Red Raider
70cc twin V2
Here's a couple of pictures that show the results.
Scale Plans built P-51
- Thread starter Red Raider
- Start date
lakerider8
50cc
I may have missed it... but are you going to use retracts?
Red Raider
70cc twin V2
Yes. A plane like this has to have retracts. I've talked to the guy that drew the plans. Sierra and robart make a set that will work. I'm going to use the robart 154E for the main gear and I think the number is 160E for the tail gear. These are electric. I've got a small set in a p-40 and they work great. I like them because there's no valves, air lines, tanks, etc. and no need for a pump. If you want to, you can run them straight from the receiver battery. I do in the P-40, but will likely use a separate battery in the Mustang.
Red Raider
70cc twin V2
The problem with the Robart electric retracts is the cost. $750 does not include wheels. But it's cheaper than the Sierra if you were to convert them to electric. That's more than the engine and what I have in the plane so far. Oh, well. I'm going to buy them over a couple of months. Tail gear and control unit first, then the main gear.
lakerider8
50cc
Good. I have to agree on putting them in. I used to have an old Dynaflite .60 size P51 that I built. Those kits were sport scale, but in the air with the wheels up the plane looked great. I always lowered the wheels during the descent over the runway going with the wind then turned into the wind and landed. I used an old futaba retract servo that was slow and it looked realistic when the wheels went up or down.
Red Raider
70cc twin V2
I haven't had a lot of time to work on the Mustang the last couple of days, but this morning after some much needed yard work I decided to do a little experiment. I came into possession of some scrap 1/4inch MDF. For those of you unfamiliar with that product, MDF stands for medium density fiber board. After "finishing" the lower cowl, you have to build hold down brackets under the front end just behind the spinner ring (F1). I was wondering if MDF was suitable for this purpose since I already had some. Here's what I found out. Yes, and no. The first thing I did was take a small piece of balsa and glued it the end of the MDF with thin CA. I let it sit for a couple minutes and then with just a tiny bit of pressure it snapped off clean. No MDF stuck to the balsa and no balsa stuck to the MDF. Hmmmm. Doesn't look good. Next a drilled a couple of 3/16ths holes and tapped them 1/4x20. I soaked them with thin CA and re-tapped them. Beautiful, sharp, clean threads. Using a nylon bolt, I couldn't strip the the threads using normal effort. I wanted to know what the braking point was, so I screwed in a steel socket head cap bolt and tightened all the way down. I grabbed my big wrench and with some considerable effort the threads gave up. Way more than you would ever use on a plane, and certainly more than a nylon bolt could withstand.
Next, I took some medium CA and glued a piece of balsa to it. I let it sit while I put up the mower and cleaned up some of my mess. When I tried to break the balsa off the MDF, the balsa broke leaving wood stuck in place. The only way to get it off was to sand it off. If the glue joint is harder than the material you're working with, it's sufficient.
So, there you have it, my 30 minutes of experience using MDF in model building. Oh, yes, I'm going to use it for my hold down brackets.
Next, I took some medium CA and glued a piece of balsa to it. I let it sit while I put up the mower and cleaned up some of my mess. When I tried to break the balsa off the MDF, the balsa broke leaving wood stuck in place. The only way to get it off was to sand it off. If the glue joint is harder than the material you're working with, it's sufficient.
So, there you have it, my 30 minutes of experience using MDF in model building. Oh, yes, I'm going to use it for my hold down brackets.
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Red Raider
70cc twin V2
Ok, now I have several hours experience with MDF in modeling. I hope no one went out and bought any to use on your next project. I built the hold down plates like I said I was going to. When I trial fit the cowling, they were off by an 1/8th. That's way too much. I was wondering how I was going to get them out without tearing something up. I grabbed hold of one to give it a little tug and it came off in my hand. So much for its usefulness. I threw all the pieces I had in the trash.
Red Raider
70cc twin V2
Well, my 82 year old mother is in the hospital with pneumonia, and my wife fell and broke her foot right after having surgery. Guess what I have not been doing?!?! Right - I am not spending any time in the shop. I value my life way too much for that. Good news is, everyone is better.
After getting the fuselage framed up and the lower cowling built, the next thing to do according to the instructions is to finish sheeting the fuse, and build the wing. I think before I do that, I need to build the tail surfaces and set them in place so that I can accurately install the control rods. It will be much easier if you can reach inside from the top and bottom rather than trying to do it through the wing bay. I bought 48 inch 4-40 rods for this purpose.
BTW - if you haven't ever heard of Hobbylinc, you should look into it. They don't carry everything, but what they do have is discounted, they have a rewards program, and I have never had a problem. I bought a package of 24 Dubro rods for $18.00. JFYI
Most large tail surfacs are built similar to wings - that is - ribs placed on spars with leading and trailing edges attached to the front and rear surfaces. That's not the case with this plane. The first thing you do here, is to cut a core out of 1/8th balsa and add half-ribs first to the bottom and then to the top. I thought this was a little strange, but after cutting it out and laying the ribs on it, I can see that it will result in a strong and straight tail. It's like having a full width and length spar. You just have to be careful and make sure that it lays flat on the building surface. Hopefully tonight or tomorrow I'll have a chance to do a little work and post a couple of pictures.
After getting the fuselage framed up and the lower cowling built, the next thing to do according to the instructions is to finish sheeting the fuse, and build the wing. I think before I do that, I need to build the tail surfaces and set them in place so that I can accurately install the control rods. It will be much easier if you can reach inside from the top and bottom rather than trying to do it through the wing bay. I bought 48 inch 4-40 rods for this purpose.
BTW - if you haven't ever heard of Hobbylinc, you should look into it. They don't carry everything, but what they do have is discounted, they have a rewards program, and I have never had a problem. I bought a package of 24 Dubro rods for $18.00. JFYI
Most large tail surfacs are built similar to wings - that is - ribs placed on spars with leading and trailing edges attached to the front and rear surfaces. That's not the case with this plane. The first thing you do here, is to cut a core out of 1/8th balsa and add half-ribs first to the bottom and then to the top. I thought this was a little strange, but after cutting it out and laying the ribs on it, I can see that it will result in a strong and straight tail. It's like having a full width and length spar. You just have to be careful and make sure that it lays flat on the building surface. Hopefully tonight or tomorrow I'll have a chance to do a little work and post a couple of pictures.
wesley.
70cc twin V2
Sorry to hear that hope everyone is doing better especially your wife your gonna need someone to bring refreshments when your in deep thought on the P-51. Lol
Red Raider
70cc twin V2
You are so right! You know, its kind of ironic that you said that. Never in my 30+ years of modeling has she done that until recently. Now, I can almost expect some kind of treat while I'm out there. Even with the broken foot, she hobbled out there last weekend just to ask me if I needed something. hmmm, I wonder if there's something coming up that I've forgotten. Now I'm skeered. Thanks Wesley.