- Thread starter AdrianH
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A bit more, sorry for the poor quality video and audio especially when the compressor starts and runs. In parts I can not tell the bits of metal have dropped out, and when the torch is in mid air the arc stops and seems as though I have to restart the torch. I don’t think the unit is faulty just the way it is?
Adrian
Adrian
To be honest I don't know, I think not, but with the crappy phone camera and trying to concentrate to much on my end I can not tell. I do know that when the bits of metal drop out I can loose the arc. I know if I try to start an arc to far away from the edge of metal, by a couple of mm the arc will not start, so I do not think the hf unit is on all the time just at the start if the arc. But again, I am not sure?
The set up was not best, but I wanted to have a play
Adrian
The set up was not best, but I wanted to have a play
Adrian
Further to the above, and as seen in the video it looked difficult cutting, drop outs of the arc, sometimes not restarting for some time and in honesty the cutting was not as clean as expected.
Because of a space issue I had fitted some new standard tips I had just got off Ebay, these are shorter then the ones fitted when I bought the machine new.
Anyway, I struggled on tonight trying to cut by hand having the same issues. I had ago at adjusting air pressure and the amps setting, but during cuts I was still loosing the arc, it was unreliable and cutting crap. I also noticed the air flow would dip and build up half a kg/cm2 on the pressure meter.
I then put back on the original tips and all my issues went, no loss of arc, gas flow a lot better, cutting a lot better faster and cleaner. Hallelujah!
Not sure what the major difference apart from length, but I have 12 crap tips, thankfully they did not cost a lot. I will go back to Ebay and try to get some longer ones and see if they perform better and as the originals.
Adrian
Because of a space issue I had fitted some new standard tips I had just got off Ebay, these are shorter then the ones fitted when I bought the machine new.
Anyway, I struggled on tonight trying to cut by hand having the same issues. I had ago at adjusting air pressure and the amps setting, but during cuts I was still loosing the arc, it was unreliable and cutting crap. I also noticed the air flow would dip and build up half a kg/cm2 on the pressure meter.
I then put back on the original tips and all my issues went, no loss of arc, gas flow a lot better, cutting a lot better faster and cleaner. Hallelujah!
Not sure what the major difference apart from length, but I have 12 crap tips, thankfully they did not cost a lot. I will go back to Ebay and try to get some longer ones and see if they perform better and as the originals.
Adrian
Wallace
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Always the simple things that let you down mid project. I was thinking about the flex/ bounce, could you fit a ball transfer bearing underneath one of the upper arms to take the weight and use a piece of MDF covered with sheet steel for the bearing to run on as support?
I have seen similar in use on a youtube video. When playing again tonight I tried to watch the head and flex/bounce was not an issue, a bit of pulling with the cable but adding a support in the air type of thing eased that a bit. These cheep machines always seem to be supplied with drag tips. I know that on a proper type cnc plasma cutter they tend to have different tips that are meant to be a few mm clear of the work, I have seen many raise to piercing height then drop down to a cutting height before moving, but, I decided that as it has a drag tip on it I am actually placing the tip on the metal with a slight bit of pressure, not enough to cause to much drag , but perhaps enough pressure that the lift and bounce is not a problem.
I have a design problem with the ball bearing underneath, I could not put one on the arm that supports the arm as the arm would travel over the metal plate that is being cut and it is possible the bearing could hit a hole or edge, possibly one on the non fixed central pivot may be an idea. I am hoping I could free stand the unit on just one poiint but need to wait and see.
I still have two simple things to sort with the set-up as it is. I need to put a sleeve inside the pivots between the top and bottom bearings to stop them being pinched together, so I am not forcing the inner races out of the bearings. Also need a longer bolt to the milling table or what ever I use finally. At the moment, the M12 bolt is narrower then the T slot, and there is not enough bolt to have a washer and lock not on the table to make it solid, So i am tightening down on the top nut to stop it wobbling on the table and if I go tight enough to stop it wobbling I start to pinch the bearings together. But weekend is coming and i should be able to sort these, get a bit more height and use the normal tips, then perhaps do another video.
Adrian
I have a design problem with the ball bearing underneath, I could not put one on the arm that supports the arm as the arm would travel over the metal plate that is being cut and it is possible the bearing could hit a hole or edge, possibly one on the non fixed central pivot may be an idea. I am hoping I could free stand the unit on just one poiint but need to wait and see.
I still have two simple things to sort with the set-up as it is. I need to put a sleeve inside the pivots between the top and bottom bearings to stop them being pinched together, so I am not forcing the inner races out of the bearings. Also need a longer bolt to the milling table or what ever I use finally. At the moment, the M12 bolt is narrower then the T slot, and there is not enough bolt to have a washer and lock not on the table to make it solid, So i am tightening down on the top nut to stop it wobbling on the table and if I go tight enough to stop it wobbling I start to pinch the bearings together. But weekend is coming and i should be able to sort these, get a bit more height and use the normal tips, then perhaps do another video.
Adrian
Faster then angle grinder.
Wallace
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True, it's buggerall money really in comparison to the time to make one and I've done the same in the past. I bought some longer tips recently and for freehand work they are a revelation even for cutting straight lines against a guide.
eSCHEn
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Absolutely top job Adrian. In awe of just how smooth and accurate that is mate, very well done!
Definitely going to have to make one now...
doubleboost
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Very well done
I am now inspired to build one
I am now inspired to build one
Accuracy can be better I guess it is all about making every thing line up with the pivot points including the torch and stylus. Using inch tube helps stop some of the flexing, but means the bearings are offset! I have just been looking in an electronics catalogue to find the style of connector so I can connect into the plasma switch without sticking wires in the pins, so that should make it safer. It has been fun and frustrating to get to this stage.
Adrian
Adrian
eSCHEn
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Here's the connector for the cut40 Adrian. Definitely fits as I just got one for myself for another wee project (plasma pedal).
A bit of two core 0.75mm SY cable fits a treat. You want about 6.5mm OD for a snug fit.
A bit of two core 0.75mm SY cable fits a treat. You want about 6.5mm OD for a snug fit.
Cheers
That is cheaper then the electronics store even with postage, so ordered 4.
Thanks
