Machsupport Forum
General CNC Chat => Show"N"Tell ( Your Machines) => Topic started by: Sooty1986 on February 04, 2015, 06:20:35 PM
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Hi folks,
Have manged to find a nice little conect 121 cnc lathe locally and I'm looking forward to my first cnc refit. This will be a small lathe for my dad to play with in his retirement.
I'm literally learning as I go with this project and it's going to be a budget build. I have got a nice orac hidden at the rear of the workshop which will be my project but the conect will be a good starting point.
I haven't got the machine home yet but I will get some pictures up, it is the same model "hood" has covered in the past. I am going to try and keep the origonal motors and the DC spindle motor. Don't have the motor specs yet but I'm hoping they will be on the motor as i can't find much on it online. I have read that there are KB boards which will allow me to use the DC motor and possibly control it from Mach.
If anyone has experience with this motor type and running it with a speed controller please let me know how you did it.
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I just threw out the steppers off mine a week or two back :(
I can't remember what they were but I could only find info on one of them. I originally had planned to use steppers but I think I was going to go for new ones, can't recall if it was because they were not suitable for modern drives or if it was just I figured the older motors may be on their way out.
Sorry not much help but looking forward to seeing the progress, always good to see another lathe.
I still have the DC spindle motor somewhere I think, so if you want it as a spare you can have it for the cost of the postage.
Hood
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Thanks hood! a spare would be very useful, especially if I fremember it trying to hook it up to the bob lol!
The lathe arrived today and guest what! it came with a friend! The guy had two of these wee machines and I couldn't resresist! the second one may be sold after I convert it to fund the orac conversion but we shall see!
Hood, how do the steppers disconnect from the ball ballscrews?? Looks like there may be a tiny grub screw??
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If I remember there was a bored out piece of Alu that slipped over the end of the ballscrew and the stepper motor and just held with a grub screw or possibly a roll pin.
There was a thrust bearing there as well I think and the steppers bearing was used as the second bearing, not the best of setups but probably worked ok.
If you PM me your address I will send it off through the week some time, assuming I can find it :D
Hood
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(http://i295.photobucket.com/albums/mm154/minimad30/Mobile%20Uploads/DSC_0081_zpsnf0tdc8s.jpg) (http://s295.photobucket.com/user/minimad30/media/Mobile%20Uploads/DSC_0081_zpsnf0tdc8s.jpg.html)
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(http://i295.photobucket.com/albums/mm154/minimad30/Mobile%20Uploads/DSC_0089_zpsze2yonff.jpg) (http://s295.photobucket.com/user/minimad30/media/Mobile%20Uploads/DSC_0089_zpsze2yonff.jpg.html)
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I know now why there is a bearing on the stepper lol! I think they are either tiny grubs or roll pins. Hard to tell... managed to get the motor number of the large stepper bbut still can't see anything on the small stepper...
Also need to figure out if if the existing spindle sensor can be used!
(http://i295.photobucket.com/albums/mm154/minimad30/Mobile%20Uploads/DSC_0116_zpsjbzkpdav.jpg) (http://s295.photobucket.com/user/minimad30/media/Mobile%20Uploads/DSC_0116_zpsjbzkpdav.jpg.html)
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Hood do you know what the large alloy box is under the spindle motor?
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The " alloy box " is simply a base for the motor, nothing else.
As for the opto, I think I looked at it and decided not to bother with it, I was going to just use an Optek OPB917B but then went with the IP-S controller so ended up using an encoder.
Hood
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Not got any further with the motors.... Not a lot of info out there. Making buying drivers etc a bit of a pain, Im hoping the motors can take 1.5a as that's as low as the steppers I'm looking at go.
Hood, do you know what pitch the ball screws are on each axis?
For threading with Mach do I just need a spindle speed sensor?? Also do these sensors go back to the same inputs as like the limit/ home switches or do I need a completely separate board?
Thanks!
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I could only find info on one of the motors, cant recall which one but I may still have the info. If you could tell me the make of the stepper I can do a search of my drive to see if I can find it.
The X is 2.5mm pitch and Z is 5mm.
All you need it to put the pulse to an input and set it up as the Index Signal in Ports and Pins/ Inputs.
You will probably have to go a bit bigger on the dia of the slotted disc for best results, most go for 100mm dia with a 10mm wide slot. You could keep the smaller dia but with a 10mm wide slot it may not provide such a clean signal at higher RPM as the time between on/off states will be quite small.
