RE: Nitro models pusher Bobcat?
 

opjose, take a closer look at flt lt hurdy's pictures. He did some type of modified engine mount which has that engine sitting pretty far back.

flt lt hurdy, what did you use for an engine mount? The extreme rearward position has definitely affected how much nose weight you needed to add. I would also replace the rubber tires with foam. As always, just my 2 cents. :D

RE: Nitro models pusher Bobcat?
 

errrr.... yeah thats right mate... the engine is mounted as far forward as I thought possible.... moving it back will mean more lead in the nose... NOT what I am looking for.. need to lighten up not weigh down!!

perhaps I should move the u/c forward a bit...



stick jammer: made the engine mount myself... and I hate using the foam wheels! lol

RE: Nitro models pusher Bobcat?
 

Without too much work the booms could be moved forward 6" or so moving the boom weight closer to the CG.

Without too much work a canard could be put at the nose wheel former. If it flew OK the elevator and maybe the horizontal stabilizer might be removed or the size reduced which would reduce the boom weight.

Bill

RE: Nitro models pusher Bobcat?
 

Hi, Mark! I like the way you modified the Bobcat for EDF. @Meekskin sure has pushed his pusher propped to the limit of his props; a very good job. Hope he gets a comparison with your EDF version; though yours probably needs to the retracts, to be fair. I'm not familiar with the 4-in Haoye fan, & will be interested in some thrust figures @ your 2300watt level.

I saw the start of your thread, but my Keecat kit was delivered then so completed that EDF conversion. The Keecat is slightly bigger, & I did it mainly as a testbed for 120mm & 5" fans. I have the Neu 1912-1.5Y on my TF4000 fan at the moment. It pulles around 2300watts on 12s (51amps). My minimal fuselage boat-tail mod does not give a good air inlet, so I'm only getting 7.8-Lbs static thrust (instead of 9Lbs expected), although it shud get better in motion. With 3 other projects in queue (2 scratchs & 1 kit) I don't plan more extensive boat-tail mods, but will swap motor to test at 11-lb thrust level, & maybe even 14-lbs!! Shud bring it over so Nitrodan can shot with radar at current & higher thrust levels (not sure if airframe is good enuf for 14lbs thrust:(. I'm certain @Meekskin is technically interested in perhaps a higher speed attainable with high revving EDF, although he may be able to squeeze more out of his prop by higher glo rpm. Don't know when those props start to throw blades:(

Cheers,

Phil

ps: Your 4-in fan is probably the better fit for the Nitro Bobcat than my 120mm.
pps: Details of my EDF conversion can be found in www.Rcgroups.com/forums/showthread.php?t=722722

RE: Nitro models pusher Bobcat?
 

You are right... sorry I wasn't thinking at all... senior moment I guess.

RE: Nitro models pusher Bobcat?
 

oops... think i posted twice by mistake... how does one go about removing posts?

RE: Nitro models pusher Bobcat?
 

...nae bother ;) I'm getting there myself ;) now then, where did I put my....


...so, has anyone got any experience flying a heavyweight kitty or am I gonna be the first to report on flying a brickcat?? lol

RE: Nitro models pusher Bobcat?
 

My Bobcat weighs in at 10lbs 3 oz, sure it has a turbine on the back but it flys fine, Comes in fast without the flaps, with flaps it slows down to a kitty walk.

RE: Nitro models pusher Bobcat?
 

hapyjac2,,,what turbine do you have on the bobcat 52??

RE: Nitro models pusher Bobcat?
 

I'm flying with a SimJet 700.

RE: Nitro models pusher Bobcat?
 

that's good news to me happyjac2, thanks. Might get more than one flight outta her then :) lol

I'll let you know how I get on in a couple of weeks when I take her out for my first go... this aircraft has already been flown quite a few times with a Wren 44 Gold in it and went like billio!!!

RE: Nitro models pusher Bobcat?
 

Well, I got a pretty disturbing email from nitro today... I read in a earlier post in this thread this happen to someone else also. I was wondering if anyone else has had this happen to them, and what they did about it?


Dear Customer,


This email is concerning NitroPlane order number blah blah :).
The order is currently on hold for security purposes. For verification we need you to fax or email us a copy of your credit card and your ID or driver license. You can hide or scratch out your credit card numbers except for the last four digits. Our email is [email protected] and our fax number is (516)706-0421.

RE: Nitro models pusher Bobcat?
 

It's not unusual...

The CC company gave them grief about the transaction... typically because some item entered did not EXACTLY match up with the CC companie's records.

I've had this happen before with other companies.

RE: Nitro models pusher Bobcat?
 

Colorado
Don't do it....that emails sounds like spam.....I did a reverse phone number look up on that number they said is their fax number (516)706-0421 and it comes to a land based line in Nassau, NY. Nitroplanes is in CA. If you go to Nitroplanes.com site and click on help in the upper right hand corner of the main page you will see this. "You can reach us at the following phone number: 626.968.9860 or fax to 626.968.9830". As you can see the fax number is not even close. Try contacting them at these numbers....Better safe than sorry.

