You all rock!
I’ll do a more extensive search to make sure we are getting one that will work for us. As for foot print, I’m thinking about 2 foot but 2.5 foot maximum size for a unit. I think that would fit inside one of the cabinets or at least on top of one. I’m hoping I can dumb up enough support to get it some floor space. But, something tells me it would probably switch to Aero / RC committee for that after it has been paid off by classes.
More concerned that it folds flat like in the video. Easier to store. When stored in a cabinet items are likely to be stacked on top of it and dedicating a shelf to it is not good utilization of space inside. Next time you see me, let’s take a look at where it can be stored then you’ll have a foot-print/envelope to work with. I’ll try and find my wire and donate to the cause.
Here’s a good link on various wire cutters
Sorry I’m late to the conversation…I built architectural models for many years - bread and butter was massing models cut out of foam - we built multiple hotwire cutters…we used .005 wire, bought by the spool from McMaster. One of the best foams for getting a smooth surface was Dow blue board (extruded polystyrene) that we sourced locally in 4’x8’ by 3 or 4" thick, that was used for building walk-in coolers.
As for cutting templates, for up to about 18", we used our tabletop model, which had about a 20" length of wire attached to an arm that you could angle. Instead of a bow cutter, we strung the wire across a 30" table, connected it between aluminum posts on either side, and then followed our template. At this length we used .010 wire, but the surface was definitely not as good. Making a follower is also not that hard (like a bow, but mounted on a frame like this: http://www.demandproducts.com/Hotwire-items/item.php?l2=8,16,33&sku=GROUPSW4)
Buying a unit is not a bad idea, but building it from scratch is really not that hard…Here’s a good site to look at…Nichrome wire and transformer selection
Happy to help in any way I can…
2 Likes
Cool info Jeff,
I’ve buried my head into to many projects for this month to keep this alive right now. I’m hoping to re-excite the idea of a hot wire cutter after the reloading bench is built. I’m like you mixed on the idea of building one an buying one. If we could build a hot wire cutter that worked nicely and didn’t look like a bunch of PVC component, plywood, and random hardware. I’ll hit this thread up again when I’m ready to take the deep dive and build a curriculum to support the tool.
Thanks for sharing your interest and knowledge and I hope to tap into your experience in the future.
I just ran across this thread. I’ve got a home made foam cutting rig with about a 3’ bow. It runs off of a big A/C Variac, so the voltage is totally adjustable. It would probably be a good idea to get a bridge rectifier, as DC has less tendencies to knock you down. I used this rig for years and it works great. You just have to be careful. My big bow only needs 10-12V to cut 1 lb density foam. I bought that Variac at the old First Saturdays sidewalk sale about 25 years ago. It was only something like $25. I don’t know what they sell for now, but they make a great adjustable power source. I’d be happy to loan it to anyone who wants to cut some wings.
While variacs are great tools, my recollection is that one leg of the output is still tied to one leg of the input. So if it is properly fed, your wire is from 0 to 12 V from ground. But if line and neutral are reversed, you now have your wire at 98 to 110 from ground, which will get you equally hurt from DC as from AC. An isolation transformer before or after the variac would solve this, leaving the wire floating with only static charge potential to ground, and no path for current to flow from your secondary to ground. Even a 12 or 24 volt step down transformer with no bonding between primary and secondary (normally there is no bonding) will accomplish the same protection.
1 Like
Yes, a variac could only be used safely if it is connected through an isolation transformer. The electronics lab has both a suirtably sized variac as well as a peroperly sized isolation transformer, but they could not be dedicated to just this function.
@Nick - when I get a little time, I’ll knock out a design in sketch up and
share - wish I had some pics of what we used to do because it was pretty
dang cool, but hey, its only been since the mid-late 80’s.
1 Like
This is a home-built CNC hot wire cutter made from mdf, drawer slides and allthread rods. The only thing limiting the travel is the length of the drawer slides. Of course, they could easily be replaced with another type of linear motion.
