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

Laser Engines - Technical questions

All Topics | Latest Posts

Search for:  in Thread Title in  
Frank Skilbeck01/05/2020 08:10:35
avatar
4730 forum posts
101 photos
Posted by Tony Richardson on 01/05/2020 02:01:33:

Ok further to my previous question, Ethanol is out but where does Methyl Hydrate fall in this equation, it is also readily available here??

As Methyl Hydrate is just another name for Methanol, you should be fine! Just check if the chemical formula is CH3OH then it's methanol.

Keith England 101/05/2020 09:19:37
avatar
15 forum posts
Posted by Tony Richardson on 01/05/2020 02:01:33:

Ok further to my previous question, Ethanol is out but where does Methyl Hydrate fall in this equation, it is also readily available here??

How to go full circle🤡

Methyl Hydrate IS Methanol! Is is just a VERY archaic name for it that should have fallen into disuse a century ago.

Keith England 101/05/2020 09:19:41
avatar
15 forum posts
Posted by Tony Richardson on 01/05/2020 02:01:33:

Ok further to my previous question, Ethanol is out but where does Methyl Hydrate fall in this equation, it is also readily available here??

How to go full circle🤡

Methyl Hydrate IS Methanol! Is is just a VERY archaic name for it that should have fallen into disuse a century ago.

Tony Richardson02/05/2020 07:07:01
avatar
637 forum posts
25 photos

Frank, Keith, you will have to have a little patience with me as I am one of the older generation and have lived in Canada a long time so I can only quote the name I see or hear over here, I suspected it might be but was not sure as it is the local paint store of all places that stocks it! We in the colonies will eventually catch on or so i'm told by the visitors we have from the UK sorry used to have, lord knows when things will get back to some kind of normal.

Thank you all, and Jon I may well order a 120 or 155 for that 1/4 scale SE5a, depends if its the next build or not, oh so many kits and plans and so little time.....

Jon - Laser Engines02/05/2020 17:07:25
5510 forum posts
268 photos
Posted by Tony Richardson on 02/05/2020 07:07:01:

all, and Jon I may well order a 120 or 155 for that 1/4 scale SE5a, depends if its the next build or not, oh so many kits and plans and so little time.....

1/4 se5a needs a 180. Dont faff about with anything smaller as it wont be any good.

180 + 20x6 prop on a 1/4 SE5a will be lovely. Takeoff at just over half throttle, full power available for scale aerobatics.

Tony Richardson02/05/2020 17:31:23
avatar
637 forum posts
25 photos

HI JON, it's actually the "almost" 1/4 scale kit by Duncan Hutson engine size stated on plan is a 120?? I think you are right a little extra power is always valuable and the left stick should not have to be all the way up to keep the model flying.

Jon - Laser Engines02/05/2020 18:33:03
5510 forum posts
268 photos

what is the span/weight?

Martin Arnold 102/05/2020 21:46:38
21 forum posts
3 photos
Posted by Tony Richardson on 02/05/2020 17: the left stick should not have to be all the way up to keep the model flying.

Putting full down elevator in then !!!smiley

Tony Richardson03/05/2020 00:11:09
avatar
637 forum posts
25 photos

Hi Jon, the span is 1854mm 73 inches, and weight is in the range of 6 to 9 kg i make that about 13 to 20lb, that is the estimate on the plan, i'm assuming it depends on the amount of detail undertaken.

David Davis03/05/2020 08:49:57
avatar
3757 forum posts
718 photos
Posted by Jon - Laser Engines on 02/05/2020 17:07:25:
Posted by Tony Richardson on 02/05/2020 07:07:01:

all, and Jon I may well order a 120 or 155 for that 1/4 scale SE5a, depends if its the next build or not, oh so many kits and plans and so little time.....

1/4 se5a needs a 180. Dont faff about with anything smaller as it wont be any good.

180 + 20x6 prop on a 1/4 SE5a will be lovely. Takeoff at just over half throttle, full power available for scale aerobatics.

Oh dear .

I bought my Laser 155 to power the DB Sport & Scale SE5 which has been on a shelf for years. 80" wingspan, weight 16lbs.

So what should I put the 155 in Jon?

A SLEC Stampe? 82" span, not sure of the weight.

Or that 1/4 scale Fokker Triplane I've always fancied?

Chris Walby03/05/2020 09:47:39
avatar
1241 forum posts
303 photos

David, I like the logic...not what size engine would fit the model you have.. more what model will fit the 155...nice.

Watching with interest laugh Triplane gets my vote

Jon - Laser Engines03/05/2020 11:09:17
5510 forum posts
268 photos
Posted by Tony Richardson on 03/05/2020 00:11:09:

Hi Jon, the span is 1854mm 73 inches, and weight is in the range of 6 to 9 kg i make that about 13 to 20lb, that is the estimate on the plan, i'm assuming it depends on the amount of detail undertaken.

at that span you really dont want it to be 20lbs. I would aim for 15 as a maximum. If you can make it to 15 or less then the 155 will be ok.

