I got the idea for the monitor lift from an example online using all-thread as lead screws to drive a platform. Essentially I’m just replicating this idea but with a few tweaks that take advantage of having the lathe to make it better/stronger, easier to build, and to take advantage of spare parts I already had.
First I cut the all-thread rod to length and then I turned down one end of each to fit the inside diameter of some spare bearings. I left an extra bit on the end and turned it down to fit the inside diameter of a timing belt drive sprocket – this was later replaced with a chain sprocket due to slipping. I repeated the same on the top side of each rod (without the extra bit for the drive sprocket) and then I cut some metal brackets to hold the outer bearings. I then cut a small platform and attached two nuts to it that would connect it to the threaded rods.
These parts were all assembled into the desk; a few small shims were needed to get the rods exactly parallel. I then connected the threaded rods together with a small #25 chain drive. To power the lift I tried a few different test motors and eventually settled on the guts from a small/cheap electric screwdriver – this provided enough torque while not requiring a huge power supply. It could be a bit faster and I need to add some sound damping, but it’s working very well for an initial attempt.
I also made some mounting plates to adapt the monitors to a fixed mounting since the regular bases were too wide. The monitors were then mounted to a 2×4 that acts as a spacer and also adds strength to the platform. Once the tabletop is in place the 2×4 and the rest of the mechanism will not be visible since the monitors will rise so that their bases are just flush with the top – I’ll likely add a trim piece to block this off. The monitors also drop low enough that the table top will clear with no problems.
The last step was adding limit switches and rewiring – moving the toggle switch up runs the lift up until the positive switch is tripped, and moving the switch down runs the lift down until the lower limit switch is tripped.
Next up will be making the tabletop…
This weekend I had a chance to test the completed valve bank.
Testing revealed that some of the keys did not actuate with their corresponding valve open. On these keys when the valve (while turned ON/open) was removed from the manifold the key would strike immediately, pointing to lack of airflow through the valve as the cause. I can’t explain why this occurs on only some of the keys but the piano turns 100yrs old next year, so the inconsistency isn’t surprising. The piano could perhaps be adjusted to make these keys work the same as the rest, but I could more easily just provide more airflow via multiple valves per key – this is the approach I took. To connect multiple valves per key I created a few hollow standoffs that fit inside the valve holes in the manifold . The standoffs then have holes on their sides to allow connecting the extra valves on a 2nd layer above the rest. The end of the hole that was drilled to hollow the standoff was sealed with hot glue. Two valves solved the problem for most of the offending keys, but one extra special key required 4(!) valves in a ‘+’ configuration.
With the mechanical parts complete I’ve taken the first steps to construction of a raspberry-pi based controller that will use shift registers to power the solenoids. The raspberry pi and associated circuitry will be small enough to fit on the back of the valve manifold in the area where the paper roll would normally be. It has wireless connectivity and I plan to have it host a webpage where it can be controlled by phone/tablet. I’m bread boarding this first to prove the concept with one shift register, then once testing is complete I’ll create a circuit board to hold all 11.
A while back, in anticipation of more log milling, I made a jig for holding the chainsaw level along the length of the cut. This is basically a homemade version of an ‘Alaskan Sawmill’, with a few changes. Since I processed last winter’s log recently it made room for another in the drying area, so I finally had a chance to test out the jig this weekend. For the first cut a ladder is secured to the top of the log to establish a reference surface.
I opted on not tie the reference block into the end of the bar, since I have a limited bar length. Because of this, I also couldn’t make the reference block adjustable without introducing too much flex. Instead, I set it at the maximum board width I may need, and for all thinner boards I’ll add more wood to the block or log to shim it. This also gives me the ability to cut from both sides for a log that’s up to ~2x the bar length.
Altogether this test seemed to work great, the cut was extremely flat compared to the previous log that was cut free-hand. It was fairly slow-going though since I was using a standard chain; I have a ripping chain on order that should cut faster with the grain, I’ll install it before finishing this log.
It was only a matter of time before this happened – the player piano (original post) is a real workout to play manually. Since it works on vacuum, I had set aside the motor from an old vacuum cleaner for potential use in powering the piano. Tonight I built a small box to contain the vacuum motor and connect it to the piano. The box is made from MDF, partly because I had scrap that needed to be used, and partly because it’s very heavy & sound absorbing. I made the big fitting by cutting/milling a square from scrap, I then bored a hole in it on the lathe and welded it to a scrap of pipe.
One very large hose goes to the manifold powering all the key bellows, and another smaller hose powers the vacuum motor for the tracker/scroll mechanism. I didn’t notice the smaller connection at first, so I had to go back and tap a fitting into the connection for the large hose; there’s still enough room for both to connect though.
Overall it seems to work great, this effort was definitely a quick proof-of-concept though and I’ll need to go back and fix/test a few things:
#1 – Motor controller to slow down the vacuum motor. Currently it has way more vacuum than is actually needed and slowing down should reduce noise from the motor.
