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

PICA 1/6 P51 Mustang ... looking for advice

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

PICA 1/6 P51 Mustang ... looking for advice

Old 01-05-2011, 07:55 PM
  #1  
Lightning Fan
Thread Starter
My Feedback: (17)
 
Join Date: Nov 2002
Location: Hartland, WI
Posts: 277
Likes: 0
Received 0 Likes on 0 Posts
Default PICA 1/6 P51 Mustang ... looking for advice

This one is for some of the guys that have been around a while.
At our local swap meet this weekend, I caught sight of a hangar weary Mustang fuse in primer, hanging forelornly from a hook. I went over to it in between selling my stuff, and looked over the wing and fuse. All glassed, in primer, but obviously stored in several places along the way ... dings in the glass, edges where the flaps go broken, etc. But she looked pretty good to me, and there was a PICA kit box with stuff in it. Long and short of it is that I got it for $30.
At home, I found the unknown builder had done a good job, and all the parts ... rudder, flaps, aileron, finished cockpit, spinner, cut canopy ... were all there. Clearly, the build stopped just before final paint, and she has sat idle, until I got her.
1/6 scale, 74 inch wingspan, ABS cowl, weighes 9 pounds 8 oz without engine or gear. Fixed gear right now. Plans say she comes in at 14 pounds, AUW. Box calls for a .90 to 1.08 two stroke.

My ultimate intent is to retrofit retracts, clean her up and get going on it once I finish another project. I've read about reinforcing the retract mounts, better than the plans show.
However, engine selection has me thinking about what I might need to acquire. She has beam mounts, which have 2" spacing. I have an ST3000 which looks like it will barely fit, if I open up the beam mounts 1/4", which is possible, along with some other front end mods. I have access to an ST2300, which I'll trial fit tomorrow, but I would need to buy (cheap though)... it looks like it will fit for sure, and there are posts that support that idea. I've got a variety of gas engines but nothing seems to fit without a lot sticking out. The ST's seem to fit, and the dimensions of the ST2300 seem to make sense better than the ST3000. The Ed Moorman discussion on big gas engines seems to indicate that both engines will turn an 18x6-10, although obviously the 2300 will have less oomph.

There are a few posts about this bird out there ... not many. Any of you guys ever own and fly one? What engine was typical? Looks like some were built with CJ retracts ... anyone crash one and have the retracts lying around looking for a new home? What tail wheel retract mech was used? Should I dispose of the ABS cowl and go to FiberGlass Classics, or will this one work? The spinner is the old backplate with screws in eight places approach ... any bad experiences there?

And, of course, the most important question ... how did she fly?

I'll be entertained by any stories or advice on this bird.

Regards,
Rikk
Old 01-05-2011, 08:18 PM
  #2  
thailazer
 
thailazer's Avatar
 
Join Date: Mar 2008
Location: Liberty Lake, WA
Posts: 1,566
Received 4 Likes on 4 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice

Not sure about the P51, but a friend and I built Pica T28's. The Pica kits seem to get heavy real fast if you are not careful, but since your fuse is done, not much chance of affecting that now. I found the fuse a bit tough to build for some reason so be glad that is done for you. I think a 90 two stroke should be plenty for it if is light, but it will get heavy fast if you "engine up". Pica kits seem to be pretty good flying products. Keep us up to date on your project.
Old 01-05-2011, 08:34 PM
  #3  
Dash7ATP
 
Dash7ATP's Avatar
 
Join Date: Mar 2002
Location: Smithfield,, VA
Posts: 1,013
Likes: 0
Received 0 Likes on 0 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice

Good for you on what seems to be a good deal, although it may take a little work to reach flying status.  I have no experience with that model, but something close enough to make a suggestion. I have a P-40 with about the same span. It's powered with a YS-1.20 four stroke, and it's more than enough power, All up weight with retracts is very close to what you should have.  A header is available that allows me to keep the entire exhaust system enclosed without cuting the cowl.

