Powermax 85 question

[tinman13]

Should this amount of pitting on a 65 amp nozzle cause it to not cut all the way through? It cut 8 pierces and about 2 feet of straight cut and then blew back without piercing all the way.
Cut specs are to specs in the book.
I tried 45 amp first with the same results.

Thanks, Steve

[magma-joe]

tinman13,
I just got my Powermax 85. I was reviewing the manual on the automatic versus manual air pressure control. Just curious, have you been running in automatic or manual? I noticed the 85 has a spring loaded electrode. When the arc starts and air flows the electrode raises upwards. I would think it could be a source of problems if it was allowed to get dirty and it stuck or moved up partially when the air pressure was applied? Maybe something to check?

Questions for Jim

In the Powermax manual it states that in automatic mode the air pressure is automaticly set based on torch type and lead length. Since there is no data imput by the user, I have to wonder how does the machine know what torch type and lead length are connected to it? Thanks,

Magma-joe

[WSS]

Steve, The specs in the book for pierce height might be a little low on the 85, especially for thick plate. with the older 1650, I usually back off about double the recommended height. This does lower the life slightly, but keeps that stuff off the nozzle. I heard somwhere that the conical flow/spring assist set-up actually gets better as you cut, sort of a "break-in". try running a countersink lightly by hand in the nozzle to knock off the stuff stuck to it. It will probably run good. It looks like a hard pierce nailed it. Is it concave when new? The 1650 parts stick out a little. That is the first 65/85 nozzle I have seen

WSS

[jimcolt]

There are pin connectors on the different length and types of torch assemblies that indicate to the plasma system what torch is installed, further, there is an internal pressure transducer, and, different air pressure settings are called up (from the internal microprocessor board) depending on the amperage level set, and the process chosen (gouging, normal cutting, auto pilot mode)

Jim Colt

Originally Posted by magma-joe tinman13, I just got my Powermax 85. I was reviewing the manual on the automatic versus manual air pressure control. Just curious, have you been running in automatic or manual? I noticed the 85 has a spring loaded electrode. When the arc starts and air flows the electrode raises upwards. I would think it could be a source of problems if it was allowed to get dirty and it stuck or moved up partially when the air pressure was applied? Maybe something to check? Questions for Jim In the Powermax manual it states that in automatic mode the air pressure is automaticly set based on torch type and lead length. Since there is no data imput by the user, I have to wonder how does the machine know what torch type and lead length are connected to it? Thanks, Magma-joe

[jimcolt]

I cannot see much from the picture, and you don't provide any details regarding what material, thickness and specifications you are cutting at. Also...info regarding the machine ....torch height control and brand/ model of machine. Assuming you are following the specifications...then you certainly should be getting more than 8 pierces and 2 feet of cut!

The cut specs in the Hypertherm manual are correct...I stand behind them 100%. Changing to a higher pierce height will of course work....but is not neccessary if all of the parameters are set correctly.


Jim Colt Hypertherm

Originally Posted by tinman13 Should this amount of pitting on a 65 amp nozzle cause it to not cut all the way through? It cut 8 pierces and about 2 feet of straight cut and then blew back without piercing all the way. Cut specs are to specs in the book. I tried 45 amp first with the same results. Thanks, Steve

[tinman13]

Sorry, I guess I didn't define it too well. 3/8 a514 (T1) plate clean surface.
Cut specs out of the book for 65 amps.
My machine is a Koiki 1200 converted to CNC control using CandCnc THC.
It cut the holes at 30ipm with thc off, they all cut well.
The outside cut was at 45 ipm. 130volts. The first two feet cut well then started blowing back, not cutting through. I was able to bump the feed rate down to around 35 to 38 ipm and it cut through to finish the part.
I have cut quite a bit with the new machine and this the first time this has happened. Actually the first sign of any problem!



Thanks, Steve

[jimcolt]

Your Powermax65 will cut 3/8" material at up to 78 inches per minute....so there clearly is something wrong if you had to reduce the speed to 35-38 ipm!

