By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

rc plane crash - 68% pitts challenger robbie skipton at raf cosford

All Topics | Latest Posts

Search for:  in Thread Title in  
john stones 121/07/2016 21:26:00
avatar
11152 forum posts
1503 photos

Modellers under pressure ?

You need a hobby fellas smiley

John

Keith Simmons21/07/2016 21:45:51
450 forum posts
9 photos

You have my full respect Robbie.

Enjoy your hobby and do what tick's your boxes.

Keith

Former Member21/07/2016 22:10:02
3578 forum posts

[This posting has been removed]

Robbie Skipton - Skip Model Designs21/07/2016 23:23:59
103 forum posts
1 photos

I love large models! Dont Get me wrong.. But as im now at the old age of 30... My eye sight is going.... So my excuse is "i need bigger planes to be able to see them in the sky"...,.. It always looked like a foamie to me lol

Phil 921/07/2016 23:43:35
avatar
4287 forum posts
247 photos

did it fly like a foamie?

Robbie Skipton - Skip Model Designs22/07/2016 00:21:35
103 forum posts
1 photos
Depends what i was doing. It was very light on sticks when doing slow stuff, and when i was doing harriers with it last year, was certainly as slow as a foamy. But didnt glide to well
Nigel R22/07/2016 09:15:48
avatar
3500 forum posts
532 photos

I'm late to this one, so excuse me if what I say has already been said.

I'm not sure full size procedures are relevant to this discussion. This isn't a machine capable of carrying human (or any other) life.

The model was a superb looking bit of kit. We have no reason to suspect maintenance was not in accordance with LMA procedure.

The model was being flown away from spectators, in a display area where any kit problems would minimise any risk to spectators. It sadly suffered engine failure at the worst possible moment. Downwind at low speed and low height with a crowd nearby your options are as minimal as it gets. I don't see anything in the video that calls piloting skills into question.

To my mind the only real lesson coming out of this is that multi cylinder two strokes have a big weakness, if they lose all power when one cylinder lets go for whatever reason.

All the best to Mr Skipton getting the replacement bipe in the air.

The Wright Stuff22/07/2016 09:34:22
avatar
1381 forum posts
226 photos
Posted by SuperNash on 22/07/2016 09:15:48:

I'm not sure full size procedures are relevant to this discussion. This isn't a machine capable of carrying human (or any other) life.

The model was a superb looking bit of kit. We have no reason to suspect maintenance was not in accordance with LMA procedure.

 

Agree with all of that. Safety is very, very important, but it has to be credible and proportional. The funny thing is, the critics who are pointing out the dangers due to it being practically full size are generally the same people who, last week, were busy telling me that, in fact, small models could be much more dangerous than big ones!

Edited By The Wright Stuff on 22/07/2016 09:35:20

MattyB22/07/2016 14:30:21
avatar
2014 forum posts
31 photos

There is no question in my mind that the model was being operated safely, the pilot took the appropriate action and people were never at any risk. My post a page or so back was simply expressing the view that if a) this is a known issue with ZDZ engines, b) no amount of maintenance or checking can prevent such an issue occurring, and c) ZDZ do not respond to queries and are not obviously working on a fix, I personally would not want to invest in a multi-thousand pound airframe to be powered by the same engine that failed. The idea of losing a model like this to an unavoidable but known mechanical failure is bad enough; losing a second would be even more painful.

Edited By MattyB on 22/07/2016 14:30:40

Bob Cotsford22/07/2016 14:38:49
avatar
8248 forum posts
454 photos

At least Robbie needn't be worried about the warranty if he wants to helicoil the plug threads nowlaugh

Robbie Skipton - Skip Model Designs22/07/2016 20:10:25
103 forum posts
1 photos
We are trying to come up with a locking system to solve this issue.... all else fails gaffer tape solves all lmao
Owdlad22/07/2016 20:23:24
222 forum posts
140 photos

Trying to be constructive, so can you please clarify the problem

1. Is it the plug that's coming loose?

2. Or is it the plug cap that's detaching from the plug

Robbie Skipton - Skip Model Designs22/07/2016 20:35:53
103 forum posts
1 photos
The plug unwound from the engine while in the plug cap. So both detached from engine
Peter Android22/07/2016 20:50:35
avatar
61 forum posts
2 photos

Just a thought, maybe ?

**LINK**

Former Member23/07/2016 00:19:55
3578 forum posts

[This posting has been removed]

Gary Manuel23/07/2016 08:59:02
avatar
2190 forum posts
1540 photos

Robbie,

Just a thought. Is the plug cap one of the proprietry ZDZ types with the grub screw?

Maybe the plug cap part is somehow interfering with the plug to cylinder head contact area, allowing it to unscrew?

If so, it might be an idea to switch to the more conventional plug cap / spark plug.

This is the type I'm on about. As you can see, this had been running VERY rich when I bought it.

PS - very much looking forward to your build log, if you decide to do one.

dscn4518low.jpg

Frank Skilbeck23/07/2016 09:13:24
avatar
4603 forum posts
101 photos

On racing motor bikes, they use wire locking to stop nuts and plugs from coming loose, is this an option here. Or failing that some form of tab washer, but that would make the plug stand off and hence lower the compression ratio slightly.

Robbie Skipton - Skip Model Designs23/07/2016 09:20:23
103 forum posts
1 photos
The plug system on this motor is not the one pictured above. It is simply put plug in a torque up.

I cannot use wire on the plug as above due to the caps.... alreadt thought of this methord
Owdlad23/07/2016 13:34:51
222 forum posts
140 photos

Glad you mentioned that you torque the plug up. Is it around 7-9 lb ft ?

I believe the problem is to do with expansion as Aluminium expands roughly twice as much as Steal.

Have you tried to re-torque the plugs up at operating temperature ?

Bob Cotsford23/07/2016 15:26:03
avatar
8248 forum posts
454 photos

Google says that they are taper thread plugs, not the straight thread types we are all more familiar with. I can imagine these going quickly from a tad loose to goodbye plug. If you throw away the warranty is it worth getting the heads bushed and tapped for straight thread plugs?

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E! 

Latest Forum Posts
Support Our Partners
Cambridge Gliding Club
Wings & Wheels 2019
CADMA
Sussex Model Centre
electricwingman 2017
CML
Slec
Sarik
Advertise With Us
Latest "For Sale" Ads
Has home isolation prompted you to start trad' building?
Q: The effects of Coronavirus

 Yes - for the first time
 Yes - but Ive bashed balsa before
 No - Ive existing projects on the bench
 No - Im strictly an ARTF person

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us