Scratch and Kit Built Aircraft Discuss and share your scratch built or kit built aircraft as well as building techniques, methods, mediums and resources.

Herr Pitts 24"

Old 07-04-2012, 06:54 AM
  #1  
Bill G
Super Contrubutor
Thread Starter
 
Bill G's Avatar
 
Join Date: Oct 2005
Location: West Central PA
Posts: 4,422
Default Herr Pitts 24"

This was one of those kits at the LHS like the Herr GeeBee R2 I bought and built, that was just begging someone to buy and build it. Almost feel sorry for kits that have been on the shelf for 10 years, still unbuilt. I watched a few videos of a guy on You Tube that has one, which flys extremely well. Hopefully this will be a good flyer.
Attached Thumbnails Click image for larger version

Name:	Pitts_Herr_1.jpg
Views:	245
Size:	50.5 KB
ID:	161086   Click image for larger version

Name:	GeeBeeHerr_41.jpg
Views:	204
Size:	103.0 KB
ID:	161087  
Bill G is offline  
Old 07-04-2012, 01:38 PM
  #2  
Unclebuck21228
Member
 
Join Date: Apr 2012
Location: Sumter, SC
Posts: 48
Default

My LHS has no balsa kits at all! All options are ARF, PNP or some other acronym that means little to no assembly required. It's great to see people still build.

I miss all those long slender boxes at the LHS with the little picture on the end full of wonderful wood.

Good luck on your build your gee bee certianly looks fantastic!
Unclebuck21228 is offline  
Old 07-04-2012, 03:21 PM
  #3  
startazz
Member
 
startazz's Avatar
 
Join Date: Feb 2009
Location: Norwich,Norfolk UK
Posts: 228
Default

Great job there Bill and the finish is as good if not better than any model you can buy at my LHS.

I keep saying to the Mrs that i want to start building from plans,something that will take me a while to finish so i can spend the winter nights in my hanger just having loads of fun,tools to play with plenty of tea and a lot of head scratching knowing me.

Who knows it might be this winter that i just might take it up,thanks for sharing Bill and good luck on the maiden not that i think you will need it mate.
startazz is offline  
Old 07-04-2012, 04:05 PM
  #4  
Forge
Member
 
Forge's Avatar
 
Join Date: Mar 2008
Location: CT
Posts: 439
Default

Bill,

Nice I just love seeing balsa framework going together and forming a new shape that will actually fly in the end.

Nice work, always fun to watch. ...keep up the great work. I visit this Scratch and Kit Built forum a couple times a week, and really enjoying seeing what's going on.

Thanks!

Forge
Forge is offline  
Old 07-06-2012, 03:12 PM
  #5  
Bill G
Super Contrubutor
Thread Starter
 
Bill G's Avatar
 
Join Date: Oct 2005
Location: West Central PA
Posts: 4,422
Default

Thanks for all the comments. I really wasn't expecting much interest in this one.

Buck it is nice to have a LHS with a kit stock. I don't often buy them, but I look through them ever time I'm there, even though I've seen them all. I guess there are a number of shops without kits, as another in the area only has one or two in stock, if that.

Forge I've been gaining appreciation for this type of framework, as the weight is much lighter than my usual keel-and-former builds. I'm becoming more of a fan of stringer construction than heavy former construction, and they do look nice also.

Startazz the plan building is a good way to go, especially if you don't have the parts. After a few scratch builds, these go together too quickly like ARFs. I also try to find subjects that will take a while to build, versus ones that will finish so quickly that they will outspend me.

On the thoughts of light weight and projects outspending me, don't laugh at what I'm thinking of using for the power system. I have an IPS A-geared 180 brushed motor with around 30 flights on 3s with a 9x7" prop, in a GP Hellcat. The little motor proved itself well, along with the ESC that came out of a twin brushed GWS Islander, now brushless, that had over 100 flights on it. The setup should be reasonably well suited to the plane, as the smaller outrunners tend to have higher kv's than needed for a plane like this, where you want a larger prop setup for thrust, versus speed. Ran on 3s with an 8x6 slowfly prop, it seems like an ideal setup for the plane.

