Kits 3D Hobby Shop Edge 540

RandyDSok

Well-Known Member
I wouldn't remove any more of the remaining front portions until after you get the motorbox kit in and do a dry assembly. Then only remove what the MB kit already supplies.

The motorbox as well as any other formers are made of light plywood... birch is probably the most common. The stringers, ie the thin pieces between running between the formers up to the front, are made of balsa as are any of the sides. The rear portion that is left will be a good example of what is ply and what is balsa.

Use standard thin CA for most of the assembly... Epoxy only in the landing gear area... ie the box where the gear goes into. Don't get any epoxy into the area that the landing gear slides into, but you can use it on the front and rear portions. Optionally, you may want to consider not actually glueing in the LG... instead insert the gear followed the plywood shim that holds it into place and then just use 2 wood screws to hold the shim in with... insert the wood screws from the front so you can get to them later in case you want to remove them to replace the gear at some point. As I mentioned, this last suggestion is optional... many, including myself, just glue the LG and the shim in as mentioned in the assembly manual, the gear should last a long time either way.
 

Tony

Staff member
Mono vs Ultra, it's like a battle of ford vs Chevy lol. Monokote is cheaper and works like it should. However, if you ever have to peel it up and restick it, you may have some of the color come off since the color is in the glue side. Ultracote is more pliable and will stretch better when doing a large section. And it shrinks better. And if memory serves me correctly, the color is in the plastic, not in the glue side, so you can pull it up and restick it if you need to. And you more than likely will lol.

When I built my Telemaster, I used wood glue. But, if I would have had CA, I would have used that. On the pieces that just hold the structure together, use the CA. On the motor box, I would use CA, then back it with some epoxy after the CA has dried. This will ensure that nothing comes apart. Remember, weight is the enemy on these, so use the epoxy with caution.

As far as covering it, I would use the biggest piece that I can get my hands on. The bigger it is, the easier it is to work with I think. You will need an iron and a heat gun, or a hair dryer will work as well on high. Cut the piece about an inch bigger on each side, and tack it on the corners while making sure to pull it tight. Once it's tacked, Start pulling it tight and using your iron to adhere it to the frame. When it's done, trim the excess, hit it with the iron again, then grab the heat gun. Don't focus the heat in one area, or you will burn through it.

And if you can get the old motor mount box off, I would just reuse it. There are angles cut into it that make that plane fly true in the air. You can give it full throttle, and there is no pitching up or to the left. Can't wait to see it done.
 

RandyDSok

Well-Known Member
This model actually uses cheap "chinacote" in order for them to help keep the cost down... so you won't find an exact match on the market. Ultracote Orange is very close being just a slightly browner tint.

As far as I know... all of the other 3DHS planes use Ultracote so finding a match for them is relatively easy once you know which color is used.
 

Rc-Help Member

I Love This Site!
Well thanks Tony,
I don't have an iron so I may have to get some one from the club to help me with that.

The pieces they sent me fit perfectly except I think they sent one piece that is wrong. Here are some pictures of it in pieces and after I dry fitted them together. Now, another question, should I build the box before I mount it or build it on the plane starting from the outside and work my way in.

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Tony

Staff member
It depends on how it's built. Some have to be built on the firewall, others can be built on the desk, then glued to the firewall. Looks like you will have this bird in the air in no time.
 

RandyDSok

Well-Known Member
Well thanks Tony,
I don't have an iron so I may have to get some one from the club to help me with that.

The pieces they sent me fit perfectly except I think they sent one piece that is wrong. Here are some pictures of it in pieces and after I dry fitted them together. Now, another question, should I build the box before I mount it or build it on the plane starting from the outside and work my way in.

I compared the parts you have assembled and they appear to match my own parts on my fuse... The only thing I see missing on your assembly is the rear former that goes onto the rear of the battery tray... Your other pic actually shows that piece I'm speaking of still in the remainder of your fuse.
 

