dave wrote:
actually, I just installed an old computer fan in there, because the
original "gave up the ghost" after only 23 years of service. and because
I had a dozen of those big ol' 115 volt AC computer fans sitting around
doing nothing. you can SEE this project, illustrated in it's full glory, at
http://machines.awardspace.com/overclocked_my_welder/
call me a space cadet, but that's what I did... :-). I also considered
cutting a big square opening into the case rear, and installing a big
squirrel cage blower sticking OUT the back of the welder, but decided I
didn't want to "kill" the shop space, or mangle-up my 'fairly new'
welder that much...yet
I am on my second Miller Thunderbolt, these to me are by far the cream of the
crop when it comes to little stick welders for the home. I agree that the fan is
the most problematic issue. The welder I have now developed a horrible screech
some years ago which turned out to be the fan. I found that simply tightening
down the mounting screws fixed everything.
If you blow these out every so often and lubricate the shunt like it says in the
manual, they last a long long time. Well, you do have to keep to the duty cycle,
which is of course their biggest drawback.
I don't use either the stock/standard wheel mount, the original power cord, or
the original welding leads. I surplused the wheel mount kit, replaced the
original power cord with 10-SO3 with a proper welder plug (although for many
years I ran it using a 30/50A dryer plug), and replaced the too-short ground
lead with a longer one with a 200A Tweco spring clamp, and replaced the too-long
stinger lead with one the same length as the ground clamp. I tried using a
twist-type rod holder but went back to the original Miller clamp type, works for
me and it's easy to change if I ever want to.
I made a little cage for mine out of 1" square steel tubing. If you look at the
bottom pan of these welders you will see that they are designed for bolting
down, but the holes aren't quite punched out. I made the bottom frame for my
cage, then set it on the ground and put the welder (sans cover) onto the frame
where it would go, then drilled through the bottom pan using a small bit in a
hand drill. Then I removed the welder from the cage, used the small holes to
locate on, and drilled and tapped the cage bottom frame in 4 places 1/4-28, then
drilled out the welder base plate for clearance and then it was easy to bolt the
welder down to the cage bottom frame. Then I took the welder back out, finished
fabricating the cage (which has casters) and painted it, then bolted the welder
down and it's been in there ever since. You can see it in the back in this pic:
http://tinyisland.com/images/splate2.jpg (not the best pic, but you get the idea).
Were I to make that cage again, I'd add an electrical junction box on the side,
with 2 outlets, and I'd wire the welder to the Jbox and run a 4-wire 220VAC
power cord out of the Jbox. If you call the two 220V leads L1 and L2 and the
neutral lead N, I'd wire one outlet from L1-N and the other from L2-N, and run
the ground to the welder frame. I might even add a second box and use some power
factor correction capacitors (run caps which would make the welder look less
inductive, lowering the imaginary component of the current to it, allowing more
margin on the wiring running to the welder). I'd also use bigger casters. This
little welder is very portable on wheels when you have the top of a solid cage
to grab onto, and a piece of plywood cut to fit the top makes a handy table in
use. The outlets would be for 4½" grinder/sanders or anything else, just because
I seem to always always run a 117V extension cord whenever I weld, so why not
make it a little easier?
sorry for the long post, I like my Miller too ..
GWE