HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old May 02, 2007, 07:07 PM
Unrepentant Carnivore
jamesdr's Avatar
Brandon, Fl
Joined Mar 2005
2,499 Posts
New Product
Hobby-Lobby Mustang P-51D RTF

I've done some searches here on Groups to see if anyone has flown the new Hobby-Lobby RTF P-51 - so far, some comments but no real discussion. So, if anyone knows of a thread, I'll shut this one down and join it - otherwise, I'll keep this one going.

HL has some very interesting RTF kits now. RTF used to be equated with crud (or worse). But this one has caught my eye on a couple levels. A four-blade prop, cool details on the mains, a tail wheel near where it should be. The running gear is also intriguing - BL motor and 3 cell lipo, full house control surfaces. Even a Tx and Rx. All for 200 bones. And when they had the 20% off crash sale, I just could not pass it up.

Anyway, I just got confirmation of shipping from Tenn. The route from there to here in Northern California is the SLOWEST in the world. But it will get here. I will be pulling the Rx and replacing it with a Spectrum one, other than that, will see how she does.

There are lots of P-51's on the market. Some fly great (Alfa's), others are good (GWS w/ a BL motor), but most are simply wretched. Iíve not done a RTF since I tossed my last Aerobird Challenger in the trash over two years ago. I feel kind of like Iím cheating with a RTF. Will be a good way to see just how far the hobby has come in 2 years.

Jim
jamesdr is offline Find More Posts by jamesdr
Reply With Quote
Sign up now
to remove ads between posts
Old May 03, 2007, 04:43 PM
Unrepentant Carnivore
jamesdr's Avatar
Brandon, Fl
Joined Mar 2005
2,499 Posts
<Groan> FedEx picked it up on the 2nd, will be delivered on the 8th. I think it comes via riverboat. Well, I guess the build will / should be virtually non-existent.

Jim
jamesdr is offline Find More Posts by jamesdr
Reply With Quote
Old May 03, 2007, 04:57 PM
Registered User
Joined Dec 2006
34 Posts
Finally Hobby Lobby is offering a RTF warbird! Not everyone has the patience or skill for building. Anyway, looking forward to reading your review of the Mustang.
Redbird25 is offline Find More Posts by Redbird25
Reply With Quote
Old May 03, 2007, 05:32 PM
Registered User
Rural Westchester, NY
Joined Oct 2005
667 Posts
Oops.

Ooops - silly me I missed your thread and started another. Mister Moderator if you want could you close my thread and move my post here . . .

My thread was:
Art-Tech Mustang P51 RTF Owners and Adapters Thread


Joe
2Sunny is offline Find More Posts by 2Sunny
Reply With Quote
Old May 03, 2007, 05:54 PM
Unrepentant Carnivore
jamesdr's Avatar
Brandon, Fl
Joined Mar 2005
2,499 Posts
Hey Joe

Good report! Thanks! At least I know the pedigree of the kit.

Do you think the lack of thrust for a loop from level is due to the 4 blade prop or just not enough grunt from the motor?

Jim
jamesdr is offline Find More Posts by jamesdr
Last edited by jamesdr; May 03, 2007 at 08:13 PM.
Reply With Quote
Old May 03, 2007, 07:43 PM
Registered User
Rural Westchester, NY
Joined Oct 2005
667 Posts
Hey Jim,

That's a great question. Now that you bring it up I suppose it could be a function of the prop. I don't know what the pitch of the propeller is but if I had to guess I would say the pitch is relatively high and that could be a big factor. Here's what Hobby Lobby says which makes me think you're on the right line of questioning

Quote:
The big 4-bladed prop provides lots of thrust with only moderate speed
I have to work the next four days, but I promise to put a watt meter on the engine next Tuesday. Can't wait to hear everyone else's experience . . .

Joe
2Sunny is offline Find More Posts by 2Sunny
Reply With Quote
Old May 03, 2007, 10:51 PM
Registered User
kahloq's Avatar
Fort Collins, Colorado, USA
Joined Dec 2005
7,821 Posts
If its only moderate speed, then the pitch is somewhat low...probably about 5.
I have an Alfa Corsair that I had a 4-blade FSK prop on it which was 9" diameter and 7 pitch and the plane flew well, but not fast. Since this RTF Mustang is billed as a beginner capable plane, then I doubt the prop would even have a pitch better then 6.

