Laser 310FT

[Ron Gray]

OK tank now shifted forwards and lowered by 15mm

 

 

 

Im retaining the power distribution board

 

[Jon H]

Yea thats the ticket. 👍

[Ron Gray]

Just got to wedge it in place with more foam, and cut new vent and fill tubes!

Edited April 14, 2023 by Ron Gray

[Kevin Fairgrieve]

Flew a treat.

 

 

[john stones 1 - Moderator]

Nice shot Kev.

[Ron Gray]

Brilliant Kev, thanks.

[Jon H]

excuse me, but where is my video? 😛 

[Ron Gray]

I was rather busy so didn't check if a video was taken - my bad!

 

All I can say is that I didn't have time to run the engine in the garden as I usually do so its first run under my ownership was at the field for its 'maiden'. Normal procedure of spin the prop with no glow attached for about 20 secs, attach glow driver (plugs are in series) touch the started and she fired and ran. Let it warm up then checked for tickover to make sure it wouldn't roll forwards then a few throttle blips followed by a quick run up to (nearly) full revs. Now normally I would run it at full revs for 10 secs to make sure everything was OK but this time I didn't and just took it out onto the runway, ¾ throttle and it fairly leaped into the air. A couple of circuits to get back the feel of the 'plane (6 years since I last flew it) and some very slight trimming then it was into some gentle aeros with vertical climbs. Not unlimited vertical but plenty good enough to do some big loops. then back down to land running onto the grass to act as a brake (no wing and the Revolver just want s to keep going). Then realised that the throttle couldn't be cut (it could in the pits!) as it wouldn't run slow enough, gosh it can ticker at very low revs! So screwed both needles fully in but it still kept running, blessed Lasers just want to keep running. Opened both needles fully still no joy but eventually got one pot to die then the other. So a bit of mechanical throttle adjustment is required to sort that out.

 

To sum up, the 310FT is a bit of a beast and whilst not a power match for a DLE 55RA (original motor in the Revolver) it is not that far short and sounds so much better.

 

Next time I will make sure someone is taking a vid of it!

[Jon H]

22 minutes ago, Ron Gray said:

I was rather busy so didn't check if a video was taken

 

Yea no bother 

 

 

[Jon H]

10 hours ago, Ron Gray said:

To sum up, the 310FT is a bit of a beast and whilst not a power match for a DLE 55RA

 

Dle55's do about 6500 on 23x8 menz if i remember correctly? I have tried a 22x8 apc on the 310, and saw 7000, but never tried a 22x8 menz. I would expect it to be a little slower, so they might both do about 6500rpm but the dle with an inch more diameter. 

 

That isnt bad though. 55cc 2 stroke vs 51cc 4 stroke. 

[Ron Gray]

I used to fly with a 23x8 Menz on the DLE in the Revolver, I'm using a 20X8 Menz with the FT and have also got a 20x10 Falcon to try too. But I was very pleasantly 'surprised' by how good the FT was bearing in mind my DLE was the RA with a can attached so was no slouch. The FT, with that prop, was a bit loud on WOT so I may try a bigger prop too but as it was only running WOT a few times it wasn't an issue, it was just nice to be able to 'bimble' along with the FT at about 3000 listening to that glorious 4 stroke sound. 

 

Happy to say that the Giant Revolver now has a new lease of life!!!

 

Promise to video it next time.

[Jon H]

I would guess the 20x8 menz was up near 8000? APC 20x8 runs around 8000-8200 so i would assume about 7700-8000 for the menz as i have not tested one of those yet. 

 

I tested a hiprop 21x10 and saw 6500, that might be a nice match when it comes to the sound and should give good power too. It will be a bit if a case of suck it and see. I use the same prop on my Sea Fury and the 360v had no trouble hauling its 23lb bulk even at half throttle. The 360 will clearly have more go at the top end, but even so the 21x10 hiprop looks like a decent option to try. https://www.rapidrcmodels.com/21-x-10-beech-wooden-propeller---gas-5363-p.asp not too costly either. 

 

In fact i need to do a propeller stock take and order some up. A few of my wooden ones have been scrapped due to age. 

[Ron Gray]

That's not a bad price for that prop, I'll wait and see how the Falcon performs first before I spend (even more) money!

[Jon H]

Props are always a waste of money. You buy 10, but only ever use one as you find the right one for the model and the rest just sit in a drawer as you just buy another one of the good ones if you bust it. Its why i simply cannot justify a carbon prop at 70 or 80 quid a throw. 

 

How was fuel consumption on the 310 by the way? I tested my 360 yesterday and it chomped somewhere between 14 and 16oz in a longer than normal flight of around 12-14 minutes. I forgot to record the exact time and was estimating the fuel use as one tank 14oz tank was half full and the other about 1/3 as one cylinder was a smidge out of tune and some fuel leaked from that side while i was faffing about. 

[Ron Gray]

I've just checked the log file and the 1 flight that I did lasted 13 minutes from starting the engine to kill, with a flight time of about 9 minutes from take off to landing. When I drained the tank I would say that there was just under a ¼ of a 19oz tank left. The engine was running slightly rich (as per factory settings) but not too far out so my 19oz tank will be OK for most flying but I may just get a 24oz one to give me that bit more.

[Jon H]

So thats about 14.5oz used in the air? Not bad for 50cc and i suspect it was given plenty of beans. I bet that will improve with some needle tweaks. The slow runs are likely a bit rich as i need to upgrade my test bench to a more optimal setup for the flats. Just havent got round to it yet. 

[Ron Gray]

32 minutes ago, Jon - Laser Engines said:

and i suspect it was given plenty of beans

What me?!!!!!!

[Ron Gray]

I wanted to check the lack of tickover experienced on Sunday so decided on a garden run and took this vid of it.

 

 

[Ron Gray]

Problem found!

 

 

[Jon H]

Not important in this case as the engine will likely fly again soon but for anyone else watching a run as in the video with lots of idle and not much high speed is a great way to make your engine go rusty, especially if it is going into storage. When ground running before you turn it all off give it a good thrashing to make sure its well up to temperature. I would recommend full power for 10 seconds, throttle back by 500rpm and hold for at least half a minute, then back to full power for another 10 seconds before dropping down to idle for 5 seconds, then pinch off the fuel. Lock at TDC if its going in storage and its job done 🙂 

 

 

 

[Ron Gray]

You also have to remember that the whole point of this garden run was to sort out the engine not cutting on low throttle so a lot of the time in this first vid was at low revs, in fact in the first vid I had to cut the fuel supply by pinching the fuel lines. Once I found out what the problem was, as shown in the short vid, the plan was to reset all of the adjustments I had previously made to get it back to ‘normal’. Unfortunately I ran out of time today so I will be running it again tomorrow when I will be setting the tickover and will be checking the top end as the second part of the garden run. 

As Jon pointed out, this engine will not be going into storage and will be up in the air again asap!

Edited April 19, 2023 by Ron Gray

[Ron Gray]

I also replaced the fuel tank with a 24oz one which will give me about 50% more capacity!

[Jon H]

13 hours ago, Ron Gray said:

I also replaced the fuel tank with a 24oz one which will give me about 50% more capacity!

 

It will be up there for a week 😉 

 

Glad you got the throttle sorted. Running your balls into something is never recommended. 

[Ron Gray]

Engine sorted, tickover fine but more importantly it cuts when I hit the ‘kill’ switch!

[Ron Gray]

I failed to take a video of its first flight but managed to capture one today