rpm, but I was surprised by how much the current draw went down. Much more than I would expect.
Bear in mind these are bench tests, but I double checked both sets of results just to be sure.
Now the acid test.
I do not have any fixed wing 4s packs, so I borrowed a 5000 Hardcase pack from one of my helicopters. The higher capacity may skew the result a little, due to less voltage sag under load, but I don't think it will be much.
Anyway, with 11 x 5.5 and 4s pack I got these figures.
Current draw of 33a and rpm of 9900. Both pretty much what I was expecting.
I did not try the 12 x 6 prop. I would question Keith finding of 37a on 12 x 6. Given the difference between the two props on 3s, I would expect over 40a and the magic smoke to come out.

So, conclusions.

My Riot takes 3s 2200 packs in the supplied battery carrier, so I was a bit reluctant to try 4s and the surgery involved.
However given that I get almost 2000 rpm increase for only a couple of amps or so in current. might be worth a try.
Flies ok on 3s, but to live up to the advertising blurb, 4s on 11 x 5.5 is an option.

Hope this helps

Jeff

[Capt Kremen]

Just servicing my very much tinkered with 'Riot' before another seasons flying. (Now eight (8) years old according to my flight log book!)

My previous posts and review have detailed the numerous changes and substitutions of equipment I made to this airframe.

As this topic is about upgrades and motor/battery performance here are my notes:

Currently using a, (now discontinued), 4-Max PPO-3530-1100Kv motor on 3S and a 10x5 prop. The model is far from 'supersonic' but it can easily perform all sport manoeuvres i.e. Loops, Bunts, Rolls, Spins, Stall Turn and combinations of these. I did try a 4S pack with a(nother) motor but personally found the extra omph wasn't warranted and if anything wasteful as the airframe reached its VNE i.e. max speed and unlikely to go faster before flutter and self-destruct took hold!

The comment from 'MaxThrust' about the change of prop ... Mmmm well they may say that, but any supplier with a job lot of props as 12x6 were perhaps not available, (or any substitute items), would likely do that!

Meanwhile, my 'Riot' has had its 'Major' and is serviceable for another seasons 'hack' flying in all winds 'n weather, for training, fun sport aeroes, touch 'n go, refresher training, an all-rounder providing IMHO, parts are changed and modified.

[Keith Miles 2]

Thanks for recent comments guys.

Yes, can confirm:

3S, 12x6, 30A, 7600rpm. A calculated 330w or 90w/lb. Poor performance requiring about 75% throttle just to stay straight and level at a very modest speed.

4S, 12x6, 37A. A calculated 550w (in round figures) and about 150w/lb. No tacho reading taken so currently unknown but we had to keep a VERY firm grip on the model so unable to cover our ears! Excellent performance rather than ballistic and now directly comparable to my heavier IC Wot4 with a well used and somewhat tired 10 year old Irvine 40 in it!

That said, I have to accept that I won’t get a twenty minute flight out of the Riot whatever I do! (coughs and places tongue in cheek!).

It does look more and more to me that the Riot, as supplied, does, indeed, fall short of both its description and title.

Increasing the rates (as recommended in the manual) ain’t going to solve a seemingly “marginal” power issue without an “upgrade” of one or more components and maybe some “reconstruction” as well.

Maybe it’s time for a rethink and a V3, even if it means raising the price or, if not, a softening of the claims and perhaps a new model name?

I imagine that a Wot4 on electric power would cost around £250 or so to put together plus batteries so would have thought that there was still room for competition here even after addressing the Riot’s shortcomings.

Meanwhile, I will persevere!

Oh, and amongst other things, I have yet to test on 11x5.5, which will be my first move before spending any money!

Edited By Keith Miles 2 on 03/01/2020 14:24:57

[colin wray 2]

my riot is exactly as it came out the box it runs no 2200 3s battery and the prop that came with it 12x6 it has flown in varying winds never had a problem with lack of power it will loop roll stall turn in fact anything my limited ability will let it do

[Kim Taylor]

Keith,

Whilst I have no doubt that you are experiencing what you describe, I don't think it's typical of the Riot.

I use a 3200 3S setup, everything else standard but with an APC-E 12x6, The model is good in the vertical, as long as you don't 'dawdle' (i.e. it won't accelerate from a near stop vertically). It will float around very happily, albeit slowly, on a whiff of throttle and will cruise around at half throttle quite happily. It will loop and bunt from level flight (once you've upped the control throws).

