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Laser Engines - Technical questions


Jon H

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Thanks chaps the JE sounds perfect . My old little starter struggles on my OS 120ax and my Laser 180s on cold days so it’s finally time to bite the bullet . I do have an old 6s LiPo from when I once briefly tried electric 😊.
 

Chris I think someone would need to be very clever to flick my 200v into action on a cold day ! 
I use reverse flick with great success on Laser 180. 155, 100 and the 80 . My 70 either needs forward flick or a starter motor. The larger 100-180 lasers I find easiest to flick start. Bigger engines have more prop momentum and I . Always find them easiest to start. When the engines are already hot from previous flights  I use a starter as the fuel evaporates making flick starts harder .  

Edited By Tim Flyer on 23/03/2020 20:47:28

Edited By Tim Flyer on 23/03/2020 20:47:53

Edited By Tim Flyer on 23/03/2020 20:48:39

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Posted by Chris Walby on 23/03/2020 20:26:09:

This is a good time to bring the subject of hand starting Laser engines up.

Electric starters are okay, but they mess the ali spinners up, good news they keep my fingers out of the prop arc!

Jon, what's your recommendation on hand starting (all sizes) of engine and the best technique?

Can you reverse flick them?

Yea the reverse flick is the best way. Flicking them the right way is likely to not end well!

I would prime heavily , flip it about a few times to clear it, and then back flick it.

It depends on a good prime though, and if you cant get a finger in and prime it then dont bother and just use a starter. I use a starter on all of my lasers at the moment as they are all buried in cowlings.

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Just wondering Jonathan, what is the likelihood of the V twin glows being re-introduced? There seems to be a demand for them from what I can see. I realise that we are all locked down for at least a couple of weeks and probably longer but I was just wondering.

Edited By David Davis on 24/03/2020 09:43:28

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Posted by Jon - Laser Engines on 24/03/2020 10:00:34:

My availability page tells all. I do wonder why people dont read it smile p

**LINK**

Oh we all read it Jon, but there is the 200V sitting there tantalisingly out of reach with “out of stock” against it and there is us stuck at home itching to get a plane ready to fly and refreshing the page regularly to see if the “out of stock” sign magically disappears, hell it’s now my home page 🤡.

And we don’t know if it’s going to happen in days, weeks, months 😥😭

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‘Oh we all read it Jon, but there is the 200V sitting there tantalisingly out of reach with “out of stock” against it and there is us stuck at home itching to get a plane ready to fly and refreshing the page regularly to see if the “out of stock” sign magically disappears, hell it’s now my home page 🤡.’

Comforting to know I am not the only one.

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Re starters. I too have a pair of fully cowled Laser 180 models, so decided to buy a starter. The larger JE had been recommended but as it doesn’t come with a guarantee for what sounds like a regular switch problem I opted for an Align starter. First goes with it couldn’t turn the 180 and I was pretty disappointed as it is rated for up to 50cc motors. Well as I am new to Lipo batteries I read some stuff and then gave the new 3s 220ma battery a few charge cycles. Big difference and more than happy with it now. Also worth noting the day I first tried it it was only 5 degrees in the garden.

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To be honest, right now we arent even sure if we can stay open.

One of our guys was accosted by the local constabulary on the way in today and given a grilling on why he was out. He argued that its difficult to take a 5 ton CNC machine with him on a motorbike so he is unable to work from home.

Material supplies are also a problem so if we run out of metal to work with its the end of the road anyway.

We are also no longer accepting customers to collect/drop stuff off.

Finally, heaven knows what the situation will be with postage so its all up the air at the moment.

In the meanwhile i suppose its time to go make a noise on the test bench.

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On the JE starter switch melting situation it noticed that it was much worse when the starter was new. I suspect the arcing caused by the contacts touching does something to the copper and it becomes more resistant to welding over time. Also the starters were not designed for lipo and its instant belt of high current.

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Posted by Chris Walby on 24/03/2020 11:37:14:

Jon, why does the starter come with a lipo battery holder option ?

