Sourkraut

bdleon75.... I have a GMS.61 in my Raptor F22 and I really like having the extra power for takeoffs and landings. It fit in the snoot pretty good but I had to add a little extra tailweight to get it balanced. The GMS.61 is a very good running and powerfull motor and the price is hard to beat. But if I can make a little suggestion, put in th GMS.76 or the Tower Hobbies .75. They have the same mounting dimensions as the .61 GMS and are more powerfull and lighter also. I have all three of these engines and they are all great. The only reason I used the .61 is that I had it laying around and no home for it so it went into the Raptor. I wouldn't even consider flying this plane with a .46 size after flying it with the .61.

Curt

hogflyer

Sourkraut,

This brings up another question - is the airframe robust enough to handle the power and increased speed from a .61 or .75/.76 over the long term?

I’ve had a guy offer me an F-22 PTS NIB for $200, I’m thinking of offering him $150 (he paid $100 for it on feebay) and installing an OS .55AX. I also have an Evolution .61, OS .61SF long stroke and older K&B .61. I’m not sure if the OS .61 and Evolution would be a good match though since they both like to swing larger props at lower RPM’s. The K&B, on the other hand, may not match the .55AX for power.

Hogflyer

bdleon75

Sourkraut...well unfortunately(i think) i didnt get a chance to read the thread this morning. i left for work this afternoon and stopped by the hobby shop he only had one NIB GMS .61 left, no other GMS to be found. he said they've been on backorder for awhile. So i bought it.oh well. the motor looks well built and the price, gosh you cant beat it. 79.99 for 2 hp. the muffler is kinda obnoxiously big. [sm=50_50.gif]i'll have to redo the balance i know, but do you remember how much weight you added to the tail. Maybe i'll get lucky and it will fall within the cg range. im currently at 6in on the money. we'll see. also in case it wasnt in your post, i forgot already, what size prop. i bought a 12x6 apc.

bdleon75

oops almost forgot to ask what about a tuned pipe, whats your thoughts on that(for the GMS .61)

Sourkraut

I never even thought about a tuned pipe. I just went with the stock can.... less tuning problems that way. You won't have any ground clearance with a 12x6. I am using a 11x7, 11x8 and even trying an 11x9. I put a longer nose gear in (out of a Tiger 60 kit) and I went with 3.25 inch foam wheels to get good prop clearance. I am not sure how much weight I put in the tail but it was enough. I've got it balanced right in the middle of the cg range. You got lucky to find a GMS .61motor in stock anywhere. They have all been on backorder from the hobbyshops since late last fall. The .61 will fit the bill just fine, but with the same footprint and a whisker lighter, the .76 would have been awesome too. Beef up your firewall with a couple pieces of tristock and epoxy and you will be fine. I could only sqeeze an 8oz tank in mine and I can get about 6-7 minutes of flightime. You don't want to push the threshold and have to deadstick that bad boy!![X(] Make sure you have some reserve left for landing.

Curt

ajflt

i just got the magnum 61 and the wt is apox 25oz the trn45 wt is apox 20oz most post show the cg is tail heavy and ive noticed the same thing on the ground but dont khow if thats true in the air planing on flying this weekend with instructor , there was one guy who put 91 in and says it flys really fast 100 plus mph so i figure the 61 is the ticket for speed and indurance, by the way ama sport aviator did test that 2balade 11-5 with 45trn eng gave this plane a top speed of 66mph in dive with flaps down what do you think,a 61 with 11-8 prop 15% meth 18%caster/sen oil blend allready beefed up rec sides next to front landing gear and thinking of adding more support 1/4 ply to areas next to fuel tank ive seen alot of post saying this thing is great and alot saying it really blows as a trn this is my frist plane but have been hovering walkera 35c 400 class heli and playing on sim for about a year now ie. cobra,heli ,3d heli,hughes heli, curttisr3c really fast plane,bf109,su-26,pitts,and a couple jets and really slow park flyers not so much fun

djsdog

I flew mine off the grass last Sat and this morning. Sat with a 10-8 three blade, no power, to slow engine speed, the stock evolution 45 was way underpowered but once airborn and up to a little speed she flew OK.

Flew this morning with the prop that came with the plane (3-blade). On short grass rolled about 100 feet and lifted off only about 4 feet into a 5 mph wind and down she came into some nice tall soft grass. Broke the plastic nose gear frame, hope a dubro or sullivan or some fits in there.

What kind of RPM should that evo make with the stock 3-blade? I got about 11500 out of it? Seems like this engine does'nt wind up all the way? And that goofy high speed adjustment thing...........?

I've got an old HP .61 that may just be the ticket but the prop is going to be the problem because of ground clearence. I'm thinking about an 11x7 3-bladed Graupner with that HP 61???????

ajflt

took mine to the field last weekend with the evo45 on with 11/5 two blade prop worked well but im still going to put the mag61 on for speed with a 11/8 prop let me khow how the 61 does on yours please

ajflt

by the way go to ama site and look at sport aviation section peviews of f22 up grades gives good specs with 3 blde and 2 blade up grade

djsdog

I just put a 10x6 prop on the raptor last night and test ran the motor. It ran about 14500 RPM. That prop cleared the concreate by about 1 inch. Thats not much extra for off the grass. How do you clear that 11-5?

bruce88123

You may want to put taller gear legs on it.

djsdog

Yea, at least on the front. I broke the nose gear bracket (plastic) when she went into some tall grass off the runway (second flight). I don't know if Dubro or Sullivan makes a replacement or not. Oh well a trip to the LHS is always a good thing I always say.

