Hello all, I also am in the process of assembling a Spot On 50 and so far so good. Im putting a Thunder Tiger 75FS on it. Its all mounted and all electrics are on the plane, every thing is about ready but im waiting for a 90deg exhaust manifold to arrive so I can mount the pipe where i want under the plane. Does any one have any reccomendations on about what prop to use with this bird? Suggested props per engine instructions are as follows: Stunt/Aerobatic- 11x8-9, 12x7-8, 12.5x6, Scale- 13.5x8, 14x7, 11x7(3blade). What would yeild the best pattern performance?
THanks

I would try betwen a 12 x 8 or a 13 X 8. Also try in the forum of engines. You will love this plane I'm flying it with a Saito 82 with a 14 X 5 and a YS 63 with a 13 X 6. Both option are good, but i feel the Saito pulls it better even with a 13 X 6 prop and also with a 12 X 8. I think your TT will pull it so as well.

Happy Landings

Luis Meza

I just bought the Spot On from a local hobby shop and after I got it home I noticed it was the A249. Not the the a249R???? []

Were there some issues with the original.? It obviously must have been in the store for over a year??? I noticed on post #44 that the wing root is different and the wing attachment is different. On the "R" does the wing bolt on to the fuselage and then the belly pan is attached?? That's probably a better arrangement than gluing it to the wing, although, I could live with that.

Normally when a company upgrades a model it is to correct problems with the original?? Does the 249R fly better??? Also were there other problems?

I plan to put an O.S. 55 with a pitts muffler on my plane.

Rally, my question is...SHOULD I RETURN THE A249 TO THE STORE AND ORDER THE A249R????[&o]

Thanks.

I have this version (A249) and I never had have any problem with it. I think that you will not have any problems either. It's a beautiful flier.

Happy Lanings.

Thanks.

I have three other planes with the belly pan attached to the wing and they are fine.... Just one less thing to come off. I do however fill the lightning holes with some very light plywood so I don't stick my fingers through ith covering[]

On the R version what holds the belly pan on???? I see the 2 pins in the front. How is it secured in the back??

pilomeza, What engine do you have on yours? Any other modifications??

I have had two Venus's, both crashed in the learning curve and now I have a Venus II. I love the big pattern plane but it's 16 oz of fuel every flight with the Saito 150. I want another 50 size pattern plane I can fly all day.

Hi, TomTreese
I'm using a YS .63 right now with a 13x6 and 14X5N propeller. But I had also flown the Spot-On with a Saito .82 and a 14X5N propeller. For me the Saito gives her a little more power.
If you like saitos I really recomend the Saito Vs. the YS. The Saito is easier to adjust and flies very nice with only 15% Nitro, the YS is more difficult to adjust, and needs at least 20% nitro.
I'm flying the Spot-On with the YS because I moved the Saito to another plane.
My son (he is my mechanic) intalled the engine at an angle of 90 degrees, is easier to start and have a very good ventilation in the summer (specially down here in Texas) with the transparent dummy cowl provided by World Models is easy to draw with a marker the holes for the cilynder and the needles. I'm attaching some pictures than can help you. The HS needle hole is bigger so I can reach for the LS needle with a screwdriver.
Just my 2 cents.


Happy Landings.

Thanks,

I have an O.S. 50 and 55 but I think the 55 would be best. It can turn a 12x7 or 12x8 prop. I'm going to mount it horizontally with a pitts muffler. I had a Venus 40 with an O.S. 46 inverted and it was a nightmare to start and keep running till I rotated the motor. 4-strokes are much better inverted than 2 strokes. I also have a Saito 100 I could use but that's over 20oz of motor (and nose weight) vs the 16.5oz with the 55+pitts.
I don't mind trimming the cowl to get better motor performance.
I think I'm going to keep the original I have. There is no wharping in any of the parts and the only difference I can see is the front of the wing and the aileron servos are recessed. Some comments I've read is that the 249R has some down inccidence issues??? No Matter....the one I have looks fine. It's only a $139.00 ARF

O.K.
I started today and the O.S.55 (16.5 oz)horizontally with the pitts fits very well. Will use an APC 12x7 or 12x8 prop.

I used Radio South CA hinges, don't trust the cheap hinges. I usually use pivot points on larger A/C but will only use them on the rudder on the Spot On.

I started to install two Futaba S 3151 servos in the wings and now know why they changed the servo mounting in the A249R. The standard servos are too high, tall, to fit in the wing. they press on the covering on the top of the wing[]. So I'll order a pair of Hitec HS225 mighty mini's. their depth is less than 7/8".. I'll have to extend the mounting blocks insteatd of raising the present ones. This way the servo is not sticking so far out of the wing.

I think I'll use larger wheels since we have a grass field.



The plane out of the box on required 5 minutes of shrinking the covering.

hey i am getting ready to start building my spot on 50 and i am wondering how this motor would work on it for flying at 6000ft...since i am in denver...it is the evolution .61nx http://www.horizonhobby.com/Products...rodID=EVOE0611 i was looking at the saito .82 but i dont have that much money to spend right now

thanks

or would it be better to go with the .60nx because it is in the .46 cas so it is allot lighter

I'm setting mine up with an O.S. 55 and that should have plenty of power. It's only a 5 pound airplane. I chose the OS 55 with a pitts muffler over the Saito 72 because it saved 1/2 pound in weight.

I have not been able to fly it since we have had more snow here in Virginia this year than I can remember. Global Warming My[:'(].

