Trouble cutting leather

[allenayres83]

Im having problems with the simplest of things. I am trying to get smooth cut lines. Are my cut lines ever going to be perfect and right on my template lines? I seem to drift off a little. Also when I am making curved cuts they tend to look choppy instead of smooth. I try to sand it down to where it looks like a smooth profile but when I bevel my edge it is very obvious that there is still same jaggedness to my cut. Any pointers on what I could do to improve? I am using a #2 Xacto knife if that matters.

[Jorge700]

La práctica ase la bb perfección

[fredk]

19 minutes ago, allenayres83 said:

Im having problems with the simplest of things. I am trying to get smooth cut lines. Are my cut lines ever going to be perfect and right on my template lines? I seem to drift off a little. Also when I am making curved cuts they tend to look choppy instead of smooth. I try to sand it down to where it looks like a smooth profile but when I bevel my edge it is very obvious that there is still same jaggedness to my cut. Any pointers on what I could do to improve? I am using a #2 Xacto knife if that matters.

I think your blade is too small. Its cutting only a few mm at a time so it can wander easier. The wider the blade the more it cuts. Even a box cutter blade is better

Use a good straight edge for the . . .  errr . . . .straight cuts. When I cut a curve I tend to not only draw the blade around but also to turn the leather. Often, on outside curves I use leather scissors/shears

[zuludog]

Could be that an Xacto blade is too small. A Stanley/box cutter/utility knife has a bigger blade; the handle is bigger/fatter so you get a firmer grip; and they're not very expensive.

You could also consider a clicker knife, with the interchangeable straight and hooked blades, which is a bit more expensive, but not impossibly so. Straight blade for straight cuts; hooked blade for tighter curves

As mentioned by FREDK, if you hold the handle flatter you will get more of the cutting edge in contact with the leather

Firstly mark out the shape of the piece with a scratch awl/round awl; then make a light cut around the template; then deeper and deeper cuts, staying in the same groove all the time till you've cut all the way through

Even new Stanley knife blades work better when they've been stropped

Have a look at YouTube videos for people making the sort of things you're interested in and you'll see how they do it 

[LumpenDoodle2]

My preferred way is to use a leather silver marker around the template, then with the template removed, follow the line with a round awl, then either use a round knife, or for lots of curves, I use a small Stanley knife.   Doing it this way allows me to tweak patterns a little bit for a bit of personalisation for each item, but it also stops me getting into a bit of a rush,, and so not wander off the line.

I also think that it’s important to make sure that whatever knife you choose, it fits comfortably in your hand.   It’s way easier to follow the  curves if you have full control of the knife, and it’s proper sharp.   Stanley knife blades are disposable for a reason, and starting out with a few minutes stropping my round knife is quite relaxing.

Edited January 19, 2021 by LumpenDoodle2

[Hardrada]

Xactos are just one cutting tool to have and they're not suitable for everything.

What weight is the leather you're cutting?

If you have to make several passes with the knife, you're increasing the chances of going off with each pass.

Methinks you need to get additional cutting tools, such as a half-moon knife, a Japanese skiving knife, and an Olfa snap-off utility blade. The latter is probably the cheapest and more accessible and easier to use option for you right now (not that that means you shouldn't procure the others): if you're cutting thick leather you can pull more blade out (I normally pull out the blade(s) up to two notches when cutting >8 oz leather).

https://www.olfaproducts.com/olfa-l-5-fiberglass-rubber-grip-utility-knife-18mm.html

[Webicons]

In addition to the comments above I cannot stress the importance of a strop to polish your blades.  Exacto blades are pretty sharp but a few passes on a leather strop will make it scary sharp.  
Its an easy project too.  Just mount (glue) a piece of vegtan onto a piece of wood.  Load it up with green compound and polish all your blades.  You’ll be amazed the difference it makes. 
 

I’ve used many different blades, some pretty expensive, but I make 80% of my cuts just using a Japanese style skiving knife in aogami blue steel.  You can find them reasonably priced around 40 bucks.  Just my 2c.

[AzShooter]

I normally used a Stanley Knife but lucked into buying a Head Knife from Tandy.  I know, there are better Head Knives but I wanted to test the waters first.

Most important is to keep it sharp.  Stropping is the key but a good set of stones also helps. The reason for the Head Knife is that I can cut curves very easily compared to a straight knife.

I'm still learning how to use it and what platform to cut on.  Self Healing matts work but the knife will get stuck sometimes.  A hard plastic cutting board works but when I'm doing a large cut the head knife is the key.

[Tugadude]

For long, straight cuts, especially on stretchy leather,  I like to use a rotary knife.  I find that you can eliminate almost all of the "pull" that can cause leather to deform as you are cutting it.  If you haven't tried it, I recommend you give it a shot.

[allenayres83]

19 hours ago, Hardrada said:

Xactos are just one cutting tool to have and they're not suitable for everything.

What weight is the leather you're cutting?

If you have to make several passes with the knife, you're increasing the chances of going off with each pass.

Methinks you need to get additional cutting tools, such as a half-moon knife, a Japanese skiving knife, and an Olfa snap-off utility blade. The latter is probably the cheapest and more accessible and easier to use option for you right now (not that that means you shouldn't procure the others): if you're cutting thick leather you can pull more blade out (I normally pull out the blade(s) up to two notches when cutting >8 oz leather).

https://www.olfaproducts.com/olfa-l-5-fiberglass-rubber-grip-utility-knife-18mm.html

I am cutting 5-6 oz leather. I will definitely try out all of your suggestions and hopefully see some improvements with practice. So will these techniques help to the point where my curves wont be choppy? Or is some sanding to round things out to be expected?