prop!
 

hi

I’m having problems when I try to prop hanging my model does not want to climb to a 80 or 90 deg vertical. I balanced the model recommended (180mm) and I also use a CG machine. When I changed the prop to a 11X4 this made more improvement then 12.25x3.7.What prop should I get 12x4 or a an other recommended prop 13x4w?

The motor is west 50 T1 + pipe and 12.25x3.7 model hype 3D

thanks alan

RE: prop!
 

There are a lot of variables in prop selection.

You can try all these props on the ground pulling on a fish scale and see which one offers the most thrust

RE: prop!
 

The 12x4 APC will let it rev up like it wants to...a lot more so than the 12.25x3.75 and will give you better throttle response.

RE: prop!
 

I think APC makes an 11-3, I don't know what a West 50 T1 is but it would likely let most 50 sized engines over rev. But if that is an engine made for high reving then that might work.

RE: prop!
 

If your plane is about 2.3-2.5 kilos (or even some more too) then your engine should have no problems climbing of of a hover with the 12.25-3.75 prop, and most every other prop to. Is your engine tuned properly? what rpm`s are you getting?? A healthy 50 size engine should manage to pull 4-4.5 kilos and will be more than enough to pull out of hover.

My own favourite synthetic prop for 3-D is the APC 12-4, or I use wooden 12-4 and 13-4`s on my 50 size 3-D engines

RE: prop!
 

My Webra 50s are much happier with the apc 12/4 than the other sizes.

Denis

RE: prop!
 

rpm 12300& i think it about 2.2KG .im going to try the 13X4w i will let you know.

RE: prop!
 

Your rpm seems very low. That West engine is supposed to be one of the strongest 50 size engines out there. For comparising purposes my MVVS .49 swing the same prop at 13600 rpm and my ASP XLS .52 a couple of hundred more. Are you sure that you have leaned it out enough? Well broken in?? What pipe are you running?? What fuel??

I think the 13-4W will be more sluggish and not make you very happy. That engine needs to rev to make its best power. I would get the 12-4 and try to squeese the most rpm out of it. If you are not using a very restrictive pipe or bad/wrong fuel that engine should spin that prop at 14K or better and pull like an ox

RE: prop!
 

What?

Your average .46-.50 will really struggle to pull a 3Kg model out of a hover with any real authority and I've yet to see one that will even hover a 4-4.5Kg plane at all.

My TT46Pro engines will spin an APC 12x4 at a shade under 14K (with 5% nitro fuel, a Tower/GMS muffler and and 12% hi-performance oil) which provides *good* pull-out on anything that weighs 5lbs (2.25Kgs) or less. An ASP52 (one of the most powerful engines in this class) will still struggle to give decent pull-out on any airframe that weighs more than about 5.5lbs (2.5Kgs)

Yep, the APC 12x4 is (IMHO) the best 3D prop if you want plastic but I fly nothing but *good-quality* wood props now. They rev-up quicker, provide more thrust, are cheaper and just as tough as those frail APC 12x4s.

Anyone who's trying to do 3D with a .46-.52 on an airframe that weighs much more than 5lbs really needs to buy themselves a profile that weighs in at 4.5lbs all-up and discover what *real* 3D flying is all about. The "fun" factor will go up by a factor of ten or more.

Good grief, my Mojo60 profile weighs 5.5lbs (2.5Kgs) and has a Saito 100 up front, spinning a 15x6 prop at 9.800 RPMs. Now *that's* good power and vertical :-)

RE: prop!
 

What`s there to what about? I really don`t think his plane weighs 3 kilos unless it is VERY VERY heavy built. I`ve never said great pull out with incredibly authority, but I flew my harrier 46 which was about 2.7 kilos with both the MVVS 49 and the XLS 52 and had absolutely no problems pulling out of hover, later I put in a 91 twostroke and that was incredible;). The major point here is that his engine is underperforming and we should try to find out why.
My profile was weighing in at exactly 2.4 kilos and was a rocket out of hover with my XLS 52 (let me add to that that I have broken 15K on the APC 12-4:D). Lately I too have been mostly using wooden props for 3-D applications, so we agree there;)

All my 3-D planes now have more than 2-1 thrust-weight ratio ( someone said I was crazy to put my 180 fs in my Harrier 90, but it was just perfect:)), but to just pull out of hover doesn`t call for that much power and that is what ALANXP is trying to acchieve, and he will once that West engine does what it is supposed to do;)

Oh, I forgot something, my MVVS pulls 4.3 kilos on a digit fish scale and the XLS is a little stronger (in case that is what made you WHAT! my previous post) I have modded my engines and I`m not saying his engine will produce such numbers, but to climb a plane of about 2.5 kilos or a little more out of hover should be well within the reach of the West .50

RE: prop!
 

i mix my own 18%semisynthetic oil 5%nitro

RE: prop!
 

Ahhh, I read the last posts over again and I suspect a slight misunderstanding here:) I never ment that a 50 engine is more than enough to pull a plane of 4-4.5kilos out of hover, but rather that a good .50 engine will pull that amount of kilos on a scale. a plane at 3 kilos would surely be punishing for a .50 engine

RE: prop!
 

Weigh your plane ALANXP and tell us how much it weighs, My guess is about 2.5 kilos

RE: prop!
 

This is the combo: http://www.westonuk.co.uk/index_041.htm

Why is it not able to pull out of hover? Clearly the engine is not producing the power it is supposed to do. The fuel seems fine and the prop are within what the producer recommends so I suspect the tuning to be less than perfect.

RE: prop!
 

hi

I tuned the motor and its spinning at 13500rpm (prop 12.25X3.75) but it didn’t prop hang and then I tryed the 13X4w like you guys said the throttle response was slow
it didn’t prop hang. What should I do? Should I adjust my trust line??? Thanks alan[:o]

RE: prop!
 

Hi!
Try a 12x4 APC!
But what do you mean by: "It did not prop hang"!? 2,5kg is too much for a .40-.50 engine. That's what my You Can-Do .60 weights powered by a MVVS 15cc (.91) engine.
Or... are you a total novice at hovering???

RE: prop!
 

Jaka i know how to prop hang I meant when I try to prop hanging my model does not to climb to a 80 or 90 deg vertical and moves forward like a slow harrier

RE: prop!
 

APC 12.25-3.75 spinning at 13500 rpm is good and will produce about 4 kilos of thrust. This should be enough to lift your plane vertical out of a hover. If your plane isn`t able to hover then it is because of wrong balance or set up. Did you weigh the plane yet??

I had no problems going straight up with my Katana profile weighing 2.3 kilos and only powered by a 61 Fs (it was slow, but still)

RE: prop!
 

I balanced my model upside down should I balance my model the opposite way

RE: prop!
 

what about up turst?

RE: prop!
 

The usual way of balancing a 3-D plane is to fly at about half throttle and then roll over up-side down and then the plane shall fly straight or just barely drop down, if it rises it is too tail heavy. You should be able to hover even if you have less than perfect balance, I`m really not sure just what your problem might be? Maybe you just need more stick time??

RE: prop!
 

what about the trush line???????

RE: prop!
 

Add more UP elevator so you can hold the model in a more vertical position.

Terry in LP

RE: prop!
 

Up thrust is not very common, right and down thrust are what`s used. Try more tail weight