rv7driver

My Feedback: (105)

David, what retracts are you using?? Thanks, Pete

doxilia

My Feedback: (3)

Hi Pete,

I'm using Hobbico 10 size mains. They are light, inexpensive and seem right for this size model. For the nose gear I'll use a Robart 1/2A gear. I could have used Robart 1/2A all around but I recently used the mains on another model and getting the linkage installed was rather complex. Also, your rails need to be notched to pass the gear which weakens the support. In short, the Hobbico mains are easier to install and I believe better designed. They also fit the ply mounting plates per plans to a T.

The only thing about this size retract is that they come with 3/32" struts. 1/8" would be preferable as the wheels I like for these size models (Dave Brown Lectra Lites) come predrilled for 1/8". However, I plan to use 1/8" GP axles as bending struts is not something I enjoy and they also solve the wheel problem. I suppose a short piece of brass tubing over the strut inside the axle holder will take care of the misfit.

http://www.robart.com/retracts/12A.aspx

For the 20 size Tipo I chose Robart's 2 lb trike gear which are quite a bit beefier. A pneumatic version of these is also supposed to be available at some point. Maybe a nice pneumatic alternative (for a 20 size model) would be Spring Air's 602 micro's.

David.

P.S. You cores are going out first thing tomorrow morning. I'll send you a tracking #.

zubba

Dave,
Good choice on you retracts i may have to borrow your idea on the next 20 size i do.
I went with the 620`s on the 20 curare. but weight is more than your choice i am sure.

-Jason

doxilia

My Feedback: (3)

Jason,

the 602's certainly look like a nice set! Probably much more durable and sturdy than the Robart which have plastic casings.

Weight - that'd be interesting to find out. I just weighed my e-Nanorare (electric) set along with the two servo's I'll probably use. Without linkages, axles or wheels we're looking at 118g or 4.16 oz. - maybe 5.0-5.5 oz. total all included.

Might you have a figure for the 602's? It seems like there are a number of 20's being built this winter.

David.

zubba

Dave,
The 620`s should be here wed/thurs, it will be interesting to see weight wise.
I will have a small air tank extra, but no servo`s ,i use the jet-tronic single http://www.airpacmodels.com/twe/prod...products_id=41
And no extra linkage, but the 620`s dont look light i have not used this small of a series befor so i am not sure.
I hope i am even close to your current weight.

-Jason

doxilia

My Feedback: (3)

Jason,

those are interesting valves. They claim a shipping weight of 0.70g !! That must be 70g...

I didn't quite understand how they work. Do they require a servo for actuation?

Let us know about the 602's when you get them.

Robart's pneumatic equivalent are here:

http://www.robart.com/retracts/2-5lbPneu.aspx

No details yet.

David.

zubba

Dave,
That valve is slick, no servo just plug it into your gear channel, last 2 i used no programing needed just plug and play.
It acts as the servo and the valve and linkage one hose in and one out.
With spring airs there is only 1 air line so it cleans up installs alot.
And there about the size of a micro servo to boot.

Those robarts look like they will be the 20-size retract of choice if the price is better then the spring airs.
Spring airs are great but weight and price is the only down side.

-Jason

PS I dont even know why i put retracts on.
I have yet to put them up in flight, i always have in the back of my mind that i tweeked my gear back enough on take off they will get wedged up.
Our field is fine shale with no grass to be found,so one gear up landing is well, bad very bad !
I use them on my starfire but the looks on that plane can only improve.

rv7driver

My Feedback: (105)

David, thanks for the info on the retracts. Did you recieve your MK stuff yet? Pete

doxilia

My Feedback: (3)

Any time Pete,

and no, no yet. I expect it will arrive this week.

David.

doxilia

My Feedback: (3)

After being unable to get back on the Deception for some real building, I'm back on it.

1/8" fuse sides cut. Wings and stabs need completing so that I can make my fuse cutouts. I'm kind of cutting and kitting at the moment so that I can move along a little faster with the build. The 2 ply 1/8" laminated FW is cut as are the spinner ring, F2, F3 and the tank floor. The tank opening in F2 remains to be done. I'll use 2 dowels to mount the wing at the LE and 1 screw to hold down at the TE.

