I made a Dust Collector – Part 2

Curse you Wandel, for stealing my thunder!

Whatever. Nobody cares about your little website anyways.

 

So, at this stage of the project I had an impeller and a motor, and nothing in between.

I needed something in between.

Fortunately, my motor came with a pulley attached.

IMAG1309

 

…Very securely attached…

I cobbled together a gear puller with some scrap metal, clamps, a magnet, and a coupling nut.

IMAG1312

 

Now that I had removed the pulley from the shaft, I proceeded to remove the coupling nut from the pulley…

Impeller - Motor Pulley

 

Impeller - Motor Pulley

 

Over at the lathe, I began to cut away at the pulley to turn it into a hub.

Impeller - Hub

Impeller - Hub

 

Aaaaaaand, it’s a hub.

Impeller - Hub

 

I laid it on the center of the back of the impeller and marked the locations of the  holes I had drilled in the hub since the last picture…

Impeller - Mount

Impeller - Mount

Off camera, I drilled out the holes and attached the hub to the impeller and the motor shaft.

Impeller - Test

I hooked it up to a foot pedal switch and it was time for a test!

 

Holy crap! Time to change my underpants!

 

…to be continued.

I made a Dust Collector – Part 1

A while back I bought a leaky air compressor for $50 because it had a good 3HP motor on it that I figured I could use someday for something, probably.

When Mr. Wendel built a small dust collector with a tile saw motor, I knew my old motor had found its destiny.

Little did I know that this would lead to one of the scariest things I have ever built (and I’ve made a good number of catapults and potato cannons in my day).

I needed to make three things: an impeller, a cowl, and a motor mount.

Everything I needed I already had laying around, so I figured this would be a good way to use my tools and my time. At the very least it would be an educational experience.

First: Thing 1 – Impeller

To start, I cut some 1/4″ plywood into two identical discs by taping two squares together with double-sided tape and then spinning them across the blade on a screw I had driven through a thicker board (a rudimentary form of a dedicated circle-cutting jig)
Impeller - discs
Impeller - discs
Impeller - discs
Impeller - discs

A piece of oak I had in my scrap bin became the impeller fins. I printed out a template and glued it to the piece of wood and then cut out the pieces freehand on my bandsaw.
IMAG1187
Impeller - Fins

Since this was a remnant piece of wood, it was not the same thickness all the way through, so I removed some wood from the top of each fin after setting it against the bottom of my milling machine vice to ensure that they were all the same height.
Impeller - Fins
Impeller - Fins
Impeller - Fins
Impeller - Fins

Using 9 fins, the math was easy, I placed a fin every 40-degrees around the bottom disc. The tilt was determined based on what looked best to me, then I just measured the offset from the 40-degree lines and placed the tip of the fin on one line and base of the fin on the other.
Impeller - Assembly
Impeller - Assembly
Impeller - Assembly

After setting everything in place dry and ensuring in all aligned properly, I applied glue to the top and bottom surfaces, set them in their pre-determined places around the bottom disc, and then set the second disc on top.
Impeller - Assembly

I didn’t want to mess with clamps, so I set the assembly on a known flat surface (my table saw) and set another known flat surface on top (yes, that’s the table top from the old scroll saw) and piled some heavy metal pieces on that.
Impeller - Assembly
Impeller - Assembly

After letting the glue set overnight, I took the assembled impeller to the drill press, where I used a 4-inch hole saw to open one side as the air inlet.
Impeller - Inlet
Impeller - Inlet

Next I set a large ball bearing on top of a metal cylinder in the vise and balanced the impeller on top of it.
Impeller - Balance
Impeller - Balance
Impeller - Balance

I used a forstner bit to remove wood from the heavy side until the impeller stayed level while balanced on the bearing.
Impeller - Balance

So, now I had the impeller… part 1 complete.

Polespear Upgrades Update

After my previous modifications resulted in a slow spear that kept maiming and releasing fish, I went back to the shop and made it better.

To increase the speed, I ordered a 1/2-inch diameter band, but that turned out to be so stiff that I could barely stretch it, and if I did it bent the spear, so, that didn’t work.

Then I tried just adding a second band to the spear.
Untitled

This actually worked quite nicely. I had effectively doubled the power without making it too difficult to stretch.

Win.

Now to solve the problem of the fish wiggling off the spear.

I wanted to add barbs to the spear tips, so my first thought was to use a file. After looking at my file assortment, I realized that this would remove too much metal, and the barbs would really just be notches, they wouldn’t extend beyond the diameter of the tip, so I’m not sure how effective the would be.

