HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Aug 20, 2011, 01:32 PM
Registered User
Staggerflyer's Avatar
Tama, Iowa USA
Joined Dec 2007
567 Posts
You would have to look up the weights for the engines you want. I don't have that info.

I built the entire plane without any motor work first, so I could use the power components to balance. I set my prop drivew at the indicated location, then put the plane on the balancer. I then used the battery to find the balance point. That's where I made the battery mount.

Doing it that way does make the finished product slightly nose heavy, because you don't include the wood for the battery mounting, but it is very small. Heck, the different props I have are different enough in weight to affect CG.
Staggerflyer is offline Find More Posts by Staggerflyer
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 30, 2011, 10:21 PM
Registered User
Staggerflyer's Avatar
Tama, Iowa USA
Joined Dec 2007
567 Posts
Well, I finally got to check the incidences and wing twist. I used the front cockpit floor as my zero point. My wings both come out as basically zero incidence. However, I do have some twist in both wings. It is built in on both. The bottom wing is zero on the left, +1 on the right. The top wing is zero on the right, and -3/4 on the left. All measurements were taken at the rib just inside of the aileron opening. I put washers under all four front N strut mounts, which only brought the right bottom wing to +3/4.

I tried loosening N strut mounts, it did not change the twist. I also tried losening the cabane screws, no change, so the twist is in the wings. I tried changing the N struts side to side, which required undoing all the brackets. No change. Will have to try doing the Monocote twist trick next.

Next, I checked balance. I still cannot get a spin, either direction. I can get a very lazy spiral if I use aileron, but no snap. Since I originally balanced with a 6 cell battery and a heavy Zinger prop, and am now flying with a 5 cell battery and a light weight Xoar prop, the balance point has moved to the rear of the indicated balance point. So I'm going to try some Pinewood derby car weights to move the point back a little at a time. Will post the results when I get to flight test. We have our annual Veterans Home display/airshow this Saturday, hope to get some testing done there. If it doesn't rain. Slight chance being shown tonight, that was not there this am.
Staggerflyer is offline Find More Posts by Staggerflyer
Reply With Quote
Old Sep 10, 2011, 05:25 PM
We shall serve the Lord
kingsflyer's Avatar
United States, TX, Kingsland
Joined Sep 2005
4,827 Posts
Thanks for the post on the review thread. I'm still thinking of converting the review model to electric:

http://www.rcgroups.com/forums/showthread.php?t=1414922

Do you have any idea how the Rimfire 120 would perform on a smaller prop (16x6) and 6-cells? The reason for the question is that I have a lot of 5000 mah 6-cell packs already and no 5-cell packs.

McD
kingsflyer is offline Find More Posts by kingsflyer
RCG Plus Member
Latest blog entry: LEDs on my T-28
Reply With Quote
Old Sep 10, 2011, 08:16 PM
Registered User
Staggerflyer's Avatar
Tama, Iowa USA
Joined Dec 2007
567 Posts
Quote:
Originally Posted by kingsflyer View Post
Thanks for the post on the review thread. I'm still thinking of converting the review model to electric:

http://www.rcgroups.com/forums/showthread.php?t=1414922

Do you have any idea how the Rimfire 120 would perform on a smaller prop (16x6) and 6-cells? The reason for the question is that I have a lot of 5000 mah 6-cell packs already and no 5-cell packs.

McD
Hi McD. I think a 16x6 might be to little pitch, as the Rimfire 120 is a 450kv motor. That gives an unloaded rpm of 9990 with 6cells, 22.2v. I think a 16x8 would probably do better. Could be wrong. Props are cheap in that size range, so experiment. This plane will fly well with less thrust, just not as fast. We know that from the slow flight characteristics. I'm still experimenting with props and cell #s, so... I just don't get to fly as often as I'd like, so experimenting takes a few weeks to get done.

I built my tray/box to hold 6cells, but the props I had at the time pulled to many amps for 6 celss, so I dropped to 5 and she flew well, 18x8 MAS wood. The next week I tried an 18x6 and was more pleased. This past weekend I tried the Xoar 17x8E, and was very very pleased, so... Better vertical and cooler motor/ESC/batteries after flight. Longer flight time, also. By over 2.5 mins. I think I'm just about there.