As I said before, I cannot really see the condition of your nozzle orifice, however there is a very nice section in the Powermax65 /85 manual that describes how to evaluate the condition of the consumable parts. If the nozzle orifice is out of round or nicked...that will cause it not to cut through fully. A nozzle can be damaged on one pierce if the pierce was done too close to the plate, or without adequate pierce delay.

The other thing...the CandCNC height control is arc voltage based, and I notice you have set the voltage to the suggested voltage (130 volts) as listed in the Hypertherm cut chart. It is more important to do a test cut...and adjust the voltage setting until the torch is at the recommended physical height (which should be .060", or 1/16"). If the torch was running too high off the plate....that could be cause for the lack of penetration.

Also....are you using the hand torch or machine torch? Either way, make sure you are using the shield (220817) that is for machine cutting....do not use the hand cutting shield as this shield is designed for drag cutting....and forces the arc to be too long when used with a THC.

Let me know if any of this helps...


best regards, Jim Colt

Originally Posted by tinman13 Sorry, I guess I didn't define it too well. 3/8 a514 (T1) plate clean surface. Cut specs out of the book for 65 amps. My machine is a Koiki 1200 converted to CNC control using CandCnc THC. It cut the holes at 30ipm with thc off, they all cut well. The outside cut was at 45 ipm. 130volts. The first two feet cut well then started blowing back, not cutting through. I was able to bump the feed rate down to around 35 to 38 ipm and it cut through to finish the part. I have cut quite a bit with the new machine and this the first time this has happened. Actually the first sign of any problem! Thanks, Steve

[tinman13]

"Your Powermax65 will cut 3/8" material at up to 78 inches per minute"

WOW..... not here.

New nozzle and electrode will not cut through at 68 ipm. I just tried it.
The book lists 68 ipm as production settings.......

I think I have pierce height dialed in by now as I have done literally hundreds of pierces with this machine with no problems until this.

130 volts seems to hold stand off height very close to .060, it's hard to tell exactly as the slats have a lot of slag build up and I'm sure the plate doesn't lay perfectly flat.

The orifice in the nozzle looks straight looking through with a magnifying glass, the pitting shown in the picture is only about .025 deep.

"If the torch was running too high off the plate....that could be cause for the lack of penetration."

How much would too much be?


Yes It's a machine torch and parts are as spec'd as in the book.


Thanks for your help.
Steve

[WSS]

Steve, in the second picture it looks like the cut picked up again. Was this a re-start or did it finally pop through and start a good cut again. It looks like it lost it right at the turn, is this a common factor? Our 1650 will cut with a little lag line at 60ipm w/60a parts, 55ipm and the lag dissapears (on 3/8" AR). With a new nozzle I run the book specs for volts and as it wears I will add a volt or two to keep the distance. If I come up close to a pierce crater I wll raise the volts five or so and then drop when past the problem area.

Something does not seem right. Are you traveling clockwise for outside and CC for inside?

WSS

[tinman13]

That cut was done ccw on the outside. I bumped the feed down as it was cutting till it cut through then readjusted the volts till the height was right.

I had just done an order of parts all 3/8" ar400, five plates, about fifteen parts with somewhere around one hundred pierced square holes.
This was a T1 part using the same cut specs.
I have not noticed a difference between alloys before......
It doesn't seem like that should make a difference, but who knows?
I sure don't seem to achieve there stated production specs though.

Steve

[jimcolt]

The specified cut height is .060"....plus or minus .010" is probably acceptable.

The book speeds for 3/8" as listed in the manual are: Optimal speed, 45 ipm, maximum speed, 78 ipm. Optimal speed is for the best edge angularity with minimal dross....max speed is the maximum with a new set of consumables.

You are cutting T1 , which is a high strength steel....which will have an effect on the process as well. The book specs are done with a standard A36 grade steel, as that is the most common steel used.

Jim Colt