Logo
Builders' Plan Gallery  |  Hip Pocket Web Site  |  Contact Forum Admin  |  Contact Global Moderator
August 11, 2020, 09:05:30 PM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with email, password and session length
 
Home Help Search Login Register
Pages: 1 2 3 4 5 6 [7]   Go Down
Print
Author Topic: Polikarpov Po-2  (Read 8087 times)
0 Members and 1 Guest are viewing this topic.
DHnut
Gold Member
*****

Kudos: 18
Offline Offline

New Zealand New Zealand

Posts: 806



Ignore
« Reply #150 on: November 21, 2013, 06:24:52 PM »

Pete, It looks really neat. The trimming process is always a bit frought but CO2 allows you to throttle the engine to the powered glide level and by the look of the velodrome the walls are soft. I have the tank in the Comper close to the CG because the weight of a full tank is significant and a bit in front of the CG does help to deal with the power burst. My 26" Comper is about 60 gm so 40 gm does not look out of court. Good luck for the weekend
 
     
Logged
danmellor
Titanium Member
*******

Kudos: 58
Offline Offline

United Kingdom United Kingdom

Posts: 2,290




Ignore
« Reply #151 on: November 22, 2013, 01:41:13 PM »

Pete, don't worry about trimming TOO much! 44g and all that wing area is pretty good. My SE was 54g. If you can, start with about three degrees of down and right thrust and slight left rudder and have the motor barely ticking over to get some idea of the circle as the power runs down. This does mean hand launching, but there you go. Most of the hideous crashes I've had indoors have been caused by the turn opening out as the power dies off. Assuming you (and Mr. Deadman!) have got the CG and incidences right, the rest SHOULD be fairly straightforward. He says, laughingly...

Good luck!

Dan.
Logged
Pete Fardell
Palladium Member
********

Kudos: 150
Offline Offline

United Kingdom United Kingdom

Posts: 5,773


Topic starter


Ignore
« Reply #152 on: November 22, 2013, 04:40:11 PM »

Thanks for the encouraging words, Dan and Ricky.
 Dan, I'll try your trimming scheme, although I might do a little chicken run along the ground first. Side and down thrust is already in place and the CG is nearly right I think- possibly still a bit nose heavy. The incidences may or may not be as plan, depending on how accurately I put it together (that's a 'not' then). Two things concerning me, neither of which I can do much about now; one is the rather uneven washout (no two wings quite the same!) and the other is that the bottom wings will probably not stand much impact. They're joined with a single spar through a notch under the fus. The Deadman version's wings were knock-offable. Oh well, better pack the old cyano!

« Last Edit: November 22, 2013, 04:57:04 PM by Pete Fardell » Logged
danmellor
Titanium Member
*******

Kudos: 58
Offline Offline

United Kingdom United Kingdom

Posts: 2,290




Ignore
« Reply #153 on: November 22, 2013, 05:04:02 PM »

In that case, Pete, I would try some tentative test glides at home, over a big bed! Unless you have access to KeilKraft issue long grass, that's probably the safest; rather than over a hard velodrome floor!

Cheers,

Dan.
Logged
Pete Fardell
Palladium Member
********

Kudos: 150
Offline Offline

United Kingdom United Kingdom

Posts: 5,773


Topic starter


Ignore
« Reply #154 on: November 22, 2013, 05:16:07 PM »

Just went and stood in the bedroom and aimed it at the bed, but couldn't bring myself to let go!
So tomorrow it will have to be- hard floor or not!
Logged
danmellor
Titanium Member
*******

Kudos: 58
Offline Offline

United Kingdom United Kingdom

Posts: 2,290




Ignore
« Reply #155 on: November 22, 2013, 05:30:51 PM »

Chicken! I always feel the need to have at least some indication of a model's suicidal tendencies before risking it over a hard floor. You are obviously made of sterner stuff...

Again, good luck!

Dan.
Logged
g_kandylakis
Gold Member
*****

Kudos: 50
Offline Offline

Greece Greece

Posts: 725




Ignore
« Reply #156 on: November 22, 2013, 05:35:44 PM »

I would first go with taxying and slowly build up power.

