I'm getting ready to put together a Tiporare in classic format (pipe & trike retracts) and am considering what radio equipment to use. I will be using a Futuba 10C 2.4G radio and am looking at servos. I am considering using the Hitec HS 5245 MG digital mini servos for the control surfaces (1 for each aileron). They have [email protected]/[email protected]/in. Given that back in the day we used standard servos with only about 50 oz/in, would these Hitec be adequate and a good choice? I'm considering a Hitec HS 5065MG (micro) for the throttle, do you think this would be a good choice? On a somewhat unrelated topic, would you build your flight system around 4.8v or 6v battery packs?

Final question is on retracts, what is the current thinking of retracts for this type of plane? Air or servo based? If servo based, what would be recommended? My last tipo in the 80s was about 8lbs so I assume with the newer radio equipment a modern day one could be built lighter?

Gring,

nice - another Tipo!

Retracts: This is a matter of personal preference but typically for trike setups, air or electric is the way to go as the setup is simpler. If you do go mechanical, then MK gear are nice but a little hard to get. And if you go with MK (or other mechanical), be sure to use two servos to simplify life for yourself. Frankly, I think the best all around solution for classic pattern trike designs is to go with Spring-Air or Robarts pneumatics unless you are trying to build a re-creation.

Servos: The HS-65HB is a great choice for throttle - fast, strong and precise. A great little servo even for reduced scale classic pattern models (like my Picorare - a 40" span Tipo! ).

For control surfaces on a 60 size model, I'd rather use Karbonite gears than metal. The latter are not needed and eventually can produce slop (steel not Ti). Hitec designed Karbonite gears for this reason. In terms of what brand and type there are many options for a classic. Again, personally, on a precision ship such as the Tipo, I'd rather use digitals or, if the pocketbook restricts this, I'd use coreless analogs. Coreless servos are very nice and center precisely. I'd use ~70 oz/in servos on aileron/elevator controls and something perhaps a little heftier on rudder. I'd setup the rudder with a P-P linkage.

I am actually doing exactly this on a GP glass Tipo. I'm using Kraft multicon gear on mine so I have a total of 6 servos in the model (+ 1 amp for the gear) with one being used specifically for steering. A picture of my radio install is shown below. In your case, if your fuse is made of wood, I'd install a steering servo (a flat one would do nicely or another 65HB) on the tank floor and use the space for the steering servo in my layout for the retract (pnemuatic) servo. Of course, you might need a larger plate (or a separate one) to mount the valve. An option would be to put the throttle and gear servos up front behind the tank plate and under the front wing mounting point. On wood fuses this is nice because you don't have a screw plate that gets in the way of the radio install. Finally, I strongly recommend that you install your elevator servo for linear output if you are going to use a forked pushrod. Other options would be dual rear mounted servos or to use an MK elevator bellcrank system. Both are nice but neither is classic. A Dave Brown arrow shaft pushrod is the honorable way of setting up the elevator linkage.

Hope this helps.

David.

P.S. I just read the end of your post and see you built one in the 80's - you can dismiss most of what I said above regarding layout - you probably have your own system.

I forgot - batteries:

If you are using a 2.4 radio - definitely 6.0V. 6V would be preferable in general actually provided your gear is meant to work at that voltage (Rx, Sx). Some analog coreless servos were not designed to be run at 6+ volts (full charge) but be careful with low voltage on 2.4 gear, especially Spektrum. My personal favourite for juice is a 2s 2300 A123 pack - absolutely rock solid! I might take 5 minutes just to write about that but if you are familiar with A123's, it won't be necessary. [8D]

If you don't like LiFe or regulated Lipo packs, go with a 5s NiMH pack. (Dang! Those A123's are cool though...)

David.

Quote: "Dang! Those A123's are cool though"
__________________________________________

Hi David,
I just received two A123 2S receiver batteries for my 12FG 2.4GHz.
Haven't finished reading the instructions...haven't charged them yet.
Do I understand you are using these without a regulator?
I've been wondering if I need a regulator or just use them full-strength.
My question is: "Will it shorten the life, or otherwise damage my digital servos? (BLS451 Futaba Digital Brushless)
FASST FLIER

Thanks for the info. I'm not concerned about "classic" as much as I am with updating the plane's electronics to the smallest, most modern stuff. This is why I was looking for information on those particular Hitec servos. Also, I thought there was a thread on a scratch built curare or tipo that was something like 20 pages where the guy painted the plane but has not yet flown it. It had a lot of detail regarding the build, but I cannot find it any longer. It wasn't the 13 year timp build thread.

Gring,

it sounds like you might be thinking of Ed Lyerly's Curare build - very nice:

http://www.rcgroups.com/forums/showt...ghlight=Curare

However, there are several Curare builds on both RCU and RCG - all worth looking into. Is your Tipo going to be built from scratch or a short kit or is it a glass Tipo?

Most of the info I provided has little to do with staying "true to classic" except possibly for the elevator pushrod setup which is a standard on pattern planes regardless. (2m pattern uses a variation). If you want specifics on a given servo ask around the electronics forum - I haven't used that particular one but I believe they are sport servos if memory serves me. Primarily I would not use MG servos on control surfaces - these aren't 25%+ planes.

