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!

Comments

[nerd12]

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

[Kaelessin]

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

[TheGeekFather]

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.

[Uncle Kudzu]

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.

[JMRaphael]

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?

[Uncle Kudzu]

That sounds like a good idea for making something with a little more substance than the foam. Molding and casting would be a whole 'nother can of worms, but this 'ible is a great way to get the turned original.

[just pick a name]

It might make life easier to glue the project to one of the sanding disks instead of the backing pad so you can just unscrew it and use another one instead of having to scrape your backing pad.  It would also give you one more use out of a worn out sanding disk.  Nice idea!

[marc.cryan]

Thanks - that is a good idea.

[doxsys]

Nice work! Do you know if Craftsman still offers the MiniTool set? (I haven't had much luck googling for it.)

[marc.cryan]

Do you know if Craftsman still offers the MiniTool set?

It does not look like they do.

You should contact Craftsman, this is a neat product for hobby use - well suited for the Instructables crowd.

This is too bad -- I've noticed a major decline in the quality and variety of tools available through most retailers.

Woodworkers Warehouse used to have an amazing selection of chisels and lathes - I don't know where you would buy one today adn I don't mail-order and any tools that could kill me.

[whiteoakart]

Harbor Freight Tools has lots of inexpensive tools.  They are probably all made in inland China and will give you lead poisoning.  I shop there and haven't died yet.

They have retail shops and online shopping. 

Here is their findastore:

http://www.harborfreight.com/cpi/ctaf/retail_stores.taf

[marc.cryan]

Thanks.

[LakeLivin]

Can anyone think of a liquid that would work to saturate the formed piece so that it would become hard (and heavier) upon drying? Obviously it would have to be something that wouldn't harm the foam when applied. Given the right substance and a good dose of creativity I'd think one could greatly expand potential applications using this technique... e.g., what would happen if you tried to saturate the formed piece with polyurethane or some type of plastic resin? What about something like watered down white glue? (can you even water down white glue, lol?)

[whiteoakart]

I have used this kind of foam extensively for model building. Here are a few tips on finishing:

1. The foam will not absorb any liquid. It is a closed cell foam, not like a sponge.

2. You can not use any solvent based paint or resins on the foam. It will melt quite quickly into a nasty goo.

3. Some things you can use to coat and seal the foam: spackling, epoxy resin, plaster, watered-down white glue or wood glue, acrylic paint, or latex paint.

4. Once you seal the foam, you can use any type of paint or finish on it. HOWEVER, if you have even a pin hole open to the foam, it will dissolve from the inside out. Trust me on this. I once lost 30 hours worth of work on a model for a college packaging design class.

My favorite sealing medium to use is epoxy resin. It gives a nice hard coat that sands well. You can build up many coats to make a thick shell and hollow it out with acetone through a hole in the bottom, but this makes a toxic goop that you will need to clean up.

Here is a 1/4 scale design of an imaginary futuristic Formula 1 car I did as a student many years ago. It is made with this kind of foam and epoxy resin. Finished off with automotive grade base coat/clear coat paint.

[kissiltur]

I don't know about saturating the foam (it's closed cell foam, isn't it? Would it absorb anything at all that didn't dissolve it?) but if you wanted weight you could insert metal rods into the centre. A big wood screw would be ideal since it would not need gluing, just driving in as usual.

[LakeLivin]

Good idea. Would give the piece a higher quality feel with the extra weight. Also, wonder if you could put the screw in first, but sticking out a little bit so you could mount the screw in the drill instead of gluing the foam? Or would it tear up the inside of the foam when rotating (or spin the foam independently of the foam)? Wish I had some foam to try it. . .

[kissiltur]

I doubt that the foam would be mechanically strong enough, unfortunately. I think you would end up with a beautifully hollowed out piece. If the screw were glued in then that might work, but then the screw would not move again. Or... what about gluing a dowel into the foam and driving a screw into that? Probably more trouble than it's worth. And you'd have to be very careful about the glue you used.

[foughtyp]

You can use Zinsser Primer on foam and after two coats use any paint, even spray, if you like. But if there is any exposed foam, spray paint will melt it. Also silicone caulk works well for bonding two pieces together.

[LakeLivin]

Very useful info, but doesn't quite get to what I was wondering. I.e., is there anything that u could use that would saturate the piece throughout which would then harden, creating a heavier 'solid' piece instead of the lightweight foam one you'd get if u just painted it?

[froggyman]

you could try soaking it in glue

[Creaturiste]

Very neat! Thanks! Blue foam is even denser than pink, and will withstand more sanding without chipping off. Prop shops use it a lot for accessories, characters, and even sets. A mention that foam dusts aren't good for the lungs (and awfully static-messy) would be a good thing to add, as well as the advice to use a proper filter in a shop vac, and a dust mask.

