Cutting and shaping masts: tips on how to do it.

[Peterhudson]

I am halfway through a Kit model of HMS DIANA (progress in the build blog section) - I have arrived at the ‘making the masts’ section.  I can work most of the processes out and read up methods in various guides,  I have a small lathe to allow me to shape the spars and yards and will experiment in due course.  The area that perplexes me is the method by which the top section of the mast is cut square so that the main top and cross trees/trestle trees can be attached to the mast.  I want the top section to be neat and correctly square so doing it by eye is fraught with danger.  Any clues on how to turn the top section of 10mm walnut dowel into a true square??  Peter 

[VinceMcCullough]

Peter

 

since you have a lathe, I’d do it the other way around. Start with a piece of square stock, shape the top to the appropriate dimensions and then turn the rest of the mast to the required round cross section. To make this easier you might want to plane the portion to be turned down to an octagon.

 

Vince

[Bill Brown]

Definitely agree with Vince, I think it’s better to start from square stock.    It’s easier to drill all your holes first prior to rounding.    You can use the 7-10-7 rule to turn your square stock into an octagon.    I typically just use a hand drill for rounding as I don’t have a lathe but a lathe is better still.   Best of luck

 

Bill

[Peterhudson]

Thank you Bill and Vince for your advice.  I will certainly try this method, especially transitioning via an octagonal shape however, I do have a lot of good quality walnut dowel which ideally I would like to use.  The advice in one of my modelling books is to file the end square - again this seems a little rough and ready.  I’ll continue to mull this one over. 

Peter 

[wefalck]

Don't know what lathe you have, but having/making some sort of dividing stops at the spindle will be a very valuable modification to the lathe. The watchmakers have what is called a filing rest as attachment for their lathes, which allow to do exactly what you want to do, namely filing square flats onto round stock. If you are interested, I can provide more details.

[shipman]

Hi wefalck. I have Unimat SL and 3. Never seen a filing rest made or adapted for these.....any suggestions, please.

[allanyed]

An extremely detailed description on making the lower masts is in Volume IV of David Antschel's The Fully Framed Model.   It will likely answer all your questions on how the mast parts are made and assembled.

Allan

[wefalck]

A filing rest basically consists of two (normally hardened) rollers that can adjusted in height. Opinions diverge, as to whether the roller should be placed outside the workpiece or the workpiece in between them. I think both ways work. Here is a more or less random example from the WWW:

Here a guy makes such a filing rest for his Taig-lathe: http://www.deansphotographica.com/machining/projects/filingrest/filingrest.html

The design probably could be simplified and adapted to the Unimat. You either need a bridge between the two bars or make it as an attachment for the cross-slide. There is one available commercially for the Sherline, but the price is indiscently exaggerated.

 

 

The height is adjusted by a nut and a locking nut:

 

 

You then also need a kind of brake or stop for the headstock spindle. There are many different ways for doing this ...

 

 

 

 

[shipman]

A picture is worth a thousand words. Thank you for that.

[druxey]

Seems like using a sledgehammer to crack a nut. None of my masts and spars have seen a lathe. It is not difficult to start with square stock marked out (don't need a four jaw chuck!), cut it eight-square except fo the square sections, then round off the parts that need it, using strips of sandpaper back and forth until the 'flats' just disappear. You don't need a lathe with a long bed ($$$), 4 jaw chuck ($$), steady ($$), filing rest ($$) or other paraphernalia. Just pencil and rule, sharp chisel and sandpaper. There; I just saved you a ton of money!

[Jim Rogers]

Milling Machine

 

[shipman]

Lathes, milling machines, band saws, bench saws, Proxon this, Proxon that.

When did this hobby become a rich man;s preserve?

Oh, I forgot, you will never get the affluent to admit to having enough.

There's never been a ship model subject that couldn't be entirely built using simple hand tools and a will to do it.

[Justin P.]

3 hours ago, druxey said:

Seems like using a sledgehammer to crack a nut. None of my masts and spars have seen a lathe. It is not difficult to start with square stock marked out (don't need a four jaw chuck!), cut it eight-square except fo the square sections, then round off the parts that need it, using strips of sandpaper back and forth until the 'flats' just disappear. You don't need a lathe with a long bed ($$$), 4 jaw chuck ($$), steady ($$), filing rest ($$) or other paraphernalia. Just pencil and rule, sharp chisel and sandpaper. There; I just saved you a ton of money!

I agree, I actually found using a lathe to be more work.   I tried at first because I had one, and wanted to use it.   Eventually I settled on square stock, an Ibex finger plane and sand paper.   Much easier.   

[wefalck]

Machines are for clumsy people like me ... I would indeed start with round stock and mill on squares with my milling machine and the dividing head.

 

I also think that, when you are working on more modern ships, where machines were used to make them, you need some form of machine tools to reproduce the exact shapes required. This is not to say, that there aren't some gifted individuals who are able to produce geometrically exact shapes (round or other) just with hand-tools. For most other people the difference will be visible.

[shipman]

I wouldn't let a clumsy person near a screwdriver. But I do appreciate your point of view.

[wefalck]

It has perhaps also something to do with patience. I myself am very patient, when I can be reasonably sure of the satisfactory outcome of an operation, but become rather impatient, when I am not sure - rather counterproductive, I know. If I had to shape spars by hand, I would be rather unsure that I get it right the first time, which surely leads to scrap. If I do it with the aid of a machine tool, I know that my own, uncontrolled movements are eliminated and success only depends on how cautiously I turn cranks and plan the machine movements.

[Justin P.]

I think people can sometimes get bogged down in equipment and machine tools if led to believe they are "needed" to achieve a satisfactory result.    I think if your are an efficient and knowledgeable user of mills and lathes then by all means, we all do things our own way.    Not knowing someones experience or skill set with mills and lathes, they wouldn't be my recommendation for something like masts and spars. I think its important to remember that perfect results from machines require a certain level of understanding and knowledge with those machines.   Hand tools, in my opinion,  can be a bit more forgiving even if result as not as exact. 

 

I know my scrap pile consists of far more machine mistakes than it does mistakes made by hand tools.