Plasma cutter question

[elkriverfab]

I was just wondering if anyone had any experience with Hobart plasma cutters.

I was just looking around and wanting to upgrade to a machine with more cutting amps in the future.

Does anyone have any experience with the Hobart airforce 625?

I am wanting to cut heavier steel plate 1/4 and up and was just wondering.
I also will still need to dial down for thinner sheet as well.

I have been using hypertherm and have been very happy with that brand but like I said, just wondering if anybody out there has had any experience with the Hobart brand.

Any help would be great.

Thanks.

[eggauto]

I built my table on a very limited budget around a Hobart 250ci (Insert laughter here) but had lost mt job to south of the boarder and with barely any income and the 250 in my shop I gave it a try. To my amazement it has cut about 30 sheets so far ranging from 18 gauge to 3/16 and hasn't missed a beat. It took a few modifications to get it to work with a table but hey it does what I need.

[Mountain Home]

I don?t use a Hobart, I use a Miller but from what I can see they are about the same. I have got good cuts when I get everything set right, the thing I don?t like about the Miller is the lack of choices for consumables and the poor excuse for a owner?s manual . If you go to the Hobart website and download the manual for that machine you will see what I mean, they have one little graph to show to show recommended cut speeds, not much there to help with settings. I wish I had gone Hypertherm and will Be replacing my Miller very soon.

[muzza]

My response is probably pretty irrelevant as I'm on the other side of the world and it was some time back. Quite a few years ago I had a Hobart welder, back up service was almost non existent but that may have been more the fault of the local service agent rather than the brand.

I'll be purchasing a new plasma in the very near future and there is only one brand I'll be purchasing. That decision is based on so many positive referrals but more importantly the pre and post purchase support offered by one of their totally dedicated staff who frequents every related forum I visit always offering assistance almost instantaneously. Thanks to Jim Colt, regardless where I purchase my unit downunder, you can be credited with the sale.

An old saying "It is better to have paid a bit more and lost a little than to pay too little and lost a lot" not that they are any more expensive than other leading brands.

Murray

[elkriverfab]

Murray,

I too agree with you.

My hypertherm has been great.
I was just wondering if anyone had any luck with the hobart unit.

I guess you should not stray from what works

[jimcolt]

I have tested the 3 current Hobart systems. They are:

1. The 250 ci. This unit has 12 amps output, yet has an internal compressor for truly portable use. It is rated to cut 1/8" maximum materials thickness at 35% duty cycle. I was able to sever some 1/4" (very slowly). Hobart is not using an italian torch from Trafimet as a cost saving measure (They used to use Hypertherm torches). This unit operates on 120 VAC.

2. The 500i. This unit will operate on either 120 VAC (25 amps) or 230 VAC. It has 27 amps maximum output, and is rated for 3/8" severance cutting. I was able to barely sever a piece of 1/2"....although I ruined the torch nozzle(tip) in the process as it is of a non shielded design. Does a decent, but slow job on 1/4" and thinner, although it is difficult to hold a proper standoff with the torch. Non shielded Trafimet torch.

3. The 700i. This unit produces 40 amps at 50% duty cycle. Rated for 1/2", yet will sever 3/4" maximum....very slowly. The torch is non shielded, and with contact to the plate serious sticking (double arcing) occurs......short nozzle (tip life) was observed with the Trafimet torch.

They are all priced lower than comparably powered Hypertherm and Thermal Dynamics systems, however with the torch design (same torch that is used on many of the Chinese import plasma systems) expect higher overall operating costs due to slower cut speeds and more frequent consumable parts changes. I also could not find any sign of machine torch availability...just hand torches.....and no torch quick disconnect as found on the Hypertherm and T-D units.

That is my unbiased report!

Jim

[VoltageDrop]

I built my table on a very limited budget around a Hobart 250ci (Insert laughter here) but had lost mt job to south of the boarder and with barely any income and the 250 in my shop I gave it a try. To my amazement it has cut about 30 sheets so far ranging from 18 gauge to 3/16 and hasn't missed a beat. It took a few modifications to get it to work with a table but hey it does what I need.

I realize this post is 10 years old but I'm curious if this machine is still working out for you? I have an old Hobart AirForce 625i that I'd like to build a CNC table for but I'm curious if it's worth using or if I should plan to sell it and get a HT or TD cutter. What did you have to tap into inside the plasma to get it working? (ArcOK, etc?) I also haven't found anything specifying whether it's HF start so does anybody know if it is? It has pilot arc but I've read that's not conclusive. Thanks in advance for any advice!