[sharlston]

ive made on of these and varnished this with varnish then sprayed it gold thanks for idea 5 stars

[marc.cryan]

Awesome!

[fatherofthree]

I love the idea! I'm thinking I could use a variable speed router to do this also - thoughts? As for painting, craft stores have a foam paint that is like a primer - it seals the foam so you can use regular spray paint over it.

[scavanger]

I'm sure a router is going to spin WAY to fast. A variable speed drill would be a better option I'm guessing.

[Dartag]

I tried a dremel, and the RPM was just too fast, making it impossible to use with foam. It seems best to stick with standard, low-RPM tools. If your router fits into that role, and can be solidly anchored to the bench with the point aimed directly up, then yes, you should be able to use it for this.

[jwzumwalt]

You can use most latex "water based" paints for this.

[domestic_engineer]

I'm thinking I could use a variable speed router to do this also - thoughts?

In general anything that spins can be made into a lathe - it is just a question of safety. Foam is good to experiment with because the foam will typically break first.

The chuck on my router doesn't close enough to hold the sanding pad shown in this Instructable (that is as far as I got)

For safety - I always start on the lowest possible setting, usually I flick the power on-and-off quickly just to see how the set-up will move.

It is best to rotate the piece by hand before turning on power. But with alot of non-lathe power tools this is not possible.

Please let us know how you make out!

[Dartag]

I am thinking of making my first 'ible as an update to this 'ible. I had some great success with some of the items being exactly what is listed above, but I also had great success with some modifications. NEGATIVE FINDINGS: As mentioned in a response below, Dremels (even the low setting of variable speed Dremels) turn far too fast to be effective as a foam lathe. POSITIVE FINDINGS: The craft store has green foam blocks, usually used in fake flower arrangements. The package I got (five large blocks, each that you could cut into four squares for chess pieces) was enough for a full side's pieces (along with a little extra for screw-up) for about $4. If you have a regular drill (not square-backed like shown above), you can use one of these foam blocks and set the drill in it to give you the exact upright position needed. I found that rough sandpaper (about 80 grit) was all I needed to get my rough shape. I did not need to use a knife at all, except an old never-go-dull knife to cut the foam into a square block before securing it to the drill, and a box cutter for taking the piece off the foam cylinder after the piece was done. Instead of doing this fully free-hand, I created jigs. I took the chess piece designs, cut the "positive" piece out of the printout, and cut the negative exactly in symmetrical half length-wise. I copied one of the negative halves onto the corner of a thin piece of wood and cut the negative half into the wood. Then, with the foam block turning, I just slowly and gently pushed the jig into the foam, and once it reached the middle, I had a fully formed, fully symmetrical, lovely chess piece. It ends up being slightly less detailed than the pieces marc.cryan showed above, but for my needs, it worked great! You can also turn out a ton of these in very short order. I had all sixteen pawns cut in less than an hour. Cutting the jig into a piece of sheet metal would probably get you far better detail, and would last longer.

[marc.cryan]

Nice - Do you have any photos? I look foward to your instructable!!

I think GIANT FOAM LATHE would be a good one too - I just don't want to buy the foam!

[codongolev]

cool, now you have chess pieces that when you're losing, you just sneeze and say "whoops!".

[NetReaper]

you could use the cut out to cut a half inch peice of wood, then just glue sand paper around all the bends and just us that with the spinny

[jspence1]

Hey THANKS for the Sculpt or Coat idea!! I'm going to order a gallon. Looks like a great product just to have around ... jbs/

[Blakeney]

Genius - I'd love to try lathe work but it's beyond my budget right now. Great instructable - not only on how to make a foam lathe but a basic primer on how to use one. :)

[legobrick55]

One word, WOW! That is amazing. Very cool idea and a nice work it looks professional. Now I can make stuff on a lathe without going to my grandpa's house. =]

[jspence1]

Is there another material that is easy to work but is more durable?? I want to make a design that is four or five feet long and about 2 to 3 inches wide. After I make it, I want to cover it with a protective coat of plaster. I am really stumped as to what type of material to use. Tks, jspence/

[ScaryTrout]

You could lathe the foam and then do a cast of it. I believe the process is called lost foam casting. You should be able to cast something very robust.

[bad ass pope]

Just out of curiosity, what on earth are you making?!

[jspence1]

I am trying to make a durable design for around a doorway. Down in MX, they carve the design out of stone. Designs are usually like a vine or flower or even a snake. In a MX house, it looks good (but is very expensive). I want to copy one of their designs and attach it around the doorway so it has to be durable. I thought of plaster of paris, but it is not strong enough. I don't want to use cement since it is heavy and fragile in a small casting. Maybe I can use fiberglass - but the resin is expensive.

[bad ass pope]

Sounds cool, let me know how it goes :-) P.S. is MX Mexico? I don't think I'm from around your part of the world.