So I instead cut slots at an angle with my hacksaw, and then was able to bend the metal outwards to form a proper barb.
Untitled

Done, and Done.

I went out to test it later that evening.
I didn’t see many fish for a long time, which is always a limiting factor in these tests.

But then, as the sun was going down, I saw a decent sized black perch and squeezed the trigger.

BANG!

The extra power made all the difference and the fish never knew what hit it… because it’s a fish.

The barbs were probably unnecessary in this case, since the polespear nearly blasted straight through the cute little fishy, but they certainly made the fish more difficult to remove from the spear, so I consider them a success as well.

Too bad I don’t like the taste of perch.

I gave the fish to the cats on the jetty and went home with a puffed chest and a bounce in my step.

I’m beginning to think of this design as a poor man’s speargun.

I like it. It’s simple and effective.

But now it has me thinking of other ways to make a cheap speargun…

Stay tuned…

Funting with a Polespear

I have recently added a new hobby to my life.

The timing couldn’t be worse, really.

I already have a 2 year-old daughter, a baby boy due any day, a full time job, a wife, and a large number of unfinished projects, but now I have to accommodate the compulsive urge to kill fish with pointy objects.

I grew up in the Seattle, Washington area and always enjoyed fishing, but somehow, since moving to San Diego 10 years ago, I haven’t found to time to go fishing.

I guess the problem is that I’m pretty busy with many other areas of my life, and it’s hard to justify spending a few hours on a weekend sitting and  waiting for a fish to commit seppuku with a hook on a string.

Then I discovered spearfishing. Spearfishing is different, it’s like snorkeling with a purpose. It’s not just sitting around waiting, or even just swimming around and looking, it is hunting. Fish hunting. Funting. 

I’ve gone twice now, and I’m mildly obsessed.

As is the case with most of my hobbies, it’s not enough for me to just participate in spearfishing, I have to improve on it, customize it, make it better, or at least make it my own.

To this end I modified the tried and true polespear to add a trigger mechanism.

The polespear design is simple: it’s a spear with a rubber band attached to the base. To kill a fish with it, you hook the rubber band with your thumb, stretch the band toward the tip of the spear, and then grab the spear shaft near the tip in order to hold the band under tension. Then you point it at a fish nearby and loosen your grip, allowing the spear to lurch forward; ideally impaling the fish in the process.

The idea to modify this weapon came to me when my friend complained about his hand getting tired from swimming around holding the polespear cocked and ready to shoot. 

I decided that the polespear would be better if it had a trigger, and came up with this design:
PoleSpear

Then I built it…

First I took a piece of stainless steel and shaped it into a snug-fitting collar that I attached near the tip of the spear with a spring pin.
PolespearMod

Then I glued together a few pieces of wood (something like teak that I had laying around from old patio furniture), drilled a hole through it (slightly large than the spear shaft), cut it to and arbitrary shape using the bandsaw and affixed a little latch (also made from stainless steel) to hook onto the collar.
PolespearMod

To keep the spear from traveling too far, I added a collar at the base with some soft rubber tubing to act as a cushion when the spear is stopped (I think the piece of rubber is an in-sink garbage disposal adapter).
PolespearMod

To use the spear, I hook the rubber band through the wooden handle, and then slide the handle up the spear till it latches onto the collar at the tip.
PolespearMod

PolespearMod

And then I fired it at a piece of plywood.
PolespearMod

I will hopefully get to use this to kill a fish this weekend, if my son doesn’t disrupt my plans by being born.

Update: I used this over the weekend and probably killed a few fish. I say “probably” because I didn’t actually “catch” any fish.

The rubber band I used is the standard light-duty polespear band, and the added weight/drag of the collar seems to have slowed the spear down just enough to really damage a fish but not actually skewer it. The result is that there are an number of disabled fish hobbling around the waters off the San Diego coast, if they are lucky. The unlucky ones died slowly Saturday morning, trying to figure out why I feebly stabbed them with a dull piece of metal.

The trigger itself worked beautifully, and I’ve ordered a more powerful band that should many little fish fatherless when I next enter the waters.

Inca Bandsaw Fence – Part 3 – The Fence

And so we come to the conclusion of the Inca Bandsaw Fence series.

At this stage I had a rail for the fence to slide on, a carriage that follows and locks onto the rail, and a mounting bracket extending vertically from the carriage for the fence itself.

The best material I found to make a fence was extruded aluminum rectangular tubing (about 1.5 inches wide and 3 inches tall). Aluminum extrusions tend to be very straight and since my saw’s table is also aluminum, using a harder metal could possibly damage the table over time.