David.

JC,

excellent choice! Actually no, I do use a 6V regulator. One of the great things about A123's (or 2s Lipo's) is the possibility of constant voltage delivered to the control system throughout a day. Using 6V+ packs allows, through a regulator, to deliver a clean 5.6V or 6.0V as desired. This is particularly important on 2.4 gear (Spektrum in my case) which requires voltage to function properly. Old fashioned NiCd 4.8V packs don't provide that peace of mind for Spketrum Rx's. The one important thing to watch out for is voltage drop on A123's when it happens - it will dive fast and hard. Solution? Don't let it happen. A123's charge to full capacity in 15 minutes! Also, given their 30C rating, they provide a pretty flat voltage curve even without a regulator.

Having said that, I know of several who don't use a regulator since full charge is in the 7.0V range. For some radio equipment that is not a problem but the longevity of your servo's and clean filtered power of a $10 regulator can't be beat.

Nice servos!

David.

Hi david, thanks for the link, but that wasn't the one I was thinking of. It was a thread here on RCU.

I'll probably buy a short kit to build from

Back in "The Day", many of us used Kraft radios, and KPS-14II servos. We used one servo for both ailerons, as well as one a piece for the rudder, and the elevators (both halves). These servos, which were "average" for the day, had 27 oz/inch torque, and a somewhat more fragile gear train than many of today's servos. I never experienced any servo related failures (due to the servos being underrated), nor was it an issue. Somehow we got by without today's super servos. I think that we can safely say that your choice of servos will be more than adequate, if not overkill for the application.

And overkill is O.K. Especially when it comes to a difficult to replace classic airframe.

-Robert

P.S. Like Dox says, go with the carbonite gears.

Gring,

you might want to check out Don's classics selection. He has three to four Tipo scales up for short kit purchase:

http://www.eurekaaircraft.com/plan_kits/tiporare.htm

The various scales he's producing stemmed from this thread started about a year ago:

http://www.rcuniverse.com/forum/m_78..._1/key_/tm.htm

The 10 and 20 size aren't posted yet but they should be some time this year. I believe he's also working on an 81" (2m) size. I hope to build a 72" version some time later this year (probably early winter).

If you're interested, here's a link to my 40" size scratch build thread:

http://www.rcuniverse.com/forum/m_8858351/tm.htm

David.

David, thanks for the links. Eureka is where I was planning on getting the short kit from. I would still like to find that Curare build here on RCU. It was a scratch build that was very detailed in every respect.

Gring,

I did a quick search on Curares here and didn't come up with anything recent. I've only been a member of RCU for a little over a year (albeit a somewhat active one) so I likely didn't see it if it's older than that. There has been a lot of exchange on Curare's over this last year but no complete build threads that I remember.

In fact, there aren't any complete build threads of the Tipo either - this I'm more certain of. This is part of the reason I did the Pico build thread but arguably I did leave out some details. Although the Curare and Tiporare share similar heritage, I don't think a Curare build thread would help a Tipo build that much - their internal structure is different and Don's short kit should ease the process a fair amount.

I have taken a number of pictures of my Pico build most of which are not posted on the thread. If you have any doubts or questions regarding the frame-up I'd be glad to help if I can. As mentioned, the Tipo goes together pretty easily and the trickier part is getting the nose section to proper contour. This really comes down to experience more than "seeing how someone else did it".

Here are a couple of suggestions stemming from my Pico build:

I believe Don's fuse sides will come with the stab cutout already made. You will also receive the new structure fin ribs. After a few exchanges on the topic (mostly in the reduced plans thread) Don changed the construction of the fin to a simpler than plans wing like rib design. In order to insure accurate symmetry of the fin, I'd bond the fin sides to the fuse rear top while lying flat essentially making them an extension of the fuse sides. Once your fuse is framed up, you can then insert the bottom rib and fin post to space them out properly and line them up on the C/L. This should yield a nice continuous line to the fuse arc which is actually straight behind F3 to the fin post. The critical rib, which is next, is the top rib. This rib will dictate whether your fin ends up warped or not. Make sure the rear fin sides are bonded at a perfect plumb line to the fuse top and then insert the top rib naturally to bring the front together. The sub LE and lower support goes in next followed by the mid rib which is brought up to profile snugness in the assembly. Don's measurements are accurate so it should line up nicely with the sub LE and tuck in at the rear. A little contour sanding all around and you can then lay down the two bonded LE blocks on the sub LE centerline and sand this to contour.

I cut a straight piece off the front of the blocks at the bottom at the 1/4" height point (in my 40" span build) so that the fuse top sheet would mate nicely. I then used a smaller amount of filler to produce a smooth continuous transition. The full scale uses a 1/2" top sheet if I recall correctly so you'll want to notch the blocks back to the 1/2" height. Note that this brings the fuse top back a little further and requires a longer length than shown on the plans. Leave the excess of the sheet off the front and once the fuse rear is finished, cut off and sand the front to match the angle of the fuse sides. I think my build thread shows these details well enough.

I hope that breakdown is of some use. I know it will help me as a reminder in my larger 72" build.

David.