Keith's Electronics Blog

The previous cutterhead prototype from about a year ago that used a tattoo gun motor reciprocated the blade at a high speed and cut the fabric well, but stalled easily in the foam spoilboard. I needed more torque and I was hoping I could get by with less speed.

And now I remember how I stumbled across the idea to use a tattoo gun motor — Nick Poole’s SparkFun post on building a tattoo gun from one of their cute widdle gearmotors, which are available in a wide range of gear ratios and output speeds. So when the tattoo motor didn’t have enough torque, I ordered two different speeds of the micro gearmotors from SparkFun, following Nick’s path of innovation.

(more…)

If I’m going to try to develop a CNC fabric cutter, it’s going to be called the CutterRouter.

There, got that out of the way.

If I’m going to try to develop a CNC fabric cutter, at least the prototype and ideally the final version will use all commodity components plus easily-fabbed parts (3D printing, lasercutting, easy woodworking with common shop tools and not requiring a high degree of accuracy). The self-imposed choice of commodity components makes me want to use a readily-available X-ACTO® blade as the knife.

If I’m going to try to develop a CNC fabric cutter, I want to develop a working prototype cutterhead first. It’s the only part of a CNC fabric cutter that’s significantly different than a 3D printer or mill. So if a cutterhead can be made to work, the rest is easy; if it can’t be made to work, the rest is moot.

(more…)

Surely by now the sewn-product industry has CNC fabric cutting?

Yes, but I don’t know much about it and my acquaintances haven’t worked at places that use it. What I’ve been able to find appears to start around $30-40K for a fairly short table, with extensions available. That entry pricing only makes sense for a fairly high volume of product.

Could we do better, and is there a market for it if we could?

(more…)

In the sewn-product industry, product development can have a rapid-iteration phase that would be familiar to anyone in hardware or software development. Whether it’s testing the fit and strength of a new backpack or checking the fit and appearance of a garment on the fit model, a single prototype at a time may be made and revised weekly, daily, or even more often.

In the garment industry, “made to measure” refers to clothing whose pattern is made from measurements of the individual wearer and then either drafted algorithmically or pieced together from library parts for each possible value of each collected measurement.

In product development and in made-to-measure production, a number of factors of fabric cutting are different than in mass production:

• The manufacturer or producer may be making a single quantity, certainly only a small quantity.
• The manufacturer or producer is unlikely to be making multiple sizes at the same time.
• The above factors rule out the long markers used in mass production.
• The above factors rule out lay-ups of many plies of fabric.
• The manufacturer or producer may not even have a marker — pattern pieces might be hand-drafted and on separate pieces of paper or oaktag (card stock).

I can’t speak definitely about every possible cutting scenario in product development and made-to-measure production, but I can cover common cases.

(more…)

I volunteer in the sorting room at my local thrift store about once a week and a few years ago, one of the guys who processes electronics and appliances showed me this thing out on the sales floor and asked whether I knew what it was. Pizza cutter? Linoleum cutter? Don’t know; but it’s a beautiful piece of machinery, so I bought it.

By the time I left the store that night, we’d figured out together that it was a fabric cutter. And as it happens, by now I know a lot more about the topic than I did then.

(more…)