decombs21

Okay, so one receives a set of plans and wants to cut wood.

How do you go about it? Do you cut out the ribs, bulkheads and formers from the plans (better yet, copy them) and paste them to the wood or what? I'll have a bandsaw shortly and wanted to break it in properly. Isn't there some way to just transfer the images from the plans directly onto the wood and bypass cutting our paper?

And while you're thinking about that ... Will someone share with me how you go about enlarging a set of plans? I understand about changing stringer sizes, wood thicknesses, types and adding ribs or stringers to make up or fill in for the increase in scale but I'd sure like to hear from someone who has done this numerous times.

It would be greatly appreciated,

Dave

Dsegal

How To Create Patterns on Wood

Layout the pattern directly onto the wood.
Use a pencil, straightedge and drafting tools such as a compass and French curves. This is simplest with straight line shapes.

Pin*****s
Place the plan atop the wood and use a pin to make a series of holes through the plan and into the wood. Remove the plan and then "connect the dots" on the wood. This seems a low-tech method but in practice is very accurate, especially for curves.

Tracing shapes
Tracing paper
Tablets of tracing paper are available from CVS and Staples stores. Place the paper over the plan and trace with a pencil or pen. The pattern can be fixed to the wood by applying a glue stick to its back or using a removable-type spray cement. The pin***** method can be used or you can simply cut directly through the paper into the wood. This is a fragile pattern not intended for multiple parts. For greater durability the tracing can be glued to light card stock and then cut out for a template.

Mylar drafting film
This is a sturdy plastic with a roughened surface to take pencil and ink.A brand called "See-Temp" is sometimes advertised in modeling magazines. The mylar is easily cut with scissors or knife and can then be placed on the wood and traced around the edges.

Photocopying
This sounds like a great way to go but there is a hidden danger in the inability of the ordinary office copier to make an accurate same-size copy. If you use a copying machine first place a scale on the glass window and make a copy. Then place the scale alongside its photo image and measure the discrepancy. Even a one percent error means you will be off by 1/4 inch over 25 inches. Try to adjust the copying magnification on the machine to get the most accurate result. And if you come back and choose another machine at the print shop you will have to do the calibration test all over again.

Once you have made the photocopy it can be copied to the wood by pin*****s, cutting through the paper or transferring the ink onto the wood.

Ink transfer
Tests must be made for any brand of copying machine due to variations in their technology. And practice on scrap will avoid waste of good wood.

Heat transfer
The common process employed by copiers uses heat to fuse a powdered toner onto the paper. By placing the photocopy face down on the wood it may be possible to transfer the image, in reverse, onto the wood. Use a household iron for this.

Solvent transfer
The toner may be soluble in thinner such as lacquer thinner or dope thinner. Place the copy on the wood, image side down, and then dip a cotton swab into the solvent. Don't use too much liquid. Then draw the swab around the outline of the part and while pressing the swab down.. The liquid will briefly make the paper transparent so you can see what you are doing. Then lift the copy off. It may be possible to repeat this if enough toner remains on the paper.

Rib templates
When many identical pieces such as wing ribs must be cut it is useful to produce a rigid template. Lite-ply works well as it is cheap and easy to cut.. The pattern can be transferred from a photocopy by using a solvent-dipped swab. Then cut out the template- an electric scroll is perfect for this. Sand the edges to the final shape. If desired, the edges can be hardened by dribbling thin CyA adhesive. Place the template onto the balsa and draw the knife around the edges. Finger pressure is adequate to hold the template in place but pins can be pressed through the template to secure it. Note: omit the spar notches from the template so that the cutting movement with the knife will go more smoothly. Afterwards, the ribs can be stacked and pinned together so that the spar notches can be marked and then cut out

BMatthews

Dave, these are all popular past topics for the Scratch forum. Have you read back through the last year or so's worth of posts? Try the Search using "scratch" as the keyword. It'll keep you busy reading for at least a night. Then come on back for specifics.

