How to Customize Solid Tank Treads

by Your Own Hands

Tank is a symbols of powerful modern weapons. It is able to destroy a big area in a short

time. If you are interested in assembling robots, or customizing car models, a tank would be

a good design pattern. There are all kinds of tank tread kits in the market. But most of them

are childish, like toys, not powerful weapons at all. If you want to make your tank the most

devastating robot in people’s eyes, hand-making tank treads using bicycle chains fit you most

and you can customize everything about it, such as color and size. Please follow this

instruction to make a customized tank tread.

This is a tank robot sample with hand-making treads from bicycle chains:

Figure 1: tank sample

Introduction

The tank treads in this instruction are made of bicycle chains. The basic idea is that to combine two chains together into one tread by many plastic chips. It is a time-consuming job which requires lots of accurate operation rather than a hard technical job.

This job should be performed in an engineering design studio which cutting and drilling machines are available. You should make sure the studio is a standard one where safety is guaranteed and protective goggles are available before working there. You also need a big table to assemble the treads.

The steps you should follow is not complicated:a) Unwind bicycle chains and make them in suitable length.

Then reconnect the two ends of the bicycle chains.

b) Cut plastic boards into many pieces of small rectangle-shaped chips. They should be in a particular size also and the size should be calibrated carefully before you cutting the boards. To cut the board, you need two machines - Geared Head Drill Press (a drilling machine) and Bandsaw (a cutting machine) (I will explain them later). They should be available in engineering design studio safely.

Before you using these machines, you need to get training by stuffs in the studio first, because they could be dangerous if you don’t follow the rules. In addition, whenever you are operating these machines, please wear protective goggles.

Notes: If you feel uncomfortable to use these big machines, then you have to use saws and drills to do the same job, which could be annoying but still doable.

c) Combine the chains and the plastic rectangular chips together using screws and bolts. The tread should fit your wheels if all the measurements are accurate before.

This work is not hard, but time consuming. To get two perfect tank tread to fit your wheels and robot, it will take 15 hours or even longer because of the repeated trims. So please consider this job as an extended job instead of a one-day job.

Figure 2 (Source: Pubshop

http://www.pubshop.co.uk)

Figure 3 (Source: Urban Remains

http://www.urbanremainschicago.com)

Materials and Tools

Materials

1. A big Plastic board (Figure 4)

2. Bicycle chains1 (you will need two bicycles chains for one tread, so to make two tank treads in one tank, you will need four bicycle chains)

3. A Bicycle chain tool2 (Figure 5)

4. Screws and bolts (Figure 6)Notes: screws and bolts should match each other and the size of screws tips should fit in the interspace between two pins in a chain link

Tools

1. Geared head drill press3 (Figure 7)

2. Bandsaw4 (Figure 8)

Figure 4

Figure 5

Figure 6

Figure 7

3. A hammer and a Pliers (Figure 9)

Steps

1. Set up the bicycle chains

1) Unwind bicycle chains

At first when you get your bicycles chain, you need to unwind it into a straight line to be able to measure the length, which means you will use the chain tool to split the bicycle chain from one point. Any points are ok.

Warning: the chain tool is not as easy as it appears to be.You can also go to watch a video about how to use a chain tool: https://www.youtube.com/watch?v=wr3GfSrL68k

i. Place the chain in the chain tool (Figure 10)On the chain tool, there is a pair of protruding tabs2. One of the tabs will fit into the center of one link of the bicycle chain, while the other one fits into the center of the next link of the chain. You should place the chain properly in place so that the pin of the bicycle chain is held in the center of the tool. Now the tip of movable screw2 should be aiming at the pin of bicycle chain.

