Subject:
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Re: Help needed for hopper feed assembly.
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Newsgroups:
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lugnet.build, lugnet.technic
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Date:
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Sat, 21 Sep 2002 03:25:36 GMT
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Viewed:
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944 times
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In lugnet.build, Geoffrey Hyde writes:
> I need something which will dislodge the 2x3 and 2x4 bricks from the treads
> found in Technic set 8257
I'm missing something here: why not just let them fall off the end of the
mechanism as the tread goes around the sprocket?
> and add extra
> sets of treads so that more than one brick type could be sorted at one time.
I built something similar for moving soccer balls, and discovered that it's
not a great idea to try to put the mechanisms end-to-end to make a longer run.
The balls tended to "stall" in the gap between the two belts. The force of the
balls coming along behind them would dislodge them, but there were always one
or two stragglers that would just sit there and spin. This might not be as big
a problem with bricks, though. (I know you're talking about multiple treads
in parallel, but I thought you might be thinking about "going long", too).
I considered running the treads on an incline, making one end one brick higher
than the other, so I could move the ends of the adjacent belts one stud
closer. But I didn't try it, because I abandoned the whole tread approach for
other reasons.
Another problem I encountered was that the treads had "taken a set" (much like
bias-ply tires) while in storage: I keep them in snack-size Ziplocs, so they
spent months sitting in much the same position as they would be mounted on a
pair of sprockets. But I nested one inside the other, so the inner one had a
concave bend to it. This caused a noticeable variation in speed as the motor
labored to force that concave section around the sprockets. The solution was
to mount the tread on a pair of sprockets, crank it around until the concave
section was pretty well centered on one sprocket, and leave it in the sun for
a while (an hour or two, as I recall). This left the tread much closer to
round, and it ran *much* more smoothly.
> I had thought of using the Technic Link Tread
That's what I switched to. Something that's not obvious until you've actually
played with them is that, thanks to some clever design work in Billund, you
can snap a 1x3 or 1x4 plate (or maybe a brick of the same size, but I'm not
sure whether it would keep itself aligned with the link as well as the plate
does) onto the conveyor link. What I did to move soccer balls was put a 1x3
plate with 2 1x1 round bricks on the link, which tended to jostle the ball
into a centered position as it went up, improving the odds that it would drop
nicely into the parallel-axle contrivance that catches it as it goes over the
top. As a cost-saving measure, I was able to put two ordinary links between
each pair of conveyor links, without risking having the balls drop into the
works. I dunno whether you could get away with two, but you certainly should
be able to alternate one-and-one without (much??) risk that a 2-by brick will
get itself all diagonalized and jam up the mechanism.
Since I was able to order the links from Pittsco, the cost compared favorably
with buying more Technic treads on Bricklink. And the link approach allowed me
to use a much steeper incline (not a concern for you, but lifting is one of my
key requirements for one design).
A couple of other items from our "Looks-Interesting-but-as-yet-Untried"
Department: it appears the the 30x14 VR wheels (often available for a pittance
on BrickLink) can be used to drive the usually-cheaper Town-style (Arctic and
Alpha Team) treads. And those new curved-slope-wedgie pieces look promising as
a way of joggling bricks into alignment to feed them into a sort-by-length
mechanism.
HTH,
Ran
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Message has 1 Reply:
 | | Tread storage
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| A solution to this problem is to turn the treads inside out, and put them around one of the large spoked wheels from the RIS[1]. It's a near perfect fit. (...) (22 years ago, 21-Sep-02, to lugnet.build, lugnet.technic)
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Message is in Reply To:
| | Help needed for hopper feed assembly.
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| I need something which will dislodge the 2x3 and 2x4 bricks from the treads found in Technic set 8257 - I need a means to pop them off without the use of excessive or damaging force. The primary use of this hopper is so that I can rapidly and easily (...) (22 years ago, 14-Sep-02, to lugnet.build, lugnet.technic)
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