jbarchuk

• jbarchuk commented on Technovation's instructable The Brachistochrone Curve21 days ago

Sorry, I like the demo, but there's a structural problem that causes an error. The balls are not leaving the launcher at the same time.In Pic 18 above, look at the gap between the bar that holds the balls, and the 'floor' of the track where the balls will be contacting the track. With the balls loaded, it takes less travel of the retaining bar to release the steeper ball than the shallower ones.Below is a screencap from the vid. The two steeper balls have already left the gate while the shallowest one is still there.I'm not saying this will change the outcome of the race, only that it's less accurate than it should be.====One way to think about why the steepest track should be the fastest is to think of the exact opposite: Imagine a very shallow 3-4 deg grade, for about 3/4 length to th...

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Sorry, I like the demo, but there's a structural problem that causes an error. The balls are not leaving the launcher at the same time.In Pic 18 above, look at the gap between the bar that holds the balls, and the 'floor' of the track where the balls will be contacting the track. With the balls loaded, it takes less travel of the retaining bar to release the steeper ball than the shallower ones.Below is a screencap from the vid. The two steeper balls have already left the gate while the shallowest one is still there.I'm not saying this will change the outcome of the race, only that it's less accurate than it should be.====One way to think about why the steepest track should be the fastest is to think of the exact opposite: Imagine a very shallow 3-4 deg grade, for about 3/4 length to the target, then a very steep dropoff to the finish. Yes, that finish will be very fast, but the way it dawdled along the first 3/4 causes it to lose.

• jbarchuk commented on mwawoodworks's instructable Dust Cyclone Cart8 weeks ago

Learn to be less easily annoyed.

That's a great design overall but I have a suggestion for the geometry. The stickout on the vertical PVC pipe is obtrusive and intrusive. It looks very easy to bump into when walking past.Rotate the vacuum CCW 135 deg so the inlet is pointing to the right-rear. I'm 90% sure it will fit that way now. Then drill another hole in the bucket platform right next to the bucket for the PVC. Might need to cut away some of the rear panel to access vacuum inlet fitting, if the PVC doesn't easily drop straight down in the fitting.

• jbarchuk commented on Madebymitch's instructable How to Make a Bandsaw Box3 months ago

Look up vids for tuning/adjusting band saw. By the flex in the blade I think you were pushing too hard. Thick-thick hardwood block, and not a coarse blade, tough work for a small machine. Let the machine cut at its speed. Excellent instructable.

You don't HAVE to use a bandsaw. Use any saw or cutting implement you like. However, think about those 6" deep internal cuts, and then think of another tool that can do it. Coping saw is all I can think of. There might be industrial size scroll saws. Not much has a blade that long and shallow.

• jbarchuk commented on o.c.2799's instructable Universal Air Slide Whistle 10003 months ago

Cool now do a trombone.Cool now add -another- -rangefinder-, two channels measuring 2 dimensions, and you've got yourself a 'free air' (rather than tabletop) theremin.

• jbarchuk commented on jenfoxbot's instructable A Beginner's Guide to Microcontrollers1 year ago

Your concern is definitely noted. Relax. It's not as bad as you think. Two paras up from that line was 'Computers have microprocessors AND microcontrollers that work together to perform many tasks at once.' Taken in that context, it's not too misleading. The whole article is too unstructured and blathery for MY taste, but I DON'T CARE because this kind of instructable isn't targeted towards you or me. As long as it causes a few people to go get an Uno, or anything, and start learning, the article does its job.

• jbarchuk completed the lesson Soldering in the class Electronics Class2 years ago