#2 – Ensure cooling is OK. Especially after slowing the motor down I need to test that air flow is good enough to keep the motor consistently cool.
#3 – Mount in piano base and complete further noise insulation.
#4 – Tee hoses (and potentially add check valves) so that manual operation still works.
Beyond that I do have plans to eventually (could be tomorrow, could be in 5yrs) automate the player mechanism using some small pneumatic solenoids I found on ebay. These would tee off of each line from the tracker bar and when they open it would simulate a hole in the paper passing by. With this it would then be computer controlled and able to play anything. By default these are off/closed, so the paper mechanism would still work fine, in computer-controlled mode I’d just need to block off the tracker bar holes with some tape.
This weekend I installed the shop dust collection system. The system consists of several parts:
Fan/Motor: I repurposed a portable dust collector fan I’ve had for a while that’s been underutilized (collecting dust, but not as intended). Space is limited in the mechanical room so since the fan won’t need easy access I mounted it high up above the air compressor near where the dust collector pipe enters the mechanical room.
Pipes: 4″ PVC DWV pipes; there are a few branches leading to the different tools. I tried to keep the overall length as short as possible and the bend radius’s large.
Blast Gates: The blast gates control the air flow though the system by blocking off unused branches. I made these with 1/2″ plywood and 1/4″ hardboard. Circle cutouts were made on the lathe to match the pipe outside diameter exactly.
Filter and Collection Bin: The portable dust collector came with a light canvas bag that restricted the air flow massively while still allowing fine particles to escape. To improve this I replaced the bag with a semi truck air filter mounted to a trash can. The theory is that air will exit the filter and larger dust/chips should fall into the trash can below. There are purpose-built dust collection filters available, but the costs are much higher for these and the semi truck filter has the same specs; different economies of scale. To mount the filter to the bin I made a plywood ring, for now they’re just taped together but I may add latches at some point. The design may need some tweaking; I’ll know more after it gets further use, but for now the airflow is excellent.
Return Vent: Having the collection bin in the mechanical room created a problem; the mechanical room is well sealed for noise reduction, so there was nowhere for the air exhausted from the filter to go. For heat/air to be retained in the shop, the exhaust air needed to return to the shop via a vent. Since I also wanted to keep the mechanical room noise level as low as possible this meant the vent needed to be sound proof. I built a sound proof vent by creating a 3ft long box and offsetting baffle plates inside of it. The sound has to reflect a dozen or more times off of the baffle plates; at each reflection it gets absorbed some by a fiberglass lining. The air, however, is able to snake around the baffles and find its way out. The inlet to this vent also points directly at the floor away from the sound sources. Somehow after adding this vent the mechanical room noise is actually noticeably quieter than when it was completely sealed. I think this may have had to do with the air pressure changes resonating in the previously sealed room, whereas now any fluctuations are equalized through the vent.
Control: For now control of the system is via a remote control outlet (repurposed from controlling the vacuum at the old shop), at some point I may integrate some low voltage switches with the blast gates so the motor will turn on as soon as any gate is opened.
(I’ve had this built for a while now, but I’m catching up on documenting shop progress tonight)
A while back I got an old Delta ‘Portable’ power planer at a garage sale; it’s helped out in a few projects already so I thought it deserved it’s own spot in the shop design. The planer requires a fair amount of space for it’s infeed and outfeed to keep the material flat, however the planer isn’t used enough to justify keeping it out on the workbench permanently. I also wanted to avoid the need to lift it out of a cabinet, so with this in mind I came up with the cart below that integrates with the cabinets. The cart rolls on double-locking casters and has folding infeed/outfeed tables that align with the planer’s table when upright. I used ‘drop leaf’ style hinges/supports to allow the tables to lock in place.
The ‘dead’ space inside is currently holding the router and router bits; I may convert this to a drawer at some point. When the cart is stored it just looks like any ordinary cabinet door.
Over the last few nights I’ve been working on handles for the cabinets. The handles are 4″ sections cut from 1.5″ aluminum angle. Before cutting to length I ripped ~1/2″ off of one side of the aluminum so the handles weren’t too wide. This was my first time cutting aluminum on the table saw, it was very quick and effective but also shot scalding hot aluminum chips in every direction and sounded like a Pterodactyl being fed through a wood chipper.
Since I may add/change cabinets in the future I wanted to make sure that I wasn’t locked into a particular brand/model of handle that could be discontinued, by making my own with standard materials this isn’t a problem and the cost was also kept to a bare minimum.
Once all the sections were cut to length I sanded the rough edges and drilled/countersunk holes on the drill press. I made a quick fixture with clamps and wood blocks to get the holes consistently located. To attach the handles to the cabinets I chiseled out a 1/8″ recess and then attached the handles flush with the door edges.
I’m undecided on whether these will keep their current ‘brushed’ looking finish or whether I’ll polish or paint them. I’ll decide that when the time comes to finish/paint the cabinets.