Looking to pull the CNC conversion trigger
Greetings!
I guess this is part introductory post and part first build thread (I hope) post. So I've been a member since 2010, purchases a PM-45 mill to learn and hopefully convert to CNC in 2012, and am finally getting around to prioritizing that as my main side project. I've done a little manual machining with it here and there, but find it a little frustrating without any sort of DRO on it like I have with the mills at my current job. There, I've used two different knee mills, one with just a DRO, and the other with an XY cnc conversion running prototrak software that I did get a chance to program once or twice.
As for a little background about myself, I've been in the automotive industry for over 10 years, starting out in parts sales, then fabricating/welding, then technician/fabricator, and finally left that industry to work in aerospace. Fabricating and welding are great, however I've grown to love the precision and repeat-ability that can be had with machining. Which brings me to today--trying to take a fancy tool in my collection and upgrade it.
My plans right now are as follows:
-Buy and build the electronics portion of the machine
-Bench test the above
-Buy ball screws, nuts, and machine any brackets/spacers/etc needed to install on the machine
-Machine grooves in the ways for oiling purposes while everything is apart, and add a 1 shot oiler at a later date. Plumb what I can in the meantime.
-Use the mills at my job to do the above machining where possible and gain more seat time machining and with solidworks
-Assemble, Test. Debug, Make cool stuff
-Convert to belt drive, stronger motor, and VFD
-Add power drawbar
-Maybe convert to a different spindle and/or a Tormach Tooling setup
Hopefully I'm on the right track here, which is the reason for my post. While I may have joined all the way back in 2010, I lurked once in a blue moon and then more so just recently. I looked at the CNCcookbook site and took in what I could and understood at the time. I also just read through gd.marsh's thread and had also read at one time jid2's build but now want to re-read them thinking I can take in more now that I have a better understanding. Unfortunately I don't know everything right now, and having a 3 month baby around doesn't let me get online anymore like I used to so this is where my questions come into play. At this point, I have the bug bad, and really want to start accumulating parts for the build but the direction of where to go and what to buy first I just don't know what's best yet. I've narrowed it down to the following two sources I believe are the way to go, so correct me if I'm wrong.
-DMM Tech AC servo kit. I'd basically buy everything they have listed on their multi-axes kit page here, sans the power supply since I'd go with a 72v one instead
DMM | CNC Systems | AC SERVO DRIVE | AC SERVO MOTOR | ROTARY ENCODER
The other option is to piece together a kit through Keling/Automation Technologies since they seem to have everything whether I'd want to do stepper or servo.
So while it's getting late, I'll try to sum it up and ask am I on the right track? Which would be the better choice? What is the difference between DC and AC servos other than one not needing to be converted from the power supply? Is it worth trying to go steppers to save a couple bucks? (More money for other mods) And if there's anything I'm forgetting please mention it.
Thanks.
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Re: Looking to pull the CNC conversion trigger
Just another post to hopefully encourage some replies.
Here's my machine hiding in the mess of some of my other tools tucked in the garage. My cardboard box chip shield can only help so much haha.
Attachment 277338
And then while doing some window shopping on Keling's site, here's what I've selected as a start. I'm not sure which USB board to go with, but I do know I'd like to not use the C10 or C11 boards offered in their kit. Any advice on either board?
Attachment 277340
Re: Looking to pull the CNC conversion trigger
i think that usb card is redundant as the smoothstepper you have shown there comes with a breakout board.
For what it's worth, I have a USB smoothstepper connected to a C10 breakout board in both my mill and lathe conversions, and I have no complaints to date.
Re: Looking to pull the CNC conversion trigger
Right, I was just listing both usb boards but would only chose one. I'm also thinking of an Ethernet connection board now too. Too many options....
Initially I see myself running the machine with my current laptop and then setting up a stand alone system that stays with the machine so I'm fine with either type of board above--just not one that uses a parallel port.
In preparation for making ball screw bearing mounts, I just picked up a Shars boring head kit off ebay last night that should be coming this week. Time to start adding more to the collection than the standard clamp and vice kit that came with the machine.
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Re: Looking to pull the CNC conversion trigger
A couple goodies showed up today. I settled on the Nema34 1128 oz-in closed loop hybrid stepper motor kit and also went with the ethernet smooth stepper, which will also use the c10 board in the kit. The boring head also showed up, but no pics of it yet.Attachment 277986
I also began drawing up the motor based off of the metric dimensions on Automations linked file but may start over now that the motor is in hand.
Attachment 277988
Re: Looking to pull the CNC conversion trigger
same steppers i have. I think you'll like them. :)
Re: Looking to pull the CNC conversion trigger
Are you running them as direct drive, or with a geared down belt and pulley setup? Right now I'm planning to do direct drive for the X and Y, but pulley for the Z along with gas strut assistance like I saw gd.marsh did.
Re: Looking to pull the CNC conversion trigger
I'm running all axis on a belt. 2:1 for x and y and 3:1 for z
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Re: Looking to pull the CNC conversion trigger
I decided to make my own enclosure so I can put that money towards other important parts. Luckily I had a sheet of 1/8" aluminum around from past protects as well as 1/16" steel that I'll be using as the insert panel. The layout will go something like this, leaving room for a 4th driver and then fuse and terminal bars.Attachment 278278
Re: Looking to pull the CNC conversion trigger
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Re: Looking to pull the CNC conversion trigger
Robbing Peter to pay Paul, or something like that....I pulled apart my spindle and coolant switch housing last night hoping to find a 220 to 110 transformer. Right now my machine is ran on a 3 wire 220 outlet, so I thought it was stepped down for the light and the pump. Wrong. The light is 24v and the pump appears to be 220--i should have looked in my manual first. Either way, I was going to need that transformer in the box. Luckily, I do have a 4 wire 220 outlet in the garage that my machine can get it's neutral wire from and give me my 110 for the internal outlet.
Attachment 278388
Re: Looking to pull the CNC conversion trigger
Who ever did the conversion on my mill had it setup with a 220 plug, and a handful of 110 plugs. I finally redid all of the electrical and wired it for a single 220 plug with a neutral. For the outlet, I just pulled new wire and added the neutral to my outlet. You could probably even just pull a neutral wire, and leave the rest.