I picked up a 36-inch piece of the aforementioned tubing as a remnant from the local metal supply store ($2.70 per pound) and cut 16 inches off to make my fence.

The fence needed to be connected to the vertical bracket attached to the carriage. My first thought was to attach it with bolts on the backside of the fence, but then the width of the fence would be limiting the cutting capacity of the saw by a full 1.5-inches. So I decided to attach the bracket to the inside of the tubing.

In order to do this I cut a slot in the bottom of the fence, right along the front edge where I wanted to attach it to the carriage.

Then I drilled and countersank two mounting holes. I transferred the location of these holes to the bracket and then drilled holes in the bracket accordingly.
Bandsaw Fence - Mount
Bandsaw Fence - Mount
Note: If you are a particularly observant reader, you will notice that I showed a picture of the bracket in “part 2” of this series, but here I am claiming that they were drilled as a step in “part 3”.  Well done.

The arrangement of the holes is not merely aesthetic. If the holes were aligned with each other horizontally, they would provide only limited vertical support. Likewise vertical holes would provide limited horizontal support. My theory is that diagonally arranged holes will be the best of both worlds.

Bandsaw Fence - Mount

I inserted brass (because it’s pretty) machine screws through the holes and secured them with washers and locknuts (to prevent loosening during operation).
Bandsaw Fence
Bandsaw Fence

And that’s it.

IMAG1284Bandsaw Fence

There is a bit of flex on the far end of the fence if to apply a lot of lateral pressure, but since my workpieces will be small and kickback is not a concern on the bandsaw, I won’t be pressing hard against the fence, so I think it is rigid enough.

That said, I’ll probably tinker with it at some point to make the far end lock in place as well.

Inca Bandsaw Fence – Part 2 – The Carriage

For lack of specific knowledge and due to a general laziness when it comes to looking things up on Google, I’m calling this part of the bandsaw fence a “carriage”:

fence scribble

(actually, I’m not certain my affliction can be considered “laziness” since I just went through the trouble of drawing a picture instead of just looking up the correct name… maybe I just feel like it is a carriage, whether or or not that’s what it’s officially called).

In any case, after completing the rail, I turned my attention to the part connecting the fence to the rail.

Essentially this works like a C-clamp, with the rail being pinched between a screw and a pressure plate. The construction may vary, but the most important aspect is that the carriage must be designed so that it is rigidly square with the rail when it is tightened in place.

I used a small piece of angle iron to act as the pressure plate. I shortened one side of the “L” (the “pressure plate” side) so that it wouldn’t hit the bolts on the underside of the rail.

Then I attached a vertical piece of steel that I milled flat and square. I kept it parallel to the angle iron by clamping a piece of metal in between it and the short end of the angle while welding it.

I drilled and tapped 1/4-20 threads into the vertical piece of steel and ran a Rockler star knob through it.
IMAG1232Bandsaw Fence - Slide/Lock

Bandsaw Fence - Slide/Lock

This tested okay, but I didn’t want the screw to mess up the rail over time, so I added a thinner piece of steel that was flexible enough to allow the fence to move while the knob was loose and still bear down hard on the rail when the knob was tightened.

Bandsaw Fence - Slide/Lock

So now I had an assembly that could be locked into any location with a mounting surface that was consistently parallel to the rail. The next step was to make a bracket that the fence itself could attach to.

I made the bracket out of a piece of trailer hitch tube I had leftover from another project.

I started by milling two sides flat and square with each other.

Bandsaw Fence - Mount

After that I cut off the other two sides and shortened one side so that the other would stick up above the bandsaw table perpendicular to the shorter side which would be mounted to the rest of the carriage assembly.

Like so:

Bandsaw Fence - Mount

I mounted this with a single 5/16″ bolt through the carriage assembly, which allowed it to be pivoted as necessary to keep the upright portion vertical (parallel to the blade).

Bandsaw Fence - Mount
Bandsaw Fence - Mount

And now I could turn my attention to the final component: Part 3 – the Fence!

Coming soon.

Inca Bandsaw Fence – Part 1 – The Rail

My little Inca bandsaw, which I love, came without a fence. For many uses this is okay, but the functionality and precision really are limited without a fence, so I set out to build one.

Outside Front

I picked up a piece of 2″x4″ rectangular extruded aluminum tubing from the local metal supply store to act as the fence itself, and for the rest I used other scraps of angle iron and trailer hitch tube I had saved from previous projects.

