Another G3 brake van

[JimG]

Are you experimenting with the body sides already built up? I would be very interested to hear more of your experiences.

Jamie,

I'm doing the chamfering when I'm milling the sides. I've just started modelling a Drummond Caledonian Diag.5 brake van - yes, another brake van which was started on paper before yours and Steve's appeared on here.

The curb rail of the van has a series of bolts or tie rods along its length with chamfering in between and I wanted to try and reproduce this. I was also looking ahead to the modelling of some Caledonian vans which have heavy outside bracing with chamfering and this would be a good test bed for methods.



I've used a 2mm ball end slot drill and positioned it to cut at 45 degrees with a depth to match the dimensions of the chamfer as near as possible. The results look good and the ball end mill gives a nice transition at the ends.




As usual you can hardly see any detail with white Plastikard so I messed about on IrfanView to accentuate the chamfering.


...which makes it just a bit more obvious.

I had thought of using a 3mm ball end slot drill but thought that the increased diameter might be a problem when dealing with the cramped conditions at the top of a diagonal on a van side.

At the moment there is a pause until I investigate a method of engraving planking to do the inner sides of the verandahs - just waiting on some engraving cutters coming from China.

Jim.

 

[jamiepage]

That really is clever Jim, and congratulations on superb results.
I fear I'm probably stuck with scratching away although you have given me an idea. I will look at a conical cutter set up in my mini router table with a follower to control depth. It might be possible to go deep enough into the acute angles and - if it works - it should provide the all important consistency. Not sure if I have a small enough cutter/ follower though.
Even in G3 the chamfer is probably only around .020 in. but it could easily look bad if too inconsistent.
Thanks again.
Jamie

 

[Steve Cook]

Nice chamfering of the outside framing, Steve. It makes all the difference if done properly.

Thanks Jamie - it was definitely worth the effort even if at times I wish I hadn't started it. I did it all by the scraping method in the end, although some form of jig would make it far easier and more consistent. I think the challenge is to come up with something that can cope with a variety of material sizes, I'm not there yet.

The latest mock up looks great, how did you do the taper on the end stanchions?

Jim, as ever, that looks superb

Steve

 

[jamiepage]

Steve, just tacked them all together on a carrier and milled them as a block in an angled vice.

 

[Steve Cook]

Thanks Jamie.
I always fail to consider machine tools in my minds eye when I look at plasticard construction, despite what you and Jim do
Steve

 

[Mike W]

"I always fail to consider machine tools in my minds eye when I look at plasticard construction"
Nicely put Steve - me too! Totally illogical and the projects on here are certainly food for thought on that.
Mike

 

[JimG]

"I always fail to consider machine tools in my minds eye when I look at plasticard construction"
Nicely put Steve - me too! Totally illogical and the projects on here are certainly food for thought on that.

Mike,

The key is to use carbide tooling for any rotating cutter - HSS or carbon steel will just cause melting during the cutting. I presume that this is because the carbide tools are so much sharper and cause less heat when working.

Jim.

 

[jamiepage]

Couldn't pluck up enough courage for the router table for chamfering, so started scraping away. A couple of fences to help and it's ok, but lacks the crispness a mechanised technique could have supplied. The chamfered ends of the chamfers could be better, but overall it takes away the harshness of undressed sections.

 

[Steve Cook]

Looks good to me Jamie
I will also be stealing the 'colouring in' technique to help get a more consistent result next time round, such a simple idea but it passed me by completely...
Steve

 

[JimG]

That's a pretty mean scraping hand. Looking excellent.

Jim.

 

[jamiepage]

Steve, I would suggest something rather less aggressive than the permanent marker I used. This particular one was the devil's own job to remove, fully living up to its name, and emerying was just de- crisping the job even more.
It really needed solvent which didn't seem like a good idea so that's one thing that doesn't translate from metal bashing to plastic.
Anyway, with some wishful thinking perhaps the residual traces will generate a subtle weathering effect under the paint- or just a horrid mess.
A soft pencil has worked just as well on the latest bits.
Jamie

 

[jamiepage]

Jim,
Sorry, we crossed. Thank you.
Jamie

 

[Dog Star]

How about using one of the non-permanent marker pens? I am referring to those for use with whiteboards... generally such markers are washable. Or maybe a strip of masking tape? (make a small fold at one end so as to ease removal of the tape after forming the chamfer).

regards, Graham

 

[adrian]

Steve, I would suggest something rather less aggressive than the permanent marker I used. This particular one was the devil's own job to remove, fully living up to its name, and emerying was just de- crisping the job even more.
It really needed solvent which didn't seem like a good idea so that's one thing that doesn't translate from metal bashing to plastic.

