Cutting Pieces Off Sprues

[Crazy Snap Captain]

Hi all,

When I cut pieces off sprues I usually get as close as possible to the piece and cut it flush using some rather expensive fine tip sprue cutters (I've invested in a pair of Tamiya and Mineshewa items). Most of the time the result is ok but sometimes the plastic gets a little gnarled on the piece or you get that white bit that just won't go away with filing? Does this make sense? Is what I'm doing the right way of cutting piece off the sprue? What techniques do you use?

[JesniF-16]

Hey Andrew. I always leave about 1/32 to 1/16, I never cut the sprue off flush... There is a chance to cut the sprue a bit too flush and leave some undercut. First I use a hard file to take it down "flush" and I follow that up with a fine grit sanding stick or block. I'm sure there are other ways but this method works for me.

/Jesse

[J-10]

I use a sprue cutter, but I leave about 1mm of the sprue bit on the piece. When I get the piece off the sprue, I use a hobby knife to trim the excess 1mm sprue bit off, then sand if needed.

[Triarius]

The "white bit" you refer to is merely a bit of strained styrene. It does not have to be removed beyond being flush with the part surface.

I use essentially the methods already described.

[White Wolf]

Been trying to find out the best way for this too. I leave a little bit of sprue on the piece and then use the sprue cutters to trim it as close as possible to the surface. Then a hobby knife to shave off even more, followed by some light sanding to get rid of the last bits. I stop when I can't feel the nub when I run my fingernail over it, but sometimes a coat of primer reveals the nub again.

[spejic]

If the connection point is along the bottom edge and the part is thin, I use something with a scissor action to remove the part. In many situation, this gives a perfect cut that does not require sanding.

[Jim S]

FWIW,

When it comes to removing parts from trees I find myself using the JLC saw more and more. Especially on clear parts as the plastic is more brittle and less

forgiving. It is also a hassle to deal with when it comes to filling and sanding.

It is nice when you can use the methods provided above, especially spejic's.

When I can use it, I just think the saw makes a clean cut, and it avoids stressing the plastic to the point of where it becomes hardened or just plain old tears

out.

It also takes more time but If I can't make a clean cut off of the tree with the saw, I chop the tree with nippers, leaving the stub long and finish it

with the saw and a light sanding or a swipe with an exacto.

Hope this helps,

Jim S

[toadwbg]

Chuck Norris doesn't need sprue cutters.

He just stares at the part and the sprue backs away in fear.

Edited December 15, 2013 by toadwbg

[Triarius]

Chuck Norris doesn't need sprue cutters.

He just stares at the part and the sprue backs away in fear.

If not, a flying roundhouse kick usually does the trick …

Have to try that, sometime …

[Netz]

Lately for pieces like wings and fuselage, I just leave the sprue stub a little long, once the fuselage or wing half has been glued I take my file and file the seam smooth,no worries about divots or stressed spots.

Curt

[Crazy Snap Captain]

Thanks for the tips lads! More knowledge gained...

[balls47]

One more post for clear parts. Use an old #11 blade (we all have plenty of those) and heat it up with a candle flame. Cuts down through clear sprue like a hot knife through butter. Use little, if any, pressure to cut the clear part. Usually, just the weight of the blade and knife will do it. Of course, cut back from the part (usually a canopy) just a smidge. Then, sand the rest of the nub off until you are happy with your work.

[jester292]

One more post for clear parts. Use an old #11 blade (we all have plenty of those) and heat it up with a candle flame. Cuts down through clear sprue like a hot knife through butter. Use little, if any, pressure to cut the clear part. Usually, just the weight of the blade and knife will do it. Of course, cut back from the part (usually a canopy) just a smidge. Then, sand the rest of the nub off until you are happy with your work.

I've been using this method with clear parts for a couple years now. It really is best for removing clear parts with practically no risk to cracking the parts.

Aaron

[randypandy831]

Lately for pieces like wings and fuselage, I just leave the sprue stub a little long, once the fuselage or wing half has been glued I take my file and file the seam smooth,no worries about divots or stressed spots.

Curt

this. I've heard a few people who do this. I need to give it a try. I mainly have a problem with rounded edges. some folks even use a razor saw to remove from the sprue. this is key with some revell/monogram kits since their attachment points are extremely close to the parts.

[Check Six]

FWIW,

When it comes to removing parts from trees I find myself using the JLC saw more and more. Especially on clear parts as the plastic is more brittle and less

forgiving.

Jim S

How thick are those saw blades?

I bought X-Acto (X215) saw blade but it's like 1mm thick! The teeth are too course for plastic; more likely for wood.