I think the ST 3000 would be way too much power,  I have a Moki 1.8 which is similar to the 3000 and I wouldn't even consider that for a plane your size.  I had it in a model with 84 inch span of about 16 pounds and it had lots of power.

Good luck with your P+51 and keep us posted.

Dash
Old 01-05-2011, 10:07 PM
  #4  
Chad Veich
My Feedback: (60)
 
Join Date: Dec 2001
Location: Litchfield Park, AZ
Posts: 7,674
Likes: 0
Received 25 Likes on 23 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice

I agree with Dash that either of the bit ST's would be overkill. I might consider the 2300 if it, and a muffler, would fit in the cowl. Something like a 1.08 or 1.20 two stroke would be my choice however. The OS 1.20AX is very compact and offers plenty of power for the 1/6 'stang.
Old 01-06-2011, 06:00 AM
  #5  
Moggy
My Feedback: (9)
 
Join Date: Jul 2004
Location: Waterbury, CT
Posts: 401
Likes: 0
Received 0 Likes on 0 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice

I think you might have a 1/5th Stang, what's the wing span? Pica came out with the 1/5 in the early 90's if my memory serves me correctly.
Old 01-06-2011, 08:32 AM
  #6  
Chad Veich
My Feedback: (60)
 
Join Date: Dec 2001
Location: Litchfield Park, AZ
Posts: 7,674
Likes: 0
Received 25 Likes on 23 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice


ORIGINAL: Moggy

I think you might have a 1/5th Stang, what's the wing span? Pica came out with the 1/5 in the early 90's if my memory serves me correctly.

They made the P-51, and the P-40 for that matter, in both 1/5 and 1/6 scales.
Old 01-06-2011, 02:34 PM
  #7  
Firebar
My Feedback: (3)
 
Join Date: May 2002
Location: Warrington, PA
Posts: 190
Likes: 0
Received 0 Likes on 0 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice

I built this P-51 model in 1/6 scale a number of years ago. Actually I built it twice. The first plane had CJ retracts and a Spring Air tail wheel retract. I added inner gear doors with sequencer and a full cockpit. I glassed the plane and painted with Hobbypoxy. I powered it with an OS 108. The plane got heavy quickly and needed a lot of nose weight to get the proper CG. The heavy flying weight made the plane land very hot. Takeoffs were a little tough and needed all of the available rudder.
Since I liked the plane and had all of the goodies so I decided to build a second plane. I redesigned the elevator and removed all of the weight that I could from the tail. This plane didn't need nearly as much nose weight to get the CG correct. I also reinforced the retract mounting a LOT. I sold the plane before I flew it but I expect that it was a good plane. Just keep it as light as possible.
Attached Thumbnails Click image for larger version

Name:	Vt56959.jpg
Views:	354
Size:	147.0 KB
ID:	1543298  
Old 01-06-2011, 06:03 PM
  #8  
Lightning Fan
Thread Starter
My Feedback: (17)
 
Join Date: Nov 2002
Location: Hartland, WI
Posts: 277
Likes: 0
Received 0 Likes on 0 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice

Moggy -
Wingspan is 74", box says 1/6th scale.
Old 01-06-2011, 08:26 PM
  #9  
rc34074
My Feedback: (5)
 
Join Date: Mar 2002
Location: Little Elm, TX
Posts: 1,728
Likes: 0
Received 1 Like on 1 Post
Default RE: PICA 1/6 P51 Mustang ... looking for advice

How strong are you about keeping the engine inside the width of the cowl? Do you want to mount the engine inverted?