I would suggest an Optek OPB 916B or 917B and you will also need a 220 Ohm resistor, but that should cost only about £10 for both incl the post.
Hood
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You will probably have to go a bit bigger on the dia of the slotted disc for best results, most go for 100mm dia with a 10mm wide slot. You could keep the smaller dia but with a 10mm wide slot it may not provide such a clean signal at higher RPM as the time between on/off states will be quite small.
Hood
I hate to question the master, but here goes ....
This looks a bit backwards.
At a given rpm, a 10mm slot on a 50mm dia. will be open for a longer duration than the same slot at 100mm dia. By 2:1 by rough calculation.
Am I wrong ?
Russ
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Thanks hood, shal look into that setup.
The motor I have is a EGE, sigma 20-3424d200-f1.8
There is nothing on the other one, can't find a wiring diagram anywhere for the larger motor. There are 8 wires total. there are 4 white wires with tracers. These are separated into two groups. Also 4 individual wires, Yellow red orange and black.
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Not sure Russ, way I see it is the slot is 10mm wide so no matter the dia of the disc the width of the slot will be the same and thus the distance the same no matter the rpm.
The difference would be that on a larger dia disc the closed sweep would be much larger in proportion to the slot than it would be on a smaller dia disc.
Then again I suppose the time would be the same.
So to summarise, F'd if I know :)
Hood
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Name doesnt sound familiar so possibly mine had different motors, I will have a search and see if I can find it.
Maybe MC will have an idea, think he kept the stepper, then again it was the newer version so maybe different.
Hood
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Ok found the pdf I had, not sure which one it is for but have attached it anyway.
Hood
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Ok going by that pdf (thanks hood!) the current motors are wired exactly the same as the unipolar setup. Based on this im happy to give them a go in bipolar
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So to summarise, F'd if I know :)
Hood
:D
An angled slot would be the same duration regardless of diameter.
For a given rpm, the parallel slot would have a longer duration as the diameter gets smaller.
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Hmm ....slot width......
From my rusty memory! :D
Even if calculated and dim used ....sometimes didn't cover rpm range ...so made it bigger
In fact made some about 1/4 the size of the circumference and worked fine.
A CD Rom painted black work nice and saves some time in making it. ::)
FWIW,
RICH
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If the cd idea works it will save me some time!
Does anyone have a diagram showing how to wire kb dc controller board to a bob. I think there needs to be some sort of isolating circuit but I have no idea.. Still learning.
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Case of try and see Russ, sure I had issues on the big lathe with a small disc, increased the dia and problem gone but that was a long time ago as when I went to the SmoothStepper I just used the motors encoder..
Sooty1986
Probably other ones on RS that would do the same job, just I got the part number from a guy years ago and it worked great for me on all the machines I used it on, even used it as limits on some machines.
Cant really recommend any places in the UK for BOBs as I have only ever used PMDX and CNC Building Blocks BOBS, the latter no longer being made.
Nowadays I use CSMIO controllers so no need for BOBs, sadlly their IP-M controller does not do Lathe threading or it would have been an excellent choice. Looks a bit more expensive at first but when you see that it has no need for a BOB, has spindle control and also analogue I/O for feed override etc, then it suddenly looks a lot cheaper.
Hood
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From my archive -
Z-Axis
Motor
Label details
Astrosym L281
Volts – 3
Deg – 1.8
Amps – 1.7
Ohms – 1.8
15kg cm (1.47Nm) (Nema 34) (google suggests detent torque of 1kg cm)
Ballscrew
12x4
X-Axis
Motor
Label details
Astrosym L163
Volts – 5
Deg – 1.8
Amps – 1.0
Ohms – 5
69Ncm (0.69Nm) Nema23 (wired bi-polar)
Ballscrew
8x2.5mm
However mine was a newer version, and there were a few differences from what Hood had posted about his.
I managed to use the original spindle slot sensor, which was a Sharp 1A05, with the SmoothStepper I used.
Connecting the KB drive will depend more on your BOB. Provided the BOB has an isolated 0-10V output section, then it's fairly straightforward, you just have to make sure you feed the 0-10V with an isolated supply. DC-DC isolated converters are only a few pound, but some BOBs come with them already fitted (I'm sure PMDX does). The main thing to remember is the control voltage on KBIC style drives is at a floating voltage, so if you connect it directly to your electronics supply, something is going to release magic smoke, hence the requirement for things being isolated.
