Go Back  RCU Forums > RC Airplanes > RC Warbirds and Warplanes
Reload this Page >

CY Model Lavochkin LA-7

Community
Search
Notices
RC Warbirds and Warplanes Discuss rc warbirds and warplanes in this forum.

CY Model Lavochkin LA-7

Thread Tools
 
Search this Thread
 
Old 02-22-2017, 06:18 AM
  #26  
Hot Rod Todd
Thread Starter
My Feedback: (1)
 
Hot Rod Todd's Avatar
 
Join Date: Oct 2002
Location: Robins, IA
Posts: 1,279
Likes: 0
Received 18 Likes on 15 Posts
Default

We had some unseasonably warm weather in February, so I was able to get the LA-7 out for a maiden flight. The DLE-120 ran perfectly from the first time I started it up, so after a few minutes of running I put the cowl on and got ready for the first flight.

It was a nice day, with a little wind right down the runway. I fed on some power and the LA-7 jumped into the air a bit early. It was not a problem, since it seems to fly very light at 38 lbs. A couple clicks of elevator and aileron trim, and it was flying hands off. I tried to put the gear up, but it didn't want to respond. I think the angle of the gear doors was keeping them from going up. I had air after landing, so I'll need to do some work, also open up the circuit to speed up the gear and help the cause. Flying around with the gear down I didn't get a chance to check out full throttle speed, I didn't want to rip off the gear doors or something. It moved along well even at half throttle with the gear down. I had a bit too much throw on the elevator, and it was a bit hot even at low rate. The aileron rates were good, with medium being about right. I set up for landing and came in with about 3/4 flaps. It seemed to want to float a bit, and my extra elevator throw didn't help the situation. I throttle up and went back around after I lofted it a bit. On the next landing I had it settled in pretty nicely. It went over on it's nose right away due to one of the struts turning. Dropping on it's nose didn't do much damage to the cowl, and the prop will be OK with a bit of sanding on the tips.

All things considered I was happy with it. It flies really well. I'll have to get the gear issues figured out, but that's not uncommon for retracts. Hopefully once I get the gear working right it will not have the tendency to nose over on landing. I may be able to take out a bit of the nose weight to help the nose over situation, I won't know for sure until I get the elevator rate set better and do some stall testing. It didn't help that the runway was very soft and made the wheels drag like pushing through mud.

Here's a couple of photos at the field. No in-flight photos yet, but I'll have some this spring I'm sure.

Attached Thumbnails Click image for larger version

Name:	DSCN3466.JPG
Views:	3438
Size:	363.9 KB
ID:	2202298   Click image for larger version

Name:	DSCN3473.JPG
Views:	3900
Size:	2.69 MB
ID:	2202299  
Old 02-22-2017, 06:20 PM
  #27  
TimD.
My Feedback: (207)
 
TimD.'s Avatar
 
Join Date: Dec 2001
Location: Jacksonville, FL
Posts: 755
Likes: 0
Received 13 Likes on 12 Posts
Default

Looks good. I have the big Dauntless with a moki 180 in it, I should get it maidened within the next few weeks.
Old 04-24-2017, 07:12 AM
  #28  
Hot Rod Todd
Thread Starter
My Feedback: (1)
 
Hot Rod Todd's Avatar
 
Join Date: Oct 2002
Location: Robins, IA
Posts: 1,279
Likes: 0
Received 18 Likes on 15 Posts
Default

I was not happy with the geometry of the stock gear mounts, so I decided to dig into the wing and modify them. At the same time I switched to gear made for the Anderson LA-7 that has a more scale length and additional power.

I had uncover the wing and add some new structure. It wasn't that hard to do, but it took a while. I didn't even bother removing all of the old mount. Just cut some of it out of the way. This photo shows the new position in relation to the stock. By changing the angle I'll be able to get the gear much farther forward and it will still fit into the bay.

The end result pulled the wheels forward a couple inches.
Attached Thumbnails Click image for larger version

Name:	IMG_0493.JPG
Views:	396
Size:	129.4 KB
ID:	2211555   Click image for larger version

Name:	IMG_0494.JPG
Views:	399
Size:	130.1 KB
ID:	2211556  
Old 04-24-2017, 07:37 AM
  #29  
Hot Rod Todd
Thread Starter
My Feedback: (1)
 
Hot Rod Todd's Avatar
 
Join Date: Oct 2002
Location: Robins, IA
Posts: 1,279
Likes: 0
Received 18 Likes on 15 Posts
Default

Once I got the gear doors mounted I took it to the field for the second flight. The ground handling was much better, and my gear came up without incident. The 26x12 prop pulls it around at good speed, and it even moves out well at half throttle. I had something happen to the gear angles on landing, I'm currently working with Century Jet to get them resolved. If I can gain confidence that it won't nose over I'll be trying a 25x12 three blade instead of the two blade. Here's a couple photos of it with the new gear at the field.
Attached Thumbnails Click image for larger version

Name:	IMG_0512.JPG
Views:	330
Size:	1.41 MB
ID:	2211557   Click image for larger version

Name:	IMG_0517.JPG
Views:	279
Size:	1.19 MB
ID:	2211558  
Old 06-23-2017, 05:57 AM
  #30  
n8622t
My Feedback: (8)
 
Join Date: Sep 2004
Location: Springdale, AR
Posts: 3,808
Received 40 Likes on 36 Posts
Default great work!!

