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Old Apr 26, 2007, 08:14 AM
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Stephan Wagenhof's Avatar
Österreich (Linz)
Joined Mar 2007
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hello docrob the six centimeter size is not right it's to small only about 3,5 centimeter. It should be bigger.
Ciao Stephan
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Old Apr 26, 2007, 08:23 AM
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New Delhi, India
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OK, let me recheck and repost the correct version.

Doc
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Old Apr 26, 2007, 08:48 AM
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New Delhi, India
Joined Jul 2005
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Ahh, I got it....I tried printing your original PDF. I printed only the section where you have the 6 cm markings and they show up as 3.4 cms. I tried enlarging the plan to 165% but that generates 165 pages .

Someone with more experience with this thing is going to have to chime in.

Sorry Stephan.

Doc
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Old Apr 26, 2007, 08:59 AM
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Österreich (Linz)
Joined Mar 2007
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Yes i know there must be a lot of white sites without nothing. Can your programm cut the white sites of my plan. I can't do this with the cad.
Ciao Stephan
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Old Apr 26, 2007, 12:27 PM
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New Delhi, India
Joined Jul 2005
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I'll give it a try, Stephan, but I'm pretty new to this stuff too. I've always just printed off other people's plans that have had the bugs worked out of them

Doc
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Old Apr 26, 2007, 12:42 PM
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Hi docrob no problem this night i tried to print it with Primo PDF. Beanie use this programm.
Greetings Stephan
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Old Apr 26, 2007, 04:57 PM
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Pollock Pines, CA
Joined Aug 2002
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Thanks seitz2c.

I'm going to try that.
Dennis

Quote:
Originally Posted by seitz2c
I use a product called Mist and shine spray on and wipe dry. car show people use it a lot for that last wipe down . you must reapply after each pull but there is no cleanup required. very slippery. Car Quest auto parts carry it
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Old Apr 26, 2007, 05:04 PM
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Ann Arbor, Michigan, United States
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anyone else with build suggestions/changes/advice on the MiG-21?
-beanie
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Old Apr 26, 2007, 05:30 PM
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New Orleans/Dallas
Joined Jan 2006
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Well, I have a suggestion, but it's not for you, it's for Alfa models. I think they should make your plane a molded kit and start selling it as soon as possible! If they don't, they'll only be missing out. I've only seen one floamy Mig-21 kit around, but yours looks so scale that I'd be it would be really popular.
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Old Apr 27, 2007, 01:55 AM
That thing's operational!
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New Orleans/Dallas
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Hey Beanie,

Hi! I seem to have run across a problem with my Mig. I was getting ready to do a little work on it tonight and have noticed that the elvator has a lot of play in it. The thing is, I can't figure out why it has so much play since the control rod was connected to both the servo horns and the control horn on the elevator torque rod with z-bends and dubro ez-link connectors to keep the rods close to their respective connections to the control horns.

There's a lot of play in the elevator's "up" elevator movement (where the back of the elevator moves up and the front of the elevator moves down.) It's not like the elevator will move up and down 1" with a simple touch, but it does have a reasonable amount of slop in it. I am going to try to post a video of it below, we'll see if it works. Would you guys recommend ttha I open the fuselage up again and try to see what the problem is? I really don't want to do that since it'll be weird trying to get it all back together back there, but if the amount of slop shown in the video is going to cause lots of problems with the control of the airplane's pitch then I will try to fix it.
I don't really know what I could do differently though, it seems like there's not much that could be changed, there is just a z-bend at each end of the control rod; one goes through the torque rod's contorl horn and the other goes through the servo's control horn. At least one of them is secured with a dubro ez-link connector, off-hand I can't remember if I put one of the servo's control horn or not. The elevators are glued pretty well to the torque rod, so I don't think that's the problem. Thanks in advance for any help that you guys have to offer.

By the way, I honestly can't remember what the slop has been like in the linkages for the control surfaces of my other parkjets since I don't have any other ones assembled here at school (I took my f-18 apart) but it sure doesn't seem like it was that much. Lemme know if I'm over reacting. It's just that, as you can see in the video, I'm barely putting any pressure on the elevator and it turns the torque rod a little bit. The other side of the elevator pretty much turns with the side I'm pushing. Will this cause control issues or flutter? Thanks again for the help.

I don't know if the vid will work or not, it was just on my digital still camera which has a small video feature and I've never tried to upload a video before so I don't know if this one will work or if it's too big of a file or what, but it might open in quicktime player since that's what it opens in on my computer.
Here is the video link: http://www.rcgroups.com/forums/showt...33#post7351283


Matt
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Old Apr 27, 2007, 02:40 AM
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Finland
Joined Jul 2004
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Matt do not be offended but while you write your posts could you put them in paragraps and such.. its damned hard to read when you write all in row..

Sorry.

And for the slop in elevator system: did you use a single carbon torque rod or did you implement my enchancements? Because my elevator had same kind of problems before is beefed it up.
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Old Apr 27, 2007, 03:56 AM
That thing's operational!
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New Orleans/Dallas
Joined Jan 2006
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Hey Ceeray,

Hi! Haha, don't worry it's ok, yeah you're right it was really hard to read! I went back and added paragraphs.
Hhmmm... no I didn't implement you changes. I just went back and saw what you did. Yup, that must be the problem that I am having. However, I can kind of see into the back of the plans from the motor extension cut-ou at the back of the plane, and I can see that the control horn at the elevator torque rod moves slightly with pressure, but it just seems like too much movement to me. I'm hesitant to re-do it though, I think I might maiden it as-is and then change things up if it doesn't go well. I don't have the right size carbon tube to do that now anyway. However, I do appreciate your help and I might try that if there's not enough pitch control for this plane. Thanks again.
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Old Apr 27, 2007, 06:52 AM
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Ann Arbor, Michigan, United States
Joined Sep 2003
4,737 Posts
hi matt- are you sure your EZ links haven't slipped? i used to use those all the time because of the ease of setting-up and getting everything just perfect. then one time, i noticed that they started loosening up. mine has a little play, but not that much. i think Ceeray's idea for the elevator system is great. i'm gonna incorporate it into my future builds and into the MiG-21 kit as well. you may also wanna check your EZ-link to see if the screw is tight enough, it may have loosened up a little.
-beanie
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Old Apr 27, 2007, 11:28 AM
That thing's operational!
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New Orleans/Dallas
Joined Jan 2006
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Hey Beanie,

Hi! Thanks for the help. Well, actually the little things I'm talking about are these:
http://www.allerc.com/product_info.p...roducts_id=225
They aren't the EZ connectors with the set-screw, although I almost used some of those but neglected to because of that same problem you described. I didn't want it to come apart in flgiht! However, these little plasctic pieces are supposed to be able to keep the rods from slipping around too much, looks like they're not really working though....
Thanks for the help. I'll have to see what to do about it...
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Old Apr 27, 2007, 11:58 AM
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New Delhi, India
Joined Jul 2005
2,600 Posts
Matt, time for me to chime in.

I've built more than 20 pusher parkjets and I've come to realize that the CF rod diameter directly reflects the amount of play you end up with on your elevator. In my early builds I used to compromise on my elevator brace by using thinner CF rods, which resulted in a lot of slop. Now I use the thickest possible tube for my elevator assembly, and with everything else remaining the same (I use the Dubro EZ connectors at both ends) there's pretty much zero slop in my elevators.

Also, I use the strongest possible servo horn (from my larger servos) to CA on to my CF tube, making sure that the hole for the EZ connector is snug, meaning the connector can't move around in the servo arm hole.

I know it's too late for this kind of advice for you, but you could keep this in mind for your next build.

Doc
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