Any “precision aid” tools?

[Kaede45]

I have been kitbashing a lot & I’ve been having fun with it, but being a perfectionist I often run into the problem of “this hole is off-center” or “these parts aren’t lining up correctly” & so on…

 

It’s very hard for me to just let it go & sometimes I spend too long trying to correct a mistake or perceived mistake & so I was wondering if anyone knows of any tools that can help with precision? Something to help find the center point of where to drill a hole, maybe something to keep the drill centered, a more efficient & durable way to fill in mistake holes than liquid green stuff, etc.? This could also apply to painting & gluing, such as best tools for painting eyes or way to more precisely & conservatively apply glue.

 

As always, any & all help is greatly appreciated, thank you very much for your time & God bless!

[apologist]

The best technique I’ve been taught for getting holes drilled straight (for gun barrels and so forth) is to push the tip of a craft knife into the area before drilling. It’s much easier to get precise, and the subsequent drilling is then guided in. 

[Grotsmasha]

8 hours ago, Kaede45 said:

Something to help find the center point of where to drill a hole

 

A trick for this is a needle. Use a pen and draw an "x" on the barrel to find centre, take the needle and poke the centre leaving a small hole. Then drill a pilot hole with a finer drill piece than the finished size you want, then drill with your intended size. The pilot hole will prevent the drill bit from wandering.

 

8 hours ago, Kaede45 said:

a more efficient & durable way to fill in mistake holes than liquid green stuff, etc.?

 

Sprue Goo. It's a hobby cement and filler you create yourself by combining old, cut up sprue and Tamiya Thin Plastic Cement. Depending on how much sprue you put in the Tamiya, you can make a very thick goo, or a thin goo. What the result of this is, a glue that also gap fills, that is also the same plastic used to make the models, making it easy to scrap, sand etc.

 

8 hours ago, Kaede45 said:

best tools for painting eyes

 

There's really nothing to make this easier other than a small brush and practice. The best technique I can offer is the following;

1- paint in the horizontal white line, you do not need to be perfect with this one.

2- paint in the vertical black line, intersecting the middle of the white line, or off centre if you'd like the model to looking in a certain direction.

3- this is the only hard part, MATCH the second eye to the first, the same width, and centring of the black vetical line.

4- paint in the flesh colour above and below the eye horizontally to clean up any overspill.

 

8 hours ago, Kaede45 said:

precisely & conservatively apply glue.

 

For glues, there are thick and thin versions of most out there. I've found GW's plastic glue applied through the nozzle to be not particulary "runny" vs. Tamiya Thin which is SUPER runny. For super Glue I use the little bottles than come with an applicator brush as the lid.

Edited March 4 by Grotsmasha

[Moonstalker]

Automatic center punch to mark the center before you drill.  Dial calipers for precise measurement to locate the center.

[Firedrake Cordova]

As @Grotsmasha mentioned it, Vince Venturella has a video on "sprue goo":

 

On the subject of eyes, you want a paintbrush that comes to a fine point, and paint that flows well (e.g. add flow improver or use Contrast for the pupils). One of the problems with small brushes is that they don't hold much moisture, so the paint dries on the bristles quickly - to some extent, this can be mitigated by using a 0 that comes to a fine point, instead of a 000.

[Heraclite]

17 hours ago, Grotsmasha said:

On 3/4/2025 at 4:01 PM, Kaede45 said:

best tools for painting eyes

 

There's really nothing to make this easier other than a small brush and practice. The best technique I can offer is the following;

1- paint in the horizontal white line, you do not need to be perfect with this one.

2- paint in the vertical black line, intersecting the middle of the white line, or off centre if you'd like the model to looking in a certain direction.

3- this is the only hard part, MATCH the second eye to the first, the same width, and centring of the black vetical line.

4- paint in the flesh colour above and below the eye horizontally to clean up any overspill.

THIS ! so much !

 

I always struggled painting eyes after the flesh was done, but for the last 3/4 heads I did I started by painting the eyes. This way you don't have to be too precise with the white of the eyes, only the pupils, and you clean up around it when you paint the flesh tone

 

For drilling barrels, I use my smallest drill bit by rolling it between my fingers (without the pin vice) approximately on the center of the barrel, 90% of the time I'm spot on and just use bigger and bigger drill bits till it's the right size.