Jon - Laser Engines03/05/2020 11:19:44
5510 forum posts
268 photos
Posted by David Davis on 03/05/2020 08:49:57:
Posted by Jon - Laser Engines on 02/05/2020 17:07:25:
Posted by Tony Richardson on 02/05/2020 07:07:01:

all, and Jon I may well order a 120 or 155 for that 1/4 scale SE5a, depends if its the next build or not, oh so many kits and plans and so little time.....

1/4 se5a needs a 180. Dont faff about with anything smaller as it wont be any good.

180 + 20x6 prop on a 1/4 SE5a will be lovely. Takeoff at just over half throttle, full power available for scale aerobatics.

 

Oh dear .

I bought my Laser 155 to power the DB Sport & Scale SE5 which has been on a shelf for years. 80" wingspan, weight 16lbs.

So what should I put the 155 in Jon?

A SLEC Stampe? 82" span, not sure of the weight.

Or that 1/4 scale Fokker Triplane I've always fancied?

 

 

The DB se5a is no good with a 155. I recommended a 180 to a customer before for this model and he didnt think he needed it so went for the 155. A short time later he was back at the factory with the engine in hand for me to test it was performing correctly as the model was under powered. It was, and an 'i told you so' followed.

The former precedent Stampe is the same. Use a 180. My stampe is 16lbs and its just perfect with the 180. A friend had one with a 155 and while it flew fine it was just lacking a little. He upgraded to a 180 and its more comfortable now

The way i always explain it is simple. The 155 will fly both models. They will takeoff, they will fly, and would probably even fly on a 120. But, a 120 powered example will have the engine screaming is crank off trying to drag this heavy parachute of a model round the sky. Equally, if you want to loop it you need to dive to well above scale speed in order to gain enough momentum to throw it over a loop. With a 180 fitted, i can put my stampe into a gentle dive at low power, then open the throttle as i pull up for my loop. The big 20x6 prop then hauls me round at a scale speed and with a nice growl as i add the power. Once out of my loop i can go back to floating about at just under 1/2 throttle.

Both the 155 and 180 deliver very similar HP but the delivery is very different.

 

In terms of the flair fokker, its much smaller/lighter and the 155 would be more than enough. I would try probably an 18x6 and go from there.

Edited By Jon - Laser Engines on 03/05/2020 11:20:53

David Davis03/05/2020 11:29:42
avatar
3757 forum posts
718 photos

Thanks Jon. It's not a Flair Fokker Triplane, it's the Arizona Aeromodellers plan. I'll get it out of its tube and have a drool before lunch.

Jon - Laser Engines03/05/2020 11:39:49
5510 forum posts
268 photos

Ah ok. Im not as familiar with that version but if its like the flair it should be 70 inch and 12lbs or so?

Scott Edwards 203/05/2020 12:27:39
216 forum posts
97 photos

Another vote for the 180 if I may, based on my own experience of them. The extra weight of the 180 is handy for balancing, and that big crankcase acts as a heatsink, so cooling is more forgiving in an enclosed cowl.

My 180's love a 20x6 (I like the Falcon wooden ones) On a 7Kg plus scale bipe, a 20x6 prop at lower revs will always be nicer to operate than a higher reving 16 or 18, and look much better too.

The 155 and 180 are both fabulous, but have a different nature. The 180 is a bulletproof thumper, pulls like a train and is as solid as hell. The 155 is much lighter, and more sporty. I've got a 74 inch pattern ship with a 155 which it's ideal for, and a 70 inch Ultimate bipe with a 180 which is a peach. No way would I swap the engines around.

David Davis04/05/2020 09:03:39
avatar
3757 forum posts
718 photos

OK. If the 155 is unsuitable for a DB Sport & Scale SE5, would their 1/4 scale Cirrus/Gipsy Moth be more appropriate? 80" wingspan and lt only weighs 12 lbs.

Jon - Laser Engines04/05/2020 10:22:55
5510 forum posts
268 photos
Posted by David Davis on 04/05/2020 09:03:39:

OK. If the 155 is unsuitable for a DB Sport & Scale SE5, would their 1/4 scale Cirrus/Gipsy Moth be more appropriate? 80" wingspan and lt only weighs 12 lbs.

Yep, the 155 will monster the moth. We have a few flying on the 155 already and they go really well and the extra power allows some wiggle room on the weight with 14lbs being just fine. you could even stretch to a 19x6 prop on this model. The engine will be overloaded, but you could waft around at mid throttle without stressing it.

I have seen them fly on 100's but the performance was scale and nothing more even at only 12lbs.

Martin McIntosh04/05/2020 12:13:51
avatar
3419 forum posts
1213 photos

I could not really tell any difference between an 18x8 or a 19x6 on my 155 when it was in the Stampe. It did not seem over loaded on either.

Jon - Laser Engines04/05/2020 15:09:16
5510 forum posts
268 photos

both 18x8 and 19x6 are starting to get pretty heavy for the 155. It will swing them, but its starting to really load it down especially if it starts getting hot and its owner insists on pushing the throttle up. Cruising around at low-medium throttle is fine though and short bursts of full power wont hurt it

All Topics | Latest Posts

Please login to post a reply.

Latest Forum Posts
Support Our Partners
CML
Sussex Model Centre
Slec
electricwingman 2017
Sarik
Advertise With Us
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

Magazine Locator

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

Find RCM&E!