Discussion in 'Aircraft & Aviation' started by Ben Gal, Mar 8, 2007.
If you look at this photo I don't think that it is difficult to see why laser cut frames make sense.
This is the first time I have used them, but I have them for the Be2 which I will do next. Everything about this build has been a titch easier because of them. This is obvious for the wing framing - 28 small ribs, each one having to be laminated and cut precisely.
The other area where laser cuts are a must is the engine (more on that later!)
Carl - after looking at your experience with these milliions of little ribs and spacers I reread the instructions and there's no doubt my designer wants these things stuck down to a paper former. So I thought - lets try it.
It works surprisingly well. The joinery is rough as it is not seen, and it goes quickly because the paper base keeps all the small parts in order. After its done you can twist the assembly through 45 degrees with no problem - it is very strong. It fits well between the wing skins but I will wait until tomorrow before I glue them up.
Thanks for the nudge on the Mustang. I'm on to the wings tomorrow. I have my hole punch, along with a little eight compartment plastic box to keep the punches in - courtesy of Bonnies Best Art Tools.
There is a wire that runs through both wings and the fuselage to keep everything in line. I decided to run a small card tube through the fuselage for this. As I had glued the skins on I drilled a hole big enough to take the tube and glued it into the fuselage sides. The ends will be clipped off.
Eric's recommended silk thread arrived. Its about five bucks for 200 meters, so will last a lifetime of card models.
The picture shows how I used it. I poked holes using the pointed tool, opening them up just enough to get the thread through. Then I wetted the ends with white glue first and pushed them in. I glued the ends down on the backside of the material. I didn't tie any knots, although this was easy to do. So far, easy to work with!
I REALLY admire your patience...
Thanks Triop. But, in fact, I'm not much of the patient kind which is why I never have finished a model (I've just done my very first wheel on the Mustang)
Anyway, I've skinned the wings and it went well. GB, I stuck the ribs down to thin paper as shown in a previous paper, glued the bottom to the bottom wing, then closed it up using a thin glue bead around the edge. The trailing edge is nice and fine and the leading edge well rounded. The wings are also very straight which is something I have had trouble with before.
A question for anyone who might know. This GPM model is an Ell. All the info out there seems to be on Elll's. I would like to put Gil's wire wheels on this model. Would that be out of place?
Second question. In my early days of browsing this site I saw a discussion of stacked disks versus rolled paper for cylinders. Does anyone know where that is?
Haha...I like that reversed washingpin (?)
That is a very handy gadget !
Never seen that before,made a couple myself.
I saw it on Gil's tutorial for wire wheels. I hope he did not have a patent on it!
Thanks Gil - the cloths pegs are more useful this way.
Nice Looking Wings
Very nice looking wings. Laser cutting is beginning to have a definite effect on cardmodeling.
The reversed clothespin is an item that I picked up from the stick and tissue modelers a long time back. Leif Ohlsson, Liaison for Kartonbau, picked up on there use and added and additional type to the lineup here:
Thanks for that link Gil - I've just modified a couple of large pegs, I haven't tried the minis yet. But, this way round, these clamps are far more versatile for us modellers. After all, these were purposefully designed to keep Granny's washing on the line on a Monday morning (ah, those were the days)
Back to the Ell. The tail pieces are layered up somewhat similar to the wings.
The lasercut pieces are nice. The designer wants you to press between the frames after completion to get the sagged fabric look.
All buttoned up with not much trouble.
The innards had to be downsized a bit, and the outside needs a butt glue. The paper is thick - and I think this needs some tidying up around the edges with coloured glue.
I've been studying the engine design for this model, which uses stacked disks. I think that it would take only a hardy modeller to tackle this by cutting out the disks with a knife. But we all have those Japanese punches, so I wondered what could be done using those.
Gil has a nice description of punching out disks here
I did a drawing of my GPM engine. It needs three diameters of disk, 3mm, 4mm, and 5mm, all Japanese Punch sizes. It needs three thicknesses, regular card, 0.5mm and 1mm
The problem is aligning the disks accurately. If the disk is 3mm or above its fairly easy to center the punch. But a centre hole is needed on the disks to be able to thread the disks onto a shaft. I found that the thinner the shaft, the easier it was to get everything on line. I chose a regular pin. The laser cut disks do not have a centre point marked - which is daft.
Incidentally the laser cut disks don't work well for this because you need many disks made out of regular paper. I found it easier to print the disks from a graphics program (in my case Illustrator) with the center clearly marked. I then pricked the center with a sharp point and pushed the pin through to get the right size of hole. Then I cut out the disks with the punch. The photo should shed some light on what I mean.
I'll carry on with this to see how it works out. But I think this could be a fast way to build stacked disk rotarys
Your build thread made me associate a new and novel method for building the cylinders. It's embarrassingly easy! First a picture of the result:
This was done in less than twenty minutes from start to here. If you recognize a 1/4" x 20 thread disguised as a cylinder it's because it was used as the embossing mold.
1. Cut a strip just slightly wider than the desired cylinders width.
2. Find a machine screw with approximately the right tpi for the cylinder.
3. Cut the strip so that it just wraps around the screw.
4. Completely wet the strip and wrap around the screw shaft.
5. Use a strip of plastic wrap to tightly wrap the paper onto the shaft.
6. Use the edge of steel ruler to "run in" the edge to the screw thread.
7. Let dry.
8. Unwrap the plastic wrap. Remove embossed cylinder.
9. Glue embossed cylinder seam but move the seam by one thread to remove helix (this wasn't done on the test sample).
10. Clean-up the ends with sandpapering.
11. For the base roll a cylinder to fit inside it and glue.
You come up with some of the most interesting ideas.. Great work.
Gil - that is clever!
I thought about the issue of different diameters of rings - see my drawing. But that could be handled by sanding down selectively.
The screw is essentially a mould. This means that you could substitute wire on a rod and get all the diameters right?
That's brilliant Gil! One of those "why didn't I think of that" moments!
Wire wound on a mandrel would work as well. You'd have to juggle the wire size and inter coil separation to achieve the proper scale "look".
And thanks for the plaudits Peter..,
So simple, yet so elegant. This is a tip I will definitely use.
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