Having flown both, it is my opinion that the model isn't as slippery as a WOT 4, so it'll never go as fast unless you up the power train substantially

I haven't got any rpm readings, but I do remember seeing 33A on my meter on the APC prop, and a little more on the original prop. It seems to me (from a distance) that if you're only seeing 37A on a 4S battery and 12x6 prop, then maybe there's something wrong with the esc (I'm assuming that you've set the end points). Even using your 30A 3S figure, my feeling is that you'd see more than 37A on a 4S (i.e. a 33% potential voltage and therefore speed increase).

It just seems to me that you haven't got to the root cause of your issues yet and are in danger of just papering over the cracks by using a 4S.

As I said, no doubt that you've been experiencing issues and have gone to a lot of trouble to overcome them, but my question has to remain - why???

Just my 2p worth

Kim

[Keith Miles 2]

Colin,

You might be missing the main point being made by myself and others which boils down to a core issue of the promises of the manufacturers not matching the experience. Were that not the case, I, for one, would be somewhat less critical.

Virtually all models will roll, loop, stall turn etc. even docile trainers with wing dihedral! The only difference is in how well they do so and how easily they achieve it.

I started flying many years ago. I am now 66. I gave up for many years before returning about 10 years ago. I am still no hot shot flyer, by any means, having never yet performed a bunt (still lacking the courage and confidence!) and I am only just starting to get to grips with inverted circuits with plenty of height! An EDF or pylon racer or similar “hot” ship would scare me to death!

The Riot is my first “average” sized electric model but even my limited knowledge and experience of electric flight suggests that 90w/lb is generally regarded as being at the lower end of the power scale i.e. basic trainer territory and no amount of increased control throws will offset power limitations.

My currently “sick” IC Wot4, (a model I moved to from a basic trainer and have been flying ever since!) is no “hot ship” but compared with my “stock” Riot the two, somewhat disappointingly for the reasons given above, are most definitely chalk and cheese in overall performance terms. No contest. And my Wot4 has never needed any upgrading or excessive increase in control throws to achieve what IT promises!

I will concede that Century (and good luck to them) seem to have sold plenty of these models and many owners may well be happy with them but would maintain that whilst it might be adequate for some it does seem to be another case of only getting what you pay for!

Oh, and for the record, I am not being paid by either Ripmax or Chris Foss and I do have several other models from other manufacturers plus a number of small “indoor” electric helis and “park” flyers!

 

Kev,

I totally take your point. but can only report my own experience and personal impressions of the Riot. Quite simply, it has not met with my expectations, by a significant margin, and for reasons given in previous posts. Upgrading to turn a model into something it isn’t is one thing, upgrading to make it what it claims to be is quite another!

And, yes, I did set the end points for throttle!

Edited By Keith Miles 2 on 03/01/2020 17:48:14

Edited By Keith Miles 2 on 03/01/2020 17:51:29

[Keith Miles 2]

Sorry, me again!

One other thing that I’m mindful of, when considering fitting physically larger batteries, whether 4S or 3S, is the avoidance of reducing the outflow of air from beneath and around the battery.

Fitting a Radient 3S 3000 required cutting out the base of the battery tray to lower the battery sufficiently in order to close the hatch. I then screwed a narrow strip of 4mm ply, lengthwise, to the ply subframe in order to fit a couple of velcro retaining straps around it which also keeps the battery 4mm clear of the subframe.

I would be reluctant to have a battery sitting flat on the sub frame and blocking off the cut-outs. The battery might remain cool but the ESC would find itself in a much warmer place!

Were I to go that far, I would seriously have to consider cutting vent slots or holes in the fuselage sides where the ESC sits!

Thoughts, anyone?

[Jeffrey Cottrell 2]

Hi Guys, few thoughts

Colin and Kim
Glad to hear you're happy with the performance of your Riots. Points out something that has always been an issue with ARTF. That is variable quality.
Some may be better than others. Only way to check is if you could supply current and rpm readings to compare with ours.
Also flight performance seems to be a very subjective thing. Mine in its standard format will loop and roll, but it doesn't do so with any authority. Seems to be struggling to do even the most basic manoevres.
Bit like flying a blancmange, not to my liking at all.
Anyway, some numbers would help.

