dem45133

Hello all again... hope you don't get tired of me asking newbie questions....

Ok... being that I was trying to be fugal in this RC project... and being completely ignorant of RC to begin with (but learning more and more everyday)... I picked up a Park Flyers digital proportional RC sys at 2.4 GHZ along with a small electric motor, a 20A motor controller, a 7.4 volt 1800 mah batery , the recieiver and three servos... all out of a Gee Bee 3D that the man flew exactly once... (you know the outcome). So he decided it wasn't for him, stripped out all the components, and sold them on eBay.

Turns out these are micro sized (I think???, 7/8 hole not including mounting lugs) servos... and are not dimentionally suitable or arm suitable for the way this 42" Ultamate Biplane ARF was built. But being I do not know what I'm doing yet... I do not know what category servos my bird was designed for or even the name of that category. The directions are basically pictorial and of very limited use for a newbie.

The mounting hole for the three needed has a servo base length (NOT including mounting lugs) of 1-9/16th inches... or 4 cm. Which category of servo is this designed for?

Also, will this category of servo work with my micro? sized 6ch receiver?

I'd go to a hobby shop and bug them with a little show and tell and find out... but seems the closest real RC shop for airplanes is in Albequrque... about 90 miles from here. Santa Fe NM doesn't have much, at least via the yellow pages.

Thanks again
Dave

Charlie P.

Those are standard size servo holes - like a Futaba S3004. Not knowing what you have it may well be designed with very limited range. Your best bet is to start with something other than a 42" Ultimate. It's a difficult model to fly and for intermediate to advanced pilots. It has no forgiveness built in as a trainer does.

Well, no model is truly difficult to fly. Take-offs, landings and any near-earth maneuver - those can be difficult.

TFF

You have to be more specific on the type of Park radio you have but you need servos like this http://www3.towerhobbies.com/cgi-bin...?&I=LXH288&P=7 as an example.

jester_s1

Are there any clubs in your area? Some stick time on a trainer and then flying a sport type plane (ugly stick, 4 star) will get you ready to handle an ultimate biplane. If you skip those steps, you'll be Ebaying your stuff soon too.

dem45133

Yes there is one in Santa Fe.... but I ended up working late last week and missed their monthly gathering. I had intended to go and see what I could observe and learn.

In thinking through the RC basic design concept.... by default there will always be a lag time from control input at the transmitter, until the servo can run from one extreme to the other.... which is unlike real flight where its action is basically as fast as you can move the stick or yoke... yes that could get interesting on a bird that has no diheidral and large control surfaces... I'm sure it also really needs well coordinated turns as well. The manual for this parkflyer RC says a with my ER61 2.4 reciever my range is 1000 ft. I don't no know much yet, but I believe this is on the short side of ranges, but should work as a start.. Has the look and feel of a toy. The RC unit also came with an E-Sky flight sim.... I haven't installed it yet... hopefully it has something difficult to get some kind of feel for.

Acutally I have an 20 year old EAA 36" span J-3 cub balsa model kit I was thinking of building and installing the micro gear in. The little electric motor from the Gee Bee 3D might be just right... although I suspect maybe a little small for it. There are no numbers on the motor but given it was only a 1800 mah 7.4 powering it and a 20A ESC it can't be too powerful (from the little I've gather surfing). First little electric motor for RC I've seen.... Axial flux concept... looked into homebuild large axial flux generator for alt E 27 ft diameter wind mill a while back. Yea I got a non conventional but 400 year old design for it too... since our home is in a marginal wind zone. No it won't generate at as high an average wattage... but will be generating 80% of the time, where as conventional would only generate 20% of the time... got into it with one of the ALT E engineers... say it would have a hard time with start up drag from the magnets at our ambient average... but he forgot that an axial flux gen is also a motor... so a secondary system can temporarily charge it and offset the magnets for a few seconds while the mill accelerates...someday I might build it too. Had a trolly system on a 18" 60 ft well casing tower all figured out too... guy wires tighten when up to fly... trolley brings the mill down to you for service... Very simple gear up for the axial shaft... its been around for at least 70 years.... with very little efficiency loss and more or less maint free... did'nt need 90 or a 120 ft tower... we're already on a ridge... but thats a story for another day.

Boy do I miss spell check.... Time for bed... later...
Dave

scale only 4 me

My Feedback: (158)

Yes,
1000' is short, that is a park flyer or indoor flyer radio, You won't want to use it in a large or regular size r/c, but if you keep that J3 close it can work
I'm no Electric flight expert, but that ESC/Motor combo actually sounds about right for a 36" cub, what size prop is with it?

I can't help you with your windmill design but you can download the google tool bar,, it has spell check built in

dem45133

Thanks Scale only...

Prop from the geebee salvage is "10x47", which is wierd. Its 10 inches but the "47" must mean 4.7" or more or less a 10 x 5? Could be just about right for the 36" J3?. Problem is the J3 is a full old fashioned balsa kit... which I'd have time into building.... If the probability is likely something like 80% or better that newbies will wreck... I'm better off with a chinese ARF of a more forgiving type than I currrently bought.

I did the biwing as the whole point of this was to learn to fly it... then substitute the wings with a modeled morphing wing for an full sized wing morphing concept I'm thinking though and designing... for a homebuilt bywing in the 100hp class. Because I will be demonstraiting fairly severe very high Cl STOL morphing into a very low Cl speed wing in flight Yea, I'm looking into designing a STOL biwing with about a 75 to 100 ft take off and landing rolls, but still be able to cruise at 120 mph... it will take a variable pitch prop too. Several homebuilt designs can cruise at 120-130 with the 100 hp.... but their stall is too high resulting in 300-500 ft or more takeoff and landing rolls. My hay field is too tight for that. Yes all my toys have live at home and eat only when I let them. I have the mechincals and loads worked through... weight will be my biggest problem. Might not work in the bywing due to upper/lower wing wakes at high angles of attack.... but some have quite a setback to the lower wing which will reduce that. I just like bywings and maybe it will be too problematic... may modify an existing design high monowing like the zenith 701 and increase its cruise. But hey, I enjoy the mental challange too... and I'm not one who buys into "it can't be done" concept until I prove it so myself. A one off home built has a totally different set of criteria than production birds or kits.

Oh, the alt E wind mill comments were just in relation to these little electrics running perm mag motors....of an axial flus design. Spent several months researching it a few years ago.

Dave

jester_s1

Your best bet for learning RC flying is to put the micro stuff away for a while, and get some time on a purpose built trainer. Every manufacturer makes one, and they come in all sizes.