HH175 Start questions

[whodat]

I just picked up a HH175 kit from TSC and have been playing with it pretty much nonstop. I have a question about the arc starts though, at high wirespeeds it bucks and kicks back at the start of the weld, throwing chunks of wire around for a second or two, then settles down into a nice steady arc. Is this because I'm running the wire too fast, or is it a machine issue?
whodat

[Paychk]

Wire to fast

Remenber there is a range of wire speed for each voltage setting, when you are out of it on the high side you'll see the spitting you've described.

[morpheus]

It could be that you have too much tension on the drive roll. How tight is the nut that is holding the spool spring on ?

- jack

[Crithpy_Critter]

read this thread on wire feed issues as I don't believe Hobart has fixed it but there is a fix embedded in the discussion.

http://www.hobartwelders.com/mboard/showthread.php?s=&threadid=1072

[Dan]

Originally posted by morpheus
It could be that you have too much tension on the drive roll. How tight is the nut that is holding the spool spring on ?

- jack

I think Jack might be on the right track. Unless Miller/Hobart has recently fixed the problem with the length of the spring (too long) for the spool hub tension on the HH 135/175 and the MM 135/175 you need to either shorten the spring or replace it with a shorter spring. The reason you need a shorter spring is because even with the nylock backed out as far as it possibly can be, the drag on the wire spool is still too much and will cause arc starting problems.

[bishopaul]

hey dan-

just curious as to what length of spring you have determined to be appropriate. i bought my hh175 back in may '02 and have never had a feed problem. i'll measure the spring length i've got & post that. if you can provide a spec. all the guys will have an excuse to get them out in the shop tomorrow (xmas).

thanks - paul

[morpheus]

Dan chronicled his spring length trials in this thread:

http://www.hobartwelders.com/mboard/showthread.php?s=&threadid=3283

[Crithpy_Critter]

I ground off about a quarter inch and got it to work OK. the spring is so stiff that fine adjusment is hard to do.

I have some other springs someplace that I will try.

[bishopaul]

ok morph but i don't want to go chopping 1/4" off of my spring if it's already short enough. i was just thinking that if dan could give us the free spring length, everyone can check what they've got...

[whodat]

Well, been playing with it a fair amount and still have the kickback/spitting at high wire speeds, but only with solid core wire. I also shotened the spring by about 3/16". Ran out of wire on a recent project and had to switch to flux core, and it ran like a dream, even at max wire speeds. Just out of curiosity, how much penetration can I expect this to get in 1/4"? I've tried a couple different weave patterns, tried beveling, tried leaving a gap, and it just doesn't want to cut deeper than about 1/8" max. Setup is 1/4"x2" mild steel strap, cut into 2"x1" chunks, welded back together, butt joints. Beveling both edges at 30-45* with a 1/16" root got full penetration, but **** with that prep my weldpak 100 could do it. I tried just about every edge prep from a simple butt joint, one side beveled, both sides beveled, leaving a gap from 1/16" to 1/8". No matter what I tried, it just didn't seem to cut very deeply into the parent metal. Flux core naturally cut deeper, but not by as much as I would have expected. Yes I switched polarity as needed. Another thing I found interesting is that the solid core wire was almost ductile when stressed to failure, maintaining a solid connection through a large bend, whereas the flux core seemed much more brittle, failing with both less force and less angle on the weld prior to failure. The best penetration I seemed to get was with lowering the wire speed significantly (from 100 to say 65-70) which gave me time to work the arc around for digging before the wire filled it.
whodat

[Dan]

A HH 175 set up with a C-25 or Co2 shielding gas and solid wire is only capable of producing short circuit transfer. Short circuit transfer is a low energy metal transfer that produces shallow penetration. Due to the low energy arc that short circuit transfer produces, butt joints on 1/4" will require beveling to produce 100% fusion of the weld joint. If you want to skip beveling of a butt joint on 1/4" steel, you need a larger machine that is capable of producing spray transfer or running a gas shielded fluxcore wire .

As for your poor arc starts, Id have to guess that your wire speed setting is too high for the voltage tap that you are using. I ve had my HH 175 for about 3 years now, and poor arc starts have never been a problem with it. Ok, I take that back. When i first got the machine I tried the door chart setting. Which was a total disaster. The wire speed settings on the door chart of this machine are too high. For example, the door chart settings for 1/8" steel with an .030 solid wire and C-25 are 3 and 80. I produced the weld in the attached picture with settings of 3 and 60.

If your wire speed setting is to high for the volt setting you are going to end up with less penetration. Ignore the door chart wire speed setting and find the actual setting that produces the best metal transfer possible for your material thickness.

[whodat]

Cool, thanks. That answers most of my questions/concerns. Any input on why the flux weld seems brittle compared to the mig weld?
whodat

[horseman1]

Whodat,

I had a similar problem when I had a poor ground clamp connection. I'm no expert like the rest of these folks, but I do have some experience at screwing up some

[cj7jeep81]

Obvious question, but is the polarity set correctly after switching wire types? I don't know if that would cause a problem like this, but one thing to rule out.

[Crithpy_Critter]

in my view, the ground clamp that comes with the hh175 is crap.

your local welding supply or tool shop should have one that's worthy.