Keith
From the readings I got, I would be suspicious of that 37a on 4s. Well worth trying, but could I suggest you start off with the 11 x 5.5 first.
Either that or borrow your friends 4s again and make sure it's fully charged and run the test again.
My figures show a 10a difference between props on 3s.On 4s I got 33a with the 11 x 5.5. Given that 4s on the 12 x 6 should be pretty close to 40a, leaving not much headroom for the esc and motor.

Capt K
I notice the motor you use in yours is now discontinued. If anyone wants to follow your lead, wonder if this might be a good replacement.

In general.

Someone posted they were not happy with the quality of the supplied prop driver. I can second that. Had to abort the first 4s run because the entire prop/driver came off.
I was doing the test on the kitchen table and eventually found the prop behind the cooker. Ooh err.
Switched to a better one from my stock to complete the test. However, awaiting fitting to another model I have one of these.
Only 40mm so a bit small to look right, but it does leave a gap between the edge of the spinner and the cowl, enough to let cooling air into the motor and esc.
Forget aesthetics for efficiency.

I'm a big fan or Turnigy LiPos. Looking on HK site I found these. From the measurements, they might fit in the battery bay unmodified. Got a couple on order so we'll see.

That's it for now

Cheers

Jeff

[Keith Miles 2]

Jeffrey,

I had already planned to check out the 11x5.5 first on 3S and then 4S. The 4S tried previously was borrowed and was, indeed, fully charged. If the lender (or another lender) turns up at the field tomorrow, we can, for now, do another 4S test with the supplied non-APC one provided that I can correct the current significant imbalance!

As I say, I am reluctant to buy any more stuff yet especially if purely for test purposes!

The four 3S LiPos were nearly a hundred quid, not to mention the seemingly ill advised additional sale to me of two 13x6.5 APCs which I will definitely not be trying!

It’s somewhat ironic that I bought the Riot as a “get back in the air quickly” model while the Wot4 was out of action, pending possible repairs!

Maybe I should just put up with the “blancmange” and see if I can fix the Wot4 instead?

Edited By Keith Miles 2 on 03/01/2020 20:08:24

[Peter Beeney]

I’d have to agree entirely with Kim, as far as I can remember I’ve never seen a Riot that didn’t perform very much like all the others; and as he also said, it does seem as though there could be some discrepancies between the motor performance figures too. However, there are undoubtably some models that are indeed not behaving themselves.

Jeff, I previously mentioned going off topic, what I had in mind was exactly this situation, the various discussions about the reasons for the odd looking amps/rpm figures etc.

So bearing this carefully in mind:-

I’ve always thought that the applied voltage, the rpm and the load are inexorably linked together, if one changes then at least one of the others will change; and always in a proportional manner. In our case it would usually be the voltage or the load that changes.
At 03/01/2020 12:03:01 you spoke about 4S and the 11 x 5.5 prop. Assuming your motor’s kV is 850rpm then on a fully charged 4S the unloaded rpm would be 14,280. You recorded a loaded rpm of 9,900, a 31% drop with a current flow of 33 amps. On 4S I recorded an unloaded figure of 14,280 and a loaded figure of 12,000 on a 9 x 6 prop, a 16% drop with a current flow of the same 33 amps. I fully realise this is far from being any sort of realistic comparison but even so on the back of my fag packet those current flow figures just do not add up anywhere along the line. Somewhere there has to be an explanation. It’s this sort of conundrum that gets me interested…

Think I’d better stop there….

PB

[Keith Miles 2]

Just noticed that I seemed to have called Kim by the wrong name!

Please accept my sincere apologies.

I have a mate called Kev but he’s a dipstick which makes things even worse!

[Keith Miles 2]

Posted by Peter Beeney on 03/01/2020 20:06:34:

I’d have to agree entirely with Kim, as far as I can remember I’ve never seen a Riot that didn’t perform very much like all the others.....

Or, to quote Jeffrey, “blancmange” as opposed to the “Sherry Trifle” printed on the packaging?

Sorry, couldn’t resist!

And I like both.

[Keith Miles 2]

Just fitted the supplied 11x5.5 ready for tomorrow’s test. It took over half an hour as I again struggled to stop everything rotating while I tightened the nut! Grrrrrrr! No such problems ever encountered with IC!

