FAST FOAM LATHE

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Introduction: FAST FOAM LATHE

Here is a quick and easy way to start turning (making stuff on a lathe) - without a lathe, wood, metal, or any of the correct cutting tools. This covers the basic concepts: setup, rough cut, pattern, shape, finish.

Here are the basic steps:

SETUP
-Assemble simple drill lathe
-Cut stock (pink foam)
-Mount stock on lathe

Rough Cut
-Shape the square stock to a round cylinder

PATTERN PREP
-Find or make a pattern
-Cut out the positive and negative profile
-Transfer pattern to rough cut stock

Shape
-Follow the pattern
-Cut largest diameter of first feature
-Cut smallest diameter
-Connect the cuts
-Check against pattern
-Sand

Finish
-Sand with fine grit
-Seal or paint
-Polish
-Remove

Step 1: SET UP

I used the Craftsman MiniTool set for this project. It is a bunch of tiny shop tools (drill, grinder, router, skill saw) that ware all powered from a variable 12V DC supply. This is nice because you can simply tape down the drill trigger and use the power supply to control drill speed and on off. This is not essential, a full size drill could easily be used, with a small set of quick grips on the trigger.

This lathe uses a face plate, so the work is only supported on one end instead of two. The face plate is okay for small projects, think of it like a potters wheel. This face plate is from a Craftsman sander attachment for a drill. (does anybody know what it is called?)

To assemble the lathe, just put the sander attachment in the drill chuck and mount your drill on a workbench.

Next - cut the stock to roughly square. For this project I am using pink foam insulation. This is easy to cut and sand and if it flies off the lathe it will not hurt you. (I do cannot guarantee that you will not get hurt). You could also use white packing styrofome, but the pink foam an a smaller "grain" to it making for nice cuts. Plus I had some in my basement.

When cutting the stock you want the final piece to be as square as possible, this will make the next step easier. Cut the stock to the length about 2 inches longer then your final product will be. (You will need to sacrifice the bottom portion, and it helps to have room for error on the top as this will be your first cut). I think that 8 inches is the limit for this faceplate technique.

Now - Mount the stock on the face plate. I do this by using HOT hot glue. I have a big Craftsman glue gun that gets very hot. I use this with high temp wood working glue sticks. They take about 5 minutes to start melting and are yellow for some reason. I also use this method for mounting wooden stock on the faceplate of a full size wood lathe. The only problem I have had is getting all the glue off the face plate for the next project. With a wooden face plate you can use a heat gun, or throw it in the oven. With the plastic face plate used here you will have to scrap it off carefully.

Great - now you are ready to start turning!

Step 2: ROUGH CUT

Rough cut is the step where you turn the square stock into a round cylinder.

I did this using a utility knife and course sand paper (fabric backed is best for this)

Here are the basic steps:
-Turn on the drill on a low speed.
-Stand aside, If the whole rig flies apart, then try again
-If it stays together, slowly start cutting and sanding until you have a rough cylinder.

Cutting technique:
Foam is pretty soft, so start slowly. The goal is to remove the square edges without destroying the set up. With the drill running at a medium slow speed, look straight down at the spinning stock. The outer square edges will create a fuzzy blurred circle - this is what you want to remove. In the center you will see a pretty solid circle, this you want to keep. Start outside the blurred circel and slowly bring the tool in until it makes contact. It will feel like it is vibrating against the square corners. Work slowly and evenly up and down the block. I sarted with a utility knife to get off the bulk of the corners, then switched to a course sand paper. You are done when the vibrations pretty much stop. When in doubt, leave extra material on the peice it is easy to take of latter and hard to put back!

Step 3: PATTERN PREP

Turning can be done freehand - or by using a pattern. It is useful to learn how to use a pattern if you want to make a lot of one thing (like a chess set). I'm using a pawn as an example.

Steps: PATTERN PREP
-Find or make a pattern
-Cut out the positive and negative profile
-Transfer pattern to rough cut stock

-Find or make a pattern
-I used a pattern from - http://www.freechesssetplans.com/
-I find it easiest to resize in power point. I made a few sizes that would be close, then held the blank cylinder up to them to pick a size. You need the diameter of your cylinder to match the largest diameter in your pattern (or at least be close)

-Cut out the positive and negative profile
-Carefully cut out the profile using an exacto knife. Both the positve and negative profiles will be useful.

-Transfer pattern to rough cut stock
-Mark the major featurs on your cylinder. I do this by holding up the positive profile to the spinning blank sylinder and markin the high and low points with a marker. Mark the bottom of the peice with a thick line, this will help you to alight the pattern as you move along.

Step 4: SHAPE!!

Now here is the fun part!

It is time to shape your stock cylinder into an elegant sculpture.

In this step we will use a small exacto knife and a fine sandpaper as the primary cutting tools. When cutting chess peices, the design can be broken down into body parts. - Head, shoulder, waist, feet. It is safest to start with the feature farthest from the faceplate and work your way down. So we will start wit the head. The steps are:

Shape
-Follow the pattern
-Cut largest diameter of first feature
-Cut smallest diameter
-Connect the cuts
-Check against pattern
-Try to fix...
-Sand

-Follow the Pattern
-Start by marking the largest diameter of the sherical head on the top of the cylinder with a marker.

