How Big is Big Enough?
January 31st, 2009Common Sense Militates in Two Different Directions
Here’s an interesting Craigslist ad: CLICK. It’s a Bridgeport mill with CNC stuff on it. The CNC bits need repair, however.
Last night I was thinking about tools. I was thinking about how I had finally learned my lesson: NEVER BUY SMALL. I’ll tell you why this was on my mind. I bought what I thought was a gargantuan compressor, but it turns out to be just about the minimal size for sandblasting. For a few hundred more dollars, I could have had a 7.5 HP model which would have been better. And it would run on the same size circuit and take up the same amount of room.
I’ve also started to come up against the upper limits of my MIG welder. I bought 1/8″ and 3/16″ steel for my saw base, and 3/16″ is the biggest I can do without going to flux-core wire.
People assured me I was overbuying. Well…WRONG. I barely went big enough.
Here’s the funny thing. Right after I thought about the lesson I had learned, I started thinking about how I should go look at the Millrite milling machine I had located. Because a Bridgeport is just too big.
I immediately sensed the contrast between the two trains of thought. 1. I have been stung by buying small tools. 2. I should buy a Millrite because it’s small. I felt like I was getting a message.
But I’m still not sure what to do. I have no idea what I can do on a Bridgeport that I can’t do on a Millrite. And I wonder how much more expensive (if at all) Bridgeport tooling is.
January 31st, 2009 at 9:56 AM
Steve,
I don’t think you want that particular B’Port. It’s hard to tell from the pics, but I suspect that this is an old BOSS CNC mill that has been upgraded to newer controls. The BOSS machines are very good candidates for such a conversion, but are literally impossible to use for manual work, as there are no hand cranks.
FWIW: a B’port can be hauled in a standard pickup truck, they weigh about 1500#. Loading/unloading can be done by a boom-type of wrecker, using a forged lifting eye screwed into the 5/8-11 tapped hole in the top of the ram. Some B’Ports have a 1/2-13 tapped hole like mine does, but the 5/8-11 is more common. You could also use a U-Haul trailer behind your Dad’s Explorer.
January 31st, 2009 at 9:59 AM
UHaul will not rent trailers to Explorer owners.
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http://www.uhaul.com/trucks/faq.aspx
January 31st, 2009 at 11:07 AM
“The BOSS machines are very good candidates for such a conversion, but are literally impossible to use for manual work, as there are no hand cranks.”
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Maybe, maybe not. Sometimes people add hand-cranks as part of the CNC conversion (it’s what I did), and in this case the pictures are particularly unhelpful (no real shots of the servo motors!) Since the user upgraded to Servo Motors, he may have added hand-cranks.
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I found the Austrailian Company that the lister refers to:
http://cncteknix.com/portal/content/view/73/145/
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The controller is a 4-axis MultiTek. If it is the Aux Axis that is dead then it’s no big deal IMHO (the A-Axis is mostly used for Rotary Tables and unless you’re making your own gears, it probably won’t be missed). If it is the X/Y/Z Axis then you might need to do some creative re-wiring on the parallel port to work around it, but it is doable.
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I’m not really impressed with DeskCNC (I think Mach3 is a much better package, and you would not need to rewire the parallel port cable with Mach3…it is very configurable).
http://www.machsupport.com/
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I noticed that the controller lists for $2,842 all by itself, so you might be able to get a decent chunk of change if you decide to “part it out” on Ebay.
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All in all I think its worth a second look, but if you can’t use it in “manual mode” with handcranks, then it will probably be too much agravation for a beginner.
January 31st, 2009 at 2:19 PM
You can’t do heavy metal with a small mig- in one pass. Multi pass welding is common, and done all over the place. No mig can ever weld 4″ thick steel in one pass, but that’s done all the time. You just make several passes. It’s actually easier once you get the hang of it.
January 31st, 2009 at 9:17 PM
I bought a stick welder before my mig. I prefer the stick for heavy welding and the mig for light and sheet metal.
You need a stick welder.