More to come...

David.

zubba

Dave,

Robart has made the mini air retracts available,and the price looks good as well.
Still have yet to get my 602`s from spring air but maybe tomorrow, i will get the weight and post them soon as i get them in hand.
Going to try those robarts on my ursa major 25, so i will be able to see if there is a weight difference.

-Jason

And your build is looking great!!!!

rv7driver

My Feedback: (105)

I just got to Singapore, and after a 15 hour day and having a cold beverage I was reading about these retract you guys are talking about. My Question is having not started a build on any of davids Nano planes what kind of weight are we talking about?? lets say the D10. the Robarts look interesting which one's?

Pete

zubba

Pete,

The robart retracts i think i am going to start to use full time will be.
http://www.robart.com/retracts/2-5lbPneu.aspx
Part # 600P
Part # 602P
And the spring airs i have on order are also the 602 series.
http://www.retracts.com/Retrax_600.htm
But sadly spring air sent me a return e-mail and my 602`s have not even shipped yet.[:@][:@][:@]
And won`t untill next week. Oh well gona give robart mini`s a try on the next plane.
Gona order a set tonight of the robarts they may get here befor the spring airs i will post weight ect of both.

-Jason

doxilia

My Feedback: (3)

Excellent news Jason. I'm glad they're finally in production. I look forward to seeing and comparing weight and quality on both sets.

Pete, hope that beverage is going down smoothly... How's the temperature in Singapore... wait, 75F and heavy thunderstorms?

Are you thinking of weight of the gear or AUW? If the latter, the 10 size models (Tipo 10) should come in 'round 36 ounces - on average. Of course depends on servo's, LG, engine, exhaust, etc. but I think the models can be built fully equipped lightly at 35-40 oz. Wing loading should be in the 16-18 oz/sq ft range. The D10 is bound to be a little heavier than the T10 because of a bigger wing, longer fuse and slightly heavier use of think balsa. I'd venture that thinly ply laminated fuse sides are stronger and lighter than straight thicker balsa sides. In fact, after having chosen straight 1/8" fuse sides for the D10 I'm now debating if laminated 3/32" sides would have been better. One can really drill out laminated fuse sides without compromising strength. I learned this on 1/2A planes.

For the 20 size models the AUW is going to be in the 64-72 oz range. For the T20 and Jason's C20, the strut diameter of choice is 1/8". Spring Air's 602 gear and Robart's same model number 600 (90 deg), 601 (85 deg) and 602 (nose) have 1/8" struts. The weight of my Robart mechanicals for the e-T20 is somewhere above in this thread. The pneumatic versions look nice although at about twice the cost (~$150 for a full setup vs $65 for mechanicals. I'd factor in a second servo for mechanicals).

Pete, I believe the MK SS gear that you picked up for me has 3mm struts so a little less than 1/8". However, the MK gear uses some really nice hardened struts. I believe that this gear was designed by MK for the bulk of the 20 size kits including Jason's C20. Interestingly, the BA40 (58" span) also calls for this gear although it is a fair bit larger than the 48-52" span 20's. The only issue with the MK gear is that we want to go MK (or metric) all the way - struts, axles, wheels and collars. If I were you, walking down Singapore Hobbies, I'd be tempted to pick some SS's up for the T20 along with axles, wheels (45mm mains/40mm nose), collars and those clever retract half-moon servo linkages. If you do, and don't mind, please double your order - I'll use the same setup on the g-T20. I believe your Cosmos 20 kit came with that setup.

For the 10 size models you really need to use something very light - 3/32" struts. I wouldn't go with pneumatics on a model this size although they apparently do exist. I think Robart's 1/2A-10 gear is ideal for these guys although I find the mains a little tedious to install. The design complicates the linkage and you need to notch the parallel mounting rails/plate to pass the gear. I suppose it's OK on LG plates on foam wings but on built up wings where you're using small rails, I wasn't too happy with that. I decided to try the Hobbico 10 size mains and so far I'm happy with them. We'll see how they actually work/perform in flight but they seem sturdy and well designed. This route is quite inexpensive for a 10 size trike setup using two micro servo's.

