This is what I'm upto in R/C...
*All images on All pages are ©2008 Simon Nadler - All rights reserved.
December 2007 - I finally kicked off my Top Flite giant scale (standoff a long way) P51-D Mustang project. I love the Mustang, always have, probably always will. Fresh back from The Gathering of Mustangs and Legends airshow in Ohio (pictures coming soon) I am fuelled up and ready to go...
So a quick tidy up in the shop and lets see whats in the box. Thats a fair pile of wood!
An inventory is performed with the help of my trusty pilot to find two parts missing from the die-cut section (P51GF03 Aft Fuse). Begin assembly of the stab as per the instructions.
The TE of the stab (P51GS01) is two die-cut pieces of 3/16" balsa laminated vertically, however mine is 1/4" laser cut. This makes my TE 1/8" too thick and pushes the elevators backwards by 1/8" causing problems with the precut stab tips etc. I opted to recut these from stock and stick to the plan.
Heres a couple of shots of the stab framing, and as of tonight, about to be closed... should be finished soon.
So I skinned the stab and roughed out the counterbalance holes, going to pick up some sanding bars tomorrow to finish that and the stabs done. It doesn't have a shroud nor does the rudder unlike the flaps and ailerons so I am adding some triangle stock to close that gap. The fin is framed up and ready for skinning tomorrow as the skins are drying now.
While that is happening I'm in AutoCad figuring out an intermediate former between F9 & F10 to support my tailwheel. Yes I went for the scale one that retracts correctly... forward. I figure another former rearward of the tailwheel doors should do the trick but it is getting pretty skinny down there. Will see what happens...
Finished the fin guts and skinned both sides tonight, will rough some shape into it and possibly get into the rudder tomorrow. I bought 3 Great Planes sanding bars tonight, man having the right tools for the job makes a world of difference!
I didn't make much progress over the weekend, had a few things to do including spending most of sunday flying, however, the fin is all but done and I'm in the middle of the rudder. I made a mistake with the counterbalance slot in the fin by framing it as per TF and cutting as per documentation. Its not out by much but enough to warrant a 'repair'.
I had forgotten about the Top Flite method... where one glues on an enormous block of wood and carves it down to a sliver of its former self... phew!
Now I got that rudder counterbalance just about right, after doing some serious maintenance to my disc sander that I discovered has a warped disc , I remembered that I hate the way TF do the fin to rudder hinge line and now have to hack it off. Oh well. Next one will be that much better.
Instead of the triangle section being carved into the rudder leading edge to sit against the flat trailing edge of the fin, I'm rounding mine like the real one and adding triangle stock shrouds to hide the line. X-craft put me onto this with his Jug (http://www.rcgroups.com/forums/showthread.php?t=685431). Yeah it moves the hingeline slightly rearward, but the real 51 has this and I like it. What other reasons do I need? Extra work, but well worth it in my opinion.
I have been sick for a few days which really slows things down, well apart from lack of cash of course, but I did manage to fix the counterbalance and slot, as well as add the shrouds I mentioned earlier. The trim tab slot is opened up and I have quickly discovered that the TF is very sport scale.
Yeah I knew that and have had to 'fudge' a couple of areas already but its part of the fun. A little more time and a final sand and it should be Ok...
I managed to put some more time into the 51 this weekend and have the slab sides assembled. This gives those of you who are not familiar with the size of the giant scale some perspective... pilot buddy is 12" tall.
Was lucky enough to spend a few hours photographing a real P51 this week so that is helping with details to come. Thanks Vintage Wings
(PS) Yes my slab of glass finally arrived.
So I have managed a little more progress on the 51, still slow and steady, need to win the lottery! I tack glued the fuselage doublers together and then the balsa sides in order to get it all lined up nicely. I remember issues with alignment in the 60 sized Mustang all those years ago.
Next I split them apart and was reminded how strong half a drop of CA really is. Then the crutch and forward formers are assembled and glued in. Pilot buddy checks that all is good.
The first two firewall pieces are glued together and then into the nose with help from you-know-who. DL-50 is due in this coming week. You can see I have too much time by the joints in my tri-stock *lol* Cant do much more until my tailwheel gear arrives (Sierra) and I have decided on a Glennis tailwheel... More to come as it happens....
