Seagull Gipsy Moth ( 72

[Rocker]

Anyone have a Seagull Gipsy Moth. (72" wingspan )I have a spare Laser 120 that needs to go in a model,thought the Seagull Gipsy Moth would be good just wondered what they are like to fly and what is the quality of the kit like? Not in to building just like the lazy option of ARTF

[Jon H]

The Laser 120 would be massive overkill for this model. There are videos of these flying on 60 4 strokes in a scale way. I would not suggest anything over an 80

[Pete B]

There's a thread with some motor discussion over here, Rocker

Pete

[Rocker]

Thanks, found the thread very interesting and I think you are right a 120 would rip the wings off .I think I would be better off putting a Laser 80 in it .I need an excuse to by another Laser,I thing the Laser engines are a work of art

[Rocker]

Just flown the maiden flight on my Seagull Gipsy Moth with the Laser 80.Flew absolutely brilliant. Jon at Laser was right the Laser 80 was the perfect engine for the Seagull Gipsy Moth,The 120 would of rip the wings of it even a 90 would be a bit much .If you are thinking about this model I would highly recommend the Laser 80.

[Jon H]

Glad to hear its all gone well. I still have my eye on one of these but alas my hangar is rather full at the moment.

Any chance of a video? and which prop are you currently using? One the engine is run in try a 15x6

[Former Member]

[This posting has been removed]

[David Davis]

...so do I!

[Rocker]

Alas I was on my own so no video So once the Laser 80 is run in I will try a 15x6 at the moment I am running on a 14x6

[Jon H]

14x6 is spot on for running in. I hope you leaned it off fully, none of this running rich nonsense

I would expect about 8800-9100rpm from the 80 on a 14x6 apc and 5% nitro.

[Geoff S]

Out of curiosity I had a look at the Gypsy Moth on Kings Lynn Models website. It's an attractive model but out of stock (thankfully ). However I noticed the recommended engine is either a 90 2s or 120 fs and here it's suggested to use a Laser 80. I have no experience of Laser engines so why a much smaller one (which seems to be adequate) than the 120 recommended by Seagull?

Geoff

[Jon H]

Hi Geoff

The Laser 80 is so powerful it matches the 120.....ok, perhaps not. The real reason is that seagull have just gone mad with their engine recommendation. I think they forgot it was not a WWII fighter.

This is a common problem with ARTF kits as they regularly get the engine recommendation wrong. The 45cc black horse chipmunk is another prime example as 45cc is far too much and they have flown on 120 4 strokes. At Laser we recommend the 150,155 or 180 for this model and all of our customers have reported back with how happy they are with the performance.

I think this moth should have an engine recommendation of 60-80 and the videos online back up this view. One chap has a hopelessly underpropped OS 62v 4 stroke in his and yet it still manages to fly in a scale and sedate sort of way. 

The other thing to consider is that many modellers are not happy with a scale type performance. If you watch you tube videos you will see some people have wedged OS200 surpasses and saito 180's into 63inch warbirds and fly them on 20% nitro at about 800mph scale speed. I have also seen precedent Stampe's doing aero's that would make a full size pitts special burst into tears. Personally i do not see the point of a scale model if you dont fly it in a scale sort of way, but, there are those who just want to fly it like they stole it and for that they need power. To cover against complaints about sluggish performance manufacturers will therfore recommend a big engine to cater for the people who want a toy aeroplane and not a scale model

 

Edited By Jon Harper - Laser Engines on 29/02/2016 16:07:22

[Terry Walters]

Hi Rocker.

I have one of these kits now and I do have achoice between a Laser 80. an OS70FS and also a ASP61FS. I see you have mounted your Laser 80. Others seem to have fitted various engines but I am finding it a challenge to get any of them to fit upright without something touching the cowl and yet some folk refer to their engines as 'perfect fit' etc.

Any chance of a pic of your installation? I would appreciate it very much.

Thanks

Terry

[Mark a]

Posted by Terry Walters on 18/07/2016 11:33:11:

Hi Rocker.

I have one of these kits now and I do have achoice between a Laser 80. an OS70FS and also a ASP61FS. I see you have mounted your Laser 80. Others seem to have fitted various engines but I am finding it a challenge to get any of them to fit upright without something touching the cowl and yet some folk refer to their engines as 'perfect fit' etc.

Any chance of a pic of your installation? I would appreciate it very much.

Thanks

Terry

Hi Terry

I've mounted my Laser 80 inverted due it not fitting inside the cowl the other way up also had to turn the throttle servo 90 degrees to reach the new throttle rod position. I did fit a Saito 82 in at first and that would just about fit in the right way up but had to cut a hole in the side of the cowl for the exhaust knuckle.. Hoping to fly it this weekend so i'll let you know how it goes.

Mark.

[Terry Walters]

Posted by Mark a on 19/07/2016 21:51:07:

Hi Terry

I've mounted my Laser 80 inverted due it not fitting inside the cowl the other way up also had to turn the throttle servo 90 degrees to reach the new throttle rod position. I did fit a Saito 82 in at first and that would just about fit in the right way up but had to cut a hole in the side of the cowl for the exhaust knuckle.. Hoping to fly it this weekend so i'll let you know how it goes.

Mark.

Hi Mark,

Thanks for your info - much appreciated. I particularly wanted to keep the engine upright but I'll be very interested to now how yours gets on. I've spent a couple of afternoons pondering this and I think I can get the Laser 80 in upright...but.... not with the standard silencer on and the carb needs to set on the angle.

