I plan on building a turntable bridge using Central Valley Plate Girders
http://www.shop.cvmw.com/72ftPlateGirders-2-1903-1.htm
They will need to be cut and possibly notched. I assume I can't use a high speed tool which will melt the plastic. Using a razor to cut completely thru may require a lot of effort.
Would a razor saw be the best approach, using a metal nibbing tool for rough cutting any notches and using a file to complete the cut?
thanks
greg - Philadelphia & Reading / Reading
Somewhere I seen a tool like this for plastic. Micro Mark? I remember it was used to make window openings in a sheet styrene scratch building project.
Mike.
My You Tube
The "nibbler" may work but I would say two things about it: in my experience I think it works best on styrene sheet rather than the seemingly more brittle styrene that kits are cast out of. I can't speak specifically about CV's plate girders.
Second, it is easier (for me) to use the nibbler on flat sheet styrene, or reasonably flat such as clapboard or corrugated siding, versus the irregular surface (ribs, top beam) of a plate girder (and that depends on the casting and where you intend to "nibble" so to speak).
A really good razor saw cuts through styrene very quickly, particularly if the work can be held in a miter box. For small fussy work I also like the Xacto #16 blade, followed by sanding sticks.
Dave Nelson
A razor saw will work fine, but so would a hacksaw, or a cut-off disc: cut large, then file or sand to-size.
No need to get cutesy with a nibbler...an X-Acto with a #11 blade or a #17 or 18 blade will do notches, as will a suitably-shaped needle file. For heavy-duty cuts, use a utility knife.
Wayne
gregc I plan on building a turntable bridge using Central Valley Plate Girders http://www.shop.cvmw.com/72ftPlateGirders-2-1903-1.htm They will need to be cut and possibly notched. I assume I can't use a high speed tool which will melt the plastic. Using a razor to cut completely thru may require a lot of effort. Would a razor saw be the best approach, using a metal nibbing tool for rough cutting any notches and using a file to complete the cut? thanks
I you are going to splice pieces make cuts along the side of ribs if possible to make splices less conspicious.
I tried to sell my two cents worth, but no one would give me a plug nickel for it.
I don't have a leg to stand on.
I like my razor saw. It gives a good clean cut. For smaller cuts, I use a utility knife with a fresh blade and a metal straight edge to get, will, straight edges. I've used a Dremel, too, but it's overkill and a bit difficult to control.
It takes an iron man to play with a toy iron horse.
anyone ever try a band saw?
I have a somewhat related response, a hint actually. I saw a small hacksaw at the discount tool place, overall length about 8" with handle. I picked one up to try for modeling. Its kerf is noticeably wider than something like an X-Acto saw, but it should work for utility cutting. It shouldn't dull as quickly as a modelling saw, as it's made for metal cutting. The teeth seem fine enough to control the cut well. I have yet to try it.
Genesee Terminal, freelanced HO in Upstate NY ...hosting Loon Bay Transit Authority, run through Amtrak and CSX Intermodal
CP/D&H, N scale, somewhere on the Canadian Shield
gregc anyone ever try a band saw?
A band saw will get too hot.....it actually melts the cutting line. Just about any powered saw will do that. The key to using any powered saw, is to have a proper fence and to advance and retreat the cutting blade during the cut. Takes practice.....a lot of practice. I am able to cut whole sides of some cornerstone buildings and styrene brick streets with a 2'' table saw that way......cut a little...back-off and cut a little again. If You don't back off the cut will melt and jam the blade. Again...It takes practice.
Take Care!
Frank
PS: My current scratch/bash rolling lift bridge project:
The Bridge I'm working on scratch/bashing will be modeled after a Double Track Scherzer Rolling Lift Bridge......some are still in use today:
I've been using a milling machine and a lathe to shape styrene and other plastics. It has worked out exceedingly well. I use standard cutters. I don't slow the speed down much compared to metal.
With a band saw, and a circular saw, I expect the problem is not the teeth, but the broad expanse of sheet metal continually rubbing on the plastic. With a mill or a lathe, that generally isn't the case. If I were to use a cut-off tool on the lathe, that might be a problem, though.
You could lessen the melt problem with the saws by having a lot of set on the teeth. Going the other direction, I often cut styrene by hand with my trusty razor saw, and THAT will do a fine job of melting it if it's tending towards being thick.
A router table would probably work, but I'd be wary of getting my fingers all that close to the cutter. With a mill, you don't put your fingers near the work when the cutter is spinning.
Ed
I recently did some work with styrene that required a number of cuts. Cutting it with an xacto knife proved to be an excersise in futility with the thickness I was using.
I had recently purchased the MicroMark Mini Scroll Saw after seeing it highly recommended on several of the MR forums.
http://www.micromark.com/MicroLux-Mini-Scroll-Saw-for-Hobby-Use
It ended up being my tool of choice for the job. However, it has to be ran on the slowest speed or the styrene melts behind the blade and fuses the cut back together. At the slowest speed, this doesn't happen.
Biggest issue to contend with is that saw blades of this type tend to wander around, so getting a straight cut is a challenge.
You might want to try using a hot wire foam cutter. You can either make one or buy one. There are plans out there. I cannot find the specific one I was looking for on the internet. When I do I will post it here.
I use a jeweller's saw. Like a mini hacksaw, but with very thin, very sharp blades. Blades are about the size of 20 ga wire with teeth in the 60- to 80 teeth per inch range. Very useful.
Robert
LINK to SNSR Blog
RR_Mel I used a CV kit 1902-5 to build my turntable bridge, I used a #11 blade and that worked out great. Mel Modeling the early to mid 1950s SP in HO scale since 1951 My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Aaaaaah!*
*A.K.A. Nice work!