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New Toy…

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New Toys!Robotics

Way back in the mists of time, I mentioned how we had laser scanners in the CVRG (one of which was mounted on Dagda for a while). We used the SICK for a long while, which is a block of steel that’s pretty adept at toe crushing, only scanned through a partial circle and was enormously expensive (and later we acquired a 3D scanner which was even more expensive but could at least do 360 degrees). That was fifteen years ago though. 

Meet the modern version: 

The YDLIDAR X4, evolved from roomba sensors and possibly a knockoff of a slightly more well-known sensor. Weighs next to nothing, costs $80, fits in the palm of your hand, scans through 360 degrees seven times a second taking 5000 samples in the process (so about half-degree resolution), ranges out to ten meters on a good day with a following wind. … Read the rest

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Sliding dovetail postmortem

Desk ShelfWoodworking

So looking at the pieces of scrap I was practicing on yesterday, I see that the power-cut dovetail has a consistent angle but the edges are anything but sharp and there’s a problem with blowout:

While the hand-cut version is messier but holding:

A bit more practice would clean that up. It’s slower, but it leaves you with all your fingers, which is a plus. The back end broke out because of short grain:

But you can see that the gaps aren’t as bad at the back end due to the angle being inconsistent. There are a few different hand methods to cut the joint – I was paring the angles with a chisel but there are more accurate methods. I guess I’m doing some more practice for a while and the doing this by hand.… Read the rest

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Still have ten…

Desk ShelfWoodworking

So after weeks of not getting to the shed at all because of work and feeling pretty guilty for that, I finally got out there for a few hours today. The next step in the project is the sliding dovetails – the main desk surface shelf has been cut to the right angle, the sides are both shaped, the top shelf and middle shelf are both ready to have the angles cut but I want to get the sliding dovetail for the desk surface done first. And since I’ve been away and am now rusty, out with a bit of beech scrap to try to cut sliding dovetails in for practice.

On go the layout lines, out comes a scrap to run the router along to cut out the female part of the dovetail, I hog out the main part of the waste with a straight cutter and then cut the dovetail edges with the dovetail cutter I bought for this (it’s my only good router bit) I cut the female part out and then checked the board that I hadn’t yet cut the male part of the dovetail into and the whole board went into the female part leaving a gap.… Read the rest

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Mark Dennehy in 1 Comment