Thursday, June 30, 2016

Preparing a Base for our Above Ground Pool

Difficulty Level (Easy, Medium, Hard, Insane):

Last year, after repeated requests from my wife to get a pool, we finally decided to risk spending $200 bucks with the fear that it would become yet another unused toy. However, to our surprise, Nate proceeded to spend 2-3 hours every day for the next 2 months in that pool. I have never seen him so active, excited and happily playing by himself; it was a sheer pleasure.

Once we packed it away for the winter, I found out that a co-worker of mine used to have a bigger, heavier-duty pool that he wasn't using anymore so we came to a deal where I worked for him for a full 40 hours and in exchange I'd "get rid" of his pool and 80 foot chain link fence.

Last year, we decided to just put the 12 foot Intex Walmart pool (30" deep) right on the grass which wasn't such a great idea. The ground was about 5" uneven and the grass got thoroughly killed underneath the pool.

So, considering the uneven ground, the killed grass and the bigger pool, we decided to prepare a proper base, sized for the bigger pool, even though we decided to set up the smaller pool for another year or two until our girls are a bit bigger.

The process was not too complicated from a technical perspective, but it sure was a lot of physical labor.

First, I had to strip the sod off the area we were gonna put the base, but because we wanted to do this on a limited budget, I decided to make my own Sod Cutter Attachment to the Pull-behind Lawn Roller that I had built a few years ago.

After the sod was cut (we put it on top of the killed grass from last year), I hired a guy that was doing a pool for our neighbor to come over and level out the area for me. The ground sloped an entire 8" but it only took about 5 minutes with the back hoe. It was WELL worth the $60 bucks I paid the guy. I cannot even imagine having to dig through our hard rocky clay by hand!

After the ground was prepared I ordered 5 cubic yards of tailings (also called "Zero to 1/4" or "crusher dust"), leveled it out and compacted it with my lawn roller.

After some humming and hawing, I decided to build a 2x6 border around the perimeter to contain the crusher dust and to make it a bit neater. That part actually wasn't too hard once I decided to put in the extra work.

First, I had to find the exact size of the pool and how far apart the supporting posts would be. The dimensions are 11'-5" wide by 18' long. The pool itself is 9' by 17'. I decided to make the base 1 foot wider on each side which worked out to be a 13'-5" by 20' pad. Next I marked the exact property line with a string between the surveyor's markers, then I marked a parallel line 32" from the property line as the starting point/edge of the pool.

From there, I used the Pythagorean theorem to get an exact 90 degree angle, measured the width of the pad and hammered in the 4 corner posts made out of pressure treated 2x2s. Using my dad's laser level, I marked the 4 corner posts and strung a string around the perimeter which I could then use to set more 2x2 posts at 4' intervals all the way around the pool.

Once these posts were in and level, all I had to do was to set the 2x6s and 2x4s around the outside perimeter, screw it all together and fill up the inside with more crusher dust.

After compacting the crusher dust (I should have taken some more time as it didn't compact as much as I would have liked it to) I cut up an old, leaking 18' above ground pool that I found for free on kijiji, laid it on the pad and cut it to size.

Finally we were able to set up the 12' pool and fill it up with water. Surprisingly, it only took about 6 hours and warmed up to 18 degrees within the first day. The second day, the pool went up to 22 degrees and on the third, it was almost 25 degrees.

The last thing I had to do is cut a 2' by 2' piece of 1/2" plywood into 4 identical triangles at a 45 degree angle to screw down the tarp in each corner so the wind wouldn't blow it up and we were done.

The kids love it and I've already taken some time to play in it myself.

The area after the sod was cut
The stakes leveled to the correct height
Another view
Dumping the 5 cubic yards of tailings (I needed 1 more cubic yard later)
The kids "helping" with the distribution
My bigger two helpers
Marking out the borders
My little helper
Installing the 2-by borders
Another view
The border done
Testing out the base mat
Playing with the tarp configuration
Another 5 yards (4 for the driveway, 1 for the pool pad)
Playing with the tarp layout
Another view
The pool pad done, the pool set up and the water being filled up
My boy watching the water level rise
Ready for a swim
Measuring tape
Sod Cutter
Rented back hoe
Wheel barrow
Pick ax
Garden rake
Lawn tractor
Utility cart
5lb hammer
Sledge hammer
Table saw
Chop saw
Laser level
Cordless drill

Construction spray6 cubic yards of tailings
Five 8' pressure treated 2x6s
Six 8' pressure treated 2x4s
3" deck screws
One old, leaking 18' above ground swimming pool
Gorilla tarp tape
One 2' by 2' piece of 1/2" plywood for tying down tarp in corners


30 hrs

Over $1000

It's great to have a pool now! I love it!

Sunday, June 19, 2016

Making a Spout for my Lawn Roller

Difficulty Level (Easy, Medium, Hard, Insane):

When I first built my Pull-Behind Lawn Roller I didn't have a lathe yet so I just hacked something together for closing up the hole in my lawn roller. However, it was always leaking and I've wanted to do something more permanently so I took a chunk of metal, turned, faced, bored and threaded a 12 pitch thread on the inside of the ring. After that, I took a chunk of 2.500" aluminum I had cast with my Home Foundry a while back, cut off a piece on my Metal Band Saw, turned and knurled the outside, then turned the other half to size and threaded it to a matching 12 pitch thread.

