mutare23

Tim

Thanks for the information.

I will look forward to your report with relish

It is rather interesting to note that it would seem that almost all GSP/CMPro planes come in heavier than their advertised weight. I suppose they are not unique in this situation but some more realistic figures would be appreciated.

Having followed various other threads on their products I note that just about everybody seems more than happy with the flight of their planes though.

Good luck with the weather

Cheers

Phil

SARGE

My Feedback: (8)

How did the CG come out? Did you have to add weight to make it balance and if you did how much?

Steve S

My Feedback: (54)

Sorry I still havent flown it yet.Just about caught up with my business sch. then I gotta move this weekend but after this I will be ready for the maiden.I am shooting for next weekend weather permitting of course

In response to the finished weight goes mine came out at 12 lbs.I have owned and flown 3 other GSP models prior to this Yak and their planes always seem to come out heavier than most other planes their same size /scale.But they fly very well,I had their 60 size Giles202-65" ws with a Saito150 that was right at 11.5 lbs.Obviously quite heavy for a 60 size aerobatic but it still flew outstanding-had one heck of a nice glidepath with no tipstall traits,I had deadsticked it numerous times.I feel this Yak will fly even better,I will advise you guys as soon as I fly her.Have a great weekend[8D]


Steve

Buzz Lightyear

Guys

I will be test flying the CM Pro Yak with a Moki 210 on Sunday.
I'll let you know how it goes.

Buzz

Buzz Lightyear

Guys

The Yak has flown. I test flew it for a mate who has been flying for a couple of years.
With the Moki in it the CG was spot on. If I was going to put a lighter motor in it, I would cut holes in the wing and tail fillets, cut holes in the counter balances on the elevators and rudder.

I took off and pulled 45dec then immediatly did a full roll to the left and a full roll to the right......then a snap.....not bad for a first take off.

I brought it around and did a knife edge. It held line but would not climb.

Verticle snap and keep going up!!! I don't fly a plane around and then land it, put it in the air again and see what it does. It isn't going to make a difference to the plane if I wait a flight or 2.

I gave the sticks to the owner and he flew it for a while. He came out of a dive and the plane kept rolling to the right. He was all over the place so I grabbed the TX off him. Not sure what happened but I kept it straight and brought it in.

I made a short approach so the speed was high......but it still fell out of the air over the runway.

IMO This model is not for the beginner. In fact, a person that hasn't flown this type of model will have trouble with landing it. I know that the owner will not be able to land it.

Be very gentle with the elevator!!!

In the air it is a great model. looks great and is value for money. If you build one make it light. The owner is going to dremel everything he can to make it lighter.

Cheers

Buzz

mutare23

Buzz

Extraordinary first flight check!

I would at least like to check the trims before flogging it. In fact to be honest, these days I tend to fly the first couple of flights fairly straight to check linkages etc and then rip it up.

I suppose your testing was does done at Belconnen! They all fly wild out there.

Will be interested in any further comments you have to make about CG, etc.

I though I was going to be fairly wild with the Moki 1.80, let alone the 2.10

Cheers

Phil

forestroke

I just bought the Yak 54 and the kit looks very good. Unfortunately the only instructions I got was a large A3 size page. Is that all you guys that have it had as well?

mutare23

Forestroke

Those are also the only insturctions I got.

If you look at them closely enough there is enough detail to build the plane.

Cheers

Phil

forestroke

Thanks Phil... I figure that would be the case. I've never built a plane with plug-in wings so I wished there would be some guidance there but that's okay... I have built numerous ARFs and generally speaking, instructions, no matter how thick, are pretty much useless with the exception of WM kits. One ARF from Vietnam had instructions that had a huge stamp that said "draft" :-) and in French... pretty much just tossed those!

Buzz Lightyear

Hi Phil

I guess my flying is at a point that on take off I knew what trim the model needed. I flew the model as I said and then trimed it out. Trim wasn't going to make much difference, it wasn't in a straight flight path long enough.

The reason the plane was all over the place after the owner pulled out of a dive was the anti rotating dowels on the left wing panel were not snug enough and the panel moved around a bit. Only a hair. But it was enough to put the left wing down, thus the trim went out big time.

The CG was at 150mm from the leading edge. I would start 20mm forward of that.

I would like to know how the other Yaks out there balanced. Like I said, a Moki 210 in it made it balance on the 150mm mark.

Cheers

Buzz

p.s. Yes Phil, Belconnen. And do you still have that Hawker Hunter?

mutare23

Clever Buzz,

The old Hunter still exists, though hasnt seen air time for a long time.

I wont get to the Yak for a while due to some work commitments. Hope to have a good crack at it in late June.

I will look forward to more information on the Yak as you get to have more air time.

Cheers

Phil

kevinf2501

My Feedback: (65)

Hi

Anyone put a BME 50 on the yak with the servos on the tail?
Anyone put a gas engine on one?

Kevin

mutare23

Kevin

I think this would make the Yak very twitchy to say the least. The wing loading is already up there with only 806" of wing area.

