Welding Tips and Tricks

i have a miller bobcat 250 i came across a miller hf251d-1 i have the tig torches already the box comes with a remote can i and how do i hook this up to my bobcat to tig aluminum what else would i need besides a foot pedal

Hi, I just went through what you will need to do when I was given a HF250D-1 that I am running on my Miller Legend AD 200le.
I doubt your bobcat has a 14 pin on it, so you have a ways to go getting it together. All the hf box does is add high frequency to the arc. Plugging a foot pedal into it will do nothing, unless the HF box has a secondary contactor installed, it would be a large black box next to the gas solenoid. I lucked out, and there was one in the HF box I got, they are about 500 to buy, tho you may be able to get some other contactor to work. Here is what it looks like

The other part of the pedal control is the amperage control. Basically this is like having your fine current control in a foot pedal. It can be done, I did it by getting a miller rfc-23 pedal, and replacing the 1000 ohm resistor with a (rare as hens teeth) 36 ohm resistor, and putting a dpdt switch in my welder to switch from the rhostat for the fine current control to the foot pedal. There are severl youtubes about making a foot pedal, but you would have to make one with a honking big rheostat instead of a potentiometer. Or you might be able to get a rfc-23 and find a 25 ohm resistor for it, you would have to look up the values for the rheostat in your bobcat, and see what is closest.
Russell

Thanks for the info.I'm really just looking to be able to do some tig repair work with my boboat til I can get a proper tig machine.will the 251d hook up to my bobcat with just welding leads .if I can get by like that for a little while I will be able to get more money to get a tig machine.

You can try, get he HF owners manual at https://www.millerwelds.com/support/manuals-and-parts, use the drop down menu and be sure to hook it up right. There might be something in your bobcat's owner manual about it too.
Without contactor it will be sort of like scratch start, but should give you HF welding for alum. The pedal switch that operates the contactor also operates the gas solenoid, so without a pedal you would use a torch valve.