The only thing that was left to do is weld the outside ring to my lawn roller, slip an o-ring on the cap and screw it on. This was more of a "would be nice to have" project and not so much a "really need this" project so I did enjoy making it


The 2.75" ring with a 12 TPI female thread
The cap made out of aluminum with a matching 12 TPI male thread
Another view of the aluminum cap
The cap with the o-ring installed
The o-ring kit I bought at princess auto or harbor freight, I can't remember which one it was
Grinding off some of the tar in preparation for welding
After the ring was welded to the lawn roller
Another view
Test fitting the cap before applying some more asphalt spray
After the asphalt was sprayed on
The installed cap
Another view
Metal lathe & accessories
Metal band saw
MIG welder
Angle grinder
Ear muffs & safety goggles

1/2" of 2.500" diameter metal
1" of 2.500" diameter aluminum
One 1.750" diameter o-ring
Some asphalt car undercoating spray


2 hrs

It works great and finally seals properly

Wednesday, June 8, 2016

Fixing a Patio Chair

Difficulty Level (Easy, Medium, Hard, Insane):

My son was sitting out on the deck on one of our patio chairs and unbeknownst to him I was watching him eat when all of a sudden the chair popped and he just about fell on the ground. It was so funny and the first thought that went through his head was "Crap, I'm gonna get in trouble for that!".

Much to his relief, I said it was fine because he didn't actually do anything at all to cause it. Upon further inspection I noticed that over the years of using those chairs (and man, kids are hard on furniture) the bolt stripped the aluminum thread in the thin chair legs.

Heli-coils to the rescue! It was just a few months ago that the heli-coil sets went on sale at Princess Auto and although I've never had a use for them I figured if I spend the $20/set (one metric, one imperial) I'd have them in case I ever needed them.

The process was actually quite simple. I took the other 3 bolts out of the chair, drilled the stripped thread hole to one size larger. Then I tapped it to size (I think it was an 1/4" by 20TPI on the outside and a 3/16" by 24 on the inside), screwed the heli-coil into the freshly tapped hole and put the bolts back into the now fixed hole.

The broken patio chair
Close-up of the stripped thread
The heli-coil set with the proper size selected
Drilling out the hole
Tapping it to the proper size
Screwing the heli-coil into the freshly tapped hole
Getting ready to put the chair back together
Testing the finished chair
All done
Tap & die set
Alan key
Digital Calipers

1 heli-coil


30 min


It works great and if another one bites the dust I'll know what to do!

Building a Harmonograph for Science Fair

Difficulty Level (Easy, Medium, Hard, Insane):

For our second annual home schooling science fair, we decided to introduce our son to harmonics and machining by building a harmonograph. I had seen my first harmonograph many decades ago in a science museum in Switzerland and having a significant background in mathematics I have always been fascinated by those machines that create beautiful, yet mathematically predictable pictures.

Aside from teaching him how harmonics work, how two one-dimensional axes (x-axis & y-axis) can interact to make a two dimensional image I wanted to introduce him to work on the lathe as well as to teach him how to be consistent, determined and “suffer” through the “boring” spots in the creation of a project.

There are several people online that have created these out of wood and i have made a few of these myself with small sticks of wood joined together by rubber bands, but this time around I wanted him to create something a little more substantial.

The pendulums were made from ½” solid round bar, the pivot points were made from 1” diameter teflon held together by 1/8” roll pins. The table was made out of 5/8” MDF and the horizontal arms that joined the pendulums to the pen were made out of ½” wood dowels.

The first thing we had to do is cut two 1” pieces of 2” diameter pipe, then drill and tap two holes on oposite sides. The next thing was to cut two 12” pieces of metal and turn a pivot point in the end. Then, we had to thread a ½” by 13 TPI thread to connect the pivot point pieces to the round pipe.

The next thing was to cut two ½” pieces of solid round bar and thread one end to a ½” by 13 TPI thread to connect to the second hole in the round pipe. After that, we cut up the wood dowels and drilled two holes for the cotter pins.

Then, we had to turn three pivots and a pen holder out of teflon. The last thing was to create two pendulum weights with a brass adjusting screw.

After cutting a 32” round table with the router and the circle attachment I made from some plexi glass many years ago it was ready to put together.


Nate cutting off the first two pieces on my metal band saw
Working hard at tapping the 1/2" by 13 TPI female thread
Ninja Nate
The two cut, drilled and tapped pieces
Proud boy
Turning a pivot point in one of the pendulums
Working the lathe
The first pendulum finished
He said he was Loki with his weapon. What a kid!
Close-up of the pendulum suspension method
Making the pendulum weight adjustment knob
Getting ready to mill the teflon pivot connectors
Drilling the holes on the mill
I think he liked it
Some of the samples
Some of the exhibits from the story above
Nate making some pictures
The judges from Mad Science observing his project
Nate demonstrating how it works to the judges
Some participants trying it out for themselves
The award ceremony
The price he won for his participation
Close-up of one of the pictures
Another one
Another one
The pen mounting contraption
A triple color picture
Metal Band Saw
Metal lathe & accessories
Measuring tape
Drill press
Drill bits
Cordless drill
De-burring tool
Angle grinder
Bench top grinder
Center punch
Circle attachment for router

2” of 2” diameter pipe
6’ of ½” solid round bar
8” of 2-1/2” solid round bar
4” of 1” diameter solid round brass
12” of 1” round teflon
3’ by 4’ of 5/8” MDF
8” of ¼” by 1” flat bar
Three 1/8” roll pins
4’ of ½” wood dowel

$35.00 (for the MDF; I didn't have any on hand)

20 hrs

The project was a great success and we had so many kids absolutely fascinated that two pendulums could create such elaborate drawings with no electricity!