You can easily get better speed by dropping to a 3 blade prop or a 2 blade(most efficient for speed). All you'd need to do is a get a spinner the right size for the number of blades. GWS is coming out with 3 blade props that are designed for better performance relative to what the older versions of their muti-blades gave. the new "HD" versions will work well and will come in several diameters.
You can also use MAS(master airscrew) glow props as they do work well, but the motor on this particular plane may not have enough grunt for the slight bit of extra mass. I now run a MAS 9x7 3-blade on that Alfa corsair and its powered with an e-flite park 400 outrunner. Pretty fast

Make sure you check amp draw with a wattmeter anytime you cange props to see if tis still within the motor's limits as well as the battery's.


BTW, the Ultrafly P-51 is a really great flyer as well(not RTF), and its not wretched. The PZ P-51 is also decent, but eventually a motor upgrade is needed for fast flying. Aside from the Alfa P-51's, the FSK P-51 also fly great as long as you have the CG set properly.
kahloq is offline Find More Posts by kahloq
Reply With Quote
Old May 04, 2007, 12:52 AM
Unrepentant Carnivore
jamesdr's Avatar
Brandon, Fl
Joined Mar 2005
2,499 Posts
I'm looking forward to seeing exactly what kind of motor is in the P-51. Although the four blade prop looks great, I think the harsh reality of model flight will relegate it to occasional use. As you said, two blade props are the most efficient for speed . But as I think about it, the motor must have some guts - four blade props have a lot of drag. I'll be testing it with an Eagle Tree mini data logger - a great tool for finding out EXACTLY what is going on in flight.

Jim
jamesdr is offline Find More Posts by jamesdr
Reply With Quote
Old May 05, 2007, 06:21 PM
Registered User
Rural Westchester, NY
Joined Oct 2005
667 Posts
Minor testing tonight.

So just for kicks I checked a few items of curiosity:

1) Weight without landing gear or battery 15.60 ozs
2) Weight with battery but no landing gear 19.0 ozs
3) Landing gear weight 1.7 ozs
4) Watts at full throttle as measured by an AstroFlight Whattmeter 120.
5) Amps at full throttle 10.3 amps at 11.6V using the supplied battery fully charged.
6) Prop RPM 9570. Prop listed as a 10x6 (by 4).

So my guess is the plane was designed to meet the recommended 100 watts per lb for good sport flying, but the motor is cheap and probably produces about 65% efficiency which is impacting the high end performance.

I'm planning on ordering the parts to make a modified version and it looks to me like the price will be about $77 which seems about right.

I thought about it some more and was trying to figure why I opted for this model over all the other P51 choices after agonizing for months on end. I wanted something that didn't take a lot of time to make look nice (i.e. a GWS or FSK) nor did I want something that had a high probability of crashing on the maiden (i.e. a Parkzone or an Alpha) and I didn't want a P51 that needed a runway or a big field (i.e. a Hyperion). Given all those considerations I must admit that this model fit the bill to a "T". It looks great right out of the box, launched flawlessly, flew slowly enough to stay inside my park area no problem, and had enough hummmph to do loops and rolls even if they were a little on the weak side. All in all I think I need to show a little more enthusiasm than I did earlier because this baby is really nice, and has potential to be truely great . . .

Joe
2Sunny is offline Find More Posts by 2Sunny
Last edited by 2Sunny; May 17, 2007 at 08:58 PM.
Reply With Quote
Old May 05, 2007, 08:24 PM
Unrepentant Carnivore
jamesdr's Avatar
Brandon, Fl
Joined Mar 2005
2,499 Posts
Joe

You seem to be the only person on the planet with one in hand, thanks for the information.

How does the motor look/mount up. is it a stick mount or is is like this? Either way, a quick transplant of a TowerPro 2409-12 will put about 200 watts under the cowl. I may have to loose the four blade prop though. Just have to wail until I get my hands on it.

Jim


jamesdr is offline Find More Posts by jamesdr
Reply With Quote
Old May 06, 2007, 02:14 AM
Registered User
shschon's Avatar
United States, CA, SF
Joined Aug 2004
2,362 Posts
Quote:
Originally Posted by 2Sunny
So just for kicks I checked a few items of curiosity:

1) Weight without gear or battery 15.60 ozs
2) Weight with battery but no gear 19.0 ozs
3) Gear weight 1.7 ozs
4) Watts at full throttle as measured by an AstroFlight Wattmeter 120.
5) Amps at full throttle 10.3 amps at 11.6V using the supplied battery fully charged.
6) Prop RPM 9570. Prop listed as a 10x6 (by 4).

So my guess is the plane was designed to meet the recommended 100 watts per lb for good sport flying, but the motor is cheap and probably produces about 65% efficiency which is impacting the high end performance.

I'm planning on ordering the parts to make a modified version and it looks to me like the price will be about $77 which seems about right.