This plane has a lot of room inside also, compared with the last 3 planes I've built that were a bit restrictive. Depending on how it balances, the batt can either enter under the cowl, or through the cocpit front, giving as much range as needed. Eliminating a battery door is always a nice thing, if possible. One thing that can be misleading is how some planes end up nose heavy, when you wouldn't think so. My Herr GeeBee R2 ended up nose heavy, and I was barely able to push the 3s-480 lipo to the rear of the compartment, in order to balance it. The plane looks like it's short nosed, but it has a short tail also. Even with light sheeting on the cowl, they can become nose heavy if the battery is not located aft to compensate.
Attached Thumbnails Click image for larger version

Name:	Pitts_Herr_2.jpg
Views:	186
Size:	51.8 KB
ID:	161147  
Bill G is offline  
Old 07-06-2012, 04:14 PM
  #6  
paulatgis
Member
 
Join Date: Jun 2012
Posts: 40
Default

i had the same problem with my fat fuse halls bull dog. I had to put the battery behind the wing below the cockpit to balance. and here I was pushing the servos almost to the firewall. I've been meaning to give a Herrs kit a try. Looks like a simple clean fuse layout and easy to scale up.
paulatgis is offline  
Old 07-07-2012, 06:57 PM
  #7  
Bill G
Super Contrubutor
Thread Starter
 
Bill G's Avatar
 
Join Date: Oct 2005
Location: West Central PA
Posts: 4,422
Default

Originally Posted by paulatgis View Post
i had the same problem with my fat fuse halls bull dog. I had to put the battery behind the wing below the cockpit to balance. and here I was pushing the servos almost to the firewall. I've been meaning to give a Herrs kit a try. Looks like a simple clean fuse layout and easy to scale up.
That's where it looks like my batt will be, after sheeting the nose. Figuring in the added tail weight, and the aft weight that the wings themselves will add, I should be able to install roughly a 3s-800 in the cocpit position. This will be the first time in ages that I won't have to cut an access door for the battery. You'll like the Herr kits also. This is the 3rd I've built, and they've all gone together well. I added ailerons to the Herr Cherokee, and gave it to my flying buddy.

As for scaling up, they make a slightly larger one also. It has a molded cowl, which I would have liked. I always end up sheeting stringer constructed cowls, to give them the metal look. I thought that sheeting the lower cowl area would be a pain, but it actually went together easily with only a few sheet sections for the entire job. The 3/32" stringers are also a lot easier to join sheeting seams on, versus 1/16" stringers used on many planes this size. The cowl cap was sheeted separately and then screwed to the cowl. The sheeting was sanded flush across the two parts. Next the removable cowl cap will have the front corner rounded.

This kit included all the stringers, and about the only issue I can think of, is that it's nice to have a few extra stringers on hand. Most of the stringers included were not the ultra soft/weak stringers that some Dumas kits have, but I did find one of the four 1/8" square stock LE stringers that is softer than I care for. I always keep extra on hand, to replace in these scenarios. This kit uses 3/32" stringers for much of the fuse and wing, which adds a degree of robustness. Given that the plane doesn't have the large, heavy keels and formers that some have, the added weight isn't a killer. The Pitts wide landing gear struts are a nice feature also, as they make for a strong setup with the gear wire laminated to the front. My HE51 has a similar setup, and the gear doesn't bend and break easily as on some planes.
Attached Thumbnails Click image for larger version

Name:	Pitts_Herr_3.jpg
Views:	181
Size:	46.1 KB
ID:	161167   Click image for larger version

Name:	Pitts_Herr_4.jpg
Views:	146
Size:	36.6 KB
ID:	161168  
Bill G is offline  
Old 07-09-2012, 08:49 AM
  #8  
Bill G
Super Contrubutor
Thread Starter
 
Bill G's Avatar
 
Join Date: Oct 2005
Location: West Central PA
Posts: 4,422
Default

This project's moving along well now, with mostly covering and assembly remaining. I talked myself into framing all 4 ailerons, after initially planning ailerons only for the top wing.
Attached Thumbnails Click image for larger version

Name:	Pitts_Herr_5.jpg
Views:	141
Size:	56.1 KB
ID:	161219   Click image for larger version

Name:	Pitts_Herr_6.jpg
Views:	144
Size:	46.3 KB
ID:	161220   Click image for larger version

Name:	Pitts_Herr_7.jpg
Views:	187
Size:	60.4 KB
ID:	161221  
Bill G is offline  
Old 07-14-2012, 12:47 PM
  #9  
Bill G
Super Contrubutor
Thread Starter
 
