HH175 Wire Speed Question

[Slim]

Well, I've been practicing and experimenting with my HH175 and I think I'm starting to get an "idea" of what settings to use.

I also got some books from the local library, and the Miller education kit and have been reading about GMAW.

So I understand that a higer wire speed will result in a higher amperage, but what do the numbers on the dial of the HH175 wirespeed knob represent? It's not IPM, it can't be Amperes since the machine accepts different wire sizes -- but I can't figure it out.

I know that there is a chart in the door to tell me where to set it, but I'm trying to understand the process, and I'm struggling to figure out what the numbers printed on my machine translate to in terms of wirespeed.

I guess, similarly, if someone can answer that for me, they could probably tell me what voltage the transformer taps 1,2,3&4 correlate to?

Thanks!

[BillC]

Hi Slim,

All the wirespeed dial means is 0 - 100% speed. It does seem kind of tough when the calculators are in ipm units and all you've got is 0-100 on a dial... Even worse for you, it looks like the wire speed changes depending on if you have a load i.e. if you are welding vs shooting the wire into a bucket. Normally, I would tell you to pick two settings, like 20 and 80, and actually measure the ipm at each setting. Shoot the wire for 10 seconds, measure how many inches come out, multiply that by six to calculate what would have come out in 60 seconds, and there is your ipm. The increments on the dial are linear, so you can calculate what the other numbers on the dial mean from the two settings. I can help you with that if math wasn't your strongest subject...

According to the literature, your wirespeed is 50 - 850 ipm with a load, and 350 - 900 ipm with no load. Working with the loaded condition, that means that the slowest you can go, that is with the dial fully counterclockwise to the 0 position, is 50 ipm. The max is 850 at 100. The difference between the min and max is 800. 800 / 100 = 8, so each small increment is 8 ipm. So setting 40 on the dial is (40x8)+50 = 370 ipm. If you were good at math you may remember y=mx + b where m is the slope and b the y-intercept. Here the slope is 8 and the y-intercept is 50.

0 - 50 ipm
10 - 130 ipm
20 - 210 ipm
30 - 290 ipm
40 - 370 ipm
50 - 450 ipm
60 - 530 ipm
70 - 610 ipm
80 - 690 ipm
90 - 770 ipm
100 - 850 ipm

Regarding the voltage, the owner's manual and the sales literature both show volt/amp curves for the four transformer settings. I'll leave looking at that up to you. But you will find that the voltage changes depending on how many amps you are drawing, so the best thing to do there is to have a friend measure the voltage across the terminals while you are welding.

Good Luck!

[Slim]

Thanks Bill, for the informative reply. I'm ok with the math. I guess I should have looked at the product lit. a bit more. Makes good sense.

Any harm in (semi?) permanently mounting a cheap panel-mount voltmeter on the HH175 -- I guess it would be pretty hard to see through the helmut w/out a friend there anyway.

Thank you.

[Dan]

Originally posted by Slim
Thanks Bill, for the informative reply. I'm ok with the math. I guess I should have looked at the product lit. a bit more. Makes good sense.

Any harm in (semi?) permanently mounting a cheap panel-mount voltmeter on the HH175 -- I guess it would be pretty hard to see through the helmut w/out a friend there anyway.

Thank you.

Slim

It would be more beneficial to have a DC amp meter hooked up to the machine then a volt meter. I use a clamp on version that Aaron told me about. Of course, you would need a friend around to read this too, this way they also can fine tune the wire speed for you as you are welding.

Since the HH 175 only has 4 voltage taps to choose from it is very easy to tell which tap produces the best short circuit transfer arc for the material thickness that you are welding on. I will let you know right now, in most cases with C-25 as your shielding gas TAP #3 works best for 1/8" and 3/16". When you use the proper wire speed setting for the above mention material thicknesses tap #3 will give you a load voltage between about 18 and 18.6 volts. If you reference your Millermatic GMAW calculator you will see that this falls with in the recommended voltage range for these material thicknesses.

[Hobart Expert Dave]

Good responce Dan, Thanks for helping us out.
Dave Evans

[Slim]

Thanks Guys.

Unfortunately I probably won't get a chance to ****er with it until the weekend, but I'm very grateful for your insights.

Someday may my welds look like Dan's!

[Slim]

Dan,

I continued to practice this weekend, and also started the cutting / grinding / drilling on the pieces that make up one of your brakes -- I can't wait to get started. So, I found that I got a really strong weld, butt-joining two pieces of 1/8 bar stock using tap #2 and about 35-40 wirespeed on the HH175. I tried what seemed like every possibility and that yeilded the best looking and pretty strong welds. In the vice / sledge test, I had the 1/8" stock breaking before the welds peeled away from the bar. On a higher voltage setting, I kept burning through. I guess the travel speed might be too slow, but I felt like there was no way I could "stay straight" moving my hands any faster. I had about 1/4" stickout. On the butt joint, I got nearly full penetration.

