I made a Dust Collector – Part 3

So… I may owe some level of explanation for waiting a year between my last post and this one…

Maybe.

I made a housing for my impeller by arranging several blocks of red oak on a piece of plywood and then tracing the perimeter of my impeller onto the blocks of wood.

I appear to have lost any photographic record of this step, so please view the following for reference:
Step 2 was awesome, sorry you missed it.   I then cut this line on each piece using my bandsaw. I rearranged the cut blocks so that they made the correct shape and then screwed them on to the piece of plywood. i also smeared from Bond-O on to the inside circumference to smooth out inconsistencies and plug any gaps.  I drilled a large hole into the center of the plywood to pass the motor through and made a little platform for the motor to rest on. cowling2
I found a picture!

After cutting a hole in the front piece, I slapped everything together for another test. It Sucked. But not as much as I hoped. I sat and pondered. and then got distracted. For a year. At some point during that year, I realized why my dust collected only sucked a little, but still waited a number of months before doing anything about it. Let’s play a fun game: Can you figure out what was wrong with my dust collector? ...duh.
=== SPOILER ALERT! ===
The impeller is spinning the wrong way. To make matters worse, the motor is unambiguously non reversible.
IMAG2092So I immediately (when I felt like it) got to work. I decided to solve the problem by moving the motor around to the “front” of the assembly. This also meant that I needed to keep the impeller in the same orientation relative to the housing, and so I needed to turn the back of the impeller into the front and re-mount it on the motor shaft:IMAG2093
back coverbalancing
transferring the old hole locations to the new backplugging unnecessary holes
done now. still done.
okay, NOW I'm done.Easy peasy. I powered it up for a test run, and promptly woke my son up (I have a son, he’s almost 2 and he was asleep).

IMAG2100

Needless to say, it was louder than I hoped.

I had recalled Wandel doing some testing around making his impeller design quieter and subsequently much, much louder to make an air raid siren. So I scoured his website and failed to find the article I was looking for, but did find a comment of his on someone else’s dust collector design where he noted that “the smaller the gap between the impeller and the housing, the louder it will be.”

So I shaved 1/4″ off the perimeter of my impeller using my bandsaw and put everything back together.

Then I waited until my son was asleep again (for maximum effect) and tested it again.
This time it REALLY sucked. And it did so very quietly. Almost Dust-Sniper quiet!

And so I set in a corner of my garage until I get time to mount and duct it.

Next June is looking promising…

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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.

Granite Surface Plate – Part 2

Continued from Part 1

So, to set the scene:

I’ve got a 1200-pound slab of granite resting on a metal cart with wheels… in the back of my truck.

I also have an ingenious system of ramps and winches to load the granite into the truck.

The problem now is how to get it out.

…in a controlled manner.

As I thought this through, I broke the operation down into 3 steps.

Step 1: Use pulleys to pull the granite towards the tailgate.
Unloading1
Step 2: Re-configure the cable to pull from outside the cart’s legs.
Unloading2
Unloading3

Step 3: Once the granite is ready to role down the ramps, move the winch cable back to the “loading” position, and slowly let the cable out.
Unloading4

In practice, it went very similarly to this, at first.
Step 1:
Granite Surface plate

Step 2:
(I clamped a 2×4 onto the stand and against the back of truck cab to keep the granite from rolling back into place while I moved the cable to the other side of the leg)
Granite Surface plate

Step 3:
… here’s where I hit a snag.
Instead of rolling smoothly onto the ramps, the wheels of the granite were simply pushing the ramps off the end of the tailgate.

I tried running a rope around the end of the ramps, but that didn’t work, since I needed the keep the ramps separated to align with the cart wheels and the rope kept pulling the ramps together and askew.

So I did something a little more involved.

First I secured the granite back into place, wanting to avoid a bad situation while I worked behind the truck.

I drilled holes and then cut slots in the plywood on top of the metal ramps with my jigsaw (cutting just the wood, not the metal).
Granite Surface plate

Granite Surface plate

Then I ran one strap through each of the ramps,Granite Surface plate

and secured them to the bumper.
Granite Surface plate

Then I went back through steps 1 and 2, and this time the granite rolled effortlessly onto the edge of the ramps.

