Saturday, January 30, 2010

Phases. Converted.

When I bought my milling machine a couple years ago I was suddenly faced with the challenge of how to create three phase power. I ended up buying a 3hp VFD (Variable Frequency Drive) and hard-wiring it directly to my mill, which worked ok. For some reason, even though the mill was 2hp and the VFD 3hp, the VFD would trip when I started the motor. I had to turn the speed control right down, turn on the motor, and once it was running I could ramp it up to full speed. Other than that minor inconvenience, it was fine. When I bought my D&W bandsaw I took the VFD off the mill and tried to use it, with marginal success. My bandsaw has the original cast iron motor, refurbished, and I've read from several sources that old electric motors don't like the power created by a VFD, and may actually burn out prematurely as a result. Obviously I didn't want that.

Last summer I found an ebay store that sold phase converters either as a complete package or as a kit. I decided to buy a kit and assemble it myself. Essentially a kit contains all the parts necessary to assemble a static phase converter. All you need is a box to assemble it in. The other option is to build a rotary converter, but you need to find a 3 phase motor to use as a slave. Having heard all sorts of bad things about static converters, I opted to try and find a used motor and build a rotary converter. Unfortunately my search for a cheap, or preferably free, motor had been fruitless for months until finally I found a motor from an unlikely source. I had been calling around to scrap yards and surplus dealers to no avail, and then one day last week I decided to call an electrical contractor in town to see if he knew where I might find a cheap used motor. Dart Electric is the company that wired my house, and I learned very quickly that they are meticulous when it comes to billing. Every inch of wire in my house, every marrette and screw was charged back to me at full retail prices. Apprentices were billed out at full journeyman rates, and even when they came back to fix their own screwup they tried to bill me their hours.

Anyhow, I called and chatted with them for a couple minutes and was told to stop by and take a look through their storage sheds. A quick search turned up a 10hp, 3ph motor in what appeared to be good condition. 'It's yours, you're doing me a favor by getting rid of it' I was told. Woohoo!

When I picked the motor up I made a quick stop at the shop where I used to work to chop off the shaft. I didn't want to run the risk of something getting wound up in it, and cutting it off was easier than making a guard.

Looks complicated, but it's pretty simple. The silver capacitors are run caps, and the black capacitors are start caps. The two things in the top are contacts, to switch from start to run caps as needed. Unfortunately the diagram I got with the kit was horrible, but the seller was quick (almost instant in fact) to answer my numerous questions throughout the process.

This is my fancy Sawstop test bench. I was a bit sheepish the first time I fired it up, there's alot of capacitors in that box. I once saw a demonstration of the stored electrical potential in the tiny little capacitors from a disposable camera flash. It was nuts, it melted a screwdriver!

All done, it took about 6 hours total. Initially I thought that I would install the converter near the main panel and run a plug in somewhere near the bandsaw, but I decided it would be better to keep it close so I can turn it on and off as needed. My bandsaw is the only machine that needs 3 phase right now so I hardwired it directly to the converter. I've already noticed how much quieter the D&W runs off the converter compared to the VFD, and I'm happy to see that I can run the converter, bandsaw, and jointer all at once without tripping a breaker.

I'm one step closer to running out of excuses for my lack of woodworking productivity!

Sunday, January 24, 2010

Dust. Collected.

While I'm really itching to start a project, (I've got several pending) I have a tick list of workspace things I need to get finished before I get rolling. My bench was an important step, it's nice to finally have a permanent place for all my hand tools - I've never had that before. I built a tool board for chisels & planes, and was starting to build a row of little cubbies for misc. bench crap when I was forced to change directions. I was rough milling some mahogany for said cubbies when my allergies got the better of me. I've always had mild allergies but over the last few years they've gotten considerably worse. Dust, smoke, stuff like that can stuff me up for days. It sucks.

Anyhow, I bought this 2hp cyclone dust collector almost a year and a half ago but never set it up. Right now my machines are set up in my little garage but initially I thought it might be temporary, I hoped to convert one of the numerous outbuildings into a larger, more functional space for a shop. I figured I would just hang on before setting up the dust collector. I didn't want to run all the ducts and whatnot just to pack up and move. It so happens though that my garage has turned into an adequate space for now, and I doubt if I'll move out of it anytime soon. A couple weeks back I finally bit the bullet and started setting up the cyclone.

I hummed and hawed over a location for the dust collector, as it has quite a large footprint. Finally I decided to set it up outside. It's less than ideal, but it's quieter out there and doesn't take up any shop space. And besides, 'less than ideal' is beginning to be my motto!

Obviously I'll have to build an enclosure around the dust collector before it starts raining in the spring. For now I throw a tarp over it when not in use. Duct shopping proved to be a frustrating experience. Initially I looked at normal HVAC ducts and it looked like the duct work was going to cost more than the dust collector! Eventually I found a company in Edmonton that manufactures their own ductwork and fittings, and it ended up being considerably cheaper. I gave up trying to find actual 'dust collection ducts', that shit seems to be a myth! Anyhow, I ran all 26 ga 6" spiral ($1.99/ft) and bought most of the fittings at Rona. I bought blast gates at Busy Bee.

The setup is pretty simple, the main is teed right off the machine. One line runs to the tablesaw and one goes across the roof, tees again, and down to a manifold that branches off to the bandsaw, jointer, planer, and a sweep. I capped the other side of the tee but hope to run it to my chopsaw and router table... eventually. I was dissapointed to see that my 'industrial' tablesaw only has a 4" collection fitting that only goes up to the shroud that covers the arbor, there's no actual dust collection for the cabinet itself. I guess we'll see how it goes.

I built a shroud for the underside of the bandsaw table from a side take-off, but it needs some tweaking. I want to hold it in place with rare earth magnets, so it can just be popped off for blade changes and table tilting, but the magnets I used weren't strong enough to support the weight of the hose. I'll get some bigger ones to try, but if they don't work I might have to think of something else. I guess I could just use some tie-wire, that's pretty farmer-ish though!

Friday, January 1, 2010

Pre-Fab Base

While searching through a bunch of wood for some material to make a jaw for my front vise, I came across this piece of 12/4 maple. Look whose name was on the bottom.

If I remember correctly I stole this from Ian in a daring armed robbery. He deserves to be stolen from though, because he's so rich, handsome, and successful. I'm a modern day Robin Hood.

The best part of my previous bench was the base, which I'm re-using. I built it from a huge beam of recycled fir that I believe was salvaged from a bridge out by the Bugaboos. If Rane is still lurking on these blogs he might know more. I worked with him at the timber-framing shop, and he worked there long before me. That's where I got the beam, I bought it from my boss. Rane helped me pull nails out of it; spikes actually.



You can tell I was working in a timber-framing shop at the time, the joinery is all post and beam style. I really like the joint that attaches the stretchers to the legs. I don't know what it's called but it's the best knock down wedged tenon I've ever came across. The wedge won't eventually split the tenon like other types, and the weight of the tenoned piece alone is enough to hold the joint together. I drew a quick sketch below.