The tailwheel unit has been ordered this week from Sierra and the Lado actuator and Glennis tailwheel should be ordered tomorrow. This update includes a little more done to the front of the fuselage and my DL-50 turned up. This is one hell of a lot of engine for those of use who are used to glow, and the power this thing put out on the bench was amazing!
I have looked at every engine possible for this ship and posted polls asking what everyone else were using. One of my primary conditions was to not cut the cowl to pieces nor to have half the engine hanging out. The R52 is a small form factor and from the pictures I gathered, seemed to fit well, but I was worried about reliability with the reports of overheating etc.
I got the DL because of the good reports about performance, power, weight and best of all it was on special. In my position I still think its a good deal, but as they say, the proof is in the pudding...
As for the kit quality its pretty mediocre. The wood density varies wildly and I have replaced a good few sheets already. The fit is OK at best and reqires a fair amount of stuffing around with parts to get a good fit... in some cases a 'good' fit is impossible but you get what you pay for. The kit is cheap, its not a competition ship and perhaps my expectations are a little high, hence my not complaining too much. :-)
I have seen many gorgeous examples of this kit and strive to be one of those, so it may need more work, time, money to get there, but it will get there. All part of the fun...
The firewall is three laminations of 1/8th ply and certainly looks fragile. I have bought a prop-driver extension for the DL through Sierra that will move the engine back 1 1/2". From there I plan to use short standoffs hard mounted to an engine box that I will make out of 1/4" plywood and bolt to the firewall.
I'm not sure of the exact details yet, I'm kinda figuring it out as I go. Any better ideas?
So Santa's (Darrell at Sierra) helper flew by my house yesterday, just days before xmas to drop off some goodies :-)
First four pix show the Sierra tailwheel unit which is an amazing little piece of engineering and finally gave me some time to think about the trouble I have got myself into. I am opting to install this in the scale manner, ie: the tailwheel retracts forward instead of backwards and introduces the following issues:-
- Figuring out how to mount it, probably rails at this stage.
- Replacing the air ram for a LADO electric unit. You can see from the retracted pic that I need more throw to get the wheel up inside the fuse.
- Steering servo mounting design to allow that 50mm+ movement up and back.
As you can see it is fairly large but only weighs 193g (6.8oz) Adding the Lado unit (2.6oz) puts quite a bit of weight as far back as it can go which needs attention. The fifth pic shows the Sierra prop drive extension which helps the weight problem by 108g (3.8oz) and moves the DL50 backwards 38.22mm. I have a slight issue with the prop stud extension, but I think its just differing threads, we will see. So thats the update for now, lots to come!
Have a great Xmas!
A little more progress tonight... The stock Sierra air ram is removed for replacelent with a Lado unit (dont look Darrell)
Pilot buddy helps establish the scale location for the tailwheel axle. Doing it on paper was OK but too many questions, so I opted for my favourite CAD program and worked out how to do this.
There are a couple of unknowns in this drawing, the actual diameter of the Glennis scale tailwheel, the stroke of the Lado actuator etc which will change the mounting design a litttle.
This will be the basis for the plywood former that the Sierra unit will be connected to and will span the two formers... both of which will be modified for all this stuff. Sierra is a horizontal mount vs the vertical Robart unit.
The biggest issue right now is how to steer this unit and is consuming quite a bit of thought... yes a servo, probably a metal gear micro and probably up and to the right of the Lado acuator. There is a whisker that straightens the steering arm when there is no load so right now I'm thinking that the connection from the servo to the steering arm (cable) will be slack in all positions except when the wheel is down. Any alternative ideas here?
In trying to postion the steering servo, I have come up with 3 options.
- Option 1: create a bracket connected to the retract arm to keep connections short and simple. Downside is most of former 10A will be removed and a hole made in the crutch for the retracted position.
- Option 2: Servo in same space as retract. Downside is steering cables may get caught in the mechanics. Springs may help here.
- Option 3: Servo in next bay towards tail. Downside is a small amount of weight way back. Upside Cables less likely to get caught.
