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Wiring a ST3PF Delay Off Relay
Posted on Friday, 25-Oct-2013The Fjui ST3PF is a time delay relay switch that comes in numerous voltages and time delay ranges. When you apply power, a coil is energized which flips an internal switch. When you remove power the switch stays flipped for the set amount of time. Unlike most relays, the ST3PF is available in 110 volt AC - there's no need for a separate low voltage power source to trigger the relay. The limitation is that the load being run by the relay cannot draw more than three amps.
I use the ST3PF (bigger than I expected) for a mini sump pump that draws less than an amp. The pump is triggered by a simple float switch. Without the ST3PF to keep the pump running after the float switch turns off, the pump would be turning on and off constantly.
The drawing is presented as an alternative to the "8-pin timer wiring" one that I didn't find very helpful. The drawing shows a basic switch circuit (left) with the addition of an ST3PF (right). Only four of the eight pin connections are needed/used.
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Frame press gasket
Ryan emailed me regarding my comment that the gasket tape doesn't stick well to polyurethane and wondered if sticking it to the platen might be better.
A platen mounted gasket might stick better, but it seems like it would be easy to damage the gasket even if you weren't in the habit of sliding things in and out of the press. Mounting the gasket to a rabbet that runs around the the perimeter of the platen might work.
Despite the poor adhesion, the gasket on my first press has stayed stuck and functional. Joe recommends acetone or xylene to prep polyurethane for seaming so I gave acetone a try on my last press. I used a strip of laminate to protect the wood and a folded bit of acetone dampened (not wet) Scotch-Brite to clean a strip wide enough for the gasket. While adhesion is better, its still not as good as mounting the gasket to lacquered wood.
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Box VS Flat membrane
Peter brought this up earlier [link] and I thought I'd expand on my reply.
Flat membranes are easy to seal, but you cannot veneer things more than a few inches thick. To get maximum capacity the membrane should be as loose as possible. Let the sides of the membrane curve in from the corners as much as you can. Even though you cannot gain much on the diagonal corner-to-corner dimension, the extra material everywhere else really helps. The membrane-seal-platen design also adds capacity. With the membrane on top of the frame, lost capacity equals frame thickness because the membrane will have to travel that extra distance (if there is enough material to do so) when vacuum pulls it tight to the frame. I tried a reversible frame on my 4x8 press thinking it would increase capacity, but raising the membrane up like that had a serious negative effect on capacity.
Box membranes are a good choice for veneering thicker items but they are hard to make and seal. I don't think either of my attempts would would work well with an auto cycling setup. I'm also not sure if my glued box joint is any better than my folded one. I wonder how the commercial ones are made.
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Toe Kicks and nailers
I decided that my current job had to be done without height and width consistency. The earlier mentioned rail broke the height and having all vertical rails - including side trim - be 1-1/2" broke the width. The broken width complicates how I do nailers and toe kicks. This slowed me down because I had to both come up with a way to do them and because my boring machine setup wasn't very accommodating.
When all my horizontal panels are balanced and consistent - 32mm increments with 25.5mm 2x starts - boring for nailer and kick panels is easy. I've done the front-end math and setup my machine to accommodate it. In this case I had to think about it and decide to use the center of the narrowest cabinet for my constant (13mm x 2 starts). The problems are that it breaks another aspect of my system (holes aren't all 32mm apart - as in the image) and setting up the fence stops takes time. It may be that the center of the smallest panel approach can be a constant, i.e. save me time in the future. 
The problem is still the ease and accuracy of setting the fence stops. To be able to do that I will need stops that I can easily and accurately set to to any number. My current setup is based on a limited number of fixed stops that can be moved in increments of 32mm. I've made a micrometer based stop for my saw's crosscut fence and something like that would work well.
Another issue with the toe kicks is depth. The tile on this job may not allow a full toe kick. I didn't take that measurement and I didn't consider it when cutting the toe kick notches. Anyway, the bottom line thought is toe kick depths in increments of 16 or 32mm, i.e. flexibility and consistency. Here I only need to do the front-end math because my fence can be moved forwards/backwards in 16mm increments. I'll have to see if this is workable with the adjustable feet I use.
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Dowel connectors
Second post and already running into trouble. Yesterday the LCD on my camera quit working (... camera period) and I have too many pictures to easily find old/related ones. Yesterday involved thoughts/work on toe-kicks/levelers (added usage notes) and aligning stacked boxes. I'm working on a job where the cabinets run floor to ceiling. They have a dividing rail detail that separates two boxes by 22mm. I incorporated it by extending the box sides 11mm past the box top/bottom so that the boxes stack on the extended sides . I needed something to align the boxes. Dowel connectors don't take much space and seemed a good solution.
I had played with dowel connectors before (image) and the sample aligned quite well. I've also had good results using the pictured connector to join the 16mm bottom of metal slides/sides to the drawer face.
This time I was working with a similar connector (darn that camera) that Haffele calls permanent. The advantage is that both ends go into 10mm x 12mm deep holes, so only one setup is needed. The female end is also a simple hole, there's nothing to get hung up on when sliding the the boxes into alignment (theory at this point). The disadvantage is that they do not align well. This is noticeable when you snap the two pieces together, they aren't concentric. Hammering them in crooked makes it even worse. I ended up having to clamp the box sides into alignment, with the connectors between and barely in the holes, and then hammer the two pieces together.
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Prefinished Plywood
Classic Core is a nice compromise between plywood and MDF/PBC. I've managed to stay away from straight plywood for a long time. I got talked into using prefinished plywood for a current job. I sent 3 of 6 sheets back because they were seriously bowed. The replacements initially looked better and then didn't. Being prefinished, they couldn't have bowed that fast due to changes in the environment. Its like they had a memory - the bands held them flat until they were loose and vertically stored on my rack. The bowing is unacceptable, but what can you do, how many times can you send stuff back? The extra cost of EuroPly might be worth it. When they get around to NAUF (no added urea formaldehyde), it'll be a great "green" product - the materials are FSC (Forest Stewardship Council) certified.
The finish is surprisingly durable, though the stuff I got seems to have two coats that aren't bonded well. At cut edges, a bit of the top coat can flake off. The drawback for me is that I much prefer a continuous finish coat. Using prefinished banding leaves a veneer thickness of unfinished wood that I hate. I came up with a special applicator for applying finish to that edge. This turned out not to be as tricky as expected because the finish - at least my water-based one - doesn't stick to the prefinished surfaces. Its still lousy because you cannot have a nice eased edge. My solution was double banding, an unfinished maple edge followed by the prefinished edging. This allowed me to have a 1/16" radius on the edges. The finish they use is pretty amber and it wasn't until I had coated the exposed Maple before I thought of tinting my finish to match.
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