Enco RF-45 clone CNC convertion.
I am going to start my build thread, although things are moving pretty slow for me. This is a RF-45 clone mill (Enco) that I will be doing a lot of modifications to as the build goes. The machine will be very close to Bob Warfields IH build. Infact I have been following his build and using it as a guide for my own build. Epoxy work,Z axis mods to the head, X & Y mods for more travel, and a bit different Y axis mounting will be used. I will document and supply pics when I get a little deeper into the build.
For now here is what I have to start with.
Mach3 plus add-on wizards
Gecko 320 drives (four)
HomeShopCNC 850 servos with 500 count encoders (X,Y & Z)
SmoothStepper USB CNC controler
Antek 1440w 72v 20amp power supply
Bob Campbell Combo board (BOB with spindle control and more)
Cables for encoders & motors
A/C power filter/smoother with circuit breaker & relay
Optical limit/homing switches I am building myself
The start of a cooling system I will be making out of a parts washer.
17" LCD panel that will be built in
Industrial E-stop and enable buttons
Pent duel core2duo comp that will be built into the enclosure
The motor mounts I will build myself, and the Y axis will be a little different than I have seen anywhere.
I am building a bench/enclosure that is based off the Tormach DIY bench. There will be some mods to it and it will house the electronics in a slide out tray that will be water tight, but be easy to get to with the opening of a door and the use of sliding tracks. The cooling system will be enclosed in the bottom. And there will be room built in for the Y axis mounting that I will be doing. Basically the Y axis mount will come down from the front of the mill, but the motor will come from the back and be back under the mill base. I have some drawings of this bench and its mods but I will have to scan them before I can post them. The reason for designing the Y axis this way is to help me reach the table from a chair (a little more explained on that at the end).
The Ball screws is really the only thing I have still not figured out what to use yet. The Rockford screws have gotten very expeincive. There doesnt seem to be much feedback on the HomeShopCNC screws and I am not sure where else I can get a good screw at a fair price. I plan to try and use 1" screws but this might only work on the Z axis because of room. If I can I will use 1" on all of them but the X & Y might end up being 3/4". What ever I get will be double nuts with mounting on both ends.
The bearing blocks I am also making myself.
The epoxy work will be done after everything else is fitted so I can put as much as possible in each location.
One shot oiling will be added, but I am working on a system that uses a power steering pump off a small import car for a pump so it can be automated (and cheaper).
Any suggestions or advice will be very welcome, this is my first build. I will start getting pics and docs as quick as I can, but I am dissabled so I do move a bit slower than most will expect. This has been a plan that I have been working on for atleast 6 months (more like a year) that I have been buying parts and gathering equipment. Everything is ready to start going together, encluding the bench. I hope to be doing some bench testing of the servos and electronics this weekend so things should start happening soon. But a lot does depend on when help comes around from my son, I just cant do most of it myself when it comes to the heavy stuff. We plan to build a over head crane to assist me when the machine is running and everything will be built in a way that I can operate it from a chair. The whole deal has been very hard for me to get this far but my family has pitched in many ways to help make it happen. Hopefully in a couple months we will see chips.
Thanks Jess
First Jogging with bench test on one servo
Well its taken me much longer than I expected to get a good bench test going. Although I went ahead and started mounting and wiring before I even tried to add power ( mounting in the enclosure, not on the machine) . Sorry for no pics or vids, they will be coming. Right now I have the complete system wired and mounted as far as power supply,E-Stops, Limits, BOB, SmoothStepper,charge pump and all the little things needed to have a system that works under Mach3 control with safety features. I only have one Gecko & 850 servo running and tuned at the moment though. Tomorrow I will add the next two motors one at a time and tune them . By the middle of next week I should be able to post some pics at least, but I will try to barrow a vid recorder and post the system running G-code on the bench with all three axis and spindle control.
I will have to admit it has taken me a very long time to get this system this far. I really took my time and went over every circuit so that I knew I had it right before I even put power on the system. On the one servo I have running and tuned I am getting 286 ipm rapids with excellent start & stop response. The servo sets there died quite with extreme holding torque. It took me quit some time to get it setting there tuned this good but after I figured out all the settings and how they effected the servo and driver it went pretty smooth.
I am quit impressed with these 850 servos from HomeShopCNC, I can really make it jump when I want to (almost off the table). When I am jogging the servo its very smooth and even at the 286ipm its very quit and smooth. I think these motors are going to work out great with super response and excellent speed .
The Bob Campbell Combo board has been very easy to get setup and working right. Its been flawless and it having its own built in power supplies have made this much easier. It has three built in supplies, one 12v, two 5v with isolation on the one 5v rail for the computer side of the opto's. The limit switch's and charge pump where a breeze to get setup. I hope the coolant & spindle circuits work out as easy as the others did. Bob has been very helpful with E-mails and replied to them faster than I could go back and look for replies most times (and I sent a lot of Emails) . His support has been extremely good and his product has worked exactly as stated and it is very stable. The only problem I have had is a lack of pins which I will explain more about with feedback on the Smoothstepper down farther in the post. For the most part this is one sweet board and it doesn't take very much room to use it either, not to mention the three power supplies, Charge Pump, Spindle circuit with relays, And coolant circuit with relays that it eliminates the need for.
I will get the spindle control ( D/C motor with a encoder for threading and tapping) worked out before I post pics and vids. Even though I don't have the system mounted on a machine yet I wanting to see it go through some G-code with spindle control working.
I feel like I have been very lucky up to this point. When I put power to the system I didn't have to do any thing but tune. Even all the Mach3 and SmoothStepper setting where right from the get go. I spent a lot of time going over what it took for my config and I am pleased it worked out this easy (easy after I spent a lot of time figuring, and I mean a whole lot of time going over everything). If the rest of the build goes this good I will feel great about this build (somethings got to go wrong somewhere though, well see).
The SmoothStepper is sweet, I have the ability to push signals much faster than my system even needs (instead of being limited by Mach3 signal levels). Not much to say here because this thing is just right. I cant believe how smooth everything is running, even very slow or very fast jogs is silky smoooth. The three printer ports it has gives me plenty of pins to work with. In fact it kinda saved me because the Bob Campbell combo board is a bit limited on pins with only one port. If I was going to use a controlled spindle ( encoder for feed back on the spindle motor) the board would only support two axis in that config. Its a very nice board but I would have to say it is more setup for a lathe than a mill if you want spindle control with a encoder for threading or tapping. Loosing two axis because of being short on pins to have feedback on a spindle kinda hurts this board. Its not a deal killer though and I will try to figure a work around even though I have it covered already with the SS. With the SmoothStepper I can work around this problem. It may be possible to work around this anyway if only one set of limit pins was used so it could free up some pins ( all limit switches in a series config on one set of pins). This is not bad though because the Combo board really worded great and when you see my system it will show how much this board help make a very clean and compact setup. Compared to many other setups I have see it almost looks like I am missing something when you look at it. I have only had to use one power supply (the main feed for the servos) and the integrated Charge Pump, Spindle Control with relays and the coolant control with relay is already there with power so I want have to add anything else to get these working (Charge pump is already working).
The Campbell Combo board has two PP ports, but I don't think you can use but one or the other (I may be wrong though). When I bought it I thought I would have two ports but if you read the docs close on the BC Combo board it tells about these limitations when using a encoder on the spindle. Plus there may be a way to work around it anyway, or if using s SmoothStepper its no biggie anyway.
We have already took some pics, before, during and after the electronics setup build and I will wait till I get it completed to get the last pics before posting them (middle of next week, maybe Tuesday).
I will post back the results of the spindle control and coolant system tomarrow night ( I hope).
Jess