For me the Saito is the best option. If you don't have enough money for a new one, here in RC Universe, you can get a used one for less. I think that the Evo .61 is going to be too heavy, I'm Using a Saito 82. 17.6 oz and I needed to add some weight in the tail (about one ounce). With an Evo .61 that is 25.44 oz you're going to have to add a lot of weigth. In that case I think that the new Evo .60 even though is going to be less powerfull (I guess) the weight is almost the same as the Saito .82 and the power/weight ratio is going to be better.

Just my 2 cents.


Happy Landings

My Spot On 50 seems to be quite nose heavy. Im running a TT 75 FS engine. Does this plane usually run nose havy for every one else? Ive moved the battery pack as far back as the cable lets me and its still quite a but nose heavy. How much weight is acceptible to put on tail to balance it?

Usually, cg location is a personal thing. You start with what the manufacturer recommended, then, fine tune it to your liking.

1) If you're nose heavy, how much up elevator trim are you carrying to get it to fly straight & level hands off? What about when inverted, how much down elevator you have to push to maintain straight & level flight?

2) Have you check your wing incidence? How many degrees of positive wing or negative stab are you carrying?

After we've determine that, we may be able to fix it without adding weight to the tail, less weight is always better.

Adrian

Hi,

I would like to get the Spot On as well. I have an O.S. 56 Alpha and the above mentioned TT-75S in the box. Which engine would be the better choice for the bird?

I also would like to use the the HG-D250MG Mini Servo from Ino-Lab in order to save weight (maybe two for the horizontal stab).


Specs

Speed: 0.22s/60° (4.8V) 0.17s/60° (6v) I would use a 6V battery (5 cells).
Torque: 5.2kg.cm(72.21oz.in) at 6V
Weight: 21.11g (0.74oz)

Are these servos fast enough?

Cheers,

Michael

You are better off using a standard servo and changing the pushrods to carbon.

Those 2 servos are 1.4oz then you'll add the servo boxes and long leads and addtional clevises. A standard servo will be 1.7oz and make use of the existing set-up. If you change to carbon pushrods you save another 1 oz and will avoid the problems of matching servos.

Take a look at the begining of this thread. You'll get a good idea of how much weight can be saved by very simple/cheap changes.

If you want this to fly like a pattern plane the 56 will not be enough power. The 75 may be too heavy.

OS55 or YS63/70 are your best choices.

Colin.

Thanks Colin.

The TT F-75S weights 16.13oz (457g) w/o muffler. The O.S. 56a should be at 14.8oz (419g), the muffler weights 42g. The Y.S. 63 is at 17.9oz with muffler, I suppose.

Even though the YS is on the heavy end of the scale it has tons on power and is pumped so you can move the fuel tank back and avoid the tail weight to balance.

It's the best choice for power but I think the OS55 will give the best performance on a budget.

Colin.

I have had both, the YS 63 and the Saito 82 on my Spot On. I felt that the Saito pulls better than the YS, and also is a lot of less trouble to adjust. With a Perry Pump I placed back the fuel tank for CG purposes and the Saito has given me more than 500 RPM with the same type of propeller (APC 13X6) an the same fuel (Powermaster 20/20). The OS. .55 AX is almost the same weight as the Saito 82 with Perry Pump. And gives you a lot of power, and is also reliable and trouble free as the the Saito, the only setback is that the time of response is less, but the price is $100.00 lower.
Any way, check in the adds here in RC Universe maybe you can get a deal in one of those engines.

Just my opinion.

Happy Landings.

Thanks.

It looks like I should get a new engine anyway. The TT75S is idling around since I do not like the engine so much.

I try to look into all options (but not two-stroke).

How about the YS70S? (If it´s available.)
http://www.yspower.co.jp/en/engine/plane/fz70s.html

I am also sitting between the Osmose 70 (or maybe Oxalys 50) and Spot On 50. (I could not find a dealer, neither in UK nor DK who has got the Spot On ready to ship.)

What would be the better choice (not considering money)?

Getting a new plane and new engine anyway, who about looking up to the 90/110 class? I guess the difference is not that big in flight performance.

Cheers,

Michael

Hey Check this add out:[8D]

http://www.rcuniverse.com/market/item.cfm?itemId=603170

I think is a very good deal.

Happy Landings.

There are a few good choices in the 60-90-110 class provided you are willing to switch to E-power.

3DHS will be coming out with a 62" Osiris and Sebart has a really nice 110 size plane for less than $600. Batteries for planes in this size are very inexpensive.

Colin

My fuel tank is mounted about 3/4 inches above the carb intake. How would this effect the performance of the engine? What should and what can I do to get the tank down lower in the fusalage of the plane? The opening in the firewall is also at about 3/4 inches above the carb... can I just mount the tank level with the carb (After carving rhe bulkheads inside) and run the lines out the opening?
Thanks all,
ABV0377

If you're mounting your engine inverted the carb will be lower then mounting it horizontal...I have my OS 55 with a pitts mounted at 90* and the center of the tank is in line. I also filled the top inside of nose with light foam padding to cushin the tank. This also creates a tight fit and holds it in place.

I had two Venuse 40's from Great Planes. I originally installed an OS 46 FXI inverted and it was a nightmare. Tough to start unless you turned the plane upside down, even with an idle-bar glow plug and it went deadstick about 70% of the time when you throttled back to land. After I turned the 46 to 90* with a pitts it was perfect.