Artto Ilmanen

This is what one thinks - yet I have experienced this fenomenon when I was looking at some boating accessories. Don't recall any more the details, though.

Thanks, Richard!

Thanks Richard, is this what you are using? The Futaba HD switch is capable to handle quite much current - and is very reliable Is this similar? https://servoshop.co.uk/index.php?pid=JP22954407&area=Accs

John, you may be right - I’m happy to stand corrected

Don, Very true - I just do not know if the product range is the same here and in the USA: hence my hesitation.

By the way, it seems the genuine Futaba HD switch that I used to use is discontinued. Ant hints for a good quality HD switch? ( I happen to be preparing an order at servoshop.uk.co so I might add few switches to my order)

thanks for you all, From what you write it seems it’s ok and should not cause any premature servo failures. I think the counter-argument I have heard is based on the LiFE battery being able to maintaint the voltage better than a Nimh pack.

Thanks Richard, This is what I have been thinking, too. But isn’it so that a 5 cell NiMh battery voltage drops very quick below 6V when loaded while a Life pack stays above 6v for most of its capacity, even when loaded? Is this something to consider ? Or am I wrong and thinking too complicated?

Gents, Have you first hand experience with powering Savöx 6V servos with unregulated 2s Life battery? I came across this at https://www.savoxusa.com/pages/faq : "Our 6V rated servos can handle power from a fully charged 2S LiFe pack without any issues. However, you will need a regulator for 2S LiPo operation." -> However, not really knowing if the product range is the same in the USA vs. Europe I asked the the topic from Steve Webb (servoshop.co.uk) This is what I was answered: "Savox 4.8-6V servos are not designed for use with a 6.6V LiFe battery, you would need to use an in-line regulator to reduce the voltage to 6V." Well, I find this a bit confusing.. ? Anyways, I can, of course, forget the whole matter and use a sub-c 5s NIMH battery pack but it weights around 300g and a similar capacity Life pack weighs maybe 100g less. Also, I believe I do not need to maintenance cycle a Life battery pack but instead I can just charge it full and leave it there when I'm not flying (winter time) without any issues in terms of ruining the battery pack. Or, I could buy a crazy expensive "safety switch" with build-in regulator. Yet I have flown years using just good quality HD switch(es) in conjunction with quality battery packs. So I think the optimum setup for me would be just a quality HD switch and a Life battery powering directly (unregulated) the Savöx standard 6V servos to avoid any complicated issues. So, can I use the Savöx servos with unregulated 2s Life? What do you think? Any first hand experience? thanks! 🙂 Artto

Very well - I too was thinking of the scale exhausts for exiting the air but let’s see. However, the air inlet is also a matter to be considered. The scoop in the full size one seems to be too far below the wing to help with the air inlet.

By the way, Jon How are you planning to organize the cooling in your model? Decent baffling of course but ideas for air inlet and exit?

Jon, what do you expect, how much your painting job is going to add weight? I'm asking as I have been offered a YA Spitfire for 150€ and I'm tempted to buy as at least where I live you do not come across these often. No crashing but the model requires rebuilding as it looks ugly etc. But no fractures or cracs on the fuselage and the wing is also in good shape without any major accidents. Also, the bottom front part of the cowling is missing. The original builder just sanded sanded the wing and then painted and varnished it - no glass cloth whatsoever and the work was done very poorly, unfortunately. Anyways, the model now weighs 5600g without servos, tanks and engine + plumping, electronics, spinner, etc. Also, no pilot included in the weight. My maths shows it could weight in ballpark of 18lbs when ready to fly (how so little, maybe I need to tweak my math?). But, if I cover the wing with light glass cloth and then paint the wing I certainly add weight - but the question is how much? Any ballpark idea? I'm not experienced with this kind of painting projects. I'm still planning to mount the 240V if I can keep the weight at this ballpark.. Few pictures to motivate you - as yours looks so much better 🙂

thanks, Jon

This is interesting! Is the FT310 bolt pattern going to be the same with the 300V? I don’t recall the rpm of my 300V with a 20x8 so I wonder if the FT310 falls somewhere between the 300V and 360V in terms of power & ability to turn large props? How is the weight of the FT310?