Bill G's Avatar
 
Join Date: Oct 2005
Location: West Central PA
Posts: 4,422
Default

Should have this plane finished today, with bottom wing covering and final assembly remaining.
Attached Thumbnails Click image for larger version

Name:	Pitts_Herr_10.jpg
Views:	131
Size:	46.7 KB
ID:	161321   Click image for larger version

Name:	Pitts_Herr_9.jpg
Views:	138
Size:	47.8 KB
ID:	161322   Click image for larger version

Name:	Pitts_Herr_11.jpg
Views:	164
Size:	43.6 KB
ID:	161323   Click image for larger version

Name:	Pitts_Herr_12.jpg
Views:	189
Size:	51.8 KB
ID:	161324   Click image for larger version

Name:	Pitts_Herr_13.jpg
Views:	159
Size:	48.9 KB
ID:	161325  

Click image for larger version

Name:	Pitts_Herr_14.jpg
Views:	201
Size:	39.3 KB
ID:	161326   Click image for larger version

Name:	Pitts_Herr_15.jpg
Views:	181
Size:	48.1 KB
ID:	161327  
Bill G is offline  
Old 07-14-2012, 11:07 PM
  #10  
Forge
Member
 
Forge's Avatar
 
Join Date: Mar 2008
Location: CT
Posts: 439
Default

Bill,

Looks cool, and very nice work as usual Look forward to seeing it fly. Post some video if you have time. always a pleasure to see other builds. Gives me ideas, and gets me motivated.

All the best..

Forge
Forge is offline  
Old 07-15-2012, 06:59 AM
  #11  
Bill G
Super Contrubutor
Thread Starter
 
Bill G's Avatar
 
Join Date: Oct 2005
Location: West Central PA
Posts: 4,422
Default

Originally Posted by Forge View Post
Bill,

Looks cool, and very nice work as usual Look forward to seeing it fly. Post some video if you have time. always a pleasure to see other builds. Gives me ideas, and gets me motivated.

All the best..

Forge
Thanks. I'm looking forward to flying this one, and have sworn to fly this, and the past few builds, before starting any new ones. I really need to get out there and fly these planes/take some video. We need more builds here too, as it makes the visits here more interesting. Not much building happening lately.

The AUW came out a bit lighter than I expected at 8oz empty, and 8-3/4oz with a 2s-350 Evo. I could use a larger battery, which could be inserted in front of the servos to balance, versus where the small 2s-350 mounts. I like the idea of the small lipo however, as the low AUW should be really nice and I only fly several minute flights. The last biplane I built, the HE51 came in pretty light, and would fly on almost zero throttle. I'm expecting this one to be similar.

I found an interesting picture that illustrates what I observed, as to how the wing stagger creates unequal movement of the ailerons with this setup. It's not extreme, and likely the most undesirable effect is the negative differential of the top ailerons, versus desirable positive differential.


This method of linking at the same geometric location will create equal movement, but does not look as clean with the linkage extending above the top aileron:
Attached Thumbnails Click image for larger version

Name:	Pitts_Herr_19.jpg
Views:	278
Size:	43.9 KB
ID:	161347   Click image for larger version

Name:	Pitts_Herr_18.jpg
Views:	174
Size:	42.1 KB
ID:	161348   Click image for larger version

Name:	Pitts_Herr_17.jpg
Views:	158
Size:	34.2 KB
ID:	161349  

Last edited by Bill G; 07-15-2012 at 04:10 PM.
Bill G is offline  
Old 07-15-2012, 11:12 AM
  #12  
baz49exe
Super Contributor
 
baz49exe's Avatar
 
Join Date: Jun 2008
Location: Devon. England
Posts: 1,101
Default

Originally Posted by Bill G View Post
Thanks. I'm looking forward to flying this one, and have sworn to fly this, and the past few builds, before starting any new ones. I really need to get out there and fly these planes/take some video. We need more builds here too, as it makes the visits here more interesting. Not much building happening lately.
Hi Bill, This ones looking great ( as usual) looking forward to the maiden report.
Are we going to hold you to this quote? I'll bet you won't be able to keep to it
I decided to do exactly the same thing after the Wellesley build and now I'm remodelling the P-51 right in the middle of it and I've already got plans for the next " got to build it bird" a Westland Wendover.
baz49exe is offline  
Old 07-16-2012, 01:14 AM
  #13  
Bill G
Super Contrubutor
Thread Starter
 
