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Member postings for MattyB

Here is a list of all the postings MattyB has made in our forums. Click on a thread name to jump to the thread.

Thread: for fast electic is supreme
18/04/2019 12:44:07
Posted by Dickw on 18/04/2019 10:31:52:

The Germans hold a speed event for such planes every year, and 500 kmh is not unusual. They are even approaching 300 kmh for an under 250 gm class of model. Have a look at some of the planes and equipment on this website.

Dick

Technically impressive, but the aesthetics of some of those models... disgust As my Gran used to say, "That's a face only a mother could love"!!!

...and the winner of the "My eyes are bleeding" cup...!

Edited By MattyB on 18/04/2019 12:45:32

Thread: New Drone/Aerodrome Regulations - Is your club at risk?
17/04/2019 17:06:29
Posted by Robert Welford on 16/04/2019 20:41:08:

Sadly we are "not out of the woods" yet.sad

Despite the latest amended CAA Exemption allowing normal height limits (none for < 7kg, 400 ft >7kg) for Old Warden Model Aircraft Club, the club committee have decided to retain the 400 ft height limit that was introduced with CAP 1763 on 13 March 19.

The committee have refused to provide any justification for their decision and before you ask it isn't the Shuttleworth Trust who are insisting on a height limit.

The only upside is that if anyone were to fly higher than 400 ft for < 7kg (inadvertently) they are no longer in breach of the CAP 1763, but only of the club rule. In addition, model flying events are now free to have no height limit. smiley

Would love to say I'm surprised, but based on my single year in the Old Warden Club that's exactly the kind of thing I'd expect. Whislt I was there the committee flatly refused to countenance the idea of a website ("banned by the Shuttleworth Trust " ) or even a members only email board/forum for allowing people to communicate. This was particularly important for me as I am a w/e flyer and needed to know there would be sonmeone there to spot for me whilst I was flying. At the AGM they also annnounced changes to the constitution that had not been communicated in advance; they didn't even have enough copies of the document to be handed round so it was voted on before most people had read the proposed changes!

Needless to say I left after 12 months; the picturesque outlook and beautiful strip could not outweigh the onerous requirements that come with a full sized airfield and the ridiculous attitude of the committee. I also got the distinct feeling anyone under the age of 55 who flew at the w/es, could fly a rolling circle and suggested crazy ideas like communicating on the interweb was not welcome here...

Edited By MattyB on 17/04/2019 17:42:38

Thread: Sticky throttle
15/04/2019 14:21:24

Posted by IanR on 15/04/2019 13:47:42:

Would it be possible to cut the throttle by flicking a switch 3 times making it go through zero 3 times within, say, 1 second, or so - similar to the way in which the self-test is initiated with the S6R and S8R?

This would not be too onerous when cutting the throttle on purpose but would be unlikely to happen accidentally whilst flying or any other time.

I take the point about accidentally knocking the switch whilst flying. I am using switch SF as the sticky throttle cut switch but have reversed it so that when towards me the throttle is off and when away from me it is on. This maintains a larger gap between it and the adjacent SE switch so that my fat fingers are less likely to inadvertently cut the throttle. Also, when putting the TX down on its back, the switch is already in the "towards me" position and the throttle is off. If it was the other way round, then putting the TX down on its back might inadvertently flick the switch and enable the throttle.

However, I still think the 3-way flick would be the ultimate safe way of not accidentally cutting the throttle.

Anybody know how to do this?

See my post about an unknockable safety switches earlier in the thread - that is essentially a variant on what you are are suggesting. I'm certain you could achieve what you are looking for using delays and nested ANDs, but it would probably take more logical switches...

Posted by MattyB on 14/04/2019 13:28:41:

...PS - I actually designed an “unknockable” safety switch for my Dad’s IC models that addresses your concerns with the sticky throttle cut. It uses a three position switch and requires a sequence of movements that include a change of direction within a given timeframe in order to activate and deactivate between two states (for instance ignition off and ignition on).

It’s more complex to setup but works very nicely - downloadable example and documentation here.