[Jim S]

How thick are those saw blades?

I bought X-Acto (X215) saw blade but it's like 1mm thick! The teeth are too course for plastic; more likely for wood.

Hello,

I would have to say the blades are thinner than a #11 blade, maybe even a little thinner than a single edge razor. The blades are tempered/hardened for strength

and have teeth on both edges.

Here's are links to a couple of pop ups at UMM-USA.

http://umm-usa.com/onlinestore/popup_image.php?pID=35

http://umm-usa.com/onlinestore/popup_image.php?pID=34

For what it's worth JLC's saw has been around for a while so no doubt others have created like products by now,or offer thieir own blades that might fit

JLC's handle.

I have some of the X-Acto Blades you mentioned, and you're right. They're better for balsa or basswood.

Hope this helps,

Jim S

[Check Six]

Hello,

I would have to say the blades are thinner than a #11 blade, maybe even a little thinner than a single edge razor. The blades are tempered/hardened for strength

and have teeth on both edges.

Here's are links to a couple of pop ups at UMM-USA.

http://umm-usa.com/o...mage.php?pID=35

http://umm-usa.com/o...mage.php?pID=34

For what it's worth JLC's saw has been around for a while so no doubt others have created like products by now,or offer thieir own blades that might fit

JLC's handle.

I have some of the X-Acto Blades you mentioned, and you're right. They're better for balsa or basswood.

Hope this helps,

Jim S

Thanks for the reply.

Are those blades worth the investment to you?

I could have used one a couple of months ago but I made due.

What I like about them is the thinness of the blade and the micro teeth. But theory and functionality are two different animals.

[dnl42]

Completely agree with using JLC saw for removing items.

Removes material in a very fine kerf without stressing the part the way snips or a blade can.

In additiont to the JLC saw, I can recommend the Contour, Micro, Nano, and Pico saws from RB Productions, especially for small tight spaces. I just got the micro and nano saw a few weeks ago, and I Really Like them. RB also has a saw handle and blade similar to the JLC saw.

As also noted, cut slightly away from the part and then trim, so you don't risk cutting into the part. It only took cratering a couple o' parts to learn this technique.

[Check Six]

Completely agree with using JLC saw for removing items.

Removes material in a very fine kerf without stressing the part the way snips or a blade can.

In additiont to the JLC saw, I can recommend the Contour, Micro, Nano, and Pico saws from RB Productions, especially for small tight spaces. I just got the micro and nano saw a few weeks ago, and I Really Like™ them. RB also has a saw handle and blade similar to the JLC saw.

As also noted, cut slightly away from the part and then trim, so you don't risk cutting into the part. It only took cratering a couple o' parts to learn this technique.

Thanks for the link.

Very nice variety of tool-cutting options.

[Jim S]

Thanks for the reply.

Are those blades worth the investment to you?

I could have used one a couple of months ago but I made due.

What I like about them is the thinness of the blade and the micro teeth. But theory and functionality are two different animals.

It was worth it to me, but I am also a "make due" kinda guy so I know what you mean. I just kept an eye on the prices and when JLC's anniversary set went on sale I purchased it. It's pretty much all I use to remove parts from trees anymore.It is nice having the control to not tear or stretch small parts nor have them fly off in to the abyss. The saw is also awesome for vacu-form canopies. As far as functionality I think the blades are hard enough to cut aluminum or brass (but I never have) and work great on plastic. I primarily use the fine side as it takes less effort to "start" and makes a finer cut. One thing I use the more aggressive edge for is re-scribing. Either skimming it along a piece of dymo tape to restore a line that has been partially removed, or drawing the corner point of the blade along the tape to create a brand new line. Basically creating a fine furrow that a scribing tool will (hopefully) not wander out of. I model with "fists of ham".

Right now the basic saw with two blades is $12.50- http://umm-usa.com/onlinestore/product_info.php?products_id=35

The Anniversary set contains 3 blades plus the spacer/extender which I have never used and don't really see having a use for. Maybe re-scribing parallel panel lines, don't know. I think I'm going to try sandwiching a spare blade between two pieces of spacer stock and using the blade "free hand" without the handle.

As far as RB Productions go, I don't have their saw but everything else I have ordered from RB is of excellent quality and he offers great service. Radu is a clever guy and is always coming up with something new and useful. I wouldn't hesitate to purchase from him again if he had something I needed.

In the end it all comes down to you, and what kind of models you build. It was worth it to me because I use it all the time.

Hope this helps,

Jim S

Edited December 23, 2013 by Jim S