I wish I could figure out why it won't snap/spin. Either I need to remeasure, or just keep adding weight to the tail a little at a time. It flies like it is nose heavy, even carries a little up elevator in trim. It also lands rather fast, which would also indicate nose heavy. Three points are hard to do, it just doesn't want to stay in the air long enough to attain the right angle.
Staggerflyer is offline Find More Posts by Staggerflyer
Reply With Quote
Old Sep 10, 2011, 08:23 PM
Registered User
Staggerflyer's Avatar
Tama, Iowa USA
Joined Dec 2007
567 Posts
This past Labor Day weekend fun fly/airshow scheduled for Sat, the 3rd, was rained out, Sunday was blown out, but Monday, Labor Day, was fantastic! Good size turnout, but unfortunately, the Vets were not present.

Anyway, I had most of my airforce there. I need a trailer!!
Staggerflyer is offline Find More Posts by Staggerflyer
Reply With Quote
Old Sep 11, 2011, 07:31 AM
We shall serve the Lord
kingsflyer's Avatar
United States, TX, Kingsland
Joined Sep 2005
4,827 Posts
For your CG check, have you tried the descending 45 degree test? I think it goes something like this. You take the plane up pretty high and put it into a powered (1/2 throttle should be fine) 45 degree dive with wings level and once you have established the descneding 45 degree line, you leave your elevator level and pull the power back to idle. Then you observe how the plane reacts. If it climbs when you power back, then it is too nose heavy ( i.e. you have "up" elevator trimmed to compensate for too much nose weight). If it dives, then it is too tail heavy. I know this sounds just backwards from how you would expect a nose heavy plane to react, but it works. If this test is good enough for AJ and QQ, it's good enough for me.

I prefer this test over the just roll it inverted and see if it dives or climbs test because sometimes airfoil charecteristics or wing incidence issues can mask the real problem.

McD
kingsflyer is offline Find More Posts by kingsflyer
RCG Plus Member
Latest blog entry: LEDs on my T-28
Reply With Quote
Old Sep 11, 2011, 09:05 AM
Registered User
Staggerflyer's Avatar
Tama, Iowa USA
Joined Dec 2007
567 Posts
Quote:
Originally Posted by kingsflyer View Post
For your CG check, have you tried the descending 45 degree test? I think it goes something like this. You take the plane up pretty high and put it into a powered (1/2 throttle should be fine) 45 degree dive with wings level and once you have established the descneding 45 degree line, you leave your elevator level and pull the power back to idle. Then you observe how the plane reacts. If it climbs when you power back, then it is too nose heavy ( i.e. you have "up" elevator trimmed to compensate for too much nose weight). If it dives, then it is too tail heavy. I know this sounds just backwards from how you would expect a nose heavy plane to react, but it works. If this test is good enough for AJ and QQ, it's good enough for me.

I prefer this test over the just roll it inverted and see if it dives or climbs test because sometimes airfoil charecteristics or wing incidence issues can mask the real problem.

McD
Thanks, I'll try that. Didn't know about the 45 degree downline check.

I never relied on the inverted system for exactly your reasons. It would only work for a fully aerobatic aircraft where fully symetrical airfoils are used and everything set 0-0-0.
Staggerflyer is offline Find More Posts by Staggerflyer
Reply With Quote
Old Sep 11, 2011, 01:48 PM
Registered User
Lier, Norway
Joined Nov 2003
237 Posts
Mine is completed and fitted with a OS 160 Twin.

The rx battery and the onboard glow system battery are installed below the servoes as long aft as I could. The model then is still a bit nose heavy and seems like I have to make a room and a hatch on the bottum between aft cockpit and the tail...

I was a bit excited on the first flight som the landing are a bit fast.

After some few more flights I found out that the model floats as a trainer and it does not have any bad habbits at all.
I will make a new video with slow nice landings.
this combination is a blast to fly!


I scrapped the wing carrier system and made the lowe rwing as one piece and the upper one in 3 pieces. The centersection are always mounted and I only install the outerpanels at the field. Works flawless!

Great Planes Waco ARF / OS 160 Twin maiden (3 min 27 sec)
affas is online now Find More Posts by affas
Reply With Quote
Old Sep 11, 2011, 02:34 PM
Registered User
Staggerflyer's Avatar
Tama, Iowa USA
Joined Dec 2007
567 Posts
Beautiful, affas. I love the OS 160 twin. Mine is nearly worn out, it has been run so long.

Yours came out beautiful. Nice job. That landing looked great, nice and soft.