I normally subscribe to the theory that you cant have too much horsepower, but you also cant fit a Dodge Viper engine into a Honda Civic

Cheers

Phil

kevinf2501

My Feedback: (65)

I have decided to put in a MVVS 1.60 Gas motor from Morris Hobbies. I am going to pick it up tomorrow.
This motor should still be light enough and should make up for the tail heavy tendency. I am going to leave the servo locations and use 2 Sullivan Composite Flex Rod 4-40 36" to ensure accurate elevator movement

What you think?

mutare23

Kevin

FWIW, I think you have taken a better option. Did you consider one of the Mokis?

I use carbon fibre rods for all surfaces now and have noticed the improvement on some of my older models. The rods are light but strong with almos no flex at all.

Cheers

Phil

kevinf2501

My Feedback: (65)

Phil

I prefer Gasoline motors and avoid nitro (snot) motors for the following reasons
*Gas motors once they are tuned rarely have to be retuned unlike the finicky
nitro motors.
* I dont have to spend an hour cleaning my plane after flying.
* Gasoline is way cheaper.

I did pick up the motor from Morris Hobbies today. real sweat motor. I will post pictures
once I start building tommorrow

Kevin

mutare23

Kevin

Good luck to you

I will look forward to your reports to follow.

I've never used a gasoline engine as I've always been happy with the methanol babys

Maybe you will convince me to take a change

Cheers

Phil

Vortec

I was going to buy one of these as the LHS had one in stock when i bought the CMPro Katana...

Very nice looking plane but the wing loading and the heavyer weight pushed me to the Katana..Someone from here has bought it and i hope to see it fly as its real pretty.

kevinf2501

My Feedback: (65)

I have finally got around to posting an update on construction of my Yak54.

So far I have got the rudder, elevators and throttle linkages in. (need to do final Setup), I have the motor mounted. The MVVS 1.60 fits in great using A dubro mount. (through away the block of wood that came with the kit). The fuel tank and plumbing is done. as well as the ignition module. All thats left is to do the canopy and the wings.

I had a number of issues during construction that needed to be figured out as the instructions are vague at best.

Make sure you measure the incidences before drilling the anti rotation pins on the elevator and wings as the pre marked locations are not correct. Secondly make slots for the anti rotation pins as due to the shape of the fuse a single hole wont work. once I had the slots cut out and could attach and remove the wings I used some hard 1/4 by 1/4 stock to make a rail in the fuse to set the correct incidence
(prevents the pins from rotating)

The plans do not show the exact location for the holes for the pushrod exits and for the pull pull wires. It took quite a while to measure and make sure I got them right. The rudder mount points need to be low (in line with the bottom strip) so they wont interfere with the elvator mounts and pushrods.

kevinf2501

My Feedback: (65)

More pics

mutare23

Kevin

Looks like you are doing a top job.

I will look forward to your flight report

Cheers

Phil

forestroke

Yeah... so am I. I have one sitting in a box ready to build or sell depending on what your outcome is. Most have found this plane a little too much work.

kevinf2501

My Feedback: (65)

Plane came out heavy at about 14 pounds(including balancing). Even with an extra battery and ignition module the plane came out tail heavy. I cut out the bottom of the canopy base to remove weight. However I still needed about a half pound to balance it out 1/2 pound to balance it out.

The plane flies fine and will be great for IMAC flying. This is not a 3D plane. with the 160 MVVS the plane will not hover. (might once engine runs in or changing prop. It turns a 18x6 master airscrew at 7500.

Unfortunately on my 4th flight I had a dead stick (ran out of fuel) and had to land in the high grass. Pulled the landing gear out of the block. It also damaged the cowl and the fibreglass around the landing gear and bottom of firewall.

My overall opinion is that the gas tank is to small, and due to the construction of the formers would be very difficult to increase the tank size. I got 10 minutes flight time with the tank using Gasoline. I would think it would be much less with a comparable nitro motor. even though it is easy to repair, I am not going to do the repairs as I feel the plane is generally overweight (even without the extra battery and ignition module) therefore making the wing loading very high. Fixing it would just make it heavier. So I will just write of the $270 for the kit and call it a day on this one.

I was very impressed with the MVVS 1.60 gas motor. It started right out the box, needed a minor adjustment on the bottom end. The motor behaved perfectly (until it ran out of fuel ).

So if anybody needs a spare set of wings let me know.

I will be sticking with 50cc gas and above.

Have fun
Kevin

kevinf2501

My Feedback: (65)

PS

This ARF is definitely not for the beginner as the instructions are sparse. Its a figure it out yourself assembly.
No incedences are specified (ignore the pre marked indents for the anti rotation pins as they dont line up correct)
Also no recommended settings are provided for how much throw to have on each control surface (too much elevator will cause
this plane to snap). If anybody wants my settings (futaba 9c) I would be happy to provide them

Kevin

rcpatty

Hi Guy's,its Rcpatty from Australia,
I have just got myself a cmpro YAK 54 also they look good, hope they fly and perform better than the Katana did.
Im putting a YS-DZ 140 in mine i have some pic's ,any input would be great,any input would be great