What's your approach to cutting balsa and ply for kit builds

[David perry 1]

Generally speaking i trace the shape, tape to wood, cut outside and sand.  Then i invariably wipe off the blood, cyano my wound and give it ten minutes.  

 

I would not win builders awards.  

 

[Rich Griff]

Is woodwork still taught in schools these days ?

 

Someone has already mentioned wood "grain"....hence the expression against the grain....

 

Not read the "good bedtime reading" article yet which probably shoes stuff like this...

 

 

Sorry for poor quality of this picture from a 1968 map plans handbook.

 

I do not have a proper computer or screen unlike the ones in the library. If you have a proper computer and internet etc., you are spoilt.

 

Anyways guys have a brilliant day.

[Learner]

59 minutes ago, toto said:

 The new shed will not be until well into next year.

 

Toto

Or maybe end of the month if the trigger finger gets the urge😊

[Cuban8]

17 hours ago, leccyflyer said:

For transferring shapes and dimensions from plan to wood, I used to be an advocate of Pete Nicholson's Model Design philosophy of using a copy of the plan, temporarily glued to the wood with a Pritt stick, which was then cut out accurately with a good sharp scalpel, or sharp Stanley knife for liteply or thin birch play. The technique is also useful for thicker ply, using a scroll saw.

 

On recent builds I have traced over the parts on the plan, using Frisk film, then put that to the wood, allowing easy transfer of the dimensions to the wood - cut out being by the same good sharp tools. Any small inaccuracy built in - such as by the thickness of a pencil line, really isn't going to be critical.

I use my home scanner/printer to produce templates from either the original plan or a copy of it - useful to have a copy that you can refer to anyway during the build - easy to miss a vital detail when it's obscured by parts that are already built over the plan.  People worry about copy errors creeping in and I suppose that could be a problem, however any plan copies I've had from a print shop and those done at home on my scanner have all been spot on to the original. Being digitally scanned and printed as opposed to a complex mechanical system of mirrors and lenses and rotating print drums (used to work on photocopiers in the 70s) even inexpensive modern domestic kit is very good at maintaining accuracy.

[Nigel R]

Digital scans also don't grow with humidity...

 

End of day, if the finished masterpiece all fits together and is rigged straight, then a few mm here and there will make no difference to anything.

[Peter Jenkins]

16 hours ago, Nigel R said:

Some bedtime reading

 

https://rclibrary.co.uk/title_details.asp?ID=2672

I also used Peter Chinn's book All About Model Aircraft and found it very helpful.  Sadly, I seem to have misplaced it.  I was amazed to find that it is available on ....Amazon!  I paid £5 for my copy back in 1963 so £25 now is probably about right.  

[Nick Cripps]

Before cutting out formers, check the height and width against the plan and side views of the fuselage.

[Cuban8]

10 hours ago, Rich Griff said:

Is woodwork still taught in schools these days ?

 

Amazing how the memory works.........the question has just reminded me of my 1st year Secondary School woodwork teacher in 1969, Mr Crouch. He turned up in the school carpark one day with the most amazing thing that any of us had ever seen. A brand new, metallic bronze Mk 1 Ford Capri. Considering that most cars within the reach of ordinary folk  usually looked so dull and boring, his Capri looked like it had come from the future and appeared to be doing 100 mph just standing there. I know it's so subjective, but a Mk1 Capri in the right colour is just so beautiful.

 

Edited August 19, 2023 by Cuban8

[Paul De Tourtoulon]

Ford Capri, a real Essex boy,,,😄

[PatMc]

I scan formers, ribs etc from the plan then print to A4 size label paper. Stick the result(s) on the wood then cut & sand as necessary. Similar to the Prit stick method but easier. 

[Andy Stephenson]

Using any adhesive that has water in it to stick paper templates onto wood will make it expand. This is why I always use double-sided tape.

[Nigel R]

3m display mount works very well for paper templates. 

 

Bear in mind paper is affected by humidity differently to balsa so remove the template ASAP, unless you want parts like pringles.

[Martin Harris - Moderator]

Never had any problem with Pritt Stick.  Water softenable but dries very quickly so water content seems negligible.

[Outrunner]

Pritt stick for me too, I used to use spray mount but I find pritt stick less messy and cheaper.

[PatMc]

4 hours ago, Andy Stephenson said:

Using any adhesive that has water in it to stick paper templates onto wood will make it expand. This is why I always use double-sided tape.

I doubt the likes of Pritstick's adhesive contains enough water to make any significant expansion, label paper contains no water. 

[Dale Bradly]

I use the pritt stick method, the other option i use regularly is to print/copy the plan/part required with a laser printer. Then iron the part (toner side down) onto your balsa(etc) witn a hit iron and a bit of force. Toner is cured by heat, so the ironing process will transfer toner from the plan to your balsa, leaving a clearly visible "reverse print" directly on the wood ready to cut.

In terms of cutting, i cant live without my bandsaw, and also my 12" mitre saw. Is perhaps overkill, but i didnt buy it for modelling. Loaded with a fine kerf 120 tooth blade, it makes short work of roughing ply items down to size, cutting spars, 1/2" balsa etc.

Edited August 21, 2023 by Dale Bradly

[Andy Stephenson]

Dale,

Where do you get 120tpi blade from the finest I can find for mine is 32tpi

[Engine Doctor]

On 19/08/2023 at 09:48, David perry 1 said:

Generally speaking i trace the shape, tape to wood, cut outside and sand.  Then i invariably wipe off the blood, cyano my wound and give it ten minutes.  

 

I would not win builders awards.  

 

Sounds like a Reg Prescot sketch ( Kenny Everett) 😀. Not as funny as that though as blood really messesup the balsa .

[Chris Freeman 3]

I have found a cheap thin double sided tape very handy in the workshop, I used it to join wood together when cutting wing ribs on a old dremel scroll saw. I also use the double sided tape to adhere sandpaper to my sanding blocks and even the sanding disk. Not sure of the name of the tape, some refer to it as carpet tape and comes in various widths. I also found it works well to adhere the paper templates to the wood when cutting as it can be removed. My sanding blocks are balsa blocks as they are light and can be made wider to fit easily in the hand when doing lots of sanding. I also have some foam blocks with some ply glued to the bottom that I use for sanding.

 

When Cutting ribs I make a ply master rib and then push pins through the wood which secures it to the balsa for cutting, the pins are then secured with cyno and cut down. I also find it it easier to use wood that is not too soft as it cuts better and easier to sand and build with.  I prefer the snap off blades for cutting as I have a fear of the surgical type blades that have metal handles that can roll around and fall off the workbench into my foot     

[leccyflyer]

Just on the topic of the cylindrical knife handles rolling off the edge of the bench and going through your foot 😮, I've long found that a simple gutter along the front of the bench is a fantastic addition to a workbench, which can also serve to trap small bits, nuts, bolts and screws and on my main assembly bench, which is my old draughting machine, also houses my long rulers, lengths of carbon rod, piano wire, razor saw, clothes peg clamps and other sundries.

 

If you don't fancy a gutter, a simple wrap of masking tape around the handle to make a flag will stop the knife from rolling. They aren't my favourites anyway, and are kept for specific jobs, such as hinging control surfaces, as I prefer the Swann Morton scalpel handles.