Planer Dust Collection
Quick fabrication project to add a dust collector connection to the planer. The planer generates by far the most chips/dust of any tool, so this will be a welcome addition.
Chainsaw Sawmill v3.0
With the general success of the prototype chainsaw sawmill, I decided to make a more permanent/cleaner version. The idea is basically the same, but for easier installation/removal I decided to have this version clamp onto the bar rather then tie into the handle geometry. This version also allows for finer adjustment of thickness of cut via a sliding fence. (the previous version was only adjustable by adding/removing shims)
Trailer Light Upgrade
The utility trailer frequently gets used off-road around the yard and woods for moving downed trees/branches, compost, rock, tools, etc. As a result, the standard plastic lights have taken a beating and I’ve had to replace them at least once. Since one of the lights was broken again recently I decided to upgrade them to use a standard all-metal semi trailer style light enclosure. This style of light fits better vertically than horizontally on this trailer, so I modified the enclosure to move the circular side light from the end of the light to the side. I then welded the light enclosure onto the trailer; the size of the light worked out perfectly to connect it to the old light mount and also the top rail of the trailer on each side, making it very strong. At the same time I replaced the side running lights with a low profile LED version and added a guard/deflector made from a small section of scrap rebar.
Custom Desk – Monitor Lift Mechanism
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…
Piano Automation – Valve Manifold Complete
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.
Piano Automation Continued
Over the past week I finished the lower valve manifold plate. The lower plate connects the row of holes on the piano tracker bar to the valves on the top plate. Obviously it would have been nice to just put the valves directly over each hole, but since the valves are much wider than the hole pitch I had to instead design the manifold with the valves arranged in multiple rows. Each tracker bar hole is connected to the valve above via passages that are routed into the bottom plate. The path of each passage was chosen carefully to avoid connecting to other valves/passages and to avoid running into the bolt holes that connect the manifold halves – each valve should connect to exactly one tracker bar hole. I let the CNC router do this work; it was relatively slow going with a 1.5mm end mill in aluminum but it turned out OK.
After the passages were milled I created a gasket using wide tape. The tape covers and seals the top of the passages and a hole punched at each valve location allows each valve to connect to its passage. The tape has enough compression that any imperfections in the plates will be sealed once the plates are bolted together. I also added a lip/shelf to the back of the manifold to hold it in vertical alignment against the tracker bar.
With the manifold ready, I connected it to the piano and tried firing the outputs. Results were not good, there was some vague correlation between outputs being on and notes being played but something was wrong. I had originally assumed the air passed all the way through the valves but closer examination revealed that they actually pass air from their stem to ports near the base of the stem. Since I had the entire stem/base of the valve mounted inside the manifold there was nowhere for air to flow when the valve opened. I re-made the top plate with smaller holes and re-installed the valves with only the stem in the manifold.
Remaking the top plate solved the valve problem but there were many dead notes due to air leaks at the tracker bar. I experimented with several materials to seal the tracker bar to the manifold and ultimately landed on thick rubber outdoor electrical tape as the best performing, though many leaks remained. I found that the tracker bar was not very flat and I was able to carefully bend it back. This helped considerably but leaks still remained. I found that the force needed to push the manifold against the tracker bar for a good seal had the effect of bowing the tracker bar away from the manifold in the middle, so I added a thin aluminum lip to the shelf on the back of the manifold. The lip is just thin enough to fit between the tracker bar and the wood cover behind it and it allows the manifold to hook over the top of the tracker bar and more positively hold the bar along the entire length of the manifold with enough preload on the tape to seal. This essentially solved the leak problem.
Currently there are ~12-15 keys that I’m tracking down problems with, this started from ~20 and was reduced by working through electrical/alignment problems. On the remaining dead keys I’ve ruled out problems on the piano side, problems with the lower plate, and any electrical problems; so next step may be replacing the valves themselves. It’s possible that those keys need more airflow, which would require milling their passages deeper and/or modifying the valves; hopefully it doesn’t come to that. Once they’re all firing though then the mechanical work on this is basically done and I’ll be able to shift focus to the control system side.
Piano Automation Begins
This weekend I designed and began fabrication of the parts needed for adapting the solenoid valves to the piano’s tracker bar. This adapter will consist of two 3/8″ aluminum plates. The top plate will have holes to accept the solenoid valves, and the bottom plate will have holes to interface with the piano’s tracker bar. Grooves will be machined into the bottom plate to create airs channel between the tracker bar holes and the solenoid valves above. The two plate will then be sealed together, covering the grooves; a similar construction technique as some carburetors. As long as the grooves are carefully routed, each valve should connect to exactly 1 tracker bar hole.
I cut the 3/8″x6″ plate on the band saw and then milled to final length. I used an edge finder to locate the plate edges, and then used the mill’s digital readout to position above each row/hole. For each row I took 2 passes, first spot drilling with a center drill and then drilling to size with a twist drill. 88 * 2 plates * 2 passes = 352 cycles of positioning the X axis and drilling a hole. Once all the holes were drilled I sanded sides to remove burrs from the holes and scratches from the rough plate.
Next I installed and wired the solenoid valves in the top plate. The solenoid valves are an exact fit to the hole, but I added a bit of CA glue to ensure they stay in place. Wiring consists of scrap Ethernet cord that’s been stripped back; Every ~7 solenoids each share a common wire to reduce wiring, but it’s still ~100wires.
I’m happy with the results so far; this is by far the most precise thing I’ve made on the mill and everything is lining up perfectly. The next step will be to 3D model the grooves and convert these to paths to run on the CNC router. I’ve done some aluminum milling with it previously so it should work out OK, especially since it’s just cutting the shallow grooves – I wouldn’t have trusted the router to drill the holes as well as the mill did.
Saw Milling v2.0
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.
Kubota F2000 Snow Plow
We don’t get much snow here, but when we do it takes a lot of shoveling to get out to the road. If conditions are just right we can be stuck for several days waiting for it all to melt. As a result I’ve had a mower/atv sized plow on my watch list since last winter. Recently a new open-box plow popped up that, after factoring in their free shipping, I got for basically scrap value or less. I think the reason for the low price was that it had originally been part of a kit, but all the mounting parts were missing. For my purposes that’s OK though – no one makes a kit specific to the F2000 anyways, so I was always going to need to fabricate the mounting parts myself.
Making the mounting bar just consisted of cutting some 1″x2″ tube to length, squaring off the cuts on the mill, drilling holes for the pins, and then welding everything together. From there the plow’s base just clamped between the mounting bar and another section of tube.I made the clamping bolts fit just inside the plow base’s big hole so the plow can be rotated by loosening the bolts. Since the push bar connects to the standard implement mounting points, the plow can be raised/lowered the same way as the mower deck. I also needed to make some stepped bushings on the lathe to fit the plow base to the plow.
Kubota doesn’t list a tow/plow rating for the F2000, but it’s 4WD with a 3 cylinder diesel and built exactly the same as a ‘normal’ compact tractor, the only difference is that its seating position is spun around 180deg. For occasional plow usage I don’t foresee any issues. I may need to tie into the plow base’s rear holes for stability and to prevent unwanted rotation, but I’ll try it out first to see if this is necessary.
As part of the plow installation project I also went through the mower’s electrics and replaced a lot of corroded connectors with solder/heatshrink splices. It turns out the glow plugs hadn’t been working all along. With the glow plugs now working it starts a lot faster and in winter this will likely be a necessity to start at all.
Hacking the Player Piano – Part 1
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.