How much does yours weigh? How about some pics of the engine installation?
Staggerflyer is offline Find More Posts by Staggerflyer
Reply With Quote
Old Sep 11, 2011, 02:52 PM
Registered User
Lier, Norway
Joined Nov 2003
237 Posts
Some pictures of the engine installation and the upper wing modification
affas is online now Find More Posts by affas
Reply With Quote
Old Sep 28, 2011, 07:05 AM
Registered User
Lier, Norway
Joined Nov 2003
237 Posts
Great Planes Waco YMF-5D with OS FT-160 twin (4 min 58 sec)
affas is online now Find More Posts by affas
Reply With Quote
Old Sep 28, 2011, 08:57 PM
Registered User
Staggerflyer's Avatar
Tama, Iowa USA
Joined Dec 2007
567 Posts
Beautiful, Alf. I love the sound of the OS 1.60 twin. Great throttle work, great flying.
Staggerflyer is offline Find More Posts by Staggerflyer
Reply With Quote
Old Apr 03, 2012, 08:49 PM
Registered User
Staggerflyer's Avatar
Tama, Iowa USA
Joined Dec 2007
567 Posts
Well, here it is, almost flying season again here in Iowa. Actualy, a lot of my club members have been flying all winter. Ours was very mild this year. My job has kept me busy, so no flying for me.

I did get in quite a few flights last fall before I put my air force away. The more I fly this plane, the more I like it. Up to ten minutes flight time, now, batteries still have plenty of juice. I think I can get 11 minutes, but 12 will be pushing it, and require careful throttle control, and easy flying. My last flight was mostly touch and goes, and three point practicing, still got 10 minutes easy.

Haven't repositioned CG, yet, to busy with other stuff. That's the only thing I have to do to the Waco before flying again. Have some small repairs to make to most of the rest of the fleet, except for the Staggerwing. Unfortunately, had a bad mishap with it, and it requires a new set of wings.

Anyone else get theirs flying?? C'mon, guys, it's just a big trainer. Good 2nd or 3rd airplane, it flies that well.
Staggerflyer is offline Find More Posts by Staggerflyer
Reply With Quote
Old May 01, 2012, 07:11 PM
Registered User
Raleigh, NC
Joined Aug 2008
19 Posts
Additional Builds

Staggerflyer,

I placed the order for the ARF today. This will be a big step for me as the largest aircraft I've flown so far is 52.5" on an E-Flite Power 32, 4s battery.

Wondering if you are still happy with your choice of the Rimfire 120? Noticed another poster went with Power 110 on 8s. Haven't seen it fly, but wondering if that is true overkill? Only advantage for me would be to continue acquiring 4s batteries and run them in series versus acquiring 5s batteries. Additionally, posted photos seem to indicate that you were able to cut a smaller hole in the dummy engine for a more scale appearance that the Power 110 allowed.

Any new thoughts on your project in its second season?

Regards,

Paul
Paul J. Harris is offline Find More Posts by Paul J. Harris
Reply With Quote
Old May 01, 2012, 08:23 PM
Registered User
BIG LACY's Avatar
United States, FL, Orange Park
Joined Oct 2006
278 Posts
Power 110

Quote:
Originally Posted by Paul J. Harris View Post
.,

I placed the order for the ARF today. This will be a big step for me as the largest aircraft I've flown so far is 52.5" on an E-Flite Power 32, 4s battery.

Wondering if you are still happy with your choice of the Rimfire 120? Noticed another poster went with Power 110 on 8s. Haven't seen it fly, but wondering if that is true overkill? Only advantage for me would be to continue acquiring 4s batteries and run them in series versus acquiring 5s batteries. Additionally, posted photos seem to indicate that you were able to cut a smaller hole in the dummy engine for a more scale appearance that the Power 110 allowed.

Any new thoughts on your project in its second season?

Regards,

Paul
I haven't been keeping up w/thread, but I can tell you my 110 has more than enough power. That's the way I like my planes,even scale like this Waco. I use 5300 4 cells in series and balance is dead on. I don't believe the throttle has been over 60%. BL
BIG LACY is offline Find More Posts by BIG LACY
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Article Great Planes Waco YMF-5D Biplane ARF 72" with OS 95AX 2-Stroke Review kingsflyer Scale Fuel Planes 45 Mar 02, 2013 08:33 AM
Discussion Great Planes Waco YMF-5D Biplane ARF .91-1.20 jonnyspeed Glow to Electric Conversions 23 Apr 30, 2012 05:51 PM
Build Log Dumas 1807 - WACO YMF-5 Log w.s.chase1 Parkflyers 3 Dec 31, 2011 01:10 PM
Help! Decals for WACO YMF-3 or YMF-5 mustangmarty Flight Accessories 0 Jul 20, 2009 04:08 PM