WOW Todd!! got in late on this thread, glad to see this model since i picked one up. I sent you a message so keep up the good work its awesome!
jimmy
Old 06-27-2017, 07:03 AM
  #31  
n8622t
My Feedback: (8)
 
Join Date: Sep 2004
Location: Springdale, AR
Posts: 3,808
Received 40 Likes on 36 Posts
Default Just getting started

Pulled gear out and got the factory struts polished down with 180 grit to fit the Robart 635RS retracts
Old 06-27-2017, 07:06 AM
  #32  
n8622t
My Feedback: (8)
 
Join Date: Sep 2004
Location: Springdale, AR
Posts: 3,808
Received 40 Likes on 36 Posts
Default

Someone will have to tell me how to post pics in this new RCU format....sorry
Old 06-27-2017, 07:20 AM
  #33  
Hot Rod Todd
Thread Starter
My Feedback: (1)
 
Hot Rod Todd's Avatar
 
Join Date: Oct 2002
Location: Robins, IA
Posts: 1,279
Likes: 0
Received 18 Likes on 15 Posts
Default

Use the "Post Reply" button. There's a manage attachments button that allows you to post the images. Once you click it you'll see, it's not too hard to do.
Old 06-27-2017, 09:11 AM
  #34  
n8622t
My Feedback: (8)
 
Join Date: Sep 2004
Location: Springdale, AR
Posts: 3,808
Received 40 Likes on 36 Posts
Default

Originally Posted by Hot Rod Todd
Use the "Post Reply" button. There's a manage attachments button that allows you to post the images. Once you click it you'll see, it's not too hard to do.
Thanks Todd
Old 06-27-2017, 09:21 AM
  #35  
n8622t
My Feedback: (8)
 
Join Date: Sep 2004
Location: Springdale, AR
Posts: 3,808
Received 40 Likes on 36 Posts
Default

http://www.rcuniverse.com/forum/atta...1&d=1498584006
Attached Thumbnails Click image for larger version

Name:	IMG_3632.JPG
Views:	435
Size:	2.07 MB
ID:	2221828   Click image for larger version

Name:	IMG_3256.JPG
Views:	267
Size:	2.06 MB
ID:	2221829   Click image for larger version

Name:	IMG_3257.JPG
Views:	330
Size:	2.31 MB
ID:	2221830  
Old 07-27-2017, 10:24 PM
  #36  
warbird04
Member
 
Join Date: Jul 2017
Location: Switzerland
Posts: 54
Likes: 0
Received 0 Likes on 0 Posts
Default

Hello,

I finish my own La-7 cy models, and I want to say witch blue color do you have take?
I search in the Revell and Humbrol color, but nothing fit the color.
Do you have an information for me?
Thanks
Old 07-27-2017, 10:32 PM
  #37  
warbird04
Member
 
Join Date: Jul 2017
Location: Switzerland
Posts: 54
Likes: 0
Received 0 Likes on 0 Posts
Default La-7 cy models gear relocation

Hello every body,
I post you some pictures of my La-7 cy models gear relocation solution. The angles are scale, I self made my struts and covers to. With this issue, there is no nose over, and the 6" Wheel help for handling.
Attached Thumbnails Click image for larger version

Name:	20170722_122249.jpg
Views:	347
Size:	3.75 MB
ID:	2225895   Click image for larger version

Name:	20170722_114652.jpg
Views:	323
Size:	4.72 MB
ID:	2225896   Click image for larger version

Name:	20170722_123209.jpg
Views:	325
Size:	4.28 MB
ID:	2225897  
Old 07-27-2017, 10:36 PM
  #38  
warbird04
Member
 
Join Date: Jul 2017
Location: Switzerland
Posts: 54
Likes: 0
Received 0 Likes on 0 Posts
Default

On youtube you find an short video of my gear in progress....

I hope that helps other people who want to relocate the gear.
Old 07-28-2017, 04:43 AM
  #39  
Hot Rod Todd
Thread Starter
My Feedback: (1)
 
Hot Rod Todd's Avatar
 
Join Date: Oct 2002
Location: Robins, IA
Posts: 1,279
Likes: 0
Received 18 Likes on 15 Posts
Default

Nice job on the struts warbird 04, relocating the gear is almost a requirement on this plane if you want to minimize nose over. I put a carbon fiber 3-blade on mine, so damaging that is not fun.