Marketing. You cant sell it with one of those out of date NiCd battery holders you know. The product has to seem modern and up to date.

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"I suspect the arcing caused by the contacts touching does something to the copper and it becomes more resistant to welding over time."

Yes, the arcing will bake on crud to the surface of the copper, which will increase contact resistance.

As you've noticed an incorrectly rated switch may have trouble breaking contact, too.

I think I'd recommend making sure there is an easy way of removing the lipo if you're insisting on continuing with the crappy built in switch...

"The Sullivan just about starts most of my engines. I power it on an old fashioned 12v lead acid flight box battery."

I'm (fairly) sure the Sullivan starters are all ok to run on more volts than a 12V gel can provide. I have an old Hi Tork, currently on only a 3S lipo, which has plenty enough guts to spin over my OS 81 & 90.

A 4S lipo would easily beef it up. Maybe worth trying that before another starter?

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I've got a top end Dynatron 24 volt unit. Stuck a 5S battery on it. Wrists not up to the job, Schwarzenegger's wrists would not be up to the job.

I usually use a standard cheapie starter with a 4 s battery. Never had a peep of trouble with it. I have a small conjecture that a bit more voltage gets the motor spinning quicker from stalled, what gets the back EMF going, and the high current situation is more transitory.

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If you want to avoid the JE starter switch 'sticking' (mine did it once but was only a temporary blip) run it on 5s not 6. It will still easily throw the prop over on a 60cc gasser as well as all of the Lasers. As a matter of interest JE has this note on their website about these starters:

Please note it has come to our attention under certain conditions the use of LiPo batteries can over power the starter and cause the switch contacts to weld on. Many use LiPos without problem. In this event the switch can be removed and contacts can be separated and normal use can be resumed. This would not be a warranty repair.

I've been happily using mine on a regular basis for the last 4 years and apart form the one switch 'occasion' mentioned above it's been brilliant, and a darn site cheaper than the Sullivan one too (unless you can get a decent second hand one!!!).

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Posted by Barrie Lever on 24/03/2020 11:54:57:

I agree with Nigel, there is no better starter on the market than the Sullivan, they take an insane amount of abuse.

I bought my current Sullivan on Ebay around 15 years ago for £5.00

Brilliant.

B.

My dads sullivan will barely turn over a 25 2 stroke. Useless old heap. Its just got no torque and takes forever to spin up. Total waste of time

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I've got a Sullivan Dynatron. Useless, it wouldn't even turn over an OS 200FS. I bought both models of Just Engines starters (couldn't be bothered with changing over the different cones) and even the small one spins it over easily on 12v. Well worth the money.

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Posted by Jon - Laser Engines on 24/03/2020 13:50:34:

My dads sullivan will barely turn over a 25 2 stroke. Useless old heap. Its just got no torque and takes forever to spin up. Total waste of time

Must be something wrong, brushes or bad wiring then.

They will happily take an 80A current for around 1kW total power. If you can't spin a 0.25 then something is amiss.

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Posted by Nigel R on 24/03/2020 14:12:51:
Posted by Jon - Laser Engines on 24/03/2020 13:50:34:

My dads sullivan will barely turn over a 25 2 stroke. Useless old heap. Its just got no torque and takes forever to spin up. Total waste of time

Must be something wrong, brushes or bad wiring then.

They will happily take an 80A current for around 1kW total power. If you can't spin a 0.25 then something is amiss.

yep, the problem is they need a car battery to do anything useful. Even a small motorbike battery is not enough to deliver the amps.

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Posted by David Davis on 24/03/2020 14:55:55:
Posted by Jon - Laser Engines on 24/03/2020 10:00:34:

My availability page tells all. I do wonder why people dont read it smile p

**LINK**

I consider myself duly chastised. blush

Good smile p

I just updated it as well

While the starter chat has been great, could we start a new thread to cover the minutiae just to keep things tidy. Cheers

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