Edited By MattyB on 15/04/2019 14:25:35

15/04/2019 12:56:29

One other alternative - you could effectively add in a "dual" throttle cut functionality by linking the switch to certain flight modes. For instance throttle activation/dactivation could be enabled in Takeoff flight mode, but not in Acro or Cruise so if you knocked the switch whilst flying then it wouldn't do anything. The only disadvantage is that if you swtiched to that flight mode without noticing you'd knocked the switch you might end up plummeting quickly(!), but that should be easily remedied by an audio callout on the switch in question.

15/04/2019 12:48:18
Posted by Peter Christy on 15/04/2019 08:50:11:

Mike: Yes, that's what I suspected. Sorry if I didn't explain clearly enough initially. I'm sure there are more applications where this extra functionality could be useful (retracts?), but the limiting factor might be the displays on the lower spec Txs.

MattyB: Yes, I understand that. The problem is that the logic doesn't allow for an alarm in a NOT situation. Mike has got what I'm trying to achieve and has explained it succinctly.

Fair enough. I doubt the developers would take that one on though, purely because it is pretty niche - the vast majority of users want this functionality to result in their TX having all the switches in exactly the same positions every time they power on, and the current system does that.

The other advantage of having your switches in the identical position every time is it enables you to do a simple visual check of your TX prior to switch on; for instance I always set all mine to be "everything away from me/up" at power up. This gives a small amount of additional safety in my eyes, particularly if you do it consistently across all your model setups. The only other alternative I can think of is swapping that 3 positin switch for a 2, but it may not actually give you what you want at startup as the software will still be looking for a 3 position.

Edited By MattyB on 15/04/2019 12:48:57

14/04/2019 22:37:16
Posted by John Lee on 14/04/2019 13:10:21:

Pete I use one of these locking switches for throttle hold on my Jeti coupled with a voice warning. If a similar accessory available for your radio I'd highly recommend it, for belt, braces & a piece of string!

The problem with physical mechanisms like this is that if you want to cut the throttle quickly for safety reasons you can’t. On an electric model it’s less of an issue as closing the throttle stick should always stop the prop, but that won’t be the case for an IC engine. Given the huge functionality available in modern radios (particularly the Jeti’s and those which use open source firmware such as OpenTX) that allow software based safeguards to be put in place without that disadvantage I no longer believe physical safeguards on the TX are necessary. YMMV.

Edited By MattyB on 14/04/2019 22:44:06

14/04/2019 22:01:40

You need to switch on the preflight checks at startup from the Model Setup menu. Rather than give an audio warning it lists all the switches in their current positions after you switch on, with any that are in a position you haven’t specified clearly highlighted. It won’t transmit until you either set all the switches into the right state or manually accept the current state via the Enter button.

You can enable this from the TX itself, but it’s a little easier from Companion:

Edited By MattyB on 14/04/2019 22:06:44

14/04/2019 13:28:41
Posted by Peter Christy on 14/04/2019 12:24:46:

In the end I've decided to go for the double hold solution rather than the sticky throttle. This is simply to ensure that should a switch get knocked in flight, the motor will restart instantly when the switch is put back, and not wait for the throttle to be shut when my brain is in panic mode!

I have, however, set up logical switches to play audio warnings when the motor is armed (SF AND SA away from me) or disabled (SF toward me OR SA NOT away from me).

Now all I need to do is figure out how to enable a switch warning at turn-on when SA is NOT away from me....!

That’s an easy one - just set your audio to be triggered by a logical switch with !SA↑ (Plus any additional conditions you want using AND function).

PS - I actually designed an “unknockable” safety switch for my Dad’s IC models that addresses your concerns with the sticky throttle cut. It requires a sequence of movements on a three position switch to activate and deactivate across to states (for instance ignition ioff and ignition on).

It’s more complex to setup but works very nicely - downloadable example and documentation here.

Edited By MattyB on 14/04/2019 13:31:41

14/04/2019 11:27:59
Posted by PatMc on 13/04/2019 20:27:37:

Peter, if you want a copy of the eepe or otx file drop me a PM with our email addy.

No need PatMc; when I made those posts I also posted up an eepe on the RCSettings site and linked it from the thread.

