Build Thread ENCO RF45 Clone CNC Conversion (2024)

OK, so I don't know where to start. I guess I'll start with the design so you'll know where I'm heading.

Our 1.5 car garage shop is used for many different purposes; from metal and woodworking, to use as a greenhouse for plants in the winter, to serving as a chemistry and nuclear physics lab. So I want to keep the footprint of the mill as small as possible while not limiting its capabilities too much. I also want to make it as self contained as possible and to have all the sensitive components such a limit switches, couplings, gas struts ect. tucked away so they will not collect wood dust and grime.

I based much of my design off the excellent conversions documented here by the likes of gd.marsh and 91TSiGuy. Thank you all for the inspiration! I would especially like to thank 91TSiGuy for providing me with some of his CAD models to get me started.

Below (hopefully) is a screenshot of the overal CAD model so far. I have not modeled the head since I am not making any modifications to it, yet.
The control panel uses an elo InteliTouch screen I got on ebay and will have physical knobs for the most common controls, such as FO, RO, Joging and program Start and Feed Hold. Eventually spindle controls will be added, but are not in the plans at the moment. All the wires will pass thru the control panel swing arm and into the column, from whence they will go down into the stand were the electronics will be located.

All the motors are direct drive and tucked in close to the machine to save room.

Here is bottom view showing the mounting of the ballscrew bearing blocks and the motor couplings. It is a tight fit but results in a very clean and simple conversion. I will not be able to over travel as much as with the other designs where the bearing blocks and couplings are outside the castings, but that is not my goal and I still have more travel then stock. I have access to bigger machines if I need more travel.

I know I will need some type of counterbalance on the head to keep it from falling when power is cut to the axis motor, but i would like to avoid having gas struts or a counterweight on the outside of the machine as is the typical solution. Fortunately the column is just tall enough to allow placing two gas struts inside it, see below.

My head weighs right at 200#, well, you know what I mean .
I did some quick calculations using the gas laws and found that two of the 100# gas struts sold by McMaster produce about 180lbf while extending at free length (full extension) and require 301lbf for compression at solid length (full compression). This results in an average force of about 241lbf. I was hoping for something closer to 200lbf but without custom struts that is unlikely to happen so two 100lbf struts it is! I also figure most downward moves are at feed and most upward moves are rapids, and since the motor has more torque at feed speeds everything balances out nicely.

Here is an ISO view of how the struts act on the ballscrew mount. The studs on the end of the struts are just a slip fit in the holes, but they won't go anywhere since they will always be in compression, unless I rapid faster then the struts can keep up with, which I doubt!

I have to run, more later tonight, hopefully.
I like constructive criticism, so if you think something will not work let me know!

Thanks for looking!

Kurt

Looking forward to this thread progressing. I have been on the edge of ordering a G0704 but, i came across a lightly used Enco RF45 clone with DRO, and feed for $1300 so that Is what i bought. I will be heading to pick it up tomorrow or first of next week I hope. Plans will be for a CNC conversion but it may be a little ways down the road.

It looks like a very clean conversion you are planning, but I have a few comments.

1. I personally have had issue with gas struts needing periodic replacement on various things I have with gas struts on them . As such, I would personally not put them inside the column simply due to access considerations. It appears that access would be limited to the access panel on the back of the column whic seems like it would be tight.

2. If you proceed with the internal gas struts with the strut rod simply resting on the casting, I would provide a dimple or recess for the rod to locate on. You may have already planned this but it wasn't clear from the pictures.

3. The location of Y-axis bearing block for the ball screw being attached underneath the base casting will mean that to access it you will need to have a hole in the table you use, or you will have to lift the machine. This is not ideal from a maintenance point of view. I realize that your design shortens the distance that the motor extends out the front, but I would make a design that allows easier access. On the X axis this isn't a concern since access is easy from below.

Mike, sounds like you got a good deal. I have used a G0704 and they are nice machines but I can assure you that the RF45 type machines are much more capable. You will not be disappointed. Is the machine you purchased one of the newer ENCO models with blue paint or one of the older grey ones? The blue ones seem to have better fit and finish.

109jb, you make some good points there. You are right that the struts will likely require periodic replacement, but they are actually very easy to get in and out of the column, however I do have a hole in the table which helps.

I have been spending most of my time on the conversion and actually have the Z-axis operational, though not quite finished. To install the struts I raised the head to the absolute max and then slipped the strut in place and marked how much length needed to be removed for the rod end of the strut for it to just slip over the ledge in the casting. This ended up being around 3/8" which I parted off on the lathe. I then slipped the struts in place and positioned the lower end so they would bear as I liked on the casting. I then lowered