Bill G's Avatar
 
Join Date: Oct 2005
Location: West Central PA
Posts: 4,422
Default

Originally Posted by baz49exe View Post
Hi Bill, This ones looking great ( as usual) looking forward to the maiden report.
Are we going to hold you to this quote? I'll bet you won't be able to keep to it
I decided to do exactly the same thing after the Wellesley build and now I'm remodelling the P-51 right in the middle of it and I've already got plans for the next " got to build it bird" a Westland Wendover.
I also just remodelled a P51, which was a project that basically came out of nowhere. They're good at doing that, aren't they. The P51 was worth it though, as it surprised me by being a great flyer, and I did get video of that one.
The Wendover sounds interesting also. I know I had seen plans for them, and sure enough there are several out there, if you go balsa. One like this would be more than ample for my advanced CAD package, MS Paint enlargements:
http://www.rcgroups.com/forums/attac...mentid=2521721

....and a photo of a nice, small size flying Wendover model. Just about the size I most like.
BTW, no concerns of an undersized stab on this one:
Bill G is offline  
Old 07-16-2012, 08:47 AM
  #14  
baz49exe
Super Contributor
 
baz49exe's Avatar
 
Join Date: Jun 2008
Location: Devon. England
Posts: 1,101
Default

Bill, that's the exact article that started it off, and I'm going to scale the same plan you provided the attachment for.
Just to be really awkward I'll build it in foam just using the plan for the outlines and formers.
I know that you would do a fantastic balsa build!
baz49exe is offline  
Old 07-17-2012, 02:25 PM
  #15  
Bill G
Super Contrubutor
Thread Starter
 
Bill G's Avatar
 
Join Date: Oct 2005
Location: West Central PA
Posts: 4,422
Default

Well I forgot my camera this morning but it flies. I promise to get some video soon, as the nervous maiden is already over with. Not much to see however, as I identified a flight problem that is now corrected, so it wasn't flown very hard. I failed to check the upper aileron linkage for rigidity, when they were deflected at around 50% and greater. What happened is similar to having a locking knee unlock. The downward moving upper aileron would flop downward at this point, as the control horn was no longer moving downward, maintaining force on the pushrod as it should be. This caused the pushrod to unload. You would suddenly turn very hard in the direction already being turned in. Fortunately moving the aileron stick to the opposite direction would center the ailerons correct the problem. Scared the heck out of me the first time it happened, as I thought it was a radio/BEC problem. The issue seems to be corrected now by simply moving the aileron horn rearward a mere 2mm, as it was right on that marginal point that created a problem.

As for flying, I believe Herr did his homework on this plane. The roughly 2 to 2-1/2 degrees right thrust and 1 to 1-1/2 degrees down thrust seemed about dead on, with the tail feathers at zero trim. The recommended CG at the LE of the bottom wing seems good also. I had reservations about having an excessive climber, with the fairly steep wing incidence, but there were no issues there. Trimming the center wing struts to plan length and positioning them on the fuse stringers shown on the plan set the wing incidences identically. The same goes for the laser cut interplane struts, which also fit perfectly with the plan dihedral set. The plan set dihedral on the bottom wing causes the plane to return to level flight when centering the sticks, as good as any high wing trainer. At 8-3/4oz AUW, the plane flies as a jogging pace and lands slowly.

I ended up flying with a 3s-300 lipo, which is amply powerful for the plane. Given that the motor had many flights on 3s with a 1" larger prop, it gives me some faith in it holding up. I'm looking forward to flying the plane again and taking some video, with the control problem seemingly resolved.

Originally Posted by baz49exe View Post
Bill, that's the exact article that started it off, and I'm going to scale the same plan you provided the attachment for.
Just to be really awkward I'll build it in foam just using the plan for the outlines and formers.
I know that you would do a fantastic balsa build!
At one point I had almost switched over entirely to foam for scratch builds, as it is a good material for scratch building. If I hadn't got my speed up with balsa framing, I may have stayed with foam. Still nice stuff for building. Your method of shaping foam sections makes accurate fuses. It's a lot of work, but eliminates the "banana" effect that can come from trying to sculpt the whole thing from one piece. I built one foam fuse from sections, and it came out straighter than any of my others.
Attached Thumbnails Click image for larger version

Name:	Pitts_Herr_20.jpg
Views:	138
Size:	32.8 KB
ID:	161413   Click image for larger version