The paint I found that matched is Krylon Aqua. It comes in a spray can and is a very close match.
Attached Thumbnails Click image for larger version

Name:	DSC_6659small.jpg
Views:	267
Size:	781.7 KB
ID:	2225929   Click image for larger version

Name:	paint.jpeg
Views:	220
Size:	20.4 KB
ID:	2225930  
Old 07-29-2017, 07:12 AM
  #40  
warbird04
Member
 
Join Date: Jul 2017
Location: Switzerland
Posts: 54
Likes: 0
Received 0 Likes on 0 Posts
Default

Thank you, but do you have a color nummer, or a color name? That helps me to order this spray...
Old 07-31-2017, 04:36 AM
  #41  
Hot Rod Todd
Thread Starter
My Feedback: (1)
 
Hot Rod Todd's Avatar
 
Join Date: Oct 2002
Location: Robins, IA
Posts: 1,279
Likes: 0
Received 18 Likes on 15 Posts
Default

I don't have any special number or name. If you can get Krylon, the name is as I said. Here's a link to buy it at Walmart.com.

https://www.walmart.com/ip/Krylon-Co...&wl13=&veh=sem
Old 08-04-2017, 12:07 PM
  #42  
warbird04
Member
 
Join Date: Jul 2017
Location: Switzerland
Posts: 54
Likes: 0
Received 0 Likes on 0 Posts
Default

Thank you for the link...
You have got an incredible job, nice result, congratulation.
What is your final in flight weight?
Old 08-04-2017, 12:16 PM
  #43  
Hot Rod Todd
Thread Starter
My Feedback: (1)
 
Hot Rod Todd's Avatar
 
Join Date: Oct 2002
Location: Robins, IA
Posts: 1,279
Likes: 0
Received 18 Likes on 15 Posts
Default

I didn't weigh it, but it flies like it's pretty light. I'll have to lift it onto a scale sometime and see what the all-up weight is. I'd guess right around 31 lbs.
Attached Thumbnails Click image for larger version

Name:	DSC_6626small.jpg
Views:	221
Size:	490.4 KB
ID:	2226916  
Old 08-04-2017, 01:05 PM
  #44  
taildragger21
My Feedback: (197)
 
taildragger21's Avatar
 
Join Date: Jun 2003
Location: park city, KY
Posts: 933
Received 0 Likes on 0 Posts
Default

I'm really enjoying my Cy la7. The saito Fg84 flies it actually really well
Attached Thumbnails Click image for larger version

Name:	IMG_0220.JPG
Views:	324
Size:	139.3 KB
ID:	2226919   Click image for larger version

Name:	IMG_0218.JPG
Views:	217
Size:	58.3 KB
ID:	2226920  
Old 08-04-2017, 11:28 PM
  #45  
warbird04
Member
 
Join Date: Jul 2017
Location: Switzerland
Posts: 54
Likes: 0
Received 0 Likes on 0 Posts
Default

Ok Taildragger, can you give me more info about your LA? as the full in flight weight, the prop size and the rpm (read after 15 seconds at full throttle), is the Fg84 stock or modified, and what opening have you made to escape the hot air from the motor?
Thank you that will helps a lot.
Old 08-05-2017, 02:25 PM
  #46  
taildragger21
My Feedback: (197)
 
taildragger21's Avatar
 
Join Date: Jun 2003
Location: park city, KY
Posts: 933
Received 0 Likes on 0 Posts
Default

Originally Posted by warbird04
Ok Taildragger, can you give me more info about your LA? as the full in flight weight, the prop size and the rpm (read after 15 seconds at full throttle), is the Fg84 stock or modified, and what opening have you made to escape the hot air from the motor?
Thank you that will helps a lot.
Haven't weighed it. I'm kinda thinking like Todd in that it's probably 31 lbs or so. The fg84 is bone stock. It did run terrible with no transition until I switched from 6.6 a123 to 7.4 lipo on my ignition. Now the transition is good and top end is much better. Swinging a 24x10 fieala prop at around 6700 rpm. The cooling from the cowl exhaust is close to enough. I added a cooling louvre to the top of the cowl for more air exit for the top cylinder.
love this airplane
Old 08-05-2017, 10:45 PM
  #47  
warbird04
Member
 
Join Date: Jul 2017
Location: Switzerland
Posts: 54
Likes: 0
Received 0 Likes on 0 Posts
Default

Thanks for the infos...but I am surprised that nobody weight his airplane.... The weight of an airplaine is a important point, this is the power / weight factor that characterize an véhicle or airplane capacities.
But tell me, do you have add some weight in the nose for balancing? Do you have you make some vidéos on youtube?
Old 04-28-2019, 04:18 PM
  #48  
Patrick R.
 
Join Date: Dec 2015
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Default

ARF'S are assembled. Kits and scratch built are builds....
Old 09-07-2019, 02:12 PM
  #49  
racer-mech
 
Join Date: Jul 2006
Location: Las Vegas, NV
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
Default

Hello All, it's been great to read this thread. However, with the gear issue, did you guys change location only for scale appeal/appearance, or did you need to change the angle to prevent nose over?

Cheers
Old 09-07-2019, 03:09 PM
  #50  
Patrick R.
 
Join Date: Dec 2015
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Default

racer-mech.

I have built the Dave Anderson design LA 7 his plan had the gear in the scale location and used Sierra retacts they were also pretty close in scale. Installed them with no modifications and not have had any problems with nose overs. Powered with a DA 100 had to put 4.25 lbs up front for balance..


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.