Cutting out doors: Your techniques for keeping your blade straight?

Hey everyone, I'm new here, and this place inspired me to start building models after a 10-year hiatus :grinyes:. Anyway, my question is this: How do you make a "straight" cut through the plastic from the outside? That is, I want to cut with my blade at 90 degrees to my surface. When I cut with the back of an X-acto blade, I find that I usually end up leaning the blade to one side, which means I have an unwanted, angled edge when I'm finished.

I've considered soldering an X-acto blade to a small aluminum cube to keep it upright when cutting, but I'm not sure if I can get exert the right amount of pressure on it for it to be a useful cutting tool.:screwy::screwy::screwy:. Anybody have any ideas, or homebuilt tools?

Nick

The best thing I ever found for that were some photoetched blades made by Scale Racecars. They were almost like a hook, like a dental hook or something, but were astonishingly thin since they were photoetched metal. Unfortunately, Scale Racecars is "closed pending catalog updates." Maybe somebody else, like CrazyModeler, makes something similar?

I think you're going to be in for a bit of a challenge soldering an Exacto blate to an aluminum tube....

The best way to remove a door is to have a new door (say a resin one from a transkit) to install in the hole the original door was removed from. Cutting apart a door from a body and having both still be usefull is harder than it would seem.

But if I were going to try it, PE saws would be the way I would go. Here's my review (http://www.automotiveforums.com/vbulletin/showthread.php?t=549695) of Crazy Modeler's set.

I think you're going to be in for a bit of a challenge soldering an Exacto blate to an aluminum tube....

The best way to remove a door is to have a new door (say a resin one from a transkit) to install in the hole the original door was removed from. Cutting apart a door from a body and having both still be usefull is harder than it would seem.

But if I were going to try it, PE saws would be the way I would go. Here's my review (http://www.automotiveforums.com/vbulletin/showthread.php?t=549695) of Crazy Modeler's set.

Thanks for the link to your review:). I don't have a resin door to install, but I figure I can always buy another kit to use a second body.

here's a quick little paint program image that explains how I open panels.
http://i108.photobucket.com/albums/n4/rsxse240/model%20stuff/cutoutpanel.jpg
then I just add a hinge, or pins or something to hold it in place and badabing, smooth minimal gap doors, without hacking up two or three kits!

^^^^^
Excellent explanation :)

In addition, when cutting don't try to do it all in one go. Slowly scribe out the panel lines with a very sharp scapel etc. You'll end up working around the shutline quite a few times but this method allows far greater control and thus makes it much easier to keep the cut straight.

Another solution - albeit a slightly expensive tool to some - is a jeweler's saw.

The beauty of a jeweler's saw (which looks like a miniature coping saw) is that its blade is a thin flexible one with barely any cross-section, giving it the ability to change direction quickly.

The way you use it is to drill a small hole through the panel gap, feed the blade of the jeweler's saw through the hole, pull the blade taut and reattach it to the saw frame, then slowly cut your door out following the panel gap easy as cake.

The catch? The list price on an Exacto-brand jeweler's saw at your local hobby shop is going to be somewhere around $35. But, if you plan on regularly doing precision bodywork like opening doors, it's the best tool for the job.

http://www.theringlord.org/albums/Tools/Jeweler_s_Saw.jpg

Another solution - albeit a slightly expensive tool to some - is a jeweler's saw.

Never tried one out on plastic, but used to use one quite often for silverwork ages ago & although very versatile in the shapes it can cut, imho a very sharp scalpel blade would give a finer cut, especially as it's slicing not sawing.

I used the scalpel method that I described earlier to cut all the doors & bonnet (there's no bootlid) on a Gunze AH Sprite body. Just dug it out from amongst all the detrius on my work desk, and the door gaps are very tight,to the extent that I think I'll need to sand the edges more to allow for the thickness of the paint!

Thanks for the advice, guys! Is a scalpel blade thinner than a #11 X-acto? If so, where do you get them? I'll probably pick up a jeweler's saw as well. I've been using the back edge of a #11 for all of my cutting duties.

Great, thank you for the ideas and diagrams. Rsxse240, that's basically the technique I've been trying out.

Is a scalpel blade thinner than a #11? If so, where can you buy them?

I'll probably pick up an X-acto saw as well.

Use thread as a saw, it works very well, although it breaks alot, it cuts very thin.

I got a Zona jeweler's saw for about half the price of the Xacto one, seems like a quality item to me. With a fine saw blades you can get some excellent, very precise cuts. The night I got it I went saw happy and cut a ton of stuff just for the heck of it. It even works great for stuff like cutting out the molded floor from a car or truck chassis: Lots cleaner and more accurate than a Dremel, and about as fast too.

However, I don't know that I am precise enough to cut out a door with it. I would just use the blade/scribe method and glue some thin strip styrene to the edges to fine tune the fit. Kind of like rsxe's way, but I think it will be a little quicker. Six of one, half-dozen of the other (Only my half-dozen are better :smokin: )

Those 'click' knives, where you snap the tip off to get a new one, seem to work quite well to. Probably because of the angle of the tip and how you hold the knife in relation to the piece. Just go slow with the first few passes and get a good groove built; I've put some decent scars in doors, and myself, by going to fast and slipping out of the groove.

Use thread as a saw, it works very well, although it breaks alot, it cuts very thin.

I ve used this technique many times, it cuts razorsharp, very very thin and needs not much cleanup. I vote for you :)

Oli

rsxse240:

I love your drawing. Very easy to follow. Thanks,

haha, thanks, it's a talent! hehehe

I agree with rsxse's method, but I don't think you need the BMF. Just wait for the side-panel putty to set up a bit, then press the door into it. It will form perfectly without sticking to the door.

I also use thread to open doors/hood/trunks. Thread works nice because it cuts thin and follows the panel line. Just slowly pull the thread back and forth and it cuts like a hot knife through butter. Then just lightly sand the edges.

I used this method to open up my RX-7

http://img.photobucket.com/albums/v389/talon_454ts/RX7Ph8-1.jpg
http://img.photobucket.com/albums/v389/talon_454ts/RX7Ph8-2.jpg