Indoors a ROG is 10 times preferable to a hand launch. if the power is not enough, it simply stays on the ground... A hand launch will definetely hit the floor harder than you would like, unless it flies off the board. Just make sure you have some catchers ready...Walls are a nasty thing. Maybe not in Velodrome, but there are still obstacles to avoid - turn away from.

Give plenty of right thrust and plenty of left rudder. I would go with more than 3 degrees. That will make a constant circle, Once you have established that, try to take off by gradually adding more power. If there is enough power and speed but the plane seems to fly in quick circles, then you need to reduce the rudder a bit.

Good luck with it...

George
Logged

scale free flight & micro RC
Pete Fardell
Palladium Member
********

Kudos: 150
Offline Offline

United Kingdom United Kingdom

Posts: 5,773


Topic starter


Ignore
« Reply #157 on: November 22, 2013, 07:30:37 PM »

Thanks George! Well I've got plenty of advice now, and as I have great respect for both you and Dan I'll see how I feel on the day. I shall probably try your way first as it seems a lot less scary!
Logged
Pit
Palladium Member
********

Kudos: 130
Offline Offline

Germany Germany

Posts: 5,508


aka staubkorb


WWW

Ignore
« Reply #158 on: November 23, 2013, 08:14:07 AM »

Not sure if this has been asked, but where might one have a look at the Deadman plan for this puppy?
Logged

A Dedicated Convert to:
WWWoFF (Wonderfull Wacky World of Free Flight)

Comparing Spammers to a pile of organic waste is an insult to the organic waste!
Pete Fardell
Palladium Member
********

Kudos: 150
Offline Offline

United Kingdom United Kingdom

Posts: 5,773


Topic starter


Ignore
« Reply #159 on: November 23, 2013, 05:16:58 PM »

Well...it flew! Certainly not trimmed out yet, but it definitely flew. I stuck to George's gradual power increase ROG approach and eventually got it to take off before it zonked in sideways, then with a couple of acetate trim tabs (sorry) and several more attempts, stability improved slightly until a bit of blue-tac on the right wing finally gave quite a respectable steady flight into the net. Many thanks to catchers and trim advisers Tim H and Dave Crompton, and also Mike Watters who told me to put on the crucial bit of blue-tac resulting in that flight which gave me real hope that next time I can get it going properly. That man, and his dad have a real knack with CO2. Their models were cruising around beautifully, as they always do.
A bit of damage to the Poli, but nothing too serious. It was just that on most flight attempts I knocked a bit off and had to stick it back on, such as the nose block and tail skid. And the engine. Oh, and the rudder.
And both bottom wings and one of the N struts. As well as the fin and tailplane. But apart from that it was fine.
I really should have left off the tail control wires for now, as their elasticity was a hindrance to rudder trimming. I shall make a more bendable rudder hinge before next time, perhaps with the rudder wires just falsely connected to the rudder post rather than the rudder itself.
Anyway, thanks for all the advice so far. I feel I'm getting there so keep it coming! Not sure when the next opportunity to fly it again will be. Tim Horne might have got a short video if it came out right.
 


(Pit, the plan and  Dave Deadman's article on his original ambulance version model is in Flying Scale Models, July 2004. See reply #14 in this thread)
Logged
DHnut
Gold Member
*****

Kudos: 18
Offline Offline

New Zealand New Zealand

Posts: 806



Ignore
« Reply #160 on: November 23, 2013, 08:22:27 PM »

Pete, well done, I can relate to addong tip weight as the Barracuda I was flying last weekend was transformed with about a gram of tip weight was added which straightened out excessive left turn that had been a challenge.
The use of tabs is ligitimate in my view as it gets the trim established and gurnet flap or whatever can be added later. keep up the good work inCO2 ; it is an under rated power source.
 Ricky
 
Logged
OZPAF
Palladium Member
********

Kudos: 186
Offline Offline

Australia Australia

Posts: 5,718



Ignore
« Reply #161 on: November 24, 2013, 02:19:25 AM »

Well on the way to taming the Poli. Good to hear yo uwere in good hands and that it has survived.
John
Logged
Pete Fardell
Palladium Member
********

Kudos: 150
Offline Offline

United Kingdom United Kingdom

Posts: 5,773


Topic starter


Ignore
« Reply #162 on: November 24, 2013, 05:45:00 AM »

