Poor man’s lathe

There are times when you need to modify a part in such a way that you need the use of a lathe or CNC machine, but the cost of such a job or the wait time may not be worth it. I like to spend the day in the garage and get things done right away, but I have only the basic hand held tools, not a lathe or even a drill press. So what is a garage hacker to do when a part needs to be turned down on a lathe and you lack such a tool or the patience to wait for the shop to do it for you? Simple – make an impromptu lathe from your hand held drill!

I was working on this massive autonomous robot project and needed to adapt the axles from a pickup truck rear differential to take a set of bearings and sprockets. Sure, I could have sent them to the shop and paid $150 to have them machined on a lathe, but I did not want to fork out the dough any more than I wanted to wait a month to have this done, so I decided to pull a “MacGyver” and machine down the axles without needing a lathe. Impossible do to the precision needed? Heck no! I even added a keyway to each axle using an angle grinder and the end result was a perfect fit.
Let me show you how I adapted the axle shafts shown here to fit onto the 1 inch diameter bearings and sprockets.

A lathe in its simplest terms is a machine that spins a part so that a cutting bit can remove metal a little bit at a time. So, I knew if I could get the axle to spin, then I could just use my grinder to carefully remove the metal around the end of the shaft until it was exactly 1 inch in diameter. At this point, the axles were about 1.25 inches in diameter and tapered. To spin the axle, I welded a bolt to the center of the hub flange and then placed it in the chuck of my hand drill. The axle was then placed into a simple wooden jig and greased so that it would spin freely.

I found the drill spun the axle a bit too fast for my liking, so I needed a way to reduce the speed of the drill to about 120 RPM. Trying to tie wrap the variable trigger in place did not really work out so well, and then I remembered something about the series wound motors in drills and saws – they work with both AC current and DC current. My idea was to just reduce the voltage to the drill motor.

Going from 120 volts AC to 24 volts DC slowed the drill down to the perfect speed, yet gave it enough torque to spin the axles as I held the grinder disc to them. To power the drill from 24 volts DC, I just took two of the four robot batteries (marine batteries) and wired them in series with the drill power cord completing the circuit. I didn’t even use wires for the plug; it was just sandwiched between the two battery terminals and held there by friction.

My machining process required shortening the axles and then turning them down to exactly 1 inch in diameter at the last 2 inches on each end. Cutting the axle short was easy; I just spun up the drill and then held the zip disc on the axle until it cut all the way through the axle. I did not need the splined end piece, so it was tossed in the scrap bin.

To machine down the axles, I ran my grinding disc back and forth along the 2 inch section while the drill spun the axles at about 120 RPM. I did not push hard on the grinder, and tried to keep a constant pace as I moved it back and forth along the area to be reduced. After about 50 strokes, I would stop the drill and check the axle thickness using the bearing I intended to install.

Once the axle was just slightly larger than necessary, I switched from the grinder disc to a sanding disc so the final machining could be done more accurately.


May 24 newsletter



Feature article by Brad Graham (Radical Brad):
*** Building a rebar greenhouse – Part 4 ***


In the Atomic Zombie builders gallery
Coming soon – manufactured parts for your bike projects
Head tubes and bottom brackets
Bike builders chat
Spring into bike building – offer ends May 31
This and other AZ newsletters are here.

April 25 newsletter – AtomicZombie

Feature article by Brad Graham (Radical Brad):
Building a rebar greenhouse
Costa Rica recumbent lowracer
Edmonton trike
Chopper in Turkey
USA velomobile
Trike in Denmark
Michigan custom bikes
Australian chopper
Spring into bike building
Manufactured bike parts
This and archived AZ newsletters are here.

Trikes, trikes and more trikes!

Besides choppers, we’re getting a whack of gallery submissions for trikes. Here are some recent additions of these three wheeled wonders to the Atomic Zombie family of home built bikes:

Soon to be completed! WOLF of Mich.


David Cole
Suffolk, England


Dewey Johnson


Hey, my name is Francis Labbe, I’m from Sherbrooke City, Quebec, Canada.
This is my project named FL500. Thanks!


Fritz Schantz: Artie’s warrior is complete!
Did headtube steering to keep cable mess to a minimum.
The seat is hinged off of the wheel booms and sprung at the back mount.
Thanks for the awesome plans!


This is my version of the Warrior trike.
P.S. It rides great.
Deltona, Florida

More chopper crazy

New to the builders gallery this week:

From Estonia

 Margo Maripuu, Tallinn, Estonia

More >>

Bike builders rock!

Chopper crazy

 Choppers are always popular with the DIY bike crowd. Whether they’re made from scratch or tricked out rides with loads of bling, choppers are cool. Here’s a selection of choppers that were recently added to the Atomic Zombie gallery.
Dave Moyer
Saylorsburg, PA.
John Kemper
Rialto, California
Sao Paulo, Brazil
Stella’s Chopper.
PeterT, South Australia
Jaxon’s (3years) 1st Chopper
Hartlepool, England

How to build a phat ass chopper wheel – Part 1

AtomicZombie's OverKill chopper

Let’s face it, a chopper needs to have a wide rear wheel in order to stand out among the pack. In fact, the wider the better! I remember the days when a bicycle chopping involved hammering a cut off set of forks onto the ends of another set and then replacing the front wheel with a smaller diameter wheel.

