dumorian

My Feedback: (6)

Yes. And after my 'engine tuner' got it half way close, it has unlimited vertical. But I'm about to fire my engine tuner and provide him with a nice guide to tuning Walbro carbs, which can be found [link=http://www.rcaer.com/pages/files/Aerovate%20-%20Tuning%20a%20Walbro%20Carb%20the%20Right%20Way. pdf]here, [/link]I'm about to do some tuning myself. [8D]

BTW, icando3d2 is my engine tuner, stubborn engine starter (yes, both the engine and the person which is why they always do eventually start), trainer and good friend.

Anywho, I read on another thread that the CRC 40s have a tendency to go rich in the air, which explains my 4 stroking and extra oil on the fuse. So, there is this Walbro pressure side cover which I now has a brass tube soldered over the vent. I plan to run some fuel line from here to inside the fuse. Then the next step is to start figuring things about with regards to the velocity stack. I have a couple of the ram stacks coming. These have a slanted cut on the top and mount into a ring that bolts to the carb. So I'll be able to rotate the slant to see what seems to work the best. So, at the moment, I'm concentrating on carbs. Yes, one could say I have read too much...

BarracudaHockey

My Feedback: (11)

I'll be interested to hear how it flys with that MLD motor.

dumorian

My Feedback: (6)

Yes, how it does vs. the AUW of your build would be great information.

elderair

My Feedback: (29)

My CRRC 40 kit engine is running flawlessly with 2 gal. plus through it. No hard starts. Just stick my finger into the velocity stack until it fires at part throttle then about three flips to start it. Not rich in the air either. Lovin it and total vertical. Not ballistic out of hover but good and solid. 7200 rpm with a Xoar sword 20X8 wood prop silver and black of course! 12.75 lb. auw. dry.

leepord geko

Well I did all the weight calculations, and based off of all the specs and a few other added oz I came up with 11lbs +- if this sounds unreasonable for a gasser this engine ready to fly weighs 37oz and engine alone weighs 30oz so basically a os 160 or saito 180 so it will defiantly fly and hover with pull out at that weight, and I'm looking forward to it and I also have a Extreme flight Extra 300 50cc coming this winter which should be another good build.

icando3d2

My Feedback: (15)

it all depends on what your definition of unlimited vertical is.. The Mld is 1.7 ci the 1.6 os fx puts more power down at a higher rpm. I have a 1.6 on a .90 size showtime thats unlimited vertical and a 50cc on a 74 inch cap. im seeing alot of people putting the 28cc on 8lb planes. Im not doubting your planes im just kinda going HUH unlimited vertical. ive seen one with a 40cc and it does a good job and i have flown it the lighter set up will fly great as does the one with the 40 on it they are just amazing planes if i ever plant my plane i will have an EF in my hanger as their customer service is awsome just like there planes.

dumorian

My Feedback: (6)

Not trying to pick or anything here, but my 40cc is about 1/3 more power with perhaps a 10% weight gain. It is what I would consider ample for pull out and unlimited vertical. I wouldn't want anything smaller. It seems as if elder is experiencing the same with his looking at his prop and rpm. Mine is on the lame side right now, but it is in the middle of several tuning mods... still experimenting with timing at the moment. But, we had it all very nice at one point and it was very strong going up for like 300 or 400 feet until I cut the throttle.

Also, you will want to set everything as far forward as possible and maybe need to relocate the rudder servo tray and maybe even the elevator servos to get your CoG forward enough. I would try to lay it all out now as much as you can to try to get a feel for where it's going to come out. The EF specs are completely trustworthy. I have mine to the rear of the span. I was very surprised by this. Almost had to move some stuff around after the build. This with 3 pounds on the front... plus ProZinger prop and aluminum spinner. I think a 34 to 40cc could provide enough... Many on this thread did the Brillellis while they were available. Apparently a very nice match. I don't recall but I think that was the 36cc?