Thanks Jon, I see.. in anyways, this is promising with respect to my YA Spitty as both DB Hurricane and YA Spitfire are more or less equal aerodynamically, both beeing quite a good ones, I guess

The model flies great Jon! Congrats! From what you wrote earlier I understand you flew the model with an 18X8 on the video. since that you have experimented different props to get more vertical performance and less speed as far as I understand. How did it turn out, were the other props better in vertical performance?

Thanks Jon, Perfect, no rush but always got hear of results with different prop setups

ok Jon, I think my 240V run about 8200-8400 with the Menz 18x8. Is the prop 19x8 Menz what you are running in the Hurricane? I assume with larger prop / 7300 on the ground you are more after thrust in verticals than horizontal speed?

Very true, Jon. I did a custom exhaust for my GP Super Chipmunk / Laser 150 so I do not fear that process too much. But, I'm not very much fancying the cylinders of a 300V poking outside the YA spitty cowling. Not much, but still. That's one of the reasons I was toying with idea of a reduction gear as my understanding is the YA spitty calls for a prop larger than 18X8 which is a good prop for the 240V. I know Jon, that you have been running the 240V with a 19X8 so maybe that could be ok. However, the reduction gear, at least theoretically, would allow the 240V to reach its best power (at 9000+ rpm on ground) yet enable a large propeller to give good thrust for vertical maneuvres. But then again, theory is theory and maybe nothing to be gained in practice. Also in commercial wise not a business for Laser to develop & sella a reduction gear setup. Perfectly understandable. Also, as time goes on who knows if there will be an inline 310 (I suppose there won't be any new configuration based on the 150 cylinder) which could be the "crème de la crème" solution for the YA Spitfire. Maybe it's worth the wait 🙂 even though the inline requires substantial rebuilding of the model to handle the length of the engine plus the cooling arrangement.

Nick, I saw your post on FB - Sorry to hear of your story. Fortunately you did not loose your money, eventually. Also A lesson to learn for myself: I have been happily transferring money to random hobbyist (in Finland, where I live) with confidence I was going to be provided the items as agreed. Yet I have never been scammed but, hey, that had been your experience too, Nick! By the way, I actually posted a my add to swap my 240V to a 300V as I will be starting a project to rebuild a Yellow Aircraft Spitfire and a 300V might be a better engine for the model. Jon says he had been thinking of a 240V for his YA Spitfire but eventually decided on the 300V, though. And as my 240V is sitting on a shelve without home in anyways. Now that you posted your horror story of a scammer I'm not expecting many contacting me on my add, though..😃

Thanks for the prompt reply, Jon! While I can't see issues with my mathematical skills to calculate the correct blend I will follow this rule. 😀

Hi Jon, I tired to search for the latest Laser factory recommendation for suitable fuel mix but could not really find an answer: As you know, my engines are 2 x 150, 240V and a 300v all manufactured between 2004-2013. I just checked and it turns out I have plenty of Aerosave, ML 70 (+ some sical), Klots KL 200. All these are high viscosity good quality oils. As per earlier discussions I have been blending my fuel 5% nitro, 10 oil (or 9%oil +1% Sical) and the rest methanol. Is this still your recommendation? Or could I go for 5% nitro, 7% oil and the rest methanol? (which is the blend, as fas as I know, the blend of the new Laser 5 Pro fuel) Or should one avoid this low oil % if self-mixing the fuel, just to maintain safety margin? thanks Artto

This is quite a neat looking one:

Jon, Thanks for a simple and clear answer - makes sense!

Thanks Jon, this is clear and I think I and many others appreciate your fair reply. On the subject, I have tried to read many threads to get educated on the benefits of the reduction gear. While it's clear that a reduction gear enables using a large prop (ref. your example) which is nice with respect to scale look I still lack of understanding wether there are any true performance advantage to be gained with a reduction gear. Theoretically a larger prop can be more efficient than a smaller one but is this more theory than practice in modeler's perspective? Or could a reduction gear enable using, in certain applications, a smaller engine to produce similar performance (power) as a larger one? As you know I'v been thinking a 240v vs. a 300v