Edited By MattyB on 14/04/2019 11:29:15

Thread: C rating on Lipo's
23/03/2019 20:42:37

Short summary... almost all pack C-ratings are made up by manufacturers to sell their packs. If you have a decent charger that can measure the internal resistance (IR) of your packs you can estimate the max C rating of your packs using this tool; in my experience it tends to vary anywhere between 30-70% of the rating on the wrapper depending on brand, age and number of cycles.

Thread: Does your club prohibit the use of after-market receivers?
23/03/2019 13:21:53

As has been posted several times it is clear the pilot takes responsibility to ensure the flight can be made safely, not the committee. If an incident came to a court they would look to see what precautions the pilot had taken to ensure that was the case - i.e range and control checks done beforehand, no witnesses stating they were flying in an obviously dangerous way (such as repeated low passes over the pits) etc. The only time equipment could come into play would be if it was not certified for use in the UK for model aircraft (i.e. no CE mark and accompanying certificate of conformity), but the onus would still be on the prosecution to prove it were a contributing factor. Even if they did I fail to see how the committee could be held liable.

In reality we all know there are many other things we see in a club environment (ancient, undersized RX packs; poor quality switches; poorly thought out RX installs etc) that are orders of magnitude more likely to cause a crash. Even if that weren’t the case the assumption that compatible RXs are fundamentally more likely to cause an RF failure is highly questionable - since 2.4 came in there are lots of examples of big name brands making huge gaffes with their protocols (Futaba releasing kit with identical SSIDs; early Spek RXs with very high brownout voltages; Frsky’s first attempt at complying with the revised EU refs in 2015 etc). Banning non-OEM RXs will do absolutely nothing to address those kind of problems,

Thread: Verhees Delta
21/03/2019 20:59:08
Posted by Max Z on 20/03/2019 13:27:34:
Posted by MattyB on 20/03/2019 08:52:57: It's big enough to sleep in

That, and as Bart told us at the presentation, you can slide in head first and inspect the rudder control mechanism without the need for an external inspection opening. idea

Max.

Genius! teeth 2

20/03/2019 08:55:08

...and another longer video...

20/03/2019 08:52:57

An interesting video popped up in my Youtube feed yesterday - Verhees has built a prototype 2 seat version, and in Bugatti blue it looks quite a lot prettier and more practical. It's big enough to sleep in and you can even transport it on a trailer if needed...

Fancy a v2 Max? smiley

Edited By MattyB on 20/03/2019 09:17:07

Thread: Cheaper Teslas.....
07/03/2019 15:52:59
Posted by Piers Bowlan on 07/03/2019 05:43:40:

350kw charging? Everything I have read about charging, irrespective of the battery technology involved, links fast charging to reduced battery life. Used on a daily basis many electric car's battery performance reduces considerably after four years, resulting in not only a reduction in range but also performance. Battery replacement is a significant part of the cost of the car.

Batteries not only have problems with low temperatures but also with high temperatures too, when it comes to battery life. Teslas have cooling fans for the batteries whereas some cars, notibly the Nissen Leaf does not. The Tesla also has larger batteries and does not charge to 100%, both designed to stress the batteries less, hence improving their longevity. A £30k or £50k reduction in price would still not make me buy one however- it couldn't pull my caravan (very far). As a second car a two seat (+2 dogs) uber-basic urban runabout with a decent performance (no lead acid batteries, thank you) if short range, might be a different matter - if it was v-cheap! Nobody builds one crying

Roll on Lithium/Air and Aluminium/Air batteries, which if they could 'only' sort out the technology all our electric car dreams would come true!

Completely agree - without some kind of leap forward in battery tech these much trumpeted fast charging capabilities are going to reduce cycle life dramatically. Then there are the safety implications of charging at such high currents in highly populated areas. Would you fancy sitting in one of these vehicles whilst charging or even walking past it at the motorway services whilst 1400A are going in? No thanks...!

Edited By MattyB on 07/03/2019 15:53:34

Thread: JR resurrection?
04/03/2019 11:49:40
Posted by Peter Jenkins on 03/03/2019 23:54:32:

You can learn more about the situation here and here. I note that MacGregor Industries, while advertising the XG11 Tx and other JR products do not seem to allow you to buy them at the moment.

