Another 1440GT 3ph question(s)

[chu.c.me]

Hi Dave @B2 ,

I would be interested in a PCB. I just got my 1340GT and am in the beginning of my adventure of VFDing it. Having a PCB for a clean install sounds exactly what I need.

Let me know if it ever manifests.

Colin

 

[Mcdavis86]

I am not for sure what you mean by an "inside the headstock install," but let me assume that you mean inside the original lathe cabinet where the current control relays etc are installed. I did not want to add an additional cabinet to hold a VFD etc.

I did just this and documented the installation and all of the parts. Have you seen my posting? If not you can find it here.

The document you might want is the fifth attachment of the first posting (far right on the screen) and the title of it starts out as "PM 1440GT Part 2 VFDDescript...." This installation essentially included all of the bells and whistles I could think of at the time. I even added a few things that most people do not even use like a revolution counter. So one can just leave these out if they do not want them. Anyway, lots of folks have downloaded this document, but I am not for sure how many folks have used it. I built a solid state logic control to eliminate most all of the big relays etc. (To sort of quote @ptrotter, ... what the heck, why would I need all of these big non-modern electronic relays etc if I am installing a solid state VFD anyway.) That saves more than enough space to allow me to get everything in the back of the lathe stand, where the original controls were located, and the front switch control panel , including a braking resistor of my own construction. I used the Hitachi VFD that Mark was recommending at the time and its installation and operation went smoothly. The document even encludes the VFD programing I used. It has been working without any problems for a long time now.

Even though I tried to explain, in detail, how the electronics function, for many folks building the electronics by point to point soldering probably is a discouraging thought. So if you do not have electronics skill this maybe a turn off. I know that, while he was also implementing an ELS , @ptrotter took my design and modified the layout etc. to run his PM1340 .



Since doing the project I did spend time laying out my electronics in a pcb and even though it had a wire routing error a little soldering fix it and it worked for @bdstark .


Since I am still interested in this and might still replace my point to point soldered board with a pcb, I would be willing to re-layout the pcb board, have it made, and ship you one if you wanted to try my install. I am sure this would make it much easier. I might even having the pcb manufacturer install the electronic components (transistors, resistors, etc.) This way one would just have to install the board, VFD, etc. on a backer plate like I described and connect the wires . Getting these boards made is very inexpensive, so cost is not an issue. Also, the board componets are essentially free. The last time I did it I got 5 boards shipped to me for less than $30. By the way, at the back of the document write up I did list all of the components/parts and sources that I used and while the internet links I provided are probably broken by now, finding the parts should not be a problem since for the most part they are very common.

Are you interested in doing this? Anyone else?

PS. I only offer to do this to help folks out. I am retired and get some joy out of solving problems and helping others out. For me, this is indeed a hobby.

Dave L.

Yes, I had my head up my ass, I meant cabinet, although the oil bath may help my VFD last longer. Yes I looked through that, very nice build, probably a little more than I want to bite off. Today my father in law sourced me a 10hp 3PH motor for the low low price of free so I can have a RPC for a few hundred bucks, I’m gonna go that route for now, besides CNCs and a Hardinge HLVH I’ve never had VS and always made due, it may still be something I look at doing in the future but for now I gotta get this thing making chips. Also, I’m not going to be facing any big diameters, which is where the VS really comes in handy, although I could see it being useful for other things too like tuning out chatter. I really appreciate everyone’s help so far, it’s a great community, looking forward to giving back when I can.

 

[B2]

I would be interested in a PCB. I just got my 1340GT and am in the beginning of my adventure of VFDing it. Having a PCB for a clean install sounds exactly what I need.

Let me know if it ever manifests.