And it really helps to break it all down into smaller sub tasks and solve each parts puzzles before moving on. Some folks like to cut it all out at once to make a sort of kit. Others, like me, like to cut, glue and complete the subassemblies before moving on. I find it provides more feeling of progress.

decombs21

Thanks Dave and Bruce. I appreciate the time Dave took to respond. WOW.

I will also do a search on SCRATCH and read what I see.

Most appreciative,

Dave Combs
Fresno, CA

ljhmc

I must be doing it all wrong. I copy the plans match scales cut the plans apart and spray glue to the wood. by using a small band saw I cut the wood amnd sane with a belt sander until the pice is what I want. It all goes very fast and the pecies come out great. I had no idea I was soooooo off the mark.

Lawrence

vicman

My Feedback: (10)

Stupid me does it the same way[X(]

decombs21

OK, now for a curve ball. I want to scale up these plans to achieve a certain wingspan to suit me. Is it just as easy as asking my local copy shop to scale up by a certain percentage when I have the plans copied or no?

What I have in mind is acquiring the planset from RCM for the Super Sportster 90/120 (#1006) and increasing its wingspan to 81" or 82" (maybe more after examining the plans). You might call it a Super Duper Sportster, but then I'm easily entertained too.

I understand I may have to substitute harder woods (and thicker) and maybe add a stringer or two to accommodate the increase in size but am willing to do so to satisfy my obsession.

What do say to that?

Dave

papermache

My Feedback: (35)

decombs,
For a sport plane, just have the local copy shop scale up the prints. Unless you're doing absolute scale work, the 1/4" over 25" isn't going to make much of a difference. I use the photocopy transfer method and have never had any problem. I also keep all of the template pieces in an envelope after building, just in case of an attack of "dumb thumbs". Good luck with your obsession.

papermache

dicknadine

copying/enlargeing the plans is your 1st step. be careful as to the additional strengh of materail that has to be added, upping the thickness doesn't do the job. the distance between spars, as an example. ect. elarging twice the size, doesn't mean twice thickness. its all an educated guess-- sometimes you win, some you lose. dick

decombs21

Thanks, Dick. I have that in mind. I won't hesitate to add bulkheads, spars or wing ribs if needed.

Gray Beard

My Feedback: (-1)

Dave, I was just down there in Fresno at your local Kinkio's getting some plans printed up. Most of them have what is called an enlargment wheel that you just set the size of what you have to the size you want it to be and it gives them the precentage of enlargement. Very easy.
I always have at least two sets made up for me. One to build over and one to cut up.
I just make up two hardwood ribs with bolts going through them and sandwhich in about 10 sheets of balsa so I can gang cut them to rough shape and sand them to final shape. 10 at A time makes things go faster. If it's something that I only need one of I use spray mount and stick the cut out right to the wood. I always build A kit first so I can get all the cutting finished.
If your going to the Giant scale meet at the Fresno club next month I may see you there, love the field and pit area.
You should talk to John Lockwood about building, he does some nice work and it's fun to pick his brain.

martyg

My Feedback: (42)

Dave, great post. Very informative.
Thanks for taking the time to get it written down.

decombs21

GB,

That's good to know about Kinko's. I called them yesterday and they confirmed they would be able to do what I wanted.

I haven't seen John in over 20 years. I have heard, however, about his 100 plus pound B25. It's so large he can't enter it in scale events. I'm not currently a member of FRM but hope to be soon (after I rejoin the AMA). I'm just getting started again after being ill for many years. I'm still sickly but got to have something to do when I feel up to it and modeling is as appealing now as it was 2 decades ago, especially scale modeling.

The bird I'm going to do is an enlargement of the Super Sportster 90/120. I'm blowing it up 17% to an 84 inch wingspan. This is about size a number of the popular 1/5 scale models. It's all to get me reaquainted again.