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Author Topic: Conect 121 lathe retro  (Read 53241 times)

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Offline budman68

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Re: Conect 121 lathe retro
« Reply #20 on: December 08, 2011, 03:27:43 PM »
You do nice work there, Hood. The keyboard looks very "clean" and I would imagine it will take a bit of getting used to. Happy with the quality?

Thanks for sharing-
Dave
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Offline Dan13

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Re: Conect 121 lathe retro
« Reply #21 on: December 08, 2011, 03:38:15 PM »
Hood,

Looks good! Going to be nice little machine... hmm... somehow it doesn't sound right - small machine in conjunction with Hood ;D

Did you go with servos just because you had them lying around? Besides, looks like an overkill to use a 400W servo on the Z of this little lathe?

Dan

Offline Hood

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Re: Conect 121 lathe retro
« Reply #22 on: December 09, 2011, 05:45:47 AM »
You do nice work there, Hood. The keyboard looks very "clean" and I would imagine it will take a bit of getting used to. Happy with the quality?

Thanks for sharing-
Dave

Thanks Dave, yes keyboard is very nice indeed and a lot nicer in the flesh than it looks in pics. Quality seems to be very good as well, only time would tell how it would stand up but does seem robust.
The functionality isnt quite there yet, most of it does work via Brian Alpha plugin but there are a few things that are not quite right. Brian is wanting me to re-deign the key layout doing away with some of them and it will  also be made to function as a standard keyboard as well with a function button, so it will be the only keyboard required :-) I just need to get time  and get my head around what is in Brians thoughts as his mind is hard to read ;D. The other thing is Brain loves the way Fanucs work and I dont, I hate having to press 20 keys to do a task when one would do ;D

Hood

Offline Hood

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Re: Conect 121 lathe retro
« Reply #23 on: December 09, 2011, 05:49:23 AM »
Hood,

Looks good! Going to be nice little machine... hmm... somehow it doesn't sound right - small machine in conjunction with Hood ;D

Did you go with servos just because you had them lying around? Besides, looks like an overkill to use a 400W servo on the Z of this little lathe?

Dan

Yes Dan I am taking bad with such a small machine but the build quality does seem to be there so its not too bad :D

Was originally going to go steppers, it had them on and I have spare G202's from the Bridgeport. But its just the slow accel and noise of steppers that gets me after being used to servos.
I had most of the drives and motors already and the 400w on the Z is overkill but better that way than not enough I suppose.

Hood

Offline Dan13

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Re: Conect 121 lathe retro
« Reply #24 on: December 09, 2011, 06:15:08 AM »
Hood,

Main reason I don't like large motors on small machines is I am afraid the motor would have enough power to damage the machine should something go wrong. But you're using a servo and can limit the current/torque to a value you like.

Would you share your E-stop diagram?

What size is the lathe? What are the travels?

Dan

Offline Hood

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Re: Conect 121 lathe retro
« Reply #25 on: December 09, 2011, 06:47:49 AM »
Yes thats the beauty of servos :)

Not done the E=Stop yet, I tend to do things as I go as I find I work faster that way than trying to plan things out. Any time I have planned things I have seen better ways when actually doing it :) I will more than likely do them similar to the other machines, E-Stop, limits, drive faults etc all tied to the drives enables and sending a signal to Mach. As I wont be using a PLC on this it will be done with mechanical relays. The EStop will also kill the power to the drives but the others would just take the enables away.

Machine is a Myforld ML10 bed and headstock, about 350mm between centres, X was about 50mm but because I have fitted the motor to the back instead of the front I can get more, as much as 100mm I think, I am toying with the idea of a gang tool setup so the extra X will be handy. Swing is about 165 mm and over saddle prob about 115mm, the taper in the tailstock is No 2

Hood

Offline Dan13

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Re: Conect 121 lathe retro
« Reply #26 on: December 09, 2011, 07:06:16 AM »
Thanks for the info on the Estop, Hood. Does it work well on your other machines? I don't feel comfortable about merely cutting the power to the drives. They still have enough bus voltage to move a bit  I think. I cut power to motors and switch in braking resistors. Depending on the resistors values the motor stop pretty much instantaneously.

Sounds a quite capable lathe.

Dan

Offline Hood

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Re: Conect 121 lathe retro
« Reply #27 on: December 09, 2011, 07:15:10 AM »
The mills and big lathe stop instantly, maybe the weight/friction of the axis doing that but as the enables are also taken away from the drives the motor is not being powered. The bigger AB drives have internal shunt circuitry but the micros dont and require an active shunt if you want to use one, I have them on the Beaver but not the Bridgeport and there is no difference in an E=Stop, both Instant.
  May be different on this machine as it will have less friction but I dont think it will be an issue, time will tell :)
Hood

Offline Hood

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Re: Conect 121 lathe retro
« Reply #28 on: December 30, 2011, 05:47:35 PM »
Well not much progress, got a wee Yaskawa servo for the X axis, the wiring had been chopped off right at the exit so I opened to find out the pinout and thats when I saw the encoder disc was cracked in three places :(. Ok not so bad as I had a spare encoder with commutation tracks and  it was for the same amount of pole pairs as the Yaskawa was :) Had to make up a new mounting plate, shaft sleeve (to make the shaft a bigger dia) and a new housing for the end, got that done and the encoder fitted and lined up and the motor ran. Lots of noise when it went above a few hundred RPM so decided it was the bearings, replaced them and all was quiet but next thing was I noticed the front shaft was bent. Managed to get that straightened fairly well and finished getting it dead true by turning it down, that was OK as I had to sleeve it anyway to fit the coupling. Got all that done and the motor is good :)
 So now I have to make up mounting brackets and bearing housings and then it will be fitted.

I have decided to put things on hold for a while though as I plan to put the ESS on this lathe as well and want to use the breakout board I have been working on, have it  designed now with a lot of help from friends who know about these things :) It is going to be three separate boards.
One will be 12 differential outputs and 5 differential inputs, they will also be capable of being used as single ended I/O if the need arises.
The second board will be 12 out and 5 ins, all 24v and each being capable of being sinking or sourcing.
The third board is similar but it will be 4 out and 13 in.
Reason I am making them as separate boards is so I can choose which to use depending on the needs of the machine, some will need more Ins than outs and others the opposite so I can use two boards the same on port 2 and 3 or two different :)
Screenshot of of the pcb software rendering of the boards as they will be made before I chop into three separates. Surface mount soldering will be new to me but I have been practising, just might need to get some specs :D

Hood

Offline Hood

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Re: Conect 121 lathe retro
« Reply #29 on: December 30, 2011, 05:50:01 PM »
Oh and the reason I am making the boards wider than they need be is because I want them in Din rail mounting trays. the trays come in 108mm x 37mm sections and I couldnt quite fit them on to the 37mm wide sections so had to double them up to 74mm. No big deal for me but was a bit annoyed as I almost managed ;D
Hood