Yes, the supplied prop is indeed poor quality. Excessive flex. Not a helpful characteristic in power delivery terms! And the prop hub is way off balance, something which might not be easy to correct even it was worth trying.

So, second “upgrade” will be to bin both it and the all plastic spinner (which lacks grip at the prop hub) and replace with APC and Irvine, respectively!

At least these are relatively low cost upgrade items!

Edited By Keith Miles 2 on 03/01/2020 23:49:47

Edited By Keith Miles 2 on 03/01/2020 23:52:59

[Kim Taylor]

Posted by Keith Miles 2 on 03/01/2020 20:14:57:

Just noticed that I seemed to have called Kim by the wrong name!

Please accept my sincere apologies.

I have a mate called Kev but he’s a dipstick which makes things even worse!

Hi Keith

No offence taken, I can assure you.

With a name like mine, I get used to being called ANYTHING but Kim.

A bit like 'a boy named Sue!!

I'm following all of this with interest, because although as pointed out above performance is subjective, my Riot can't be described as anything like blancmange or jelly. Having said that, these recent cold mornings have noticeably reduced the performance, but it'll still pull up into the vertical and go on up and up and up and.......... you get the idea.

I've taken to warming the batteries in my trouser pocket for a while before fitting them, which improved things.

Kim

eta

Meant to say, when I get a few minutes spare I'll get some current and rpm figures from mine, to see how they compare. Won't be until the middle of the week though.

Edited By Kim Taylor on 04/01/2020 10:32:31

[Jeffrey Cottrell 2]

Hi Guys

Keith
Sounds like a plan to me. Let us know how you get on.
At least you have a flying site. Mine is on clay, and given the weather the past few weeks it's more suited to growing rice than flying toy aeroplanes.
Last time I went down there were a couple of swans paddling happily on what used to be the runway. Ho hum.
Couple of thoughts.
HK do a range of 'bone' props including 11 x 5.5 size here. I have one of these plus a genuine APC one and they both seem similar in stiffness.
Best thing is the price.
Also I use combined prop driver and spinner from here. These are made by a company called MPJet and are really good quality.
Only issue is the biggest is 40mm which is a little small for the model, but does leave a gap for cool air to flow over the motor.
Highly recommended.

Kim
'I've taken to warming the batteries in my trouser pocket for a while before fitting them, which improved things.'
Just make sure there is nothing else metallic in your pocket, otherwise it might not be only the batteries that get warmed up, if you get my drift

Jeff

[IanR]

In connection with prop sizes and 3S/4S batteries, the following is something I copied some years ago. I think it is from this forum but I may have copied it from elsewhere. I believe that the Mark referred to is Mark Tilbury, the designer, and, of course, this refers to the Mk1 Riot :-

I got another e-mail from Mark this morning with some more interesting information; I'm sure he won't mind me re-publishing it here:

"just a little tip on the Riot, the model has been designed to be played with, out of the box it is set to be almost a trainer but with increasing the throws it becomes a very advanced trainer / sports hack, then if you wish you can remove the cowl ( two screw ) and you will find a steel weight which can be removed. when this is removed the CG will go back around 10-15mm which will then suit the more aggressive style.
　
now for more fun and power you can mess with the power set up, we have fitted a 40 amp ESC so that you can if you wish use a 4 cell pack. if you do this you need to drop the propeller to a 10 x 5/6 and then even more power will be at your finger tips.
　
we do a 4 cell 2500 mah thin pack for £39.99, this fits the riot very well. part number ART-3F029.

as you know this model s designed to compete in a market where people have lots of different abilities which is very hard to cater for but I do feel we have covered more in one model than any other currently available. the model even fly's very well in high winds!
　
have fun with your model, that's the main thing I tried to design into it " an every day sports hack that puts a smile on your face every time you fly it."

A very experienced (and self-confessed hooligan) flier at my club has removed the metal weights, dropped the prop size as suggested above and fitted a Dynamic 4S 3200mAh lipo (from Slough Radio Control Models) without any modifications to the battery box, and flies his Riot Mk1 as though he stole it.

IanR

[Keith Miles 2]

IanR,

Some very useful info there. Pity it isn't included in the instructions!