The 2300 cylinder head is about 2 3/16 wide overall. A Jtec wrap around pitts muffler for the 2300 will add about 7/8 inch to the head width on the exhaust side. You also need to cosider how high the centerline of the fuel tank is/will be compared to the fuel inlet on the carb. If the tank c/l is much higher the fuel mixture will change some during flight. plus you may get some tendency to flood the glow plug during starting. An on board glow igniter will help here. Another solution is to mount the engine on its side with the head extending out past the side of the cowl and use a standard pitts type muffler.
A third solution is to replace the 2300 carb with a Walbro wt499 carb. this carb will run glow fuel out of the box. I have done this with one of my 2300s and it works fine. You will need an adaptor to mount the carb on the 2300 - I have been told that H9 sells an adaptor that will work well for this - it is the one they sell for their 26cc gas engine as I recall. This change will let you mount the 2300 inverted with less problems and stil run glow fuel.

Another engine to consider is the DLE20 gas engine. This engine is lighter than the 2300 by maybe 7-8 ounces. This engine just might fit in the cowl using either the original muffler or possibly with the small Jtec wrapa round muffler they make for this engine. There are a couple of threads about this engine and you might wantt to take a look at them to see ifit will fit - there are some dimensions in these threads that should tell you if it will fit.

anyway- just some info for you to consider.

Good luck

Ed
Old 01-07-2011, 05:13 PM
  #10  
WhiteRook
My Feedback: (38)
 
Join Date: Nov 2002
Location: westbrook, ME
Posts: 2,094
Likes: 0
Received 1 Like on 1 Post
Default RE: PICA 1/6 P51 Mustang ... looking for advice

let me know how you make out . i have the same kit unstarted. theres not much room in the engine bay on these
Old 01-07-2011, 08:23 PM
  #11  
Lightning Fan
Thread Starter
My Feedback: (17)
 
Join Date: Nov 2002
Location: Hartland, WI
Posts: 277
Likes: 0
Received 0 Likes on 0 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice

RCU never ceases to amaze me. I figured no one would respond, much less want to be kept up to date. Thanks to all of you for your responses.
So, as I stumble along in the RC world of the 80's, I now have before me an ST3000, and an ST2500. NOT a 2300 like I thought I would get from my buddy - he let me borrow what turns out to be a 2500. The two engines are very similar - common parts and only 5cc difference in disp. The 2500 is slightly smaller in overall height than the 3000, but both engines would require shaving the inner part of the beam mounts about 1/4 inch total. The two engines weigh about the same.
As Whiterook says ... not much room here. IF I move forward with either engine (I hear you guys that say these are too big), then I would have to chop out the lower portion of the "firewall", which is not thick enough to serve as an engine mount as it stands. I'm quite willing to get a custom Jtec muffler made, and open out the firewall as required to support that.

Someone asked if I'm mounting this inverted yup. I'm trying to get it all in the cowl with no stuff hanging out. If I'm forced to cut the cowl, then I'm going all the way and looking at gas options, which probably means gutting the old firewall completely, gusseting off the beam mounts a new firewall, cutting the beams flush, and firewall mounting.

I've been waiting on getting this engine that I thought was a 2300 to decide what to do ... but now I know I'm dealing with the 2500, or the 3000. So, now I need to cogitate a bit ... push forward with one of these engines and have a potential over power, nose heavy situation, that might not fit in the cowl, or explore other options.
Tomorrow, if I get time in the barn, I'll mock up the front end and see if the cowl will fit with either engine. It looks like the 2500 will fit if I open the beam mounts. If this works, I'll put the plane together, set it up on the balancer (I use the suspend from the ceiling rig which is detailed in HouseofBalsa.com), mock up radio locations and tape the engine in the nose. If it balances this way, and it might because these ships are apparently renowned for being tail heavy, then I'll commit to one of them.
Which sounds crazy. The 3000 spins a 16x10 at 8300 (ref http://rcfaq.com/RPMSTATS/RPMBYCC2.HTM##24). Wow.
Old 01-07-2011, 10:58 PM
  #12  
Chad Veich
My Feedback: (60)
 
Join Date: Dec 2001
Location: Litchfield Park, AZ
Posts: 7,674
Likes: 0
Received 25 Likes on 23 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice

Lightning Fan,

My experience, and that of many others I suspect, was that between the 2500 and 3000 the former was the better engine. I absolutely loved my ST 2500's. The 3000 really needed more fuel to run really good and many folks replaced the stock carb with the OS 7D carb off of the 1.08. The big ST's are not powerhouses by today's standards but I thought they were great engines. I just sold my last 2500 off a year or two ago in a big 1/4 scale Monocoupe and I'm still kicking myself for getting rid of it. If it will fit in the Mustang and not throw your CG way out of whack I would not hesitate to recommend the ST for your airplane. While it might be more than enough it is certainly not "crazy power" for a 1/6 scale Mustang in my opinion. That's my .02 cents anyway!
Old 01-08-2011, 05:34 AM
  #13  
Dash7ATP
 
Dash7ATP's Avatar
 
Join Date: Mar 2002
Location: Smithfield,, VA
Posts: 1,013
Likes: 0
Received 0 Likes on 0 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice

Guys in my club are going for the big electric option in some large planes. That would solve your space problem with the cowl. I'm not a fan of electric ( they just don't sound right, but they do have some advantages in some types of planes.

Dash
Old 01-08-2011, 01:06 PM
  #14  
Lightning Fan
Thread Starter
My Feedback: (17)
 
Join Date: Nov 2002
Location: Hartland, WI
Posts: 277
Likes: 0
Received 0 Likes on 0 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice

OK guys, time for me to stop whining "I don't know", and collect some data.
I set her up in the balancer, taped the ST2500 engine, rudder, flaps, spinner and cowl in rough position, and added lead just aft of the firewall until she came in about 1/4" aft of the plans marked CG.
woooo - boy. They were not kidding about this kit being tailheavy.
It took 3 pounds of lead to bring it in. AUW in this config was about 18 pounds, if I add in weight estimates for muffler, radio, tank, retracts and other stuff. Interestingly, 18 pounds AUW is the top end of the spec'd weight on the plans.
Looking at the fuse plans, you see at least eight formers in the tail, each one made of 1/8" ply, which I assume is lite ply. When I go to install the tailwheel (which will add yet more weight aft), I'm going to need to go in through the opening there, and at the wing saddle, and start hacking stuff out. Need more air, less wood.

Since it looks like I need a heavy engine, and I have a heavy engine, I worked to make it fit in the nose. Long and short of it is that after relieving the maple motor mounts (have not done that in a while), and opening the firewall a bit, the 2500 just fits if I set it back just a little more than the spinner backplate likes. I can fix that.
Old 01-08-2011, 01:29 PM
  #15  
Lightning Fan
Thread Starter
My Feedback: (17)
 
Join Date: Nov 2002
Location: Hartland, WI
Posts: 277
Likes: 0
Received 0 Likes on 0 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice

Some pics of the balancing and before/after engine setup.
Attached Thumbnails Click image for larger version

Name:	zx72186.jpg
Views:	163
Size:	176.1 KB
ID:	1544163   Click image for larger version

Name:	lg18193.jpg
Views:	164
Size:	173.8 KB
ID:	1544164   Click image for larger version

Name:	ot49212.jpg
Views:	145
Size:	192.4 KB
ID:	1544165   Click image for larger version

Name:	cw64002.jpg
Views:	142
Size:	229.9 KB
ID:	1544166   Click image for larger version

Name:	eq87411.jpg
Views:	210
Size:	219.5 KB
ID:	1544167   Click image for larger version

Name:	ar10350.jpg
Views:	184
Size:	146.3 KB
ID:	1544168   Click image for larger version

Name:	xa54954.jpg
Views:	185
Size:	143.6 KB
ID:	1544169   Click image for larger version

Name:	gf19121.jpg
Views:	132
Size:	175.5 KB
ID:	1544170  

Click image for larger version

Name:	nl90434.jpg
Views:	161
Size:	206.4 KB
ID:	1544171  
Old 01-09-2011, 05:58 AM
  #16  
WhiteRook
My Feedback: (38)
 