Sorry for the endless post.

David.

doxilia

My Feedback: (3)

I had to compare those gears and weights...

I checked the MK SS gear - they do use 3mm struts. Wheels designed for 1/8" struts should also work but the MK wheels are so nice. I'd use them on a glow model and would stick to Dave Brown Lectra Lite's for electric models.

The aluminum MK's are 5g lighter than the plastic Robart's! Maybe just a slice of ham but every little bit counts. 20 size mains only are in the 54g range. 10 size Hobbico mains are 32g (1.1 oz). I think that the full retract setup for the 10's could end up in the 4 oz range with wheels, collars, linkage and servo's (1 oz for two).

Here are some pics. 20 sized MK gear is anodized red; Robart gear is gray. 10 sized Hobbico gear is blue. I'm missing the 10 sized Robart nose gear.

Robart specs pneumatic 20's at 125g (4.4 oz) - gear only - so mechanicals are definitely lighter even using two servo's. We're just missing the pneumatic Spring Air 20 sized weights.

doxilia

My Feedback: (3)

By the way,

as a point of interest I ended up making my fuse 18.5% wider from F1 to F3. This is substantial bringing the FW to 2" and adding roughly 1/8" to each side of all three formers (1/4" total). Having a 2" FW allows a 4 oz Sullivan slant tank to be used in conjunction with Robart retract nose gear (#124 | 20g or 0.7 oz). The exact former sizes are (width x height):
[ul][*] F1 = 51 x 66 mm (FW)[*] F2 = 59 x 81 mm[*] F3 = 48 x 58 mm
[/ul]
In the absence of retract nose gear, the fuse can be built per scaled plans using a 4 oz Sullivan round tank (45mm OD) flush against F2 and the battery (250-400 mAh) can be installed underneath the tank leaving a little more room in the radio compartment. A tank floor wouldn't be needed in this case - only a circular opening in F2. Even so, I'd consider widening about 10% on the D10 and likewise on the T10 although there is a long dissection of fuse scaling toward the bottom of the scaled Tipo plans thread - a long post on non-linear assymetric scaling (that sounds kinda fancy doesn't it... [8D]).

I might build a hatch into both the top and bottom of the tank area. It might be only the bottom as there is no access to this area to adjust the nose gear once F1, F2, the tank floor and the gear area fuse bottom are installed.

Pete, you might find this useful in the planning of your T10. I always contemplated the wood Tipo fuse bottom to be removable especially on the small scales. There are some pictures and info on this in my T20 build thread (presently on hold).

David.

rainedave

My Feedback: (1)

Looking great David. Those MK gear are sharp.

David

rv7driver

My Feedback: (105)

Well, its 6:30 AM Xmas day here in Singapore, been up a few hours, body clock trying to re-adjust to local time, due to holiday I set here until Monday then fly my way back to the states.,we normally would be flying tonight.

David and Jason thanks for the decription of the retracts. I'll get around to building the T20 first. Got to cover my kwik fli III, then start my T2A from Dan . I'll be going down to S.H. today ( yes there open) I'll be checking for the MK SS retracts and all the stuff to go along with them,last trip they did not have any axles for the SS's (3mm) hope they got some in. Will be picking up a header for Raindave and a MK kit I purchased but left with them had to much stuff last time for all you guys. will keep you posted David on the SS's.

TO EVERYBODY, HAVE A MERRY CHRISTMAS AND A HAPPY NEW!!!! Pete

doxilia

My Feedback: (3)

Pete,

Merry Xmas to you too. Aside from family I can't think of a better place to hang out Xmas day. Have fun and many thanks!