Before I pulled the front wheels of the granite onto the downward slope of the ramp, I clamped a 2×4 across the bed of the truck, in a position that would stop the granite just after it started pulling itself down the ramps (but before it started to gain any significant momentum)
IMAG0386Granite Surface plate

With the granite resting against this 2×4, I walked around the FRONT of the truck to get to the cable on the other side of the truck bed and move the cable into the “pulling” position to use the winch to slowly let the granite down the ramp.
Granite Surface plate

Granite Surface plate

Done.
…I need a nap.
…and a change of pants.

NOTE: at all points during this process, unless the granite was fully secured, I only walked in FRONT of the truck, not behind it in the path of the granite should something fail. Keep in mind, 1200-pounds is a lot of pounds… Significantly more pounds than my one-rep max for bench press.

Safety

Granite Surface Plate – Part 1

I’ve been trawling Craigslist lately for… pretty much anything. I used to just click “for sale” and then “tools” and see if I needed anything; but the last few weeks I’ve done slightly more targeted searches.

I would type something generic in the search (“router”, “lathe”, “mill”, etc…), just to limit the number of floor scrapers and tile saws I had to sift through.

However, it turns out that even this limited filtering was excessive: I had been completely missing out on granite surface plates!

What is a surface plate? Google it.

In the unlikely event that Google brings you back here:

A surface plate is a certified flat surface with very tight tolerances for precision. It is used to check or verify the flatness of a tool or work piece. They are typically made of granite because it can be ground very flat and is stable enough to resist flexing and warping with pressure and temperature changes. It is also hard enough to come into frequent contact with metal surfaces without being worn out of true.

I stumbled across a small surface plate for $275 dollars, and it was a bit a expensive for my purposes, but I knew my father-in-law had been eyeing them too, so I sent him the link.

He replied with a counter-link: a huge 24-inch by 36-inch slab, 6-inches thick on a rolling metal stand for only $80! It weighed around 1200lbs… but only $80!

I called up my friend with a small flatbed trailer, and he was willing to lend it to the cause.

I contacted the seller, he still had it.

Game on.

I borrowed the trailer from my friend the next morning, threw some plywood in my truck to use as a ramp, and headed off to pick up my new flat surface.

I arrived at the location, got out of my truck, and it promptly started pouring down rain.

The seller came outside and we began a long process of looking back and forth between the trailer, the plywood “ramp”, and the granite, with our hands in our pockets, in the rain.

“Will the trailer hold it?”

“According to the manual, it should…”

“Should we try to get a running start?”

“…how would we stop the granite?”

“…”

<head scratch>

<other scratch>

“will the plywood ramp hold it?”

“…nope…”

“….”

“well… it’s not going anywhere, if you want to come back and try another day…”

“that’s probably a good idea.”

I forgot to take a picture of this process, but it looked something like this:
loadingProcess
And so I returned home, empty-handed and damp.

After a few sleepless nights and un-productive days at work, I came up with a plan. I had a small ATV winch with a 2000lb capacity, and a pair of loading ramps from Harbor Freight that can hold 1000lbs that I used in the past to load my motorcycle.

Loading winch

I bought one more ramp set with a coupon for $50, for a total of 2000lbs of loading capacity, and a pair of 16-foot jumper cables to power the winch for $17. With proper ramps I no longer saw any advantage to using the small trailer, so I returned it to my friend and started working on a setup to use the winch to load the granite directly into my pickup truck.
winchMount

First I welded together a frame to mount the winch in the bed of the truck, up against the cab. it has extension arms held together with bolts and installed in the truck with clamps and straps so I can easily remove and store it.

Then I covered the ramps with  1/2-inch plywood secured with carriage bolts to give the wheels a smaller step up onto the ramp and a smoother ascension into the truck.

This took about a week and a half to finish (interlaced with life in general), but I was finally ready to go get the granite last week.

The sun was shining and I arrived to be greeted with complements on my welding job and general optimism that we may succeed.

We were all impressed with how well the whole thing worked and in 10 minutes I was on my way home with my acquisition.
Granite Surface plate

I drove very slowly and arrived without incident and started the simple process of reversing the loading procedure.

Right… how exactly do you get a 1200lb piece of granite out of a truck?