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Hmm, thanks for the info on the motor and the kb controller mc. me thinks I will leave that for now, I can get by for a while without speed control. I can get the box with the pot on it and set the speed with that. as long as I can get a spindle a lot sensor to work I will be happy.
Don't suppose you have the wiring diagram for the slot sensor you used mc? There may be a chance the wiring is similar.
Question, does the thrust bearing on the motor ends do anything? I ought the force would be put on the small split pins on the coupler before getting to the thrust bearing?
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The thrust bearing is to stop backlash, the ballscrew is held captive by the motors bearing one way and the thrust bearing the other. The thrust bearing is held tight against the motors casing by the alu coupler.
As said it is not really the ideal situation as the motors bearing should not really be used in such a way but with the loads being small it is probably fine.
Hood
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I think I found the datasheet via google. I've not got it saved in amongst my 121 lathe stuff, so you'll have to do your own searching. It's usually worth a quick google of anything written on the sensor, as datasheets for most things are online somewhere.
I can't comment on the thrust bearing setup, as IIRC that was one area where mine differed, but I think all the lathes used quite a crude thrust bearing setup.
If it's any help, all the photos of my lathe can be found at https://www.flickr.com/photos/mc_mtb/sets/72157625154378941/
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Thanks for the info! I have ordered the parts from rs to make up a couple of spindle sensors. Not got much further with the drivers and BOB as the company i was looking at (Zappautomation) don't have the items i wanted in stock.
Will be using digital steppers on this build as they seem much quieter and smoother. I think the majority of parts will be coming from CNC4YOU in the uk, at least for the first build. I want to try diffrent suppliers before i convert my orac later on.
Another question guys..... When looking at limit switches i have noticed they are rated at 250v ac max. Do these work just fine with the 5v dc setup?
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Yes!
Sent from my iPad using Tapatalk
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Thanks!
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The parts are here and the wiring is underway! question, is it safe to have the cnc electronics in the Same case as the pc electronics ?I have a huge pc tower which will take it all.
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It should be fine as long as you have the wiring properly shielded and grounded.
Hood
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Right i will do that for the next build. I found an old xbox in the shed and decided it was just the right size! Everything fits and has good ventilation due to being a gaming console. I will be fitting some fans on the case to give some through air.
The bit of mdf is temporary lol
(http://i295.photobucket.com/albums/mm154/minimad30/Mobile%20Uploads/A7130E86-BC5E-47C1-9336-0B4851971BBD_zpsgsozn9v3.jpg) (http://s295.photobucket.com/user/minimad30/media/Mobile%20Uploads/A7130E86-BC5E-47C1-9336-0B4851971BBD_zpsgsozn9v3.jpg.html)
(http://i295.photobucket.com/albums/mm154/minimad30/Mobile%20Uploads/EDAAC163-3D2D-49DF-9509-08F4C6354EDE_zpsrkcnxzsd.jpg) (http://s295.photobucket.com/user/minimad30/media/Mobile%20Uploads/EDAAC163-3D2D-49DF-9509-08F4C6354EDE_zpsrkcnxzsd.jpg.html)
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There is movement! The steppers are wired up and behaving correctly, I think! The little one is getting a bit warm at idle. Can still handle it but I'm worried Iv done something wrong
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The little one is getting a bit warm at idle. Can still handle it but I'm worried Iv done something wrong
Perfectly normal. As long as you can keep your hand on them for a few seconds, they'll be fine.
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Thanks MC
Was i correct to wire the motors in series, since im using a 36v supply and running the motors at 1.5A. i can see if they will take 2A later but they are only 1A per phase i think
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Also does anyone have the XML configuration file for one of these lathes for Mach3?
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Have a question for you MC
http://www.diycnc.co.uk/spindleV4.pdf
Would this spindle board be suitable to use with a KBIC controller?
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Unless someone has an identical setup to you then a xml from them will not be any use. They would have to be using the same motors/drives and have the I/O connected to the same pins.
Hood
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Have a question for you MC
http://www.diycnc.co.uk/spindleV4.pdf
Would this spindle board be suitable to use with a KBIC controller?
Yes. It's all optoisolated with a built in DC/DC power supply, so it'll do the job nicely.
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Long time since i last updated. I managed to get the lathe working nicely (still no spindle control via mach3). Having fun using it for prototype work and have converted another machine since to the same spec.
I now have another Conect lathe with a toolchanger that i will be converting but there are a few things i still have to figure out. ill start a new build diary with this machine (will probably need your help again Hood!