Hi Colin,

We should be able to do this. I do not think the pcb will be an issue. However, you will need to think about what features you want and where you want to place/display these as you may have limited space. I do not have access to a 1340GT so I am not familiar with some of its layout characteristics. However, @ptrotter 's photo with the external gear cover removed is helpful. (This was in his discussion of his ELS design I mentioned eariler.) The 1340GT has a considerably different layout from my 1440GT. In the 1440GT the control electronics are located in the back of the lathe stand under the spindle etc. Also the front switch panel has a recessed area behind it that is larger than what is available in the 1340GT. It is unlikely that you can stuff all of the parts that I put into the 1440GT in to the 1340GT switch panel area. I think the 1340GT has the control relays/electronics at the back of the spindle, in a cabinet that is part of the lathe but isolated. It may hold everything, but the picture I see in the manual implies that it is a bit small. You could probably increase its volume by extending it out backwards and/or making it taller. Or you might house things in the front part of the stand cabinet where I see a door. I know that others have done various things and have commonly used an external commercial cabinet. The nice thing about using the current cabinet is the proximity to the motor etc so cables are shorter (less noise issues) You can also face any displays out the top portion of an extended cabinet towards the front of the lathe. You might even put some of the control switches there. At some point you will probably add a DRO, if you have not already, and this is normally put in this same location on top of the lathe. It appears that it still can. I got rid of some of the bulky plastic switches at the switch panel and replaced them with standard metal toggle and smaller push button switches (Jog, coolant, etc.) Some of these functions can still be in the front panel, certainly the Safety Stop. I assume some of the current wires run through the gear housing cover to get from the back to the front. We would have to see what you can do and what you want to do.

I do not think the 1340GT has a foot break system and so I do not see any wires that currently run toward the floor or stand. I assume there are no wires running through the drip pan?

While the features incorporated on the pcb would not need to be different between the two machines, where the wires go to connect to things probably is. Hence, the connectors that I put on the pcb most likely, but not necessarily, would need to be changed to accommodate this as power and ground were shared going to the front panel. On my machine, I put more stuff in that switch front panel than most folks need or use, hence I wanted the small displays. It worked out nicely with the smaller displays. You may not need the spindle RPM counter nor the spindle revolution counter. Most folks want a spindle RPM measure. I included them as I sometimes wind wire etc and wanted the counter. If you use a proximaty sensor/stop the counter is also nice as it can tell you how far the tool travels after power to the motor is shut down. I ran two shielded 9 conductor wires from the pcb in the back of the cabinet to the front switch panel box. If you put some of the components else where then you would use another wiring arrangement and hence a different set of pcb connectors might be convenient.

1) Where do you wish to house the electronic controls (VFD etc)? In the 1340GT cabinet or in a separate box. In the 1440GT, the depth of the housing was limited and so I mounted the VFD sideways. This is not the manufacturer's recommended orientation, but it works fine and I have not observed any problems with this. I did this in a manor that cooling was not an issue. It also oriented the VFD display upward which made it easy to see. I also replace the steel cover with plexiglass just so I could look in and read the VFD display. I mounted a small fan on this but in hindsight I do not think that was needed.

2) Which functions do you wish to keep in or add to the current front panel. E-Stop, Coolant-Auto-on-off, Jog F-R, Frequency potentiometer, motor frequency meter, spindle RPM meter, proximity stop wire connector, the power-on light can go if you have other display lights..... @ptrotter ELS discussion shows a picture of the pcb he used for his VFD conversion on his 1340GT. I worked with him on this and he decided to use a different connector layout and eliminated some features. So his pcb connector layout look different from what I did, but most of the circuit is the same.

Attached is a CAD rendering of the pcb board that I had made. I don't think I ever posted one of these images so will include it. This used discrete components. While they are not as small as smd packaging they certainly are easy to alter or repair. The size of the board is largely determined by the connectors. I think this maybe of one of the boards, or a similar to one, that I sent to @bdstark . The free version of KiCAD PCB makes it pretty easy to design and route these. Since this time I have sketched out some other circuit arrangements that may make the board a little better.

Keep in touch.

Dave L.