I've had an e-mail exchange with Jon at Laser - always helpful - to see if there are any probs in using a flexible pipe as the exhaust with or without a silencer. Jon's view is that a long enough pipe without a silencer would soften the exhaust note. I am going to try it out first in the next few days on an engine stand. We don't have a noise problem at our site at all except that the neighbours, a quarry, make more noise than we do LOL! If I'm not happy with it Jon sells an in-line silencer that will take the edge off it.

Best of luck with your at the weekend - I may end up following you if I can't get my idea to work.

Cheers

Terry

[Terry Walters]

Hi Mark,

Any news on your first flight with the Laser 80 in place? I've been trying all sorts of options with my ASP FS70 and the Laser 80. I can mount the ASP upright but still have to cut the top of the cowl to ease for the header and then it's still a fight to get the down pipe and exhaust contained in the cowl. I ran the Laser with a flexible pipe and no silencer. It wasn't over loud but the exhaust note is harsher and not for me.

So, latest is that I'm am going to put the Laser in inverted like you as I really want the Laser in there rather than the ASP. If you have any observations I would be happy to have them. I have cut a space for the tank to go on the fus floor and yet to fit the throttle servo.

Terry

[Jon H]

I'm quite surprised to hear there is trouble fitting our 80 into the Moth. Rocker do you have any photos that might help the guys out as you didn't seem to report any major issues.

I would not recommend mounting the engine inverted though as fuel tank height will be a problem

[Terry Walters]

Hi Jon - thanks for the response but don't you ever allow yourself a day off! LOL! Some rushed poor quality pics for which I apologise. Yes the 80 can be made to fit but it's how much cutting of the cowl and how the exhaust will exit and where. Mark hasn't let us know yet how he got on.

This pic - standard upright fitting.

Front view showing carb projection and the angle on the exhaust to provide clearance from the cowl top. Problem is how to provide for exhaust to open air through bottom of cowl? Silicone pipe? Flexible? Neither seem to last long in my limited experience.

Upright fitting with small silencer that came with the Laser - I assume this was an original part option at the time? Bore is quite narrow but the silencer will fit.

The small silencer/expansion box - Laser made?

Inverted with small silencer - line on masking tape of front fus indicates height of fuel tank top when installed on fus floor.

Pic below showing vulnerability of the carb when engine inverted

Any suggestions that will help welcome. I do want to use the Laser but also want to keep cowl outline as far as possible.

Thanks

Terry

[Jon H]

Hi Terry

Nice set of photos, and I do sometimes get time off!

In any event the inverted install looks like it might actually be ok, but if it were me I would go with the upright setup. The little exhaust you have there is what we used to supply with the engines back in the 80's. We replaced it with a bigger one as noise became more of an issue.

I still think that a length of flexi pipe down the side of the fuz will be the best option

[cymaz]

You could have the exhaust tube down the fuselage. Different Moths had either the exhaust down the port or starboard side. Depending on different engine installations. A piece of small bore ali tube attached with P clamps would look good

[Terry Walters]

Posted by Jon Harper - Laser Engines on 07/08/2016 15:00:10:

In any event the inverted install looks like it might actually be ok, but if it were me I would go with the upright setup. The little exhaust you have there is what we used to supply with the engines back in the 80's. We replaced it with a bigger one as noise became more of an issue.

I still think that a length of flexi pipe down the side of the fuz will be the best option

Hi Jon, thanks for the quick response. Much appreciated. Now I know there's a good chance of the inverted working I keep that as a fall back position. I'll mount it upright (Putting the mid floor back in! LOL!) and try the flexipipe. Whether I drop it out the bottom or have a go at the horizontal external pipe is a bridge yet to be crossed. Can the length of the pipe affect revs if there's no expansion box?

Cymaz - Hope Bodmin isn't too chocker this morning! Nice set up! Is that a 1/4 scale one. How do you join ali pipes?

Terry

[Jon H]

I would go the route Cymaz has done. I can supply a length of pipe that will get you from the engine and out of the cowling. You can then grab some 15mm copper or ali tube from a diy place and make up the longer length. At that dia you should not loose any performance and the noise will be quite muffled too

[Terry Walters]

I'll go for that Jon. How can I joint the two different metals? Clamps don't seem to work on flexipipe. I'll ring you later with a small shopping list and CC details! LOL!

Terry

[Jon H]

If your long pipe is copper you can solder/braze to it as our flexi pipe is stainless steel. If its ali then you will need another solution. A jubilee clip should be satisfactory

[Mark a]

Posted by Terry Walters on 08/08/2016 08:39:18:

Posted by Jon Harper - Laser Engines on 07/08/2016 15:00:10:

In any event the inverted install looks like it might actually be ok, but if it were me I would go with the upright setup. The little exhaust you have there is what we used to supply with the engines back in the 80's. We replaced it with a bigger one as noise became more of an issue.

I still think that a length of flexi pipe down the side of the fuz will be the best option

Hi Jon, thanks for the quick response. Much appreciated. Now I know there's a good chance of the inverted working I keep that as a fall back position. I'll mount it upright (Putting the mid floor back in! LOL!) and try the flexipipe. Whether I drop it out the bottom or have a go at the horizontal external pipe is a bridge yet to be crossed. Can the length of the pipe affect revs if there's no expansion box?

Cymaz - Hope Bodmin isn't too chocker this morning! Nice set up! Is that a 1/4 scale one. How do you join ali pipes?

Terry

Hi Terry

Although I haven't got round to flying my Moth yet due to mainly not having the time or the weather's been horrid I can confirm it will run just fine with the Laser inverted and the fuel tank in its original position without any flooding issues.

Mark.