 

On the occasions when I'm off center, I just "correct" the hole with a hobby knife by carving a little on one side of the hole to make it more even. this step has to be done before the last size of drill bit is used though. Then I use a bigger drill bit till I get to the desired size

[sbarnby71]

For applying glue:

 

Tamiya Extra Thin Cement 

Has a big(ish) applicator brush, but as it is so thin, you don't need to be too accurate.

 

Super-Glue 

Add a drop or two to a spare bit of card and then use a dental pick to take a tiny spot of glue to apply where you need, you waste a lot, but get great results.  You can use a wooden cocktail stick, but I use a dental pick as I can break the super-glue off it once it's dried and I get a nice clean point again

 

For barrels, I use the scalpel tip to try and make an initial mark, then use a super-fine drill bit, then go bigger.  Can't say it's 100% sure fire way, I've biffed many a barrel in my time!

Edited March 5 by sbarnby71
extra bits

[Ryno]

For applying small amounts of super glue, you can cut off the end of the loop from a sewing needle so you're left with a Y shape. When you dip the open end into super glue, the surface tension of the glue will allow you to hold a small drop in that Y for accurate placement. Bigger drops for thicker glues, smaller for thinner.

For barrels, aside from trying to accurately make a pilot hole to prevent the full size bit from wandering, another thing you could try is get a short length of copper/aluminum tube that just perfectly fits over the barrel of the gun you're drilling. If that tube is about 10-15mm long or more, you can then put in a piece of rod/wire with a sharp end point, or a larger bit, down through the tube, and use that to mark the centerpoint perfectly every time. Then you can drill with the correct size bit and you'll have an accurate pilot hole. If you still find that challenging, depending on the style of gun you could saw off the barrel and replace it with a short length of thin tube. That'll be tricky to get on straight, though, so I'd only do it if you screw up the drilling bad enough.

As others have said, SprueGoo is a fantastic tool as well.

[Kaede45]

Thank you all for the advice!

 

 I will say though, on the topic of drilling holes, I was actually referring to the holes that I’d make to put magnets into. Torsos, heads, hands, arms, etc. sometimes the arms have holes that I can just deepen/widen, so they’re not always a problem, but they can be at times.

 

I should also ask if anyone has any advice for figuring out how deep to drill. Since I’m using magnets that are 2mm x 1mm, it’d be nice to know when I’ve drilled 1mm deep so I don’t drill too deep.

 

Thanks again!

[sbarnby71]

Drill bigger then you can fix the magnets in some green stuff.

[Firedrake Cordova]

2 hours ago, Kaede45 said:

I should also ask if anyone has any advice for figuring out how deep to drill. Since I’m using magnets that are 2mm x 1mm, it’d be nice to know when I’ve drilled 1mm deep so I don’t drill too deep.

You could put a sleeve over the drill bit which would act as a depth-stop? Or paint a stripe on the drill bit at the appropriate point?

[Heraclite]

Just go slowly and check your magnet with the hole regularly until it fits completely. But as @sbarnby71 said, you can just drill a bit bigger than your magnet and set it in green stuff, or just glue it slightly recessed in the hole, it will hold just fine for small parts like arms/backpacks etc.

 

The important part is to make sure that one of your magnets doesn't stick out of its hole otherwise it will create a slight misalignement that can be pretty visible and mess with the overall silhouette of your model

[Grotsmasha]

19 hours ago, Kaede45 said:

I should also ask if anyone has any advice for figuring out how deep to drill. Since I’m using magnets that are 2mm x 1mm, it’d be nice to know when I’ve drilled 1mm deep so I don’t drill too deep.

 

You want the whole 20-40% deeper than the magnet, if the hole is too perfect, the magnet won't sit flush as the glue won't have anywhere to go. When seating the magnet use a flat metal surface larger than the hole, such as the flat of your hobby knife. You'll be able to push the magnet in flush, but no further.

To gauge your depth, mark your drill bit. You can do this with a piece of tape marking the correct depth to stop, or by painting the tip so that you stop when you can't see the paint.

[Heraclite]

3 hours ago, Grotsmasha said:

When seating the magnet use a flat metal surface larger than the hole, such as the flat of your hobby knife.

I prefer to use a flat non metal "tool" like a coffee stirrer, but it may be because the super glue I use is rather cheap and doesn't set right away. If I use any sort of metal tool anywhere near the magnets and the glue, I generally end up making a big mess with glue everywhere as the magnet jumps out of it's hole and sticks glue side first to the tool