<To Be Continued>

Filling Space

I suspect most people with milling machines fit into two categories:

  1. Professional machinists that use their machine on a daily basis
  2. People with too much disposable income and garage space that bought a machine on a whim and now primarily use it to prevent dust from reaching the floor

Although I may be wrong, I think people like me are a bit of a minority within the population of milling machine owners. I have no occupational prerogative for such a machine, but I use it all the time, for all sorts of things, whether or not it’s “necessary”, or the “proper” tool for the job. If it can be done with the milling machine, it will be done with the milling machine (or at least attempted).

The most recent use was to create a few spacers to fill gaps in my pergola. I had assembled a horizontal beam from two 2×6 boards and set it on top of 4×4 posts, but the combined width of the 2x6s was actually a bit thinner than the 4x4s, leaving an unsightly gap in the connecting bracket.

My work my not be precise, but I try to make it look good.

I needed to fill about 1/4-inch.

I happened to have some 1/4-inch plywood that would work for this task.

<start humming inspirational tune>

But I also happened to have a milling machine, so such band-aid fixes will not suffice! 

If I have the means and materials to make a spacer that will outlast the structure, the bracket, and likely human civilization itself, I will avail myself of such means and materials!

So I cut some squares out of a piece of aluminum tool plate (same piece I used for my miter saw fence) with my portable bandsaw (I love), and then used my milling machine to batch them square and bring them to their final dimensions.

Post Bracket Spacers

Post Bracket Spacers

Filler

Filler

I made a paper template and marked the hole locations on the newly square plates, which I then drilled out on the drill press.
Post Bracket Spacers

Post Bracket Spacers

Post Bracket Spacers

Space filled. Problem solved. Milling machine used.

<stop humming inspirational tune>

Miter Saw Fence

I have a monster of a miter saw.
Plywood Door

It’s a 12-inch sliding compound miter saw that I picked up from a guy on craigslist. It’s awesome.

However, I’ve been using it a lot lately and have been noticing that the angles need a lot of fine tuning to get exactly 45 or 90 degree cuts.

At first I thought it was just the positive lock mechanism needing some tweaking, but on closer examination, I found that the problem was the saw’s fence itself.

If I held a straight edge against the fence, I could see that both sides (although one more than the other) drifted further back as the neared the center, and the two sides were not parallel with each other.
Miter Saw

This meant that the angle of a cut could be wrong in three ways, depending on how I held the board (one angle if the board referenced both fence surfaces, and another angle for each of the two surfaces alone if trimming the end of a board).

I know I’ve recently outed myself as something of a rebel when it comes to precision, but not being able to cut at a specific angle when needed is always a bad thing.

But how to correct this? The fence is a single piece of cast aluminum, and can’t be bent without breaking, so I couldn’t just straighten it out, I needed to fix the surface.

When I looked more closely I saw that the fence was not bent out of shape, but rather worn out of shape. The saw had been previously owned by a production shop that used it almost exclusively for cutting aluminum, which apparently, over time, had worn down the fence.

So then I thought the solution might be the milling machine (to be perfectly honest, I try to use the milling machine as the solution to almost every problem). The difficulty with milling the surfaces flat would be keeping the fence perfectly parallel to the milling table in two different clamping positions to address each side. Ultimately this seemed like a big risk.

Then I noticed two 1/4-inch holes on each side of the fence, and realized that the solution was to add an auxiliary fence to the saw.

I wanted the fence to be rigid and thin (so as not to reduce the cutting capacity too much), and I decided to make it out of 1/4-inch thick aluminum tool plate (I had some laying around that I picked up as a remnant from the local metal supply store).
Miter Saw

I roughly cut two 3-inch wide strips and squared the edges on the milling machine (I knew I needed it!). I then marked the locations of the holes and edges in order to keep from mixing up the two parts, and then countersunk and drilled holes (in that order) to line up with the holes in the fence.
Miter Saw

Unfortunately I countersunk the wrong side of each piece, but luckily the hole positions are mirror images of each other on the left and right sides of the fence, so I just pretended I meant to do that and casually attached them to the opposite side with beveled machine screws and nylon lock nuts.
Miter Saw

That’s it.  Now I have a straight and sturdy secondary surface that I can shim if necessary to get a perfectly true alignment and then never think about again.