Thanks. Yes,it's all in one piece and I'm very happy. It is a shame about the tabs, as even 'invisible' acetate doesn't exactly enhance the scale appearance, but without moveable ailerons I'm afraid they are a necessary evil for me. The blu-tack at least I can replace with a little bit of more discrete lead.
I was very pleased with the consistency of the Telco too, so thank you Dan for tuning it up before you sent it to me. The Gasparin you sorted on my Chazal monoplane was going well too and giving some promising flights. I think I still prefer rubber as a power source, but the co2 bug is beginning to bite a bit harder!
Logged
danmellor
Titanium Member
*******

Kudos: 58
Offline Offline

United Kingdom United Kingdom

Posts: 2,290




Ignore
« Reply #163 on: November 24, 2013, 12:16:42 PM »

Yeah!! Good to hear she survived, Pete! I'm usually too chicken to attempt initial trimming of a CO2 model indoors. Sometimes, though, it can't be helped and I get VERY nervous...

I look forward to seeing this one in the flesh!

Cheers,

Dan.
Logged
Russ Lister
Free Flight Modeller .... sub 250g!
Palladium Member
********

Kudos: 73
Offline Offline

United Kingdom United Kingdom

Posts: 4,418


Russ Lister



Ignore
« Reply #164 on: November 24, 2013, 02:25:51 PM »

Laying down my analogous gun and getting back to modelling (I was a rubbish gunslinger) .... great to see that you have got it flying already Pete  Smiley
Logged
TimH
Guest

« Reply #165 on: November 24, 2013, 07:57:39 PM »

Video of one of the Polikarpov flights.

http://youtu.be/pEbpv4_sWHQ

This wasn't the best flight, but it was the best that I got on film.
I was supposed to be a catcher, but every other flight went round in a left circuit so I thought I was safe to film it. I didn't know whether to keep recording or drop the camera and run when it went straight! Thankfully it was undamaged (on this occasion!)

Tim
Logged
Pete Fardell
Palladium Member
********

Kudos: 150
Offline Offline

United Kingdom United Kingdom

Posts: 5,773


Topic starter


Ignore
« Reply #166 on: November 25, 2013, 06:57:02 AM »

Many thanks for that, Tim! I'd much rather you filmed it than worried about catching it. Whatever happens now, the flying evidence is there! In any case, like most models, it only flies in circles when there are catchers in place. When they're not, it makes a break for it!
Logged
Russ Lister
Free Flight Modeller .... sub 250g!
Palladium Member
********

Kudos: 73
Offline Offline

United Kingdom United Kingdom

Posts: 4,418


Russ Lister



Ignore
« Reply #167 on: November 25, 2013, 03:06:45 PM »

Showing real potential there Pete .... the ROG is very smooth  Smiley
Logged
Monz
Platinum Member
******

Kudos: 152
Offline Offline

United Kingdom United Kingdom

Posts: 1,231



Ignore
« Reply #168 on: February 04, 2014, 06:46:58 PM »

Found this uploaded today:

https://www.youtube.com/watch?v=blnn0ZyqGQ4
Logged
Pete Fardell
Palladium Member
********

Kudos: 150
Offline Offline

United Kingdom United Kingdom

Posts: 5,773


Topic starter


Ignore
« Reply #169 on: February 04, 2014, 07:07:41 PM »

Thanks for finding that, Monique. Lovely! The engine even sounds like my Telco a bit!
Logged
Monz
Platinum Member
******

Kudos: 152
Offline Offline

United Kingdom United Kingdom

Posts: 1,231



Ignore
« Reply #170 on: February 04, 2014, 07:14:47 PM »

I'm just subscribed to a chap that does great vids, this being one of them.

His Youtube channel: https://www.youtube.com/user/auldm?feature=watch

And this was at Old Warden too...
Logged
OZPAF
Palladium Member
********

Kudos: 186
Offline Offline

Australia Australia

Posts: 5,718



Ignore
« Reply #171 on: February 05, 2014, 01:59:02 AM »

Thanks Monique - those vids have the best audio I've heard.
John
Logged
Pages: 1 2 3 4 5 6 [7]   Go Up
Print
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!