David.

rv7driver

My Feedback: (105)

Well, went to S.H. yesterday, and purchased my Santa gifts also got your header Raindave, and for David I have the following: 1 set SS retracts (metal ones) they no longer make the SS's in Metal all plastic now!! got the last 2 sets 1 for me 1 for David. 40mm and 45mm MK wheels. 1 set each for david and myself. retract linkage (half moon) David you can have 1 or 2 your choice. and also the single servo 3 wheel retract linkage (not being made any longer) 1 for you David 1 for me!!!!!! S.H. did not have any 3mm axles and again no longer made, guess we just have to bend the struts now. I also ordered 4 ea. 150cc oval tanks, will pick them up next trip.

I'll PM Raindave and David. Cheers from Singapore, Pete

doxilia

My Feedback: (3)

Wow!

Pete, I can't thank you enough! I'm just going to have to pick up my building pace with all these goodies. I've been a little lax lately with all the festivity preparations. In any case, this nice little package certainly will make my Xmas. It's going to be cool to see the little Tipo's one day - 2009 will be an exciting year!

Santa (that is me up at these latitudes) brought me some really good Single Malt Fudge candies and Mrs. Claus (not knowing the first thing about RC - bless her heart) got me a great book on Mediterranean cooking - something I enjoy doing given the right occasion. However, the biggest thrill I got this Xmas was watching my two kids' expressions early this morning when they saw their stockings... no substitute.

This news Pete put the same sort of look on my face as they had this morning -

Time for some rest, David.

rv7driver

My Feedback: (105)

David, glad I could help with that look!, I had the same look on my face when I walked in S.H., Mrs. Yong saw me and said welcome back Pete... she knew I was going to drop a few dollars!!! and I did. I will be having Xmas when I get back New years eve, can't wait I'll be seeing that look with my family's face. Being gone is part of the job and they understand completely. Almost forgot I'll be off for 23 days, will get a few builds finished.

Pete

doxilia

My Feedback: (3)

Pete,

23 days sounds like a nice break to spend with family and the hobby. I've had to celebrate Xmas in the new year a few times myself. Typically it felt well deserved.

Once I recall, back when I was a graduate student, I had a stack of 150 exams to grade and mark from my Oceanography 101 class. It was December 22nd and I had to decide whether to lug the 3 boxes with me to the West coast where family was back then, celebrate Xmas with them but have to spend Xmas day going through the papers or stay back in town and get it done. I opted for the latter and was one of only two people to sign in to the closed University. It's not that the work was so bad but somehow being almost the only soul on campus made it somewhat somber... it was so quiet you could hear the sound of the pencil going over the papers. It took me two days; the 24th and 25th. Instant soup was had for dinner...

Not on par with say, being in the forces, but I little anecdote nonetheless.

Have a good and safe flight back.

David.

doxilia

My Feedback: (3)

A quick update,

fin and rudder framed up. Lightening holes, rudder shaping and final sanding to be done after completion of fuselage.

Stabs sheeted with 1/32" balsa. Trailing edges installed and sanded to shape. These will be used as templates for the stab fuse sides cutouts followed by attachment of leading edges and stab tips.

The wing core prep is almost complete with retract pushrod routing to be finished. I think I finally settled on how best to do this - this is arguably the most complex aspect of this small scale scratch build (I'd venture). I anticipate that the nose gear will go in fairly easily and will be operated by a separate HS-55 servo mounted inverted on the fuse side in the gear bay.

Once the stab is finished, I'll be moving on to completing the wing. Elevators will have to wait until I find balsa stock of the right thickness. Empennage is coming in around 1.5 oz for the complete stab/elevators and 0.6 oz for the fin/rudder. I'm hoping to be able to end up with 16-18 oz airframe leaving me 22-24 oz for engine and gear. All still a bit of a guess at this point.

Happy new year to all!

David.

jmb52760

David,

Looking good. Will you do anything to further strengthen the horizontal stabilizer joint?

It's unclear to me what Jim K. had in mind for this. I have decided to use microglas and epoxy on my .60 Deception. It's just a gut feel that I should strengthen it because of the very narrow empennage. I know that this is adding weight in just the wrong place, but with the microglas I can make this a very thin layer.

Does anyone else in RCU land know what the original Deception used here?

Mitch