Well, those days are history, and now a custom chop may involve a year of work and several hundred dollars of machined “bling” in the mix. Things changed about 10 years ago when department stores began mass producing these chopper bicycles with 4 inch wide tires, something that was not available before that time.

At first, I was thinking “cool, a new source of parts”, but then I started seeing these cookie-cutter factory jobs all over the place, and they all looked alike. In fact, the only difference between these so-called “customs” was the color and the eight digit serial number. Seeing this sacred ground infected by the big box stores made me take drastic action, and I set out to make a chopper that would mock these department store bikes both in look and in cost. I wanted to blast the chopper proportions way out there and do it for only a few bucks, so I designed OverKill.

To spew insult at these 4 inch wide rear wheel departments store chops, I would have to go way overboard on the rear wheel, so I started looking at ways to fit a motorcycle wheel to a bicycle hub. After a few prototypes I realized that I was only a slight bit larger, having tires of 5 or 6 inches in width. I scraped the motorcycle wheel idea and went to the auto wrecker to scrounge up something bigger, much bigger.

After a bit of digging, I found an old steel rim with a 15 inch wide drag slick, and that formed the basis for the OverKill Chopper. After that, many other creative chops started popping up based on the OverKill plan, each with some amazing custom twist. Am I laying claim to inventing the car wheel chopper? No sir, but I would like to think I had a hand in putting these department store chops back in their rightful place – well behind the real custom.

So, let’s have a look at how easy it is to whip up a phat rear wheel for a bicycle chopper. All you need is an old steel rim with a tire and some common bicycle parts. I didn’t have room in this release to show the creation of the wide hub, so we will just start with the process of lacing the wheel, which is much easier than you might think.

Figure 1 – Getting ready to lace a car rim

At this point, we have the custom wide hub which is made from an old steel BMX hub and a set of 72 matching spokes. Why 72 spokes? Because the original hubs had 36 spokes and I drilled a second set of holes on each flange to double the number of spoke holes. This allows the creation of what is really 2 laced rims on each side of the car rim to offer both strength and a thick look to the finished wheel.

Spoke length is not important here, just use common spokes made for a 20 inch rim when you are lacing a 15 inch car rim, and they will fit. If you know something about lacing a bicycle wheel, forget it now because the technique used to lace a car rim is completely different and much more simplified.

Figure 2 – Adding the first two spokes

Start by handing the hub by two spokes as shown in Figure 2. These are both “inside spokes”, meaning that you push them into the spoke holes on the hub towards the inside of the rim so that the round head is facing outwards. Spin the spoke nipple around two or three times to hold the spokes in place. Be careful when pushing the spokes around that you don’t scratch the paint on your rim. The spokes are sharp at the ends and will easily mark up your new paint job if you are not careful, especially when getting the last few to bend into position.

Figure 3 – Keep adding more spokes into every second hole

Keep adding more spokes to the rim, but only in every second hole so each spoke pair has a blank hole between them. These spokes will all be inside spokes, so they are pushed into the holes towards the inside of the rim. You will need to add 36 of these spokes to the rim.

Only turn the spoke nipple a few times, and try to turn them all about the same amount.

Figure 4 – Turn the hub to remove the slack

Once you have one side completely laced with spokes, you will notice how loose they all are. Did we use spokes that are too long? Nope, this is all part of the plan, and if you give the hub a spin, you will see that the slack is picked up as the spokes begin to exit the hub at an angle. This can be seen in Figure 4, as I have one side laced and have the hub twisted to take up the slack in the spokes. Continue adding spokes to the other side of the rim in the same manner.

More in the February 27, 2012 newsletter  >>


Ron’s sleek bike chopper


Built by Big Ron
Hey, Ron. That’s a slick looking chopper. Nice job!  
Build your own custom choppers!

Slovakia handmade recumbent trike

Dusan's prototype recumbent trike - Slovakia

See more pictures here:  Slovakia handmade recumbent trike

Build your own recumbent tadpole trike with help from AtomicZombie.com

The Wisconsin Solidarity Bike – Atomic Zombie builders forum

“The evolution… Started with this iconic image, which has become an easily recognized symbol in Wisconsin. As you can see, I greatly simplified the shape – I incorporated as many 120-degree angles as possible, so I could cut copy the same angle from one tube to many others. There were 45 pieces planned for the frame.

For structural reasons, I expanded the star to the outer edges of the frame. I ended up doing things a little differently for the rear end, putting two tubes together side-by-side. It more closely matches the original shape, and looks a bit more fancy.”

Read more and join the discussion:  The Wisconsin Solidarity Bike