Name:	Pitts_Herr_21.jpg
Views:	145
Size:	30.2 KB
ID:	161414  

Last edited by Bill G; 07-18-2012 at 12:52 AM. Reason: grammar
Bill G is offline  
Old 07-20-2012, 05:13 AM
  #16  
tobydogs
love to build!
 
tobydogs's Avatar
 
Join Date: Jan 2010
Location: nj usa
Posts: 3,693
Default

your build looks beautiful,i also have this bird in the hanger and love the way it flys. i left the stock aileron setup on the lower wing only and if i had it to do over i'd add the upper ailerons.

this is a picture of my pitts,i have a video on you tube placed there tonight. i hope youll post your vid soon
Attached Thumbnails Click image for larger version

Name:	airshots 037.jpg
Views:	139
Size:	118.4 KB
ID:	161494  
tobydogs is offline  
Old 07-20-2012, 12:29 PM
  #17  
Bill G
Super Contrubutor
Thread Starter
 
Bill G's Avatar
 
Join Date: Oct 2005
Location: West Central PA
Posts: 4,422
Default

Originally Posted by stuart View Post
your build looks beautiful,i also have this bird in the hanger and love the way it flys. i left the stock aileron setup on the lower wing only and if i had it to do over i'd add the upper ailerons.

this is a picture of my pitts,i have a video on you tube placed there tonight. i hope youll post your vid soon
Looks nice Stuart and good to see another of these out there. Is yours the larger 30" version or the 24"? It was in the car with flying gear yesterday, but we got soaked and really needed it too, so I can't complain. I need to get a video up soon though. I also need to put some detail on it, like yours has. With it all white, if you fly even 100 feet away with it flying crosswise to you, it's really difficult to determine the orientation.
Bill G is offline  
Old 07-20-2012, 12:33 PM
  #18  
JetPlaneFlyer
Super Contributor
 
JetPlaneFlyer's Avatar
 
Join Date: Mar 2009
Location: Aberdeen, Scotland
Posts: 6,122
Default

Originally Posted by Bill G View Post
This method of linking at the same geometric location will create equal movement, but does not look as clean with the linkage extending above the top aileron:
first rate building.. I'm looking forward to a video.

Just wondering on the aileron linkage, why you didn't make a horn that stuck out directly behind the TE. That would have saved having the horn stuck up on the top and having to notch the TE on the top aileron. You would have still got equal movement.

Like this one:
JetPlaneFlyer is offline  
Old 07-20-2012, 10:26 PM
  #19  
Bill G
Super Contrubutor
Thread Starter
 
Bill G's Avatar
 
Join Date: Oct 2005
Location: West Central PA
Posts: 4,422
Default

Originally Posted by JetPlaneFlyer View Post
first rate building.. I'm looking forward to a video.

Just wondering on the aileron linkage, why you didn't make a horn that stuck out directly behind the TE. That would have saved having the horn stuck up on the top and having to notch the TE on the top aileron. You would have still got equal movement.

Like this one:
Not a great reason, but I don't care for the appearance of the linkage in plain view, at the rear of the ailerons. Done again, they would be mounted there, and may end up anyway.
Bill G is offline  
Old 02-26-2022, 10:18 PM
  #20  
glideher
New Member
 
Join Date: Mar 2018
Location: new york
Posts: 7
Default

Originally Posted by Bill G View Post
Thanks. I'm looking forward to flying this one, and have sworn to fly this, and the past few builds, before starting any new ones. I really need to get out there and fly these planes/take some video. We need more builds here too, as it makes the visits here more interesting. Not much building happening lately.

The AUW came out a bit lighter than I expected at 8oz empty, and 8-3/4oz with a 2s-350 Evo. I could use a larger battery, which could be inserted in front of the servos to balance, versus where the small 2s-350 mounts. I like the idea of the small lipo however, as the low AUW should be really nice and I only fly several minute flights. The last biplane I built, the HE51 came in pretty light, and would fly on almost zero throttle. I'm expecting this one to be similar.

I found an interesting picture that illustrates what I observed, as to how the wing stagger creates unequal movement of the ailerons with this setup. It's not extreme, and likely the most undesirable effect is the negative differential of the top ailerons, versus desirable positive differential.


This method of linking at the same geometric location will create equal movement, but does not look as clean with the linkage extending above the top aileron:
can we see any videos of your pitts in flight? how was the maiden flight?
glideher is offline  

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2022 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.

Page generated in 0.16826 seconds with 37 queries