One thing I learned from CNC foam cutting is to get the best cuts, you need to go slow and keep the wire to a temperature of “just hot enough”…
Nice! I’ll load the sketch-up concept this weekend - for a manual
machine…
···
On Wed, Mar 16, 2016 at 9:44 AM, Joe Helmstetter wrote:This is a home-built CNC hot wire cutter made from mdf, drawer slides and
allthread rods. The only thing limiting the travel is the length of the
drawer slides. Of course, they could easily be replaced with another type
of linear motion.One thing I learned from CNC foam cutting is to get the best cuts, you
need to go slow and keep the wire to a temperature of “just hot enough”…Visit Topic
http://mandrillapp.com/track/click/30332197/talk.dallasmakerspace.org?p=eyJzIjoiRXl3Ti1xZ2RUZjJ2Um8ycDZfbllRc0wzZ1RFIiwidiI6MSwicCI6IntcInVcIjozMDMzMjE5NyxcInZcIjoxLFwidXJsXCI6XCJodHRwOlxcXC9cXFwvdGFsay5kYWxsYXNtYWtlcnNwYWNlLm9yZ1xcXC90XFxcL2Z1bi1zdG9yeS1hYm91dC1mb2FtLXBsYW5lLWVuZ2luZWVyaW5nXFxcLzc5NDVcXFwvMjlcIixcImlkXCI6XCI0ODdkZGI0MjQ0MTM0ODE1ODc4ODFmYTY1NGExNWIyZVwiLFwidXJsX2lkc1wiOltcIjYxODliYjA1MjA3MjkyNTc1NGIyNTQ4NmI5NzM1MTE5YjRmZjI5MzlcIl19In0
or reply to this email to respondIn Reply To
jlcourtman
http://mandrillapp.com/track/click/30332197/talk.dallasmakerspace.org?p=eyJzIjoiRU5LdldfS2tBNlZzOGgycF9XOE9UZVQ2aGowIiwidiI6MSwicCI6IntcInVcIjozMDMzMjE5NyxcInZcIjoxLFwidXJsXCI6XCJodHRwOlxcXC9cXFwvdGFsay5kYWxsYXNtYWtlcnNwYWNlLm9yZ1xcXC91c2Vyc1xcXC9qbGNvdXJ0bWFuXCIsXCJpZFwiOlwiNDg3ZGRiNDI0NDEzNDgxNTg3ODgxZmE2NTRhMTViMmVcIixcInVybF9pZHNcIjpbXCI4M2YwZjA2ZjViNWQ2ZTc4MjMyZTEyZmM1NDAyMDk4N2ZiMTY1YjZjXCJdfSJ9
March 9
@Nick
http://mandrillapp.com/track/click/30332197/talk.dallasmakerspace.org?p=eyJzIjoia3VDNkxndnBBeXFOZnQ0MnlUVVNfUFlLNWpvIiwidiI6MSwicCI6IntcInVcIjozMDMzMjE5NyxcInZcIjoxLFwidXJsXCI6XCJodHRwOlxcXC9cXFwvdGFsay5kYWxsYXNtYWtlcnNwYWNlLm9yZ1xcXC91c2Vyc1xcXC9uaWNrXCIsXCJpZFwiOlwiNDg3ZGRiNDI0NDEzNDgxNTg3ODgxZmE2NTRhMTViMmVcIixcInVybF9pZHNcIjpbXCIzNDEzNzBjMTJjZGY4MzUzODgzYTVhZWNkYzg2NDY5NjA3Yjc3NzAwXCJdfSJ9
- when I get a little time, I’ll knock out a design in sketch up and share
- wish I had some pics of what we used to do because it was pretty dang
cool, but hey, its only been since the mid-late 80’s.
To stop receiving notifications for this particular topic, click here
http://mandrillapp.com/track/click/30332197/talk.dallasmakerspace.org?p=eyJzIjoiYTdkUy1vMnJrZ0lHZEkyN1FxdDFPNkx0eFJFIiwidiI6MSwicCI6IntcInVcIjozMDMzMjE5NyxcInZcIjoxLFwidXJsXCI6XCJodHRwOlxcXC9cXFwvdGFsay5kYWxsYXNtYWtlcnNwYWNlLm9yZ1xcXC90XFxcL2Z1bi1zdG9yeS1hYm91dC1mb2FtLXBsYW5lLWVuZ2luZWVyaW5nXFxcLzc5NDVcXFwvdW5zdWJzY3JpYmVcIixcImlkXCI6XCI0ODdkZGI0MjQ0MTM0ODE1ODc4ODFmYTY1NGExNWIyZVwiLFwidXJsX2lkc1wiOltcIjYxODliYjA1MjA3MjkyNTc1NGIyNTQ4NmI5NzM1MTE5YjRmZjI5MzlcIl19In0.
To unsubscribe from these emails, change your user preferences
http://mandrillapp.com/track/click/30332197/talk.dallasmakerspace.org?p=eyJzIjoidE1vV1ctZDk2YmdnOUJyOG5uRDZMM3VmbUJVIiwidiI6MSwicCI6IntcInVcIjozMDMzMjE5NyxcInZcIjoxLFwidXJsXCI6XCJodHRwOlxcXC9cXFwvdGFsay5kYWxsYXNtYWtlcnNwYWNlLm9yZ1xcXC9teVxcXC9wcmVmZXJlbmNlc1wiLFwiaWRcIjpcIjQ4N2RkYjQyNDQxMzQ4MTU4Nzg4MWZhNjU0YTE1YjJlXCIsXCJ1cmxfaWRzXCI6W1wiYjM5MDJlMzYwMGUxNTM0NzE4NGI1MTUzMGZkYzNmMDIzNWNlZmIxYlwiXX0ifQ
Jeff Courtman