There are basically three parts to the fence assembly (and three corresponding blog posts):

  1. the rail
  2. the carriage
  3. the fence

The carriage and the fence are connected to each other and slide along the rail to set the distance between the blade and the fence. The carriage must be able to lock itself in place at any point along the rail.

My typical approach to any project is to just start building and figure things out as I go (for typical results, see my cyclone separator). I tend to rely on relative measurements (“about this big…”, or “the same size as that…”) rather than actually measuring with a ruler or tape measure. Since this project required a greater level of precision than my typical project, I did nothing different (I’m not entirely certain where my ruler and tape measure are anyways).

Bandsaw Fence - Rail

I determined the length for the rail by marking a piece of scrap hardboard while holding it against the bottom of the saw’s table.

After cutting the rail (a piece of 1″ angle iron) to length I used the same process to determine the proper location for the mounting holes. I drilled the holes a little large, so that there was some slack for adjustments.

Bandsaw Fence - Rail

Short segments of angle iron are pretty straight but they have some scaling and bubbling from the forging process which I filed off and sanded a bit to ensure that the surface was flat (enough).

I happened to have a couple of metric bolts and lock washers that fit the threaded holes in the table, and installed the rail.

Bandsaw Fence - Rail

Next step: the carriage…

‘They Don’t Make ’em Like They Used To’

“They don’t make ’em like they used to.”

We hear this phrase frequently when people are discussing tools and machines.

The old tools from the 1940’s – 1970’s are generally regarded as the best of their kind. This was the golden age of manufacturing, when men were men, women were men, and cast iron was liberally applied to everything in sight.

Table saws, band saws,  milling machines, shapers, jointers, lathes, pretty much any non-portable tool, you only have to scan a few blogs to find scores of DIYers and professionals proclaiming the virtues of their old machines and descrying the inferiority of the modern equivalents (to see what I mean, just google the phrase “Chinese crap”  …   actually … on second thought, ignore that suggestion).

Some companies recognize this appeal, and work it into their product line. Powermatic, for instance, charges a premium for their tools because they DO make them like they used to (Harbor Freight, on the other hand, sells almost nothing but Chinese sheet metal).

You generally won’t hear me dissenting from this view that older is better. I have an old Rockwell table saw that I fixed up and love to use (although I bought it because it was cheap, not because it was old).

However, I have never bought into the idea fully. It just doesn’t seem possible that modern design and manufacturing techniques could have universally degraded. Granted, I do get pretty upset when tools are advertised as “improved” when all they have done is add a laser; but there must be cases in which the old tool had some deficiency and the newer tools have corrected it.

This brings me to my latest Craigslist experience.

I was browsing through the current tool postings when I came across something I had never seen: a 1940’s scroll saw.

1940's Dunlop Scroll Saw

It was big, heavy, had a good motor, and was only $30 so I bought it, thinking I could tune it up and replace my current scroll saw.

I got it home and started to take it apart.

The first thing I noticed, was that the blade was “tensioned” by a spring loaded plunger at the top. There was no mechanical linkage between the lower and upper blade mounts, which meant that the tool could ONLY cut on the down stroke. Which meant that many modern blades with a mix of down and up cutting teeth could not be used with this tool, and the blade had to be thick and rigid enough to not bend when being pushed through a cut.

1940's Dunlop Scroll Saw - top
This was the first setback but I continued to break down the tool still thinking there may be hope.

I took off the cover for the lower housing and saw two things:

  1. The mechanism to to convert the rotation of the motor to the raising and lowering of the blade was a heavily lubed set of slides, not the ball-bearing + rod and piston design I had expected. 
  2. The housing was full of oil!

1940's Dunlop Scroll Saw - reservoir
I couldn’t believe it! This thing was so inefficient and high-friction that it used an oil reservoir  to keep the parts from overheating and wearing out!

Either that or this was an extraordinarily rare four-stroke internal-combustion scroll saw.

As I did a little more digging and research, I found that these old scroll saws are really not comparable to the new ones.

Because the blade cannot be tensioned, the blades must be thick and rigid (relatively), so they cannot be used for delicate scroll work or tight curves which, in my opinion, are the only reason scroll saws exist.

It occurred to me that this tool was basically an upside-down, non-portable jigsaw that could not do anything my band saw could not do better, and which was unable to keep pace with my smaller modern scroll saw.

They don’t make them like they used to, and it’s a good thing (at least for scroll saws). Since it was only $30, I don’t feel too bad about picking a lemon. Plus I got a nice little motor and I can probably re-purpose the cast-iron table from the saw. Otherwise, this is scrap metal, and I don’t feel guilty about its unceremonious demise.

