View Full Version : Circle Cutting Guide
06-22-2009, 06:16 PM
Thinking about getting a circle cutting guide like that shown below.
As I understand it, you simply make a divit in your material where you want the center of the circle to be using a punch and instert the center point in to that divit and begin your cut.
My question is to anyone that has used one, how easy is it for that point to slip out of the divit and ruin your cut/circle? I'm guessing, with one hand you hold and manipulate the torch, and with the other you use to keep the center point held firmly in place within the divit? I ask because I would prefer not to spend the extra $80-100 on a "deluxe" version that comes with a magnetic base if what is shown below satisfactory.
- Not neccisarily this particular guide, but something virtually identical for use with my Hypertherm Powermax 45
06-22-2009, 08:23 PM
I have one, but don't use it. I cut plywood circles from plywood (get to use the inner and outer!) or use cans that happen to be the size I want to cut.
06-22-2009, 08:51 PM
Or make your own. No too hard to do. They work well, but take practice. Two hands arn't needed once you get feel. Think of it only as a guide. If you count on the device to hold you on the circle, you will fight and lose. You still need to control the torch to keep it on the circle.
06-23-2009, 09:50 AM
I'd rather have the roller wheel between the cutter and the pivot pin.
Cutting a circle from the edge of a sheet would leave a lot of waste with the wheel needing to stay on the surface.
Waste not, want not.
06-23-2009, 05:20 PM
I'm definitely open to the idea of fabbing up my own circle guide (would save me $100 which is always welcome!).
If you have made your own, would it be possible to post some pictures so I can get a few ideas? Maybe even a short description?
I appreciate the help fellas :cool:
The only part that looks special is the torch collar thingie. The rest looks prettey simple fab.
HF has some pretty substantial magnetics for cheap. I think I might weld some rod stock at center as a pivot; stack on some washers for height; then bar stock with a 'torch holder in one end, drilled as needed for radius. The 'roller' might just be a skid or a small, all metal caster.
My 2 cents.
ps late thought: roller or skid next to the torch holder at the middle of the bar stock (bar stock double length and maybe wider) so you can drill as needed with the roller/skid outside or inside the circle.
06-23-2009, 07:24 PM
Doesn't the torch need to be flush with the workpiece? That device looks like it holds the torch above the workpiece a bit.
06-23-2009, 11:54 PM
I'd rather have the roller wheel between the cutter and the pivot pin. ... Waste not, want not.
The only problems with putting the wheel permanently between the torch and the pivot are that the minimum size is limited and you have to hold the center down or it will cantilever up. Being able to move it to the inside or outside is the way to go, IMHO.
06-26-2009, 11:29 AM
I ponied up for the circle cutting guide(Hypertherm 027668) and it works good.I usually use the magnet but the biggest challenge is to controlthe speed of movement to get a clean edge.I have never used the pivot that uses a dimple in the stock.
06-26-2009, 11:35 AM
This is the Harbor Freight one I bought some years ago for about $6.00, is pretty well made, and it seems as nice as the much costlier ones at my LWS. The collar is too small for some plasma guns, but any of that is simple enough to 'adapt':)
06-27-2009, 09:56 PM
I have that type, badge by Miller. I had to cut some 26" circles for a pit, I acquired a stick of 1/4"x20 and replaced the original hex piece. I did find w/the rollers setup as the pick, torch was **** to keep square w/the matl., so I made a small mod that allows the two rollers to be in the inside of the torch toward the center, worked much better, they are bent to follow the proper arch and will not skate. As far as the point at the pivot, yeah it is too blunt and if I didn't use the offhand to keep pressure on the center punch mark it would move and screw up the circle as it did when I had to trim the od of some SS circles for a pit. Oh well just tig up the gash. For the tip clearance it helps when using an extended tip.
06-28-2009, 07:28 AM
Here is one that I made a while back. The end is just a large washer that I trimmed down to a nice size and welded to a rod connector. I still need to cut down the washer that rest between the cutter guide and the O ring. I may still look for a collar of some sort and use a set screw to hold it to the torch. What I have works good for now. It isn't professional and it didn't cost 100 bucks but its mine and it works.
After looking at the preview I remembered that I used the rod connector to the washer, I ground it all down nice and used a 1/4" nut on the all thread to lock the connector to the thread.
06-28-2009, 03:33 PM
I have the one from Miller, would be just as happy if it had not cost over a hundred dollars. As someone mentioned the outside roller can cause considerable waste, but I usually just use a drag tip with no roller to get around that problem. I've never had the point of the guide loose contact with a good center punched dimple. I've only used it a few times and definitely have not gotten my money's worth out of it so far. Of course I could say the same about the plasma cutter itself at this point too.
09-02-2011, 11:29 AM
I found this one that looks as if it works with any type cutter, they have included a short video as well so you can see how it would work.
09-03-2011, 08:00 PM
I have the miller guide and just drag the part where the wheel goes off the edge. Here was our first project. We had to make an extension to cut the outer dia.
10-11-2011, 03:39 PM
grnlwn....Why does that make me want to visit Wal Mart??? :confused: Is it some Subliminal message...
01-18-2012, 08:47 PM
Here one for $15. Seems simple and effective.
Has a YouTube demo.