In terms of the sound, it definitely sounded more like frying bacon using tap #3 and wirespeed 40 or 50. At the tap #2 the popping was slower, and it seems louder.

Seems to me that those settings are low both on voltage and on wirespeed -- I come to that conclusion from the sticker inside the door, from everything I've read here, and from the calculator.

So the $64,000 question is how fast should I be traveling? How do I judge the right speed? Put it this way: right now, I'd say I'm moving my hands fast enough that I don't think there is any way I could do a weave or any pattern and stay reasonably straight.

Thanks

[newbie]

If you want to slow down shouldn't you turn up the wirespeed? To keep from burning through , that is.

[JoeHobart]

In my experience, the closer to 'sizzle' you are, the better you are dialed in. I use audio clues almost exclusivly to get it dialed in for the materials im using. When you can hear popping, you are usually on the verge of stubbing, ie: you dont have enough volts to properly melt the wire with the wire feed speed you have selected. This is why i like the tapped HH series, it makes the parameters easier to dial in. Check out the thread on Spray transfer basics I posted a link that has an excellent description of the short circuit process. Check that out, youll see what i mean about it.

Despite the many beautful 'tig-quality' oscillations on the many pics on here, for most joints, a straight line is all you need, if your parameters are correct. I only weave on filets, laps and vertical joints when im talking materials in the 1/8th inch range. Every joint is a little different, and its hard to make statements like 'always' and never', but that is my thought. Also keep in mind, that the only purpose of a weave is to increase the deposited material. If you have properly matched wire size, this becomes easy. It would be tough to run a Tee joint with .024 wire on 3/16" without a weave and get a good profiled bead, but would be easy with 030 or 035 wire. I like using 24 and 30 in my hh175, and 030 is the best 'all purpose' size.

I judge my travel speed by the puddle. I will move just fast enough to keep a puddle of 3/8" long or so. That, for me, gives me a good profile, balanced with proper penetration. When i was in welding school, my professor liked to slow the wire speed down for educational purposes, so we could watch the movements, but when the time came that we didnt suck, he cranked it way up, and was cookin with his travel speed. Thats 25 years of production experience that let him lay a perfect bead faster than we could see the movements. Other than puddle size, i havent found any good visual cues to meter my travel speed. Once you've done the weld, you can look for undercut, tall beads and cold lap defects to see how you are doing on travel speed. I found it very helpful in my practice to run lots of coupons, changing parameters and writing sharpie notes for comparison. Stickout, travel speed, push/pull all come together to get the profile and penetration you want. I'd make a push, straightin and pull bead and then compare them to see the difference. Same with travel speed. Its just so much easier to trial by error to build 'experience' than to figure out a formula.

My 2 cents, im sure some of the other guys have better 'rules of thumb' than i.

[Slim]

Thanks Joe.

Yesterday while I was welding, I kept a numbered list of what my settings were, and changed only one variable at a time, numbering my welds with a soapstone. That's how I eventually wound up at making repeated "decent" welds at the same setting. Being able to compare my welds with my notes on the settings was very helpful.

I think I just need to keep on practicing (and reading these forums).

Next time I get to play, I'm going to get it until it sounds right (I definitely heard the sizzle) and then keep the settings there to see if I can adjust my travel speed appropriately. I will have several fillets to weld when I get to welding up the bending brake I'm making -- some of them will be of different thicknesses too. I'm guessing that welding those pieces together is a pretty long way off.

[Dan]

Slim,


Are you using a solid wire and shielding gas? If so which wire size and shielding gas?

[Slim]

Yes, I am. Sorry I omitted that detail. I'm using .030 (came with the HH175 from TSC) and 25% CO2 / 75% Argon (C-25, I think it's referred to?). I had the pressure on the gas at about 19 (when it was actually flowing). I did change the polarity around as previously I had been doing all fluxcore (also at .030).

[Dan]

OOPs, forgot to ask if you are pulling or pushing the puddle?

[zuiko]

Do you get anything from going with solid wire and gas other than nicer looking welds? I got the same setup and haven't used the gas and solid wire yet, only flux core. I'm also working on finding the right settings for various materials. Doesn't seem like the chart on the door is that useful.

[Slim]

Dan,

I tried it both ways, typically I was able to get the best (best looking and best apparent penetration) by pulling and holding the gun at about 15* angle.

Pushing seemed to result in more inconsistent travel speeds, and of course, more of a zig zag.

Most of the time I was pulling. Would it be a good idea to focus on push?