I haven't decided which to do yet, interested in your thoughts... which one would you choose, or do you have another idea?
The real 51 tailwheel retracts forward and so should mine. You do what you need to, to make that happen. I'm in no rush.
The plan is to use Lado's for the mains as well. Doug is working on a new controller due out soon (gs-2) that will incorporate door sequencing, retract sequencing, slow retract speeds and stagger so I am looking forward to that. I may need that extra battery pack to help balance things out anyways
Happy New Years all...
Good things come to those who wait... I have no patience, so these goodies seem to take forever to arrive, but here they are...
The Keleo exhaust and Soloprop unit.
I had planned for both, but wasn't planning on buying them so soon. Mark (MDanon) was selling them and it didn't take much to twist my arm Thanks Mark... you are the king of packing! Took 15m to get the prop out! *lol* The Keleo fits perfectly and is beautifully engineered weighing in at a mere 305gm, thanks Mark & Kelvin.
The Soloprop unit is also gorgeous, I wasn't finished researching this idea but had to buy it. Now I hold it in my hand its appeal is obvious, but the 18" blades look a little small. I really want the DL50 to pull some more prop as the scale one would be 26". Ha! it'll never pull that, but more diameter would be nice. I cant understand how the electric guys can pull a much bigger prop than my DL, its a monster!
NRG suggest 18x6/8 for their unit, DLUSA say the DL is good for 22×8, 22×10 or 23×8 2 blades, and I haven't found a chart to compare. I know you lose an inch in diameter to keep the pitch to 3 blades, and thought you lost another inch in diameter for the 4th blade, but cant remember the exact formula... I'm sure someone will enlighten me.
It looks like I will need a different adapter as this one is for a different engine, so I hope the money i saved in buying this isnt used up in getting the new adapter... either way I'm happy its here. Its reasonably hefty at 553gm but with all that 'junk' in the tail, I'm not too worried.... yet.
I'm waiting for my Lado unit to come in and Leo's (Spychalla) corrected and wonderful glass cowl before i can make any significant progress, but waiting is part of the game. Let me know about props, I'm sure someone has some real-world experience with DL/DA's and Soloprops...
Ok, so i pulled the Soloprop hub apart and found the adapter plate is a press-fit spool. Unfortunately I cant redrill this one as the thrust pins are exactly where the hole should be, so I'm about to email NRG for a replacement. Close but no banana as they say...
As for the Soloprop, the first pic shows the assembled unit, clearly showing the pitch adjustment ring.
The second pic shows the unit with the back plate off, those four gorgeous blades (they really are a work of art), the ring that retains them, at the bottom of the pic - the drive plate, and at the top the main bolt that holds the unit on the drive plate.
There are 12 cap screws holding the two hub halves together, and you loosen all of them to adjust the pitch.
Just so you know what all this stuff looks like assembled, heres a couple of pics...
Now that I have had this assembly sitting on the kitchen table during dinner (very understanding wife) to look at I realised a fundamental issue...
The prop drive extension pushes the exhaust 38mm backwards from the 'scale' position. I will have to modify the Keleo exhaust to cater for that. Hmmm... better start practicing my aluminium welding!
February 2, 2008 - I have made a little progress...
The tailwheel mockup with a lick of paint for my club meeting.
I think I am too fussy, as the cockpit kit I bought is a little 'vague' so I began scratchbuilding my own. Armour plate behind the pilot seat showing balsa frame sandwiched between styrene sheet.
Pilot buddy had a bad hip, so I built him a new one. Now he can sit in the pilots seat without issue.
Once the anisthetic wore off I weighed him and decided he is to go under the knife again.
A pile a 1/4" holes in strategic places and I shaved a whole 10g off him. If you have a pilot like this and decide to save some weight like this, dont bother. Body part replacement is my only recommendation.
Servo rail dry fit with two rear most formers installed. Snakes run for rudder pull-pull and elevator. Tailwheel plate dry fit.
And with tailwheel installed.
Progress is slow but moving, next I have to figure out the aluminium plate insert for the rudder horn and Leo's fibreglass cowl when it arrives...
February 6, 2008 - Progress on the tailwheel steering and rudder assemblies as follows...
