Ultimate Home Machine Shop

[jluckey]

Dave

In case DanHco takes a while to respond, his "cutter" is a pantograph style flame cutter. I designed mine after looking at pics of his. It is really big. I bet he could do a 6 foot circle if he wanted to, maybe even bigger. I can only go to about 42 inches.

 

[dkamp]

Sorry, Kraig- got called away from my desk, so didn't get back in time. Dan- sorry for the mes-spielign.

Jon- can I pester 'ya to show pictures? I've been contemplating a CNC plasma-cutter, but I really can't justify the space or cost (can I justify ANY? Not according to ANN!)... but perhaps I could make some sort of folding 'adaption' that I could set up and use my torch...

My other option is to just send CAD files to a local shop and have 'em laser-cut everything... but the one-off rate is too high for me... doesn't start getting reasonable 'till I have 20+ units cut.

 

[kmcconaughey]

Dave K2, here's a photo of Dan's setup. Note his hand in the upper right, that is attached to a variable speed motor that follows the pattern. I'll let Dan fill in any more details. I think he should patent the design......

 

[kmcconaughey]

Dave K2, here's another view of it.

 

[dkamp]

Hmmm... that's an interesting rig. I take it the pantograph follows the pattern, and cuts to 1:1... It also appears that the rig essentially just holds the cutting head at a fixed distance above the table, for a consistent cutting angle and the ability to follow the pattern.

--How does the motor stay against (or drive against) the pattern and...

--Is the flame manually operated, or is the oxygen throttle just fixed in one position for the cut?

 

[jluckey]

Dave,

Here is a pic of my motor control box that I built. The drive motor is just a 12v gear motor. The second pic is of the oxy level attachment that I built. I wanted to be able to have instant control of it. Maybe if I get fancy, I will convert it to a solenoid

 

[jluckey]

Dave,

Here is a pic of my motor control box that I built. The drive motor is just a 12v gear motor. The second pic is of the oxy level attachment that I built. I wanted to be able to have instant control of it. Maybe if I get fancy, I will convert it to a solenoid


Looks like I will have to load the images tomorrow, the server will not let me upload jpg for some reason

 

[aaytay]

Dave-
My understanding of it is that this part is a variable speed motor. The stylus at the end is magnetic and follows the contour of whatever shape "cam" is placed in the machine.

The table top is made of copper bars. The cutting torch doesn't phase them so they don't get cut up.

I learned so much being in this guy's shop for two hours, I wish I could have stayed for the weekend! Biggest thing I learned is how little I know!

 

[dhoefler]

Dave and anyone else interested-

The 100 ton cylinder will have a bore of just over 5" and the hydraulic pressue will be 10,000 psi, the same as what I am using now. The new press will have an Enerpac electric pump as opposed to the air powered pump.

The burning table works very well. I built it before I built the crawler to produce all of the plates for the steering boxes, the final drive housings, rear sprockets, plus many other parts. The cutting head is a standard Smith HD unit that uses SC-12 series tips. I have tips to cut up to 3", but have only cut up to 2" thick material. If I were to do it again, I would buy a 3 hose head rather than a 2 hose. You gain greater oxygen pressure control with the 3 hose style. One oxygen line is for the preheat and the second is for the burn.

The end of the variable speed gear motor has an aluminum housing attached that holds a large pot magnet. On the end of the housing, a knurled stylist extends which develops a couple of pounds of magnetic pull to keep the stylist against the pattern. Most units I had seen used springs to hold the stylist to the pattern. This magnetic end works very well, the biggest problem is keeping the airbourn metal particles from building up on the stylist when not in use. I always just blow it off with the air hose before use.

The cutting head is adjustable up and down with a rack and pinion system. The head come equiped with the rack already installed. The distance from the cutting tip to work surface is very critical to get a clean crisp top edge and no slag on the bottom side of the cut. The arms that the head and motor are attached to are equiped with low friction ball bearings and thrust bearings. It will follow virtually any shape, but when making tight inside corners, it works best to mill the template profile with a 1/4" diameter cutter (the same diameter as the stylist) so the stylist has full contact with the pattern in the inside corners. Outside corners can be sharp, but a small radius works best. Many times when making discs for templates, I will throw a light knurl on to assist in traction between the stylist and the pattern.

Hope that helps.

Dan

 

[jluckey]

Dan I am curious, what is a "pot" magnet. I have rare earth magnets for mine. I have not been happy with them yet.

 

[digger]

JL,

Cylindrical magnets in a mild steel pot with poles in the same plane
Threaded hole for secure fixing
Provides superior grip at contact
Pot Magnets are constructed from Alcomax III (Magnet), Aluminium Ring (Spacer) and Mild Steel (Pot)
Pot Magnets can be used in temperatures up to 220°C
Pot Magnets have an insulated magnetic circuit, preventing flux leakage when fitted into jigs and fixtures



The magnets have a variety of uses, including:

- Gripping and lifting applications
- Positioning jigs
- Soldering fixtures
- Sinking into jigs & fixtures
- Securing and fixing