Figure 8

Figure 9

ii. Rotate the screw bar so that the tip of the screw on the chain tool will push the pin of bicycle chain out into the black fixed end2. (Figure 11, 12)

Figure 11: Rotate the screw bar

Figure 12: Now the tip of screw should be inside the bicycle chain pinhole.

iii. Screw the tip in the opposite direction out of the chain. And take the chain and the pin out of the chain tool. (Figure 13, 14)

Figure 10

Figure 13: The tip is out of the chain now

Figure 14: After taking the chain out of the tool, you should have a chain which can be placed in a straight line and a pin (DON’T FORGET THE PIN).

2) Measure (Figure 15, 16)

You have to do measurement before assembling. How long you want your tank treads to be is the important issue you have to consider in advance. You can assemble your two wheels on the robot base just for test and measure how long your tank treads should be. Usually the tread should be a little bit longer than the length which is able to circle two wheels on one side. In Figure 15, the red rectangle is the tread. The blue discs are the wheels and the black thick line is the base of robot. Therefore, your tread should be long enough to circle two wheels with some distance between them. But in the meantime, the tread should not be too long as well. It has to be tight enough to have friction with the wheels so that the wheels’ rotation will bring the tread to rotate with them.

Figure 15 tread and wheels

If now you have been aware of how long you need from the bicycle chains, then in order to split the chains later, mark the position and put the bicycle chains in a straight. In Figure 16, the black bar is the entire bicycle chain. The red bar is the boundary you want to use chain tool to split the bicycle chains.

3) Split the bicycle chain to desired length.

Use the chain tool to split the bicycle chain at the red bar point in Figure 16 (the method to use chain tool is available in 1 - 1) I, ii, and iii). Now you should have two pieces of bicycle chains from the original one, one of which is going to be used later. Therefore, so far, the bicycle chains are ready with the length fitting your wheels. If you want to make two tank treads, then you should finish setting up four bicycle chains (two chains for one tread).

2. Set up the plastic chips

To connect 2 bicycle chains together into 1 tank tread, you need plastic chips, as the “bridges”, which are small pieces of plastic board. (Figure 17)

Now put the big plastic board on the table. We will cut it into small pieces.

Before cutting the board, you should understand the idea that how plastic chips, bicycle chains, and wheels work together: (Figure 18, 19)

In Figure 18, which is a back view, the green rectangle is the back view of a wheel. And the two bicycle chains are the black lines. The grey rectangle is one of the plastic chips. The

This is the length you need from your bicycle chainsFigure 16

Figure 17Plastic board

idea is to use the two bicycle chains to clamp the wheel in the middle. And the plastic chip is the connection between 2 bicycle chains and also the attachment between the wheel and chains. In addition, the friction between the wheel and chains originates from the chip. The 2 blue dots are the position for screws and bolts which are inserted into the holes we will drill later on the chip.

You can also see in Figure 19 which is a right side view. The black curve is the bicycle chain and the green disc is the wheel. The grey rectangles are the plastic chips which used to connect two chains together and press onto the wheel.

How are the screws and bolts going to connect the bicycle chains with the chips?(Figure 20)

We can see there is an interspace1 which is like a hole between two pins on each bicycle link. We insert the screws, through the holes on the plastic chips, into the gaps on chain links and use bolts to stabilize the screws on the other side. Because of conflicts, here we will utilize one bicycle chain link of every two.

As we can see in Figure 20, the screws on the plastic chips connect the two bicycle chains together. And the length of the chips is just enough to make the 2 chains stay stably on the wheels.

Figure 19: right side view of bicycle chains and wheels

Figure 18: back view of

bicycle chains and wheels

How do we get the desired-sized plastic chips?

1) Measure (Figure 20)Before cutting the plastic board into small chips, you need to know the size of each plastic chip. Use ruler to do the following measurements.

The length to make the two chains just clamp the wheel, not too loosely and not too tightly (the red length in Figure 20).

The positions of two holes. The positions of holes’ centers should be measured and marked on the chips (the two red dots in Figure 20). You have to test the position again and again to get the perfect results.