Have you tried using a little lighter fuel on a paper towel? Try it on a bit of scrap plastic first but it won't melt the plastic but may will remove the permanent marker, it does on the permanent markers I use.

 

[jamiepage]

The non- permanent markers would be just right Graham, thank you.
And thank you Adrian, I'll give it a go.
Jamie
All the chamfering done now. Almost too much fun for just one day.

 

[jamiepage]

Jim,
Just a thought because you said you were awaiting cutters from China. Have you tried Pantograph Services? I use their orange banded (carbide) cutters, and they grind to order. I normally use 2mm dia. D cutters for general profiling but they will grind to any diameter. Certainly 1mm because I've had a few, and they will also grind to a point with an inclusive angle of your choice. I forget what shank diameter they use, probably 1/4 in. or 6mm., and the reduced dia. parallel end need only be as long as you want it to help reduce breakages.
Jamie

 

[JimG]

Jim,
Just a thought because you said you were awaiting cutters from China. Have you tried Pantograph Services? I use their orange banded (carbide) cutters, and they grind to order. I normally use 2mm dia. D cutters for general profiling but they will grind to any diameter. Certainly 1mm because I've had a few, and they will also grind to a point with an inclusive angle of your choice. I forget what shank diameter they use, probably 1/4 in. or 6mm., and the reduced dia. parallel end need only be as long as you want it to help reduce breakages.

Jamie,

Thanks for the pointer to that supplier - I'm always interested in new sources but I haven't considered getting cutters specially ground for me so far, probably put off by the thought that there might be an extra cost involved. I source my carbide slot drills from Drill Service

http://www.drill-service.co.uk/Product.asp?Parent=100040020000&Tool=76

...who have a cheap (£6 - £7 each) series of cutters in 0.5mm and 1.00mm which I am tending to make my preferred size of cutter. I also go to 2mm and 5mm if I have a large area of surfacing to do.

I started looking for very fine point engraving cutters to see if I could engrave planking and couldn't find anything off the shelf in the UK. I had been thinking about this for quite a while to cut the door lines on coach sides but hadn't got round to doing anything about it. The more complex planking on the Drummond brake van forced the issue. I did find a supplier in the US - Bits&Bits - who did a range starting from a tip size of 0.o01"

http://bitsbits.com/index.php?main_page=product_info&cPath=4_43&products_id=355

...with quite a good price compared to what I was paying to Drill Service, but the postal costs from the States were horrendous - $36 to ship four of them which virtually doubled the costs. So I used their tool descriptions in Google and came up with a lot of hits on Ebay with really cheap prices and free postage from China. So I am waiting on a pack of ten 0.1mm cutters for a total cost of £6.95. I know that I might be getting what I am paying for but since I'm only looking at engraving on styrene, they might be good enough, and I can almost look at selecting the best from the ten and chucking the poor ones away.

I hope to get them by next week - they reckon 7 to 10 days for shipping.

Jim.

 

[jamiepage]

A quick snap of progress as the slow process of detailing gets underway. The temptation to glue the body together is just about being resisted for the moment because it is so much easier to add detail with each panel in the flat.

 

[jamiepage]

This van also required a wheel- type brake handle. Fabricated from a scrap end of brass, cross- holed and soldered up with brass spokes. Dimensions were scaled from works drawing but the rim looks a little too corpulent so I might skim a tad off.

 

[Dog Star]

Without the pikkies I would not have guessed as to the construction method - excellent approach. I can think how you made roughly 3/4 of the cross-section of the rim... how did you achieve the inner 1/4 furthest from the front face of the bar stock?