RE: Nitro models pusher Bobcat?
 

None of us seem to be on the same page with this. In your photos it appears your custom mount is hanging quite a bit past the rear of the fuse. Judging by how much space you seem to have between the prop and the trailing edge of the wing, that engine is pretty far back. I only have about 1/2" using an 11x7 prop. :eek:

RE: Nitro models pusher Bobcat?
 

lol, this is getting confusing!

I made the (white) engine mount that sits on a blue plywood square that was already stuck to the fuselage. The white engine mount sits flush with the blue plywood(at rear of fuselage), as you can see in the pics. The white engine mount does not 'hang' off the back of fuselage, merely 'sits' on the blue painted plywood. The gap between the rear of the engine(facing forward) and the rear of the fuselage(facing, er, rearward...) is about 1/2inch. The most I'll be able to move the engine towards the CoG is 10mm. This movement will not reduce the noseweight by much, maybe an ounce or two but certainly not the 11oz currently needed to balance it at present. Think I'll fly it as is, as now I know that there is at least one heavier model out there that flies ok.

Thanks for all your input anyway, I'll let you all know how big the impact crator is... ;-) in fact, if I have my camera handy... lol


...is an OS 61 FX really that much heavier than a Wren 44 Gold????

RE: Nitro models pusher Bobcat?
 

hapyjac2,

I have a second Bob Cat that was flown once by someone else with a Wrenn 44 and immediately retired because of the landing speed and have some foolish questions.

What mph is considered a kitty walk? A kitty walk for you might be fast as hell for me. Do the flaps cause the nose to pitch down? How much flap are you using? What I really want to know is how the flaps affect the flight and landing characteristics. Found your web site conversion.

Although I might not be able to go the turbine route the airplane is too pretty to be a hanger queen.

Thanks in advance.

Bill

RE: Nitro models pusher Bobcat?
 

You need spoilerons not flaps. 1/8 of an inch at the wing root up.

http://www.rcuniverse.com/forum/sear...single&author=

RE: Nitro models pusher Bobcat?
 

OK, now we're getting somewhere. Whoever had the plane before you added the "blue plywood square" which hangs off the end of the fuse. You added the white engine mount that sits flush with that. If you swap the needle valve around on that O.S. you should be able to move the engine forward more than 1/2". At any rate, your engine mount does hang past the end of the fuse which is not stock. ;)

RE: Nitro models pusher Bobcat?
 

AAAAAAH...... Okaaay...... that explains everything... here's a pic of the turbine on it... and my set up.

no extra weight was needed in the nose for the turbine, and the 61's mass is closer to CoG so, gotta be the u/c mass thats made it need that much extra weight up front. The turbine only had the 'too' bendy u/c hanging out and I always thought it was not up to much hence the change.... think it'll be alright to fly and land with the extra weight now that I know there are heavier models out there. one thing's for sure, I am soooooo looking forward to flying it, will let you know how I get on... weather permitting, lol British climate ;-)

RE: Nitro models pusher Bobcat?
 

Bill,
With flaps deployed on landing, aprox 30%, the plane will pitch the nose up, when flaps come down so a bit of up evevator will have to be mixed in.
Power can be kept up as the plane slows, then as you reduce power a flair before touchdown and that's it. My Tango came in a bit slower than the Nitro bobcat, but it was larger with a greater wing area.
The advantage over spoilerons is that you have much more stability and control of the aircraft. For those who are not used to flaps or do not have them available spoilerons are okay. But worlds apart when flying.

But to each his own. I think the time to add flaps is well worth it.

Good luck!

RE: Nitro models pusher Bobcat?
 

Ok heres the deal... After having their phone number being busy ALL day long I got through at 4pm central time, and was able to talk to someone. I was able to get my order sent out, and asked about the fax number. The number listed in the email, is the same one he gave me over the phone. What he said was its not a normal fax number its an email fax, so whatever. I'm glad he was very helpful, and sent the order out with out the copy of my drivers lic. Because if it would have come down to that I would not have done it, and would have not done business with them. So the plane should be here this week he said! WOOT!

James

RE: Nitro models pusher Bobcat?
 

Nowadays it's better to err on the side of safety... those Nigerian cafe's are still in business...

The CC company usually asks the vendor to verify the recipient, lest the vendor be charged back for something which was in turn cross shipped to a foreign location.

I wish NP would drop their Yahoo eCommerce site, as I - KNOW - that my CC number was at one point obtained via a Yahoo transaction and used by a scammer.

RE: Nitro models pusher Bobcat?
 

I must disagree happyjac I set up flaps on this bird and the spoilerons work the way flaps are supposed to. Flaps make this plane very pitch sensitive and in reality flaps on this plane are like spoilerons on a traditional planform. This plane behaves more like a delta planform than a standard planfrom. That's my story and I'm sticking to it.

Anyone else have an opinion, flaps vs spoilerons on the Bobcat?

RE: Nitro models pusher Bobcat?
 

not yet but I am keeping a close eye on this thread...