-Cut largest diameter of first feature
-Now cut the entire head portion to this outer diameter. Cut slowly. I like to carefuly cut the very top to the needed diameter, then I cut the rest to match.
-You can use the patterns you cut out to check the size.

-Cut smallest diameter
-Now cut the smallest diameter, mark the vertical location of the smallest diameter and cut a narrow groove to the correct depth at this location.
-Mark the loation of the widest diamter

-Connect the cuts
-Now shape the curves from the smallest to largest diameter. Work slowly and check the pattern.

-Check against pattern
-The final ball should fit neatly into the negative profile you cut earlier.

-Try to fix...
-I am usually off, but try to fix it. Or at least work it into a reasonalbe shape.

-Sand
-Lightly sand the head with a fine grit. You don't want to change the shape, but just smooth the surface.

Congratulations!!! You just finished your first feature!

You will not touch this part again until you paint or seal the finished peice.

The same basic staps can be followed to cut the remaining features.

Step 5: SHOULDERS AND WAIST

The shoulders are pretty well shaped by the time you finish the head.

The next major feature is the waist.

I set calipers to the largest diameter, then cut the entire waist to this diameter using an exacto knife and checking with the calipers.

Then remark the smallest diameter and make a norrow cut the the correct diameter, again checking with calipers.

Now connect the cuts in a smooth curve. For this cut I used sandpaper on a stick. (the next step shows this in detail).

Finally lightly sand the waist to a smooth finish, all while checking against the pattersn.

Step 6: SANDPAPER

Here are some notes on sandpaper -

Fabric backed sandpaper works very well when working on a lathe. You can buy it in rolls relatively cheaply.

But sandpaper clogs quickly - so you need a sandpaper cleaner! These are sold for use with belt sanders. It is like a giant sticky eraser that magically cleans sandpaper. This is a life saver if you are working with wet, hard, or gummy wood.

To cut the sandpaper, hold the paper down with the saw and tear. Do this with the non-gritty side towards the blade.

Once cut, bend the sandpaper over the edge of the work bench lengthwise and side-to-side. This seems to break up the glue - and prevents large chunks of gritt from falling off when the paper is bent sharply.

For cutting the waist of the pawn - it is convenient to tape a strip of sandpaper to a dowl. This makes a nice carving tool.

Okay - now back to the lathe!!

Step 7: CUT THE FEET

Now you should be pretty good with the foam lathe.

The feet can be cut in the same way as the other features. Just cut the max and min diameters first and connect the cuts.

I like to get the overall shape fist, then cut the fine ridges with a very sharp exacto knife.

Step 8: FINISH

The great thing about a wood lathe is that the entire project can be done on one peice of equipment. The foam lathe is no different. We cut the rough shape on the lathe, now we can lightly sand, apply a finish and polish.

Finish
-Sand with fine grit
-Now you can go over the whole peice with a very fine grit sandpaper (220+). If you have been doing this all along the way than you can skip it. The idea is to remove any scratches wihout changing the shape. I found this a little hard to do, as the foam is very soft and comes of easily.

-Seal or paint
-Foam is tricky to paint because many things will disolve it. I used watered down elmers glue. Acrilic paint should work, but I did not try.

-Polish
Once the peice is dry, you can pollish is right on the lathe. I skipped this part, but you can probably get a nice shine by applying a soft cloth the peice while it is spinning.

-Remove
-You are done! Now just remove the peice from the faceplate. Foam is soft so you can cut it easily with an exacto knife. I did this with the lathe turned off.

Step 9: DONE!

That is it!!

Now make more chess pieces or move on to whatever you want. This is very good practice without needing a full size lathe or any of the correct tools!

Let me know how it goes.

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    70 Comments

    I did this with styrofoam and a drill press as I needed nose cones for stomp rockets. But I did notice that if I let the glue gun get too hot, the glue would just melt the styrofoam.

    I don't exactly know why, but I'd like to try this using a block of dark chocolate as my medium.

    That's pretty awesome. Combine this with lost-foam casting and you could have metal chess pieces fairly easily.

    Also, I believe you can cut your piece templates out of sheet metal/aluminum and use that to shape the foam. Basically how you are holding your pattern to the piece in the one picture.

    how hard is the foam? it looks like thermocol and pretty weak.

    two words: Backpacking Chess!

    lol seriously though excellent results! I would love to see some people's faces though if one started playing chess with these on a backpacking trip ...especially if they and the board (which should be foam as well) were made to look like they were made of granite :D

    I do the same thing with my rotary tool and foam blocks for really small items. the bigger stuff I mostly do by hand. However I did recently make up a spindle with a plexiglass base to do some of the bigger items. I simply hold the dremel against the base and use sanding boards to round out and fine sand round foam items.

    A great idea and a very nice instructable!

    Wonder if anyone has tried any hot wire foam cutting tools combined with such a "lathe" as this? I sometimes cut foam with a hot wire to make papier mache objects, but foam on a lathe never occurred to me.

    I saw a fair number of comments wondering how to increase hardness, durability, weight, etc, but without damaging the foam. Would it work to use the foam piece to cast a mold, then choose a more heavier/more durable material from there?