As for fitting the 4S 3200 battery mentioned "without any modifications to the battery box", I'm puzzled by that unless, perhaps, he has removed the hinged hatch altogether or now has a hatch which does not fit flush and is under pressure from the battery.

The white plastic battery tray on my V2 (larger than the original I'm told), as fitted, has a maximum width of 45mm and maximum depth of 25mm.

My Radient 3S 3000 is only 26mm deep and, with the velcro strap on, the hatch could not be closed without putting strain on it, hence, as many others seem to have done, I had to cut out the base of the tray to lower the battery clear of the hatch cover.

Despite my extensive recent research, I have, thus far, only been able to find one supplier of a 4S battery of greater capacity and voltage than Century recommend (3S 2650) that will fit into my modified space, without further modification, and that's Overlander and they ain't cheap!

I also checked out Dynamic but have yet to find any dimensional information for those prior to parting with my money! From the pictures, they look pretty similar to me most others in terms of shape and dimensions. This is not surprising given that there are supposedly few manufacturers but, seemingly umpteen different names on the packs!

So, if what you say is true I, for one, would be most grateful to receive some further information, particularly regarding the dimensions of that 4S 3200 Dynamic!

P.S. And I wonder if that 4S pack available from Century has "Overlander" printed on it or comes from the same factory. The price certainly seems to be in the same ball park!

Edited By Keith Miles 2 on 04/01/2020 15:54:20

[Colin Carpenter]

I would just buy an Acrowot Foam E ! Superb performance out of the box ! Off to the bunker now !💀💀💀💀 Colin. 😩😨😨😨

[Jeffrey Cottrell 2]

Hi Keith

Those Turnigy packs should be with me within a few days, but I do have some 3s packs for my helicopters, so I can confirm some dimensions.
HK quote length as 137mm, where mine are 140, but width as 44mm where mine are 42mm.
Depth for the 3s is 17mm, so 4s should be 22 plus change.
Sounds like a winner.
Have to say I have taken a number of these packs apart, and they do have a layer of hard plastic around the cells. If need be this could be removed which could save another mm or so.
Main issue to me would be how to accommodate the power wires, but I'm sure i can invent something once I have the packs.
Anyway, £12.50 per pack not a lot to risk.
Also interested to see Mark recommends 10 x 5/6 for the 4s packs. If that size flies the model with the authority i need, reduction in current and increased duration will be side benefits.

We'll see

Jeff

[Keith Miles 2]

Jeffrey,

Thanks for the tips. Noted.

Kim,

I'm with Jeffrey on the "battery in trousers" thing. Many years ago, a parachuting pal of mine, in the early days of helmet mounted cameras and long before GoPro, put some spare NiCds in his jumpsuit pocket. On the way down, he felt a burning sensation on his leg and was seen, under canopy, kicking wildly on the way down! Batteries were in the same pocket as his car and house keys! He lived to laugh about it....eventually!

All readers,

In similar context, whilst testing the Riot again at the club field this morning, I managed to knock the end off my tacho when I got too close to the prop. Prop, spinner, and adaptor flew off and somehow took an upward curved path to end up on the roof of the workshop shelter under which were standing! Found half of the prop on the ground just behind me! Ooops! Yes, yes, I know....

Was going to replace the aforementioned items for decent ones, anyway, except for the tacho, that is. Flip and bother. MInd you it was a gift from my brother-in-law so cost me nothing. Bad news is that he was helping me with the test! He, too, will laugh, I'm sure,.......eventually.

Got some figures, though, on 3S, before disaster struck!

11x5.5, 21A, 8300rpm.

And our resident "leccy" guru (the guy who lent me the 4S recently) says that before I go 4S I should still try the 13x6.5 on 3S and reckons that, subject to a current check, the 40A ESC should even cope with a bit of "overload" as long as I don't fly at constant full throttle, of course!

Stand by for more fun and frolics!

[Capt Kremen]

Here are some pics of my 'mod' to allow larger capacity 3S (and 4S at a push) LiPo into the 'Riot'. Also the 'velcro' style wrap over strap securely holds that awful brittle plastic battery hatch closed. The strap passes through slots on the top side of the fuselage such that the ply inner frame, (trimmed down to let the LiPo in!), stops the strap see-saw cutting its way through the foam fuselage sides.