I do hope that the new outfit RC Depot and their new arm, Dee Force Aviation (DFA) get the brand going again. The T44 seems to be the renamed XG11 - a great Tx but one which needs it's firmware update service back up and running.

Based on that and other sources I have read online I don't think we can really call this a resurrection. Yes the brands and IP have been picked up, but there is really nothing of the original JR company or it's reputation of engineering excellence left. This is effectively a new startup, and I struggle to see how they will gain investment for new products or expand their reach beyond supporting the remaining handful of legacy users of the "old" JR - most people who want a premium 2.4GHz solution have alreadymoved on elsewhere, and the competition at the lower price points is probably even fiercer.

EDIT - Apparently when these land they will be £800... surprise I'm afraid at that price stillbirth is almost guaranteed; they are really only an option for die hards who don't want to give up their DMSS RXs. With no guarantee of the QC levels being the same as the old JRs it may even be a difficult sell to users of legacy JR kit.

Edited By MattyB on 04/03/2019 11:56:57

Thread: Propguy?
27/02/2019 10:47:58

This was posted on their Facebook page on 13th Feb...

"Apologies if you are trying to call. I am away overseas, normal answering calls however Sim Card has decided to fail so I cannot receive make calls or texts until further notice. I can however respond to emails most times with 24 hrs. Our website and distribution of products are not effected apart from new requirements from HMRC which is preventing us from clearing imports at the present time. Very disappointed with HMRC the the last advisory was ' we aim to respond within 15 days'...


Shambolic!"

(NB - The "Shambolic" is part of his post, not my addition) 

Edited By MattyB on 27/02/2019 10:49:22

Thread: LightThing
25/02/2019 13:29:48
Posted by Max Z on 24/02/2019 17:02:17:

Got somebody to shoot some moving pictures of me and my LightThing (follow the link to YouTube for a slightly better qualtity):

Max.

Seems to fly very well - great work Max. Quite a bit faster than I thought it would be, but clearly an excellent flier. thumbs upsmile d

Edited By MattyB on 25/02/2019 13:30:20

20/02/2019 09:56:11

Interesting model Max. How is it controlled, just rudder and elevator? I can't see any ailerons but it also doesn't look like there is much dihedral either...

Thread: DH84 Dragon
18/02/2019 17:30:55
Posted by Chris Reid on 17/02/2019 17:56:35:

Thanks for the compliments guys.

I've done the weighing and power checks now. The latter proved a bit of a puzzle as I'm only pulling 210W on 7x6" props from both motors from 2x2200 3S lipos in parallel; my standard for larger models. The Hobbyking spec for the Turnigy 2863/8 1100Kv motors says they pull 336W each at 18A and 15v, which I should have spotted is rubbish, as others have recorded on forums various. The model weighs 4lb 12oz ready to fly which around 40W/lb, rather less than some of the tables suggest for good performance. However, as fellow clubmates and I have found, brushless motor watts go further than old brushed motors watts, on which the tables are based. The static thrust is 2lb 2oz which ought to be enough. It's a vintage biplane not a pattern ship!

I've done the CG calculations which are not wholly straigtforward for a swept winged biplane. I hope I've got it right. I just need a fine day and a friendly test pilot now. I'm a safe flyer but I'm not up to first flight out of trim surprises.

I have a lightweight foamie parkflyer Spad from HK that was originally designed for 2S, but because of their strange design decisions ended up on 3S. I put it on an diet to be able to fly it on 2S in small spaces, and it has ~45W/lb.

It is perfectly flyable (from a hand launch, ROG is impossible due to it's small size), but was very hairy on the first flight. Given how much time and effort you have put into building this beauty I would encourage you to think of a way to get at least 60W/lb for your first flights, whether that is by going up to 4S or fitting new motors. The additional cost will be forgotton when you see it soaring confidently overhead, but it would be horrible to lose it because of a powertrain miscalculation.

Edited By MattyB on 18/02/2019 17:32:43

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