RandyDSok

Well-Known Member
In fact... I think I'm jealous of this MB kit vs the one I needed for my 47" Extra 300 SHP... Yours has all formers from behind the wing tube up to the motor firewall... all that is missing from the front of the plane with that kit is the stringers and balsa side panels.
 

Rc-Help Member

I Love This Site!
You are exactly right Randy, the back form was missing. I called Nolls at 3DH and he said he would get me one in the mail today. Here are some photos of my progress, I decided to build the motor box first and them form everything around it. The photos help me see how things are lining up from a different perspective.

The box has a new cowl in it.

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Tony

Staff member
Looking good Tommy. When you get everything glued together, be sure to block sand everything smooth. It will pay off with the monokote when you lay it down.
 

breeze400

Spagetti Pilot
Wow! Lol. That looks really good Tommy! Especially for your first time repairing a plane. I'm impressed! that's good enough that I think you could scratch build a pain from a kit! Brovo!
 

Rc-Help Member

I Love This Site!
I've been trying to think of a way to fix the broken sticks that form the outside ribs that the monocote sticks to. I guess I'm going to make some rectangular boxes from the thin plywood, glue them to the extended stick then slide it over the broken stick and glue it down, them after it drys sand the outside wall down for the monocote. Hmmmm.. You will see what I do when I get there.
 

RandyDSok

Well-Known Member
tr911,

Those "sticks" or "ribs" as you are refering to them... are usually called stringers. You probably only need to do a butt joint to the remaining stringer and then just glue the remaining into the formers themselves up to the F1 former. The F1 former is the portion that the motorbox itself sticks out from or is attached too. You can typically pick up balsa stringers at just about any hobby shop. If they are out, you can use a sheet of balsa of the proper thickness and cut some out with a hobby knife... but that is a little tedious without making a "jig" to assist cutting them square.

If you think one of the stringers need some additional strength where you join it at to an existing one... just run some additional stringer onto the inside or side of it and CA it into place.


breeze400,

Quick terminalogy lesson...

Scratch building is when you build from wood that hasn't been precut to shape...

Kit building - the parts, similar to the motorbox kit but of course there is enough for a whole model, are precut and you glue them all together into the major assemblies and then cover.

Then with an ARF kit... all of the building has already been done so it is only refered to as an assembly since you are already only working with the major assemblies themselves.

A well designed precut kit is really not too bad to build as many seem to think. For that matter, a balsa model repair is often not as bad as it first appears either...
 
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Rc-Help Member

I Love This Site!
I am not going to peel the whole covering off just to replace a 'stick/streamer'. I am going to butt a piece to the broken one but I am also going to put both ends in a wooden sheath about a inch in length to give the joint more strength. After the glue drys I'm going to sand down the outside so the covering will fit correctly. The sheath will also help hold it straight while the glue is drying. You will see, I'll post pictures.

Sure wood be nice to have a laser cutter.. (woodn't it? lol)
 
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breeze400

Spagetti Pilot
Rdsok: I have never scratch built or assembled a plane from a kit. I'll take part of that back. When I was about 12-14 I was in a hobby class in my shop class in middle school. Built one from scratch then. Far too long ago to remember! Lol. I'll tell you one thing, my f7f project is turning out to be quite a project for an ARF! Much more that I anticipated! Lol that's all right though. I have till march to get her together. Lol.
 

Rc-Help Member

I Love This Site!
Slowly coming together. You can see the supports I glued to the streamers. Randy, if you could take a few photos of the streamers and forms inside of yours with out the cowl I sure would appreciate it. Here s today's progress. The orange I have is a little brighter ...

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RandyDSok

Well-Known Member
I think the manual may be better than any pic I can post since it may also have other areas of interest for you to look at...

http://www.3dhobbyshop.com/assets/images/3DH-41EDGE/3DH-41EDGE-Manual.pdf

There are some ok shots of the front without cowl in the first couple of pages but on page 16 is a real good view IMO.

Also ... I'd suggest going to the main webpage for the Edge... they have several build vid's which contain several tips and tricks... including how to fit the cowl and other info.
 
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