Hope that little 10x6 Master Airscrew will pull this bird until I can get that HP .61 in her.

ajflt

I'll check out the ama site for those upgrades, Thanks

bruce88123

If you replace the nose gear - consider a Fults gear, real strong. http://www3.towerhobbies.com/cgi-bin...FVSEARCH=fults comes with mounts.

djsdog

Thanks Bruce. I'll probably do that!!!

ajflt

my f22 has 1.5 in of clearance with the 11/5 prop on it i would check your front wheel for proper alignment with the groove installed faceing the set screw raiseed all the way up as possible with red locktight on it for hard frist time landings, maybe even diegrinding a space higher up on the rod for more clearance? maybe larger tires?

ajflt

just a few pics of prop clearance and fuse up grade

djsdog

Yea, I don't have nearly that much clearance with a ten inch prop. My top of my front strut was even with the top of the plastic housing and the set screw was in the supplied grove???? As I said before I broke the plastic housing and will replace with something better and taller. Bigger wheels is in the works now also.

I installed the HP .61 last night and it fits like a dream with a new plastic motor mount. Now if I can just get the prop right. I engine standed it with a 12x7 and got about 11000 rpm. Then used a Graupner 10x8.3 3 blade and got about 11500 out of it. Am I missing something or shouldn't this thing be pushing 15000 RPM or so? It sounds strong and fast but the Tach saids different. I'm not sure about that H-9 tach?

ajflt

of what ive heard about 3 bladed props they arent as efiecient as two bladed and have more mass so rpms are lower for these size props? i dont have a tach yet so i cant really help in that department after you get the landing gear fixed let me khow how she flys with that 61 on her thanks alan

djsdog

Yea Alan,

I just had that three blade setting around and I've flown some of them but not much speed or efficiency. Power os OK at best. Taller gear, bigger wheels and the right 2 blade prop is the ticket. I've got to look up the target max speed for that motor.

djsdog

Flown the Raptor with the HP .61 about 4 times now. I installed a 1 inch longer nose gear and replaced the rear stock 2.75" tires with 3.5" (and mowed the runway). First two flights were with a APC 11x6 2 blade and it flew nice with no bad tendencies but the speed was not what I expected. Third flight I switched to a 11X8 (which tacked at 10500), the plane was a little faster and better on takeoff. Fourth flight I pulled those wing extentions off and she flew nice, a little faster and I think a less steady at slow speed. I think the only thing the wing extensions really did was shorten the take off roll a little and hold the wings up a slower speeds.

This plane is moving at about 50 to 60 MPH and takes about 100+ feet to roll off the grass. I just don't seem to be getting the speed out of this thing. The larger tires and fixed landing gear is allot of it but I don't think that old HP is putting out full power. I'm considering trying a Super Tiger .61 I've got on the shelf but it is much heavier than the HP. I want this thing to move about 80+ MPH not just fly around likme a trainer.

Oh by the way, she lands nice with about 40% flaps and with a little extra speed to keep her stable. I even had one dead stick from about 75' up and right next to the runway. Only had enouph time to land crossways and quick but kept allot of speed and no flaps. This thing has the the glide path like of a hammer.

Denny

djsdog

Well if anyone is still out there I got the Raptor back out and flew it some more. I changed radios and went from the supplied JR 600 to my JR9303. With a three position flap switch like the 9303 has I was able to set up a mid range flap setting (about 20%). The allows the F22 to get in the air quicker and seams to be more stable at slow flight until the speed can get built up.

I also (by mistake) had more aileron throw programed in and this thing REALLY ROLLS NOW!!! I also tried some 30% nitro in the old HP .61 and she liked it. But to tell you the truth, with out trying at least a hot .75 in this thing and about 80 mph I'm bored with it.

ajflt

hi again been out of the loop for awhile so your f-22 did ok with the 61 on it but only 75+ mph with it for a trainer sounds good to me,one guy put a 91 on and was stating 100+ speeds with high speed passes but had to epoxy tail

ajflt

djsdog

Yea Alan, nice to have you back.

Like I said, it flys better with the .61 but that is a really old motor that was not ran much and I don't know if it is putting out full power heck it my not even be broke in for all I know. The plane is for lack of a better word boring to me without having insane speed. To get insane speed you need more power and posibly retracts. I think this winter I'll run her through the shop and upgrade to a larger sleak engine (maybe a .75) and I think I'm going to try and put some kind of retracts in it? I was hoping someone would do it and make a tread on it. I my opinion it just would not look right at 100+ MPH with wire landing gear and tires hanging down.

Denny

djsdog

Well I'm ethier going to give up on this F-22 or give it the works. I bought a set of used retracts that are sort of home made for a F-16 (or so they said on ebay). They are on a home made frame with robart cylinders and robostruts that will fit rather nicely up into the bottom of the plane with allot of work. But when they retract they fold into a triangle shape that will fit perfectly. It may not be prototype but will definately improve the drag on the plane. Power plant will probably be a .90 of some sort with maybe a tuned pipe. It will look nice at 100+ MPH. It will probably be to heavy to have nice slow speed caracterisics but firewall it and let her rip!