[adbuch]

I built my table on a very limited budget around a Hobart 250ci (Insert laughter here) but had lost mt job to south of the boarder and with barely any income and the 250 in my shop I gave it a try. To my amazement it has cut about 30 sheets so far ranging from 18 gauge to 3/16 and hasn't missed a beat. It took a few modifications to get it to work with a table but hey it does what I need.

I realize this post is 10 years old but I'm curious if this machine is still working out for you? I have an old Hobart AirForce 625i that I'd like to build a CNC table for but I'm curious if it's worth using or if I should plan to sell it and get a HT or TD cutter. What did you have to tap into inside the plasma to get it working? (ArcOK, etc?) I also haven't found anything specifying whether it's HF start so does anybody know if it is? It has pilot arc but I've read that's not conclusive. Thanks in advance for any advice!

He hasn't been active on this forum for about 2 years now. I don't know anything about the Hobert 625I, but if it has a "soft start" then I think it should work. You would need to tap into the arc voltage connections on the main board plus splice into the torch trigger wire so that you can control the torch on/off function.

[adbuch]

The Hobart AirForce 625 is wired the same way as the Miller Spectrum 625. See the attached photos below for details on splicing into the trigger wire and connecting the work clamp terminal and electrode terminal wires for monitoring the arc voltage.
David

Hobart 625.jpg

Miller Spectrum 625 - 2.jpg

Miller Spectrum 625 - 1.jpg

Miller Spectrum 625 - 3.jpg

Miller Spectrum 625 - 4.jpg

[bob67cam]

1st i have to thank adbuch for the pics, i have been scouring the internet for anything about using a sister machine to this miller 625, mine is the hobart airforce 625, and i finally ran across this site.
that being said im hoping i can get some answers or verifications on the wiring, im completely new to this, i have yet to cut anything, ive just assembled my table from cutting edge and now attempting the wiring. the table is done and should be good, but the thc thingy is where im at and im far from very knowledgeable on the electronics but im hoping someone here can verify whether my wiring is correct or not. any info would be greatly appreciated!
here is a couple pics to show the wiring i have done

thc wired.jpg

plasma wiring 2.jpg

[adbuch]

The purple trigger wire is the one you will want to cut and splice in order have your controller operate the torch trigger on/off. The work clamp terminal and electrode terminal are the ones you will use to monitor the arc voltage for your thc. There is typically a voltage divider installed such that the actual voltage being monitored is the "divided arc voltage".

Someone more familiar with the Proma thc will hopefully chime in here with reference to the photos you show. I am thinking Robert Spark or Tom.

David

[bob67cam]

i was seeing that in your pics, the problem would be unless i pulled the trigger, it wouldnt allow current thru to where it needs to go, this is a manual torch im working with.
as far as i can tell i dont have any voltage divider, this cutter is about 20 years old now

[adbuch]

i was seeing that in your pics, the problem would be unless i pulled the trigger, it wouldnt allow current thru to where it needs to go, this is a manual torch im working with.
as far as i can tell i dont have any voltage divider, this cutter is about 20 years old now

The voltage divider is something that you have to add yourself externally. The directions for your THC may have some information about the divided arc voltage level required. Divider ratios are typically something like 50:1, 22:1, etc. depending on cutter and controller requirements.

You will need to put a zip tie (cable tie) onto your manual torch to hold the trigger switch in the closed position (like it would be if you activate the trigger by pulling by hand).

David

[djreiswig]

If he wires his switch contacts to orange & violet like he has drawn it will be in parallel with the existing trigger switch so there is no need to zip tie the trigger.

[weldguy]

That all looks good to me. Not familiar at all with the Proma THC but be sure that it is able to accept RAW arc voltage before firing an arc. If it will then I wouldn't even bother with dividing your voltage, just run it as is.

[adbuch]

i was seeing that in your pics, the problem would be unless i pulled the trigger, it wouldnt allow current thru to where it needs to go, this is a manual torch im working with.
as far as i can tell i dont have any voltage divider, this cutter is about 20 years old now

The voltage divider is something that you have to add yourself externally. The directions for your THC may have some information about the divided arc voltage level required. Divider ratios are typically something like 50:1, 22:1, etc. depending on cutter and controller requirements.

You will need to put a zip tie (cable tie) onto your manual torch to hold the trigger switch in the closed position (like it would be if you activate the trigger by pulling by hand).

David

This would be if you intended to cut and splice into the trigger wire. Otherwise you should not need to hold the trigger closed manually of your additional wiring is correct.
David

[bob67cam]

just a quick update, everything seems to be working as it should.
now its time to move on to the settings and getting it to cut well..lol

[adbuch]

Thanks for the update Bob! Let us know how you make out with your settings and cutting. Good Luck!
David

[bob67cam]

will do