You should also count how many chips you need by counting the links you will use in the bicycle chains (one of every two links are going to be used).

Notes: you probably need to assemble the chains and some sample plastic chips on the wheels to test and do these measurements.

2) Cut (Figure 21, 22, 23)Having been aware of the size of the chips, you can start cutting them. Bandsaw should be utilized here. Please follow the machine instruction in the studio and wear eye protection. You have to cut more chips than the number you need in case some of the chips broken later.

Figure 20: bicycle chains, wheels and screws from the view of back

Figure 21: Bandsaw

Figure 22: before cutting

3) Drill (Figure 24, 25, 26, 27)To drill, you will use the geared head drill press. Please follow the machine instruction in the studio and wear eye protection. You need to choose the particular drill to do the job. The drill needs to be the same size with the screws so that the screw can go through the hole you drill easily.

Figure 23: a chip after cutting

Figure 24: before drilling

Figure 25: before drilling

Figure 24: a chip after cutting

3. Combining plastic chips, bicycle chains, screws and bolts

1) Reconnect the two ends of bicycle chains into a whole (Figure 28, 29, 30, 31, 32)

We split the bicycle chains in step 1. Now it is time to reconnect them. Since the chain tool works much more inefficiently to reconnect chains than to split, it is better for you to use hammer instead.

Figure 26: after drilling one hole

Figure 27: after drilling two holes

Figure 28: use pliers to hold the pin over the pin hole of outer plate1 on the bicycle chain.

Figure 29: Use hammer to press the pin into the hole.

Figure 30

Figure 31: hammering, almost done

2) Screws and bolts (Figure 33, 34, 35, 36)Use screws to fix the chips onto the two bicycle chains.

Figure 32: a whole chain

Figure 33: chains, screws and bolts

Figure 34: inserting the screws into the interspace1 of one bicycle link

Figure 35: one chip has been set up on the two chains

Figure 36: Now the tread should be done after you screw all the chips on and you can try to cover the tread onto the wheels

Glossary

1. Bicycle chain:

Figure 37 structure of bicycle chain links (Wikipedia http://en.wikipedia.org)

Layout of a roller chain: 1. Outer plate 2. Inner plate 3. Pin 4. Bushing 5. Roller

2. Chain tool: a mechanical device used to split or break and also mend a bicycle chain. Bicycle chains have links and plates pinned together one by one. If you push the pins out using the chain tool, then the bicycle chain can be split into two parts. According to users’ intentions, the chain can be adjusted to be any length using a chain tool.

The tip of the screw A pair of protruding tabsFixed end

Interspace between two pins

(Watch videos about how to use a chain tool - https://www.youtube.com/watch?v=wr3GfSrL68k)

3. Geared head drill press: an electrical head drill press which power transmit from motor to spindle in the machine’s head.

Figure 39: a geared head drill press

4. Bandsaw: an electric power tool where a metal band blade full of teeth on one edge to cut all kinds of materials.

The screw and the screw bar

Figure 38: a chain tool

Figure 40: a bandsaw

Reference

Figure 2Caution Dangerous Machine Sign [Figures]. Retrieved April 10th, 2014 from http://www.pubshop.co.uk/catalog/cateringsafety-c-150_1191_1194.html

Figure 3 original c. 1940's american industrial single-sided die cut steel "wear your goggles" factory machine shop safety sig - the stonehouse steel sign co., denver, co. [Figures]. Retrieved April 10th, 2014 from http://www.urbanremainschicago.com/products/vintage-signs-advertising/safety-first/original-c-1940-s-american-industrial-single-sided-die-cut-steel-wear-your-goggles-factory-machine-shop-safety-sign.html

Figure 4Niabot (2011). Roller Chain Render (with numbers) [Figure]. Retrieved April 10th, 2014 from http://en.wikipedia.org/wiki/File:Roller_Chain_Render_(with_numbers).png

(The other pictures are my own photos.)