It lived a long life (72 years), but I cannot imagine it ever brought joy or even marginal satisfaction to anyone that used it. It’s just a miserable old tool.

May it rust in peace.

Inca Band Saw Part 4: The Tires and the Cut

Based on my first experiment, having replaced nothing but the guides and thrust bearings, I was concerned about the performance of the saw, but was reserving judgement until I replaced the blade and the tires, since both of these can make a big difference in the cut quality.

After hunting around online for a while, I found several recommendations for the Olson MVP blade (72 1/2″ x 1/2″) and the urethane tires from Peachtree woodworking (11″ x 3/4″)

Before installing the new tires, I had to replace the old ones, which were glued in place. I took off the upper wheel since it was only held on by a snap ring.

I had to cut off the tires, which I did by scoring the same line over and over with an X-acto knife, being careful not to score the aluminum wheel.

It was then just a matter of peeling off the old tire.

I thought about really trying to clean up the surface of the wheel, but decided that it would ultimately be more work than it was worth, since any small irregularities would be smoothed over by the new tire.

The urethane tires do not require glue as they are held on by the friction due to a tight fit.

I’m not sure how tight the fit is normally, but wow! I had quite a wrestling match to get the tires on. I used a clever strategy composed of pinched fingers, teeth, and a neck cramp, and was successful at installing both tired.

Now I re-installed the wheels and aligned them before mounting the blade.

Because the Inca band saw has flat wheels (no crown) the blade is not centered on the wheels, but is rather run along the front edge of the tire, with the teeth extending beyond the front of the tire to prevent them from damaging the tire.

I got everything beck together and made a test cut on some 3/4″ white oak.

Wow. That made a difference. I have mostly used cheap 9″ saws in the past, so I cannot say how this compares to a finely-tuned top-of-the-line saw, but it was by far the straightest, most effortless cutting I have ever done with a band saw.

I also free-handed a little bit of resawing on a piece of red oak about 4-5 inches thick and was able to easily shave off a 1/16″ slice. The wood didn’t slow the saw down at all, but the surface of the resawn piece was a little wavier than I’d like, but I have little enough experience with band saws that I’m not sure what a purpose-built resaw machine would produce, so I’ll be happy with the fact that I could easily control the direction of the blade and make a thin slice off a relatively thick piece of wood.

My next improvement will be to make some sort of fence for the band saw, but for now, I have the most usable band saw I have ever worked with.

Inca Band Saw Part 3: The Guides

When I was first examining the guides on my saw, I noticed that they were unlike anything I’d ever seen before.  Actually, they seemed to be a mismatched set.

The guides on my saw are the type that have an asymmetrical pair on each the top and bottom, with one coming from the left, perpendicular to the blade, and the other coming from the right at a 45-degree angle.

I have seen this configuration before, but what was new here was that the perpendicular guide was a small wheel, with a groove on the outer circumference that the back of the blade would ride in; and the 45-degree steel guide wasn’t touching the blade at all.

After digging through the manual, I found that this wheel guide was the “fretwork guide”, meant to support the back of a blade too narrow to be held by the steel guides. This meant that I was missing the horizontal steel guides that I would need for a regular (3/8″-1/2″) blade.

I started looking online for information about Cool Blocks and ceramic guides, having heard that these were the best for guiding the blade and keeping it from overheating due to the friction of the guides rubbing against the blade, however, being a relatively rare European saw, I would have to order custom blocks, which would be tedious and expensive.

I am a regular reader of woodgears.ca, and had seen an article regarding using hardwood blocks as guides. This seemed cheap, easy, and reversible, so I thought it would make a worthwhile experiment.

Wanting to do a little more research on this concept and general bandsaw theory, I bought The Bandsaw Book and found a couple interesting facts: 1.) Wooden guides can provide excellent support for the blade, although they wear out quickly; and 2.) Steel guides do NOT cause blades to overheat (the wood being cut generates far more heat, and the guides are only making contact with a very small portion of the blade).

Armed with the confidence that I could do no harm; I cut out a set of guides from some white oak I had laying around, saturated them with Johnson’s Paste Wax, and tested the cut.

It was terrible! The blade immediately started cutting at what must have been 20-degrees from parallel to the table.

I started to worry about whether the guides would work, but then I remembered: I’m using a saw with chewed up tires and the cheapest Craftsman blade that fits, I should probably address those problems before I start trying to fine-tune the cut.

<To be continued in Part 4: The Wheels and the Blade>