I thought about it some more and was trying to figure why I opted for this model over all the other P51 choices after agonizing for months on end. I wanted something that didn't take a lot of time to make look nice (i.e. a GWS or FSK) nor did I want something that had a high probability of crashing on the maiden (i.e. a Parkzone or an Alpha) and I didn't want a P51 that needed a runway or a big field (i.e. a Hyperion). Given all those considerations I must admit that this model fit the bill to a "T". It looks great right out of the box, launched flawlessly, flew slowly enough to stay inside my park area no problem, and had enough hummmph to do loops and rolls even if they were a little on the weak side. All in all I think I need to show a little more enthusiasm than I did earlier because this baby is really nice, and has potential to be truely great . . .

Joe
Prop RPM 9570?????
How did you get that number from? It is obviously wrong for a huge 10x6 4 blade prop to spin at close to 10000 RPM at only 100W.
That RPM number sounds more like a 7" or smaller 2 blade prop.

This is 4 blade prop did you choose the right blade number? If not or your gauge does not have this option then you have to divide the number by 4. If it is from some ESC reading you have to divide by the 1/3 pole count of the the outrunner motor.
shschon is offline Find More Posts by shschon
Reply With Quote
Old May 06, 2007, 03:36 PM
Registered User
Rural Westchester, NY
Joined Oct 2005
667 Posts
My mistake.

Actually after I went to bed I had a moment of "dee dee DEEEE" when I realized I hadn't set the blade count for a four bladed prop. It was set for 2 which is the default. Presumably that means the RPM count was off by a factor of 2 . . .

I'm away on a trip now, but I promise to remeasure correctly when I get home.

Sorry for the mistake.

Joe

P.S. I used a GloBee Tach and a flashlight for testing.


P.P.S For what its worth I believe the motor is the blue one shown on Art-Techs website which would mean:

weight 80g
rpm/V 700
output 110 watts
max current 13amps

and here is the manufacturers listing for the P51.
2Sunny is offline Find More Posts by 2Sunny
Last edited by 2Sunny; Apr 29, 2008 at 07:15 PM.
Reply With Quote
Old May 07, 2007, 01:55 AM
Registered User
Joined Feb 2007
189 Posts
I got mine a couple weeks ago. I don't have any experience flying aileron planes and I crashed on the maiden. The motor mount is plastic, and not stick mount. It is more like a four legged plastic mount. It broke when I crashed and I'm trying to figure out how to repair it. Superglue doesn't seem to want to hold at all. Anyway it's a nice looking plane, but I would think it's better for more experienced pilots. Also, the servos buzz quite a bit. I might swap out the rx and see if that helps.
tooconceited is offline Find More Posts by tooconceited
Reply With Quote
Old May 07, 2007, 07:26 AM
Unrepentant Carnivore
jamesdr's Avatar
Brandon, Fl
Joined Mar 2005
2,499 Posts
tooconceited

Sorry that you had a crash on maiden. But as I'm sure you will told here, the P-51 is not a beginners low wing trainer, no matter what the hype is. For a first low wing acrobatic plane, I highly recommend the Goldberg Tiger 400 (change the motor to a e-flite 400 or 450, the stock setup is destined for failure). Put the P-51 in the shelf for a few weeks.

Joe - the blue motor would account for the low speed but is probably necessary for the draggy 4-blade prop. Since a Mustang lives for speed, I think performance will have to trump aesthetics.

Jim
jamesdr is offline Find More Posts by jamesdr
Reply With Quote
Old May 07, 2007, 11:10 AM
Registered User
shschon's Avatar
United States, CA, SF
Joined Aug 2004
2,362 Posts
Quote:
Originally Posted by tooconceited
I got mine a couple weeks ago. I don't have any experience flying aileron planes and I crashed on the maiden. The motor mount is plastic, and not stick mount. It is more like a four legged plastic mount. It broke when I crashed and I'm trying to figure out how to repair it. Superglue doesn't seem to want to hold at all. Anyway it's a nice looking plane, but I would think it's better for more experienced pilots. Also, the servos buzz quite a bit. I might swap out the rx and see if that helps.

Try Gorilla glue you can get at local drug store or Walmart. Super strong and bonds almost anything together. Very light weight as well. Try it and you may toss all other glue into trash can.
shschon is offline Find More Posts by shschon
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Video Hobby-Lobby Mustang P-51D RTF jamesdr Electric Plane Talk 0 May 13, 2007 04:40 PM
Discussion HL Mustang P-51D (RTF) flyin C Parkflyers 2 Apr 03, 2007 05:19 PM
Hobby Lobby Alpha P-47 feedback jfrabat Scale Kit/Scratch Built 0 Jan 11, 2003 11:38 AM
Hobby Lobby's P-51 and/or corsair denverone Foamies (Kits) 3 Jul 11, 2002 06:47 PM