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FT What Did You Do RC Today : Caution Offtopic At All Times

where did you set the CG? their number seems really far back. i was expecting it to be about 2" forward of what they say. as it is now, without a battery, it's almost perfect. doesn't bode well for what's gonna happen when i do put a battery in it. :LOL:

thanks,

me :cool:
Sorry, just now seeing this message. The forums for me has been hit or miss if I get notifications.
 

PsyBorg

Wake up! Time to fly!
Got around to running this beast finally...


I take no responsibility for the stand. I didn't mount it. You can see it shaking around everywhere at idle (it sounds like it's knocking but that's just the clamp handle vibrating around everywhere!) Also always wear gloves during winter when your hands are going to be behind the engine as 100 mph wind chill when it's already 18 degrees will quickly make your hands unable to feel anything. The other guy in the video is who owns it. He's going to put it on a Top Flite 60 size Corsair...
Sounds like those valves need some adjustment. Shouldn't be poppin like that and its definitely struggling more then it should be to hold steady idle.
 
Sounds like those valves need some adjustment. Shouldn't be poppin like that and its definitely struggling more then it should be to hold steady idle.
Seemed to put along happily at 1800. We noticed it felt a little rough but let it go for a while and it didn't die or anything. I didn't check the lash, not my engine...
 
I also upgraded my slash to brushless, and it made a huge difference. For crawlers brushed is better from what I can tell, it’s better for low end torque. You can get sensored brushless motors though which are pretty good, although I think they are used more in rock racers vs crawlers. I mean, who’s trying to go fast with a crawler anyways? :LOL:
HAve you seen the hobbywing fusion setup? It has a low speed creep that would give most model railway locomotives envy! Also....brushed motors just suck lol. If I do an electric itt'l be brushless. My CA-10 scaler is brushless; sensored 5700kV 4-pole in the front.

You can always just throttle back but once you're flat out that's all ya got
 
Technically speaking but say if you had a spare hairdryer then if you strip the components down could you possibly make an edf? Because i have a spare hairdryer in mums room.
 

Ketchup

4s mini mustang
Technically speaking but say if you had a spare hairdryer then if you strip the components down could you possibly make an edf? Because i have a spare hairdryer in mums room.
I think you could, but it probably won't provide the same thrust as a normal edf. It will probably be heavier too.
 

Pieliker96

Well-known member
Technically speaking but say if you had a spare hairdryer then if you strip the components down could you possibly make an edf? Because i have a spare hairdryer in mums room.
I'm going to go with no for the following reasons:
- The motor is likely run on 120v AC, which would require an inverter (or, in the event the motor is self-commutating, a > 12 cell battery) to power. This introduces inefficiency and extra mass into the equation.
- The motors are sized to take a couple hundred watts at most, reason being is that the rest of the power budget (limited by the circuit breaker / electrical restrictions) is spent on the heating elements. 200 watts is 40mm EDF territory. The thrust figures you'll be looking at - even the theoretical ones, assuming 100% efficiency - will be abysmal relative to the motor's weight.
- Most hair driers I've come across have a centrifugal fan, which is highly inefficient compared to an axial-flow ducted fan; the air has to complete two 90° turns as it passes through the dryer. I think you won't be able to get comparable efflux (exit) velocities out of a hair dryer. Since top speed is limited in part by efflux velocity, I doubt a hair-dryer EDF would be able to get going that fast, which is sort of antithetical to the goal of an EDF.

I'd love to be proven wrong, but my intuition tells me it's easier to buy a cheap purpose-built EDF over using a component of another system which is very much not optimized for the use case.
 
I'm going to go with no for the following reasons:
- The motor is likely run on 120v AC, which would require an inverter (or, in the event the motor is self-commutating, a > 12 cell battery) to power. This introduces inefficiency and extra mass into the equation.
- The motors are sized to take a couple hundred watts at most, reason being is that the rest of the power budget (limited by the circuit breaker / electrical restrictions) is spent on the heating elements. 200 watts is 40mm EDF territory. The thrust figures you'll be looking at - even the theoretical ones, assuming 100% efficiency - will be abysmal relative to the motor's weight.
- Most hair driers I've come across have a centrifugal fan, which is highly inefficient compared to an axial-flow ducted fan; the air has to complete two 90° turns as it passes through the dryer. I think you won't be able to get comparable efflux (exit) velocities out of a hair dryer. Since top speed is limited in part by efflux velocity, I doubt a hair-dryer EDF would be able to get going that fast, which is sort of antithetical to the goal of an EDF.

I'd love to be proven wrong, but my intuition tells me it's easier to buy a cheap purpose-built EDF over using a component of another system which is very much not optimized for the use case.
Ah my mum wasn't intent on letting me cannibalise her hairdryer
 
Picked up an OS 46AX from my LHS today. As is bin, 30 bucks. She's.....not a happy camper.

















New P/S, new main bearings, she'll be right as rain. And I'll still be in for less than a brand new engine. AND I'll have the updated liner that isn't peel prone. Still a win. I bet it would have started even as messed up as it was, too, go figure. Ten bucks says if it did start and run it would have never idled worth a crap and probably would have sucked a ball or two out of the rear main bearing like it's already done with large chunks of the cage.

I'm kinda glad I'm the one that bought this engine too. Someone who didn't know as much as I might have not thought twice about it, tried to fly it, and had it grenade mid-air.



I also re-homed this poor old 4*40. Has an OS 40LA on the nose and, if I'm perfectly honest, I don't think it's ever flown on that engine. The inside of the engine smells faintly of castor but...well you guys are welcome to second guess me if you want.







The amount of Saito stickers and the cutting of the cheeks imply that, at one point, this had a Saito on it. I will probably put a Saito back on, but for now I will fly it on the 40LA. She needs some covering work...albiet minor just a touch or two with the heatgun really...and a going over. Futaba Rx, 2s LiFE are most likely needed but I haven't yet been inside the fuse. It does have a ye olde whip antennae hanging out the back though, so in all likelihood she's full of vintage radio goodness that I will not fly.

At least this time I remembered the gallon of fuel I went to the LHS to buy in the first place...




Oh, and yes, I did replace the cheese grade JIS hardware on that 40LA. I have some grade 8 M3x8 hex bolts on hand that I use for the backplate and some spare hex backplate bolts from my good 46AX that I repurposed on this engine as head bolts(I have done the same backplate bolt replacement there 'cause I like hex bolts more than allen bolts go figure).
 

mrjdstewart

Legendary member
upgraded a few parts on the SCX24 today. new brass turn knuckles, brass differential cover, skid plate, aluminum steering linkage, and new adjustable shocks to go with the brass wheel weights for the front.

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brass differential and new shocks to go with brass wheel weights for the back.

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i also love the new tires. i am still at stock shock mount height but you can see the new tires make a good amount of difference vs. stock.

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really happy with this setup right now. the weight is way low, i have tons of movement and good clearance. this thing is a beast.

laters,

me :cool:
 

Wildthing

Legendary member
Haven't done much lately, just lazy I guess :) . But I do have solid foam floats for the snow racer :) I did have to cut of the top the first day to relieve pressure as it was bulging out the sides, top cured quick exposed to the air and sealed it while the inside was still expanding but once I did cut the top off that released the pressure and the sides went back to normal. Trimmed the excess off , sanded flat and covered it. Now to design the fuse and tail. I think I will do it like a tricycle and use one of my floats off of the Lizard which is pink foam cut out like a boat hull and I am thinking of using a rudder plus the rear float for steering.

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