Cutting a slot to accept the control horn as accurately as possible. I need better tools or more design ahead of time.
Control horn is drawn out onto 1/16th aluminium plate.
Control horn cut out and slot finished.
The slot is a 'U' shape when viewed from the top of the rudder.
The control horn is a tight press fit into the rudder.
Scalloping the connection points isnt very scale but I'm hoping you wont see it with covering on the rudder.
Pull-pull wire holes drilled.
A 40mm section of snake is removed to show the idea for splicing the tailwheel wires into the rudder wires. The passing wire is looped through the brass tube and continues to the rudder.
Support blocks are long enough to support the length of the removed section and secure the snake to the wall.
The steering wire goes through the hole and has a knot in it. The tube is crimped either side of the hole.
Both sides done minus the support blocks as the green chromate is drying on them. Adjustment is at both the steering servo and steering arm on the retract.
Leo's cowl came in and it looks great!...
Cutting a slot to accept the control horn as accurately as possible. I need better tools or more design ahead of time.
Control horn is drawn out onto 1/16th aluminium plate.
Control horn cut out and slot finished.
The slot is a 'U' shape when viewed from the top of the rudder.
February 8, 2008 - Todays subject is Cooling...
One of the design decisions at the outset of this project is to (as much as possible) enclose the engine in the cowl, and with Leo's cowl being as awesome as it is, thats an easy decision.
However cooling is now a concern. I intended to route a small flexible pipe from the firewall to the radiator outlet in the rear of the aircraft but there simply wasn't room, the cockpit fills that ever shrinking void along with all the other 'stuff' that needs to go in there.
Back to good old AutoCAD for some 3D design on the fly and I came up with this plan. There is a 10x98mm gap under the fuel tank that determines the maximum outlet hole, a surface area of 980 sq mm. Obviously that is not enough to be 3 times the inlet area so I decided to build a suction fan into the ducting that will direct air from directly behind the engine head, through the fan and out the radiator door.
The first yellow section in the duct is a 60mm, 12v computer chip fan and is a drop fit in the duct (pic 3). Its rated at 10cfm and I am guessing this will be enough, tests will confirm later.
The CAD drawing is showing the duct, upside down and from the front of the aircraft. The wide flat end at the right is the size of hole in the firewall. There are quite a number of shape transitions to route through the fuselage.
To the left of the 3D model is the 2D duct exploded out flat which I printed and temporarily glued to light cardboard allowing me to build the duct to see if it works/fits.
Middle pic shows the mockup in the fuselage, its a little rough but you get the idea. Next the ducting will be made in balsa and just like the mockup, the entire center section will be removable.
2 & 3D model in AutoCAD.
Cardboard version trial fit.
Computer fan to move the cooling air.
More to come... keep watching!!
Summer 2007 - I needed to get some flight time with something a little more challenging and aerobatic for summer so I picked up a Fliton Edge 560 and transplanted the ASP 60 from the downed Corsair into it.
It flew ok but I had engine troubles, specifically carburation. Canada has never heard of such an engine so spares were not an option. Even hunting around online didn't turn up any vendors, so after Ed twisted my arm off, I caved in and bought an OS from Dan and boy did that ever make a difference! Thanks Dan.
So I flew it all summer and had a blast. The guys at the club were awesome when I broke my ankle and helped out a lot. Thanks a lot guys! Heres a couple of pics...
July 3 2007 - My trusty Thunder Tiger Eagle 40L that I built in 1989 suffered some damage at the hands of very young nephews so as I began to prep it for repair, decided that she was pretty tired and in need of some TLC. It has possibly hundreds of flying hours on the airframe - I go back to flying it after any kind of break, being so stable and easy to fly, she is great for getting the rust off my thumbs.
I removed all the covering (solarfilm) and had a hell of a time with that. Over time the color layer separates from the clear top layer and becomes very brittle. I used a combination of sanding and plate scrapers to remove all that I could and repaired minor damage to the structure. After some bog and more sanding I recovered the airframe with Oracover which is a significantly improved covering material.
I replaced the fuel tank and plumbing, wheels, canopy, pilot ;-), hinges and covering... I think it looks pretty sharp...
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