Hardinge CHNC retrofit- Another one on the way!
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I plan to retrofit the lathe using linux cnc in 2 stages. Stage 1 will be to get the lathe working using the original Hi ack servo amps and spindle motor. Stage 2 will be retrofit to 1.5kw ac servos for x and z, and 4kw C axis spindle. I have already tested the x and z axis amps with a AA battery and they seem to work good, the z axis smoked a few isolation caps, but still works. I will be replacing the caps as soon as Digikey ships the replacements. I have yet to test the spindle motor. I think If I understand correctly I need to force on the spindle brake relay, to release the brake, and then I need to ground the Inhibit pin to be able to test with a battery.
I will be using the Mesa 7i33, 7i37 and anything io 5i20 cards for control. I still need to find a good motherboard and processor for the panel pc. Will be doing a 5 wire restive touch screen with a 15 or 17 inch monitor for pc interface. I think I will be replacing the resolvers and tach with a Us Digital differential 2500 ppr encoder , since It will be cheaper than the resolver converter boards on the market. The only problem I see with that is the current amps have a 6v tach signal feedback, and I don’t know if the Us Digital encoders can provide 6v tack signal. I’m not sure if I even need the tach feedback at the amp?
encoder link
usdigital.com/products/encoders/incremental/rotary/kit/EC35
Red is where the tach feed back is at the amp, that terminal block is the amp input terminal.
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you'll need a lot of IO , but over all not a bad machine to convert .
i'd go with using the existing drivers , nothing wrong with them if they are working , it's a major job to replace them .
the majority of problems with the older electronics are as you have found dry'd out caps , but once you replace them with more modern ones they run fine .
some spindle motors do not have the brake fitted .
check out all the axis and the spindle motor using a 3v dc battery supply , theirs an actual test circuit in the manual using a pot , which works fine too .
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The only problem I see with that is the current amps have a 6v tach signal feedback, and I don’t know if the Us Digital encoders can provide 6v tack signal. I’m not sure if I even need the tach feedback at the amp?
The tach feedback to the amp is needed so the amp knows how fast the servo is turning vs the commanded velocity. If the tach is not a separate device you could leave the resolver/tach and just add the encoder.
Sure looks like a HNC not a CHNC unless the first CHNC's looked like HNC's...
My CHNC I
gnipsel.com/shop/hardinge/hardinge-18.xhtml
$1500 for shipping from OH to NV don't sound too bad, maybe a couple of hundred high...
John
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I will be using the Mesa 7i33, 7i37 and anything io 5i20 cards for control. I still need to find a good motherboard and processor for the panel pc. Will be doing a 5 wire restive touch screen with a 15 or 17 inch monitor for pc interface. I think I will be replacing the resolvers and tach with a Us Digital differential 2500 ppr encoder , since It will be cheaper than the resolver converter boards on the market.
Use the Mesa 7i49 instead of the 7i33 and you can keep the existing resolvers.
It's a bit more expensive, but likely to be far easier. Resolvers are nice things.
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The only real differences between a chnc and an hnc are the hnc had a GE550 NC control and a mechanical variable speed spindle drive.The chnc had an AB 7370 true cnc and a servo spindle drive.The chnc was more expensive.My sources tell me the AB is a bear to keep running and that Hardinge wanted a low cost control from Ge and the only thing ge had at the time was the then outdated,but rock solid 550T.The full size 1050t was to expensive and the 1050h wasnt available yet.Hardinge did use the 1050H on HLX machines ,but I have heard they didnt intregrate it very well and they had problems.
I saw the same machine on ebay and almost bought it,didnt have the room!!!
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would you be interested in telling me how you tested your axis drivers
mine look the same as yours but my lathe is a little different, instead of the control being behind the lathe it is connected by braided cable/conduit I am in the process of trying to upload photos.
they are hiak and are mounted in the large control cabinet. I would like to test them before deciding whether to replace them
thanks
bob
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The resolver is kinda a strange duck, Hardinge mechanically geared the tach and resolver up 5:1 vs the ball screw. I think this was done to increase the accuracy of the machine. because of this I am not sure about how emc or the 7i49 will handle the resolver imput. I assume that emc will be able to scale the 7i49 output to correct for this? Also its not clear if the 7i49 can output 12v to power the harowe resolvers or not? I guess they could run on a lower voltage however I think I would loose some fidelity. I think I may call mesa tomorrow to discuss. If the 7i49 will work, then I think thats the route to go.
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The Allen bradley 7300 series controlls are huge, I had 3 shipped with the machine, they weigh around 300 pounds each and are 3ft x 3ft. I tried all 3 on the machine, none worked, however I did get a free fire works show when the tantalum caps explded on one
![:laugh: :laugh:](/media/kunena/emoticons/laughing.png)
![:laugh: :laugh:](/media/kunena/emoticons/laughing.png)
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I have another hnc and like the idea of using the resolvers,but then i need a resolver and encoder board(u need an encoder on the spindle).I can scan the Hi ack book.send me your email and Ill try to get it done in the next couple days.Yes,you could use the spindle as a c axis.The pitch on the screws is .200,not 5mm...I surfed all day,Im beat....
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On the attached schematic, I jumped pin E to pin B to disable feed hold. next you just need to apply a voltage to pin H, with ground at pin G, to move the other direction reverse the polarity. I used a AA battery with some wire taped to the ends. You might want to remove the drive belts from at least the x axis for safety reasons. By doing this you are effectivley forcing the motor on. The slides will not respond to the limit swithces so you can crash the axis into its end of travel if not carefull.
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