opjose

Heh...

Meekskin

I like many other RC's have made numerous post to this forum and more people than not will agree with OPJOSE.....He is a real RC Flyer and not a wantabe....Keep up the good postive comments...

jetmech05

Howdy....whats the best way to mount a 61 to the Bobcat?...the bottom of the case of the engine is touching the airframe...is it best to cut the airframe to allow for the engine or add blocks? is there any thrust angle required?

BillS

Add blocks was easier for me.

Bill

opjose

Yup as BillS posted effectively raising the engine is the easiest way.

This affects the thrustline a bit, but the difference does not seem to be noticable.

I went the other way... I ground down the mounting block to the hardwood.

The hardwood itself is quite thick and strong so there was no problem doing this...

e.g.



There is a coat of epoxy over the ground down area above to fuel proof it.

This permits the engine to sit in the original thrust line.



The two included blocks are too soft though and you are best advised to replace them with other hardwood blocks or some other mechanism.
I did use them in the picture above, after saturating the blocks with CA to harden them... I probably will NOT do this again...

jetmech05

what about a thrust off set? for torque..oh and thanx for the answers

BillS

No left/right offset used.

Initially I flew mine with a .45 engine and found up/down offset necessary to compensate for a down tenancy at higher throttle settings. Later changed to a .50 engine and didn’t use any up/down offset.

Bill

jetmech05

thank you all...
good flyin to ya

opjose

Same here, even with .61 and .76 sized engines, I aligned the engine as close as I could to where it would be with a .40-.46 engine, and this worked fine...

In other words, lined up as if I just used the supplied blocks up against the stop.

cyborg1

Hi guys, I just got my replacement canopy, and I'm thinking of making a mold to pull other canopies (clear type). Is anyone interested in getting spare canopies? If I get enough responses, I should be able to talk to the local shop and get better prices. Let me know by PM. As of now, I don't have pricing yet, but as soon as I get an quote, I'll let you guys know.

opjose

I'd take a couple and I'll bet the NP would buy some off you too.

airborne14830

I purchased my Nitro bobcat 50 and come to find out that they failed to put the assembly manual in the box. Can anyone tell me where i can go to print a copy?

thanks

cyborg1

did you check with the nitroplanes website or talk to them yet?

opjose

Actually if he PM's John or posts on the NP support forum here, I'm sure he can get a manual e-mailed to him.

If John doesn't have one available I can scan and PDF mine for you.

HeliTB

Opjose to the rescue. :-)

airborne14830

Opjose,

Can you PDF me a copy my e-mail address: [email protected] thanks

Also, do you think for servos the Hitec 475 BB which has greater than 70 OZ of tourque witha 6v battery is strong enough for alirons, and elevator (1)? I also plan on using futaba standard servos in the rudder (2)

opjose

Sure no problem.

I'll do this tonight or tomorrow and send it off to you.

airborne14830

Thanks a bunch

HeliTB

I used Hitec HS-475HB in the Ailerons. Since I wanted to use a single elevator servo, like yourself, I used the Hitec HS-635HB which has a little more torque at 6V.

airborne14830

can anyone tell how they installed the nose gear? I have robart 530 air system and was wondering how you did the nose gear with the steering horn

opjose

The best way I've found to do the nose gear stearing is to cut a small hole in the fuselage and glue in a set of servo mounting blocks inside the fuse so you can install the servo upside down, with the control horn sticking out of the fuse.

Then you can run either a straigth push/pull wire ( with a slider arm as is typical of nose retracts ), or a pull pull system.

The wires don't get fouled up this way and you have a minimal mount of added drag.


Others have used this suggestion with great success.

cyborg1

Hi guys,

I just changed the engine from a TT pro 50 heli engine with macs tuned pipe to a OS 75 AX. While tuning the engine after runin with a regular tractor prop, I got about 14,500 rpms. However, when I changed to a zinger 11x8 pusher prop, I only got 12,500 rpms. Is this normal? What sort of rpm figures are you guys getting with your 75 engines and 11x8 pusher? Thanks!

BillS

Don’t know about an OS 75 but I have noticed the need to run a smaller size pusher than tractor prop. Also noticed that if the engine comes up to temperature or speed in stages the prop is probably too large.

I run OS 50’s for years with 10 x 7 and 10 x 8 APC tractor props. But I am using a 10 x 6 APC pusher on the OS 50. I have tried 10 x 7 APC pusher and 11 x 6 APC pusher and they did not turn up. The airplane was very difficult and sometimes impossible to get off the ground. Over a thousand rpm less for pusher props of same brand has been normal for me. Seems strange.

Bill

Crazy4Flight

My Feedback: (540)

could it be a bearing design or loading problem?

just in pusher configs the driveplate and crank are being pushed into the block...

just a bit more friction someplace???

And I do not know if any of the engines out there are designed with pusher application in mind.

opjose

Yup normal.

The plane unloads a lot in the air, producing much higher RPM's when flying.