How do you spend your time?

This is a question for people who already have operational reprap machines of one sort or another.

There has been a lot of emphasis on making reprap machines faster and faster. Presently, I am milling things at a sedate 8.3 mm/sec which is nowhere near the 30-50 mm/sec for printing that seems to be the mainstream goal.

What I've noticed, however, is that when I look at the amount of time that it actually takes me to design and make something, the milling aspect is a rather small component. If we were to talk about the time I spend with Tommelise 2.0 actually milling parts as, say, X. The total time that I take to design and figure out how to actually mill the part is maybe 6X to 8X.

Most of my time is spent in figuring out how things need to go together. I'm constantly having to remember to do things like recess bolts when I'm designing, for example.

Has anybody else noticed that?

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

Most of the projects I work on are primarily done over the weekends. It seems that it takes about 6 weekends of planning and designing to about 1 weekend of construction. Basically a 6 to 1 ratio. I am sure I could cut down on the planning time, but it would be offset by the increased building time as well as increased frustration.

Print speed is pretty important : when you've spend 6 hours designing something, every second you're waiting for it to print is extra!

Also, moving printing speed from hours to minutes is a big factor in general public acceptance. At the moment, 'you can print a coathook in six hours' is not that impressive: 'you can print out a customised Ipod cover while Eastenders is on' is much better.

The general public is used to inkjet printers at home. They can produce a full-size high quality A4 print in a few minutes. They have no understanding of the technology and the obstacles overcome by the machine and designers.

This is what we're competing against. It's unfair, but that's what we're compared to.

It does seem obvious that if you're doing primarily "one-offs" that print speed isn't really all that important. So if you're a developer, and wanting to prototype things, a slow print speed is fine, and doesn't really affect overall speed.

There are two types of activity for which print speed is important that I can think of. If you're primarily printing out other peoples designs, or of you're in production mode. That is, printing out many copies of the design once you've made it.

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I'm building it with Baling Wire

I've been printing at 16 mm/s, and try to use the entire working area of my Darwin for each build (220 mm by 220 mm) so that I can let it run overnight. I've been trying a few new designs, mostly extruders, but most of my printing time was spent printing more Darwin parts, and that is very slow. Besides, since there's a lot of demand for parts, I spend design time printing more Darwin parts; I use different computers for printing and designing, and soon I hope to be printing from SD cards.

My Darwin can handle at least 32 mm/s, maybe even 45 mm/s, but the extruder is the bottleneck - my GM3 direct drive M5 extruder won't go much past 3 mm^3/s, which is about 16 mm/s at 0.5 mm filament. I need to have a careful look at Nophead's numbers, and see whether a turbo screw drive or a pinch wheel setup will give me more print speed. I'm going to need a heavier motor for either option, so that might limit my head speed as well. I've ordered parts for both, so I can test them when I'm back in town next month.

Another issue is part quality - the firmware I was using last winter gave better results at 8 mm/s, but worked acceptably at 16 mm/s. I'm hoping that the newer code will run a bit smoother around the edges.

Wade

Wade Wrote:
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>
> but most of my printing time was
> spent printing more Darwin parts, and that is very
> slow. Besides, since there's a lot of demand for
> parts, I spend design time printing more Darwin
> parts;
>
Interesting! I hadn't heard that you'd been printing Darwin parts again. Have you a better idea, these days, about how long it takes you to print up a set?

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

Not yet, as I'm still overseas, but I'm gearing up for more printing when I get back in May. I figure a week of extruder uptime per Darwin per printed Darwin at the moment. The last set took a month, as my extruder was down 75% of the time. So, my main concerns at the moment are extruder reliability and speed. If I can increase both of those a bit, things might get interesting.

Wade

For me, it doesn't seem to matter if I am using a reprap, cnc mahine, laser cutter, or powder printer - setting up the files to print always seems to take the longest amount of time. Even if the output takes a day to be formed, it is still shorter than the time I've spent designing it and orienting it properly.

Faster speed is always better, but from my standpoint as an engineer, if the physical creation of the part is less than 1/4 of the total time spent on the part then it is fine in my book.