Join Date: Nov 2002
Location: westbrook, ME
Posts: 2,094
Likes: 0
Received 1 Like on 1 Post
Default RE: PICA 1/6 P51 Mustang ... looking for advice

my original plan was to use a 2500 , with an inverted pitts , but there may not be enough room behind the engine for this.
, pics look like your on the right track . the 1.08 would not be heavy enough , as you found out in your balancing.
Old 01-09-2011, 06:47 AM
  #17  
Dash7ATP
 
Dash7ATP's Avatar
 
Join Date: Mar 2002
Location: Smithfield,, VA
Posts: 1,013
Likes: 0
Received 0 Likes on 0 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice

Guys!  You don't need to use an oversize engine just to get the neccessary weight  for CG. About ten years ago I built a large model, an Acro Pro 180, and put a Moki 1.80 in it.  This was a nice model, but the Moki by itself was not enough.  To keep the amount of weight needed to balance it to a minimum, I added it to the engine mount. The engine used the rear radial mount,so the engine beam mounts were free. I screwed some lead to a 1/2 X 1/2  aluminum angle and extended it as far forward as possible.  This moved it at least five inches forward of being behind the firewall or even to the front of the firewall. 

I'm guessing it saved me five or six ounces.

Another trick I use sometimes if the design allows it,is to epoxy lead shot to the inside of the cowl ring. This puts it as far forward as possible. Of course, you need a fiberglass cowl. I will also beef up the cowl with more glass and carbon fiber if I need more weight forward. If added weight is neccessary, you might as well make it do something useful.

Dash
Old 01-10-2011, 04:07 AM
  #18  
Lightning Fan
Thread Starter
My Feedback: (17)
 
Join Date: Nov 2002
Location: Hartland, WI
Posts: 277
Likes: 0
Received 0 Likes on 0 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice

Dash -
I hear you.  I will push the weight as far as I can when I really put it in.  But nonetheless, I have an engine in hand that delivers the punch, fits in the space and adds weight where I need it.  But even with that engine, I'm adding a lot of weight forward unless I do something in the tail.

Folks, it looks to me like I need to open the tail on the bottom down its full length and hog it out.  I was peering in through the 2 inch x 2 inch hole in the wing saddle aft bulkhead and saw ... blocks of balsa.  There is great opportunity in that tail for weight reduction.  I'm not putting even a pound of lead up forward ... I'm just not doing it.  The rudder alone weighs 2 oz, and it is not fabric covered like the real deal.  I need to get that assembly down to an oz, which translates to around four oz in the nose.

Whiterook ... build the tail light!  There was a red sheet in my manual that was a change order to the instructions, which basically shows the inner sheets of the tail surfaces swiss cheesed all over.  I hope my builder did that.  I think you are right, I'm looking at either a handmade muffler or a custom Jtec.  I may try my hand at welding one up first.

The engine has been cleaned and oiled, and put away, and the ship is stored.  I need to get back to my P38.  Hopefully I'll get back to this project in the summer.  Thanks to everyone for your feedback, especially drawing the distinction between the 2500 and the 3000.

Regards to all,
Rikk
Old 04-27-2013, 07:17 AM
  #19  
franko-p51
Junior Member
 
Join Date: Apr 2013
Location: , IN
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Default RE: PICA 1/6 P51 Mustang ... looking for advice




Hey guys, Im new to RCU, Ive been redoing a 1/5 pica P51 that I didnt finish twenty years ago.


Im converting it to the Galloping Ghoast powered by a DLE 55RE . It has retratcs ,flaps.Im cutting off 6 inches of wing and everyting that I think it does not need Im having trouble getting the tail doors to fit well. any ideas will be helpfull. thanks, Frank

Old 01-02-2014, 10:08 AM
  #20  
lancr735
My Feedback: (4)
 
Join Date: Jul 2005
Location: Nanticoke, PA
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
Default

Does anyone possibly have the manual for the Pica 1/6th P51? Or at least the recomended CG spot? I'm willing to pay for the manual and shipping costs no problem

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


Thread Tools
Search this Thread

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.