Yeah, I ruined my 'engine tuner' after a day or two of me flying my Yak, I put the radio in his hands. To date, just seconds into the flight, he did his best ever rolling circle. Totally flat, totally a circular, no bobbing was apparent with the fuse and then two times around like this. I'd have to say that was pretty good for the first minute of flying a new model. These models are awesome! They really make me look like a much better pilot than I am... or would other planes make me look worse? All this in the sky and excellent ground manners to boot. What more could I ask for? Well, maybe the 88"... the 110"...

leepord geko

Well it had ample power on a aeroworks yak that weighed 12lbs the thing I go for now is not way overpower with compensating for weight. I lighter plane always flys better in 3d and general flying for serious Imac flying I'd rather have a bit of a heavier plane for tracking. but this plane won't be doing Imac because yaks just overall suck at Imac no offence and its not really big enough. Props IMO have the biggest effect you can put a zinger on and go well this is a ****ty plane and engine or put a vess, mejilik, menz, or xoar and say it flys half decent with the correct size. Also this plane won't have enough power for good IMAC but will defiantly have enough for 3d.

leepord geko

Anyways I finally got the plane and it needs some TLC but other than that so far preliminary checks look good. I quickly just put the engine on the firewall not permanently and it looks like a pea inside of that cowl. Will keep updated later.

dumorian

My Feedback: (6)

Ain't it great? I love these Yak cowls! A lot can fit in there and you still have more space than engine! It was a welcomed break after shoeing a 36cc into a 6 inch wide cowling... and such as that.

Actually, one of the things I like the most about this plane is accessibility to everything! And on top of that the ease of accessibility. The hatch latch quickly opens up well over half the fuse to easy access. It's one of the easiest models to prep for flight. It's just a friendly model no matter what.

leepord geko

Well got some building of it done and I modified my setup this plane I got used and It needs a new cowl other than that the weight so far with out servos, batteries, switches or rx is 8lbs I calculated in all the other stuff that I don't have yet and expect to have a weight of 10-11lbs Heres some pics! Also what are you guys using for CG? So the change is going to be just instead of running li-ions I'm going to use one a123 2300mah and one smart fly switch with deans in and two jr out. So the engine is installed along with the covering all fixed and throttle linkage working.

dumorian

My Feedback: (6)

It's been a while, but I do remember I was just forward of the rear most suggested CoG. I don't remember the numbers offhand. Do you have the manual? If not, it is on the Extreme Flight website as a PDF.

When I fly inverted, it takes just a tiny amount of down elevator. I'm happy at this CoG and haven't done any adjustment from there.

maineflyer

My Feedback: (44)

Mine is in a similar location and will fly either inverted or upright hands off. Make sure you check the incidence on the stabs. they should be at 0.
Jeff

FrankFuss

Mine balances on the wing tube, or slightly behind the center of it. Little or no elevator is required inverted. This is easy to check, just move the canopy to the side and support the airplane by the wing tube to check the balance.

Definitely check the horizontal stab incidence. Mine was way off.

In my opinion the landing gear support area can be reinforced. I pulled off the bottom covering and added some support formers to the landing gear area, and filled in the joint gaps with epoxy. I also found that the cap screws holding the landing gear brackets to the plywood sides were loose. After a couple of rough landings with no damage, this has proven to have been a good idea.

leepord geko

Thanks guys I'll start towards the 6.5" back from the leading edge root. Looks like my rx battery and the ignition battery are both going to have to be on the ignition box because of the light engine, but man is thing going to FLOAT.

FrankFuss

Adding a spinner is one way to add a little weight up front.

leepord geko

Well guys its all done there is really no need to add pictures but I will I suppose, I haven't put the new cowl on yet because I'm still waiting for it but other than that all the servos are done and everything is installed. I'm also going to order up some props from vess for the mld 28. To help the adjustment the c.g I moved the engine forward because it was contacting the bottom of the engine box and added a tru turn spinner and put all the batteries on the engine box. I'll let you guys know how the maiden goes but it probably won't happen till the spring. Also I canceled the idea of the a123's and just went with two 1500mah lipos that go through a smartfly sport reg and then off to the receiver.

dumorian

My Feedback: (6)

Excellent Leepord! Are you able to determine you AUW yet? I know you were trying to be really light. How did you come out? It sounds like with the need to place the bats on the engine box, that you did in fact knock off some weight somewhere... or was this perhaps just the lighter engine? Inquiring minds want to know!

Hopefully you'll get a nice warm day that just demands going to the field to fly (hope we get one of those someday soon... 10 degrees F here right now... brrrrrr) and you'll get to experience the sweetness of this model. It really does make me look like a really good pilot. It has exceptional ground manners and will land really slow as well. I just keep slowing and pulling the tail down and it winds up being a nice slow floaty 3-point landing.

leepord geko

Well guys I went about as light as possible on this build and still kept everything, and so far it has come out to 10.5-11lbs somewhere in amongst that range because I can't really get anymore accurate because I don't have a postal scale. Also I had to put both the 1500mah recivier batteries on the engine box along with bringing out the engine from the firewall another 3/8" and putting the ignition box and battery all on the engine box as well. It currently balances at 6 5/8" with everything except the fuel, cowl bolts and the prop, so I'm hoping with the addition of those it will bring the c.g. to 6 1/2". This build turned out to be 1.5lbs lighter than the aeroworks yak 1.20 size so it should fly really nice with a wing loading of 22.6oz/ft!!! I may get it out flying this weekend. Also I didn't change the servos so there 5625mg servos around and a 625mg on the throttle. I think this weight is very good for this size of plane! hmmmm I say "well" and "guys" to much lol.

nitro wing

My Feedback: (1)

I dont understand how you have a 28 MLD up front and both batts on the box and a rearward CG when I have a light glow OS 160 with Pitts and the flight pack aft of the wingtube with fuel tank at CG?
Is the MLD that light? Also the weight stated would seem questionable, and power marginal no?
But you are the first to try this combo,sometimes there are really good performance surprises.

dumorian

My Feedback: (6)

LOL!!!! The first 74" Yak Glider! Good job on the weight! This is going to be very interesting! It should be a floater.

BarracudaHockey

My Feedback: (11)

Mine is short of 12 pounds with a 46.

In any case, stick with that motor till you get some time on it because when I flew it in the 70" Cermark Yak review, it kept getting better and better. That one flew great at around 9 pounds or so.

leepord geko

Okay so just to put this out there the weight of the engine with everything including standoff and prop bolts etc.. the GROSS weight is 37oz and to compare to the oz engine well that engine weighs 33oz I believe with out a muffler and if you add the stock muffler or a pitts the weight increases. I don't know maybe my bird is just really light for some reason could be a number of things in the actual airframe that would make it lighter. For the power to weight ratio it should be fine I mean it apparently has unlimited vertical on anything up to about 11.5lbs, but from my findings after 3 gallons it won't do very well on a 3d plane above 12lbs, so with a weight of about 10.8lbs it should fly quite well. I also forgot to include the mount for the glow engines usually pumps up the weight a little bit.

drbenz

My Feedback: (11)

It's been a while since anyone wrote in this forum so here's my Yak story. I originally built the plane with a SPE 40 and it flew like crap. I couldnt get enough up trim and the engine was very sluggish. After much frustration the trim problem turned out to be the rear stab was out by 8 degrees. I filled the locator dowell holes and redrilled them to correct that. The sluggish problem was anothe story. I tried different carbs, ignition units, spark plugs, fuel, etc. I still could only get about 6500 on a xoar 20x8. I decided to shelf the project for a few months, I have other planes. I decided to get back to it when I saw a CRRC 50 new for $225 shipped. Its installed now and runs like a raped ape!! AUW is 13 lbs 1oz. Its nice to be able to fly a plane instead of dreading spending the whole day trying to make it work right!

leepord geko

Lol thats sometimes what I would like, just buy and fly it and let someone else do the building and finking around glad to see that yours worked now, I suspect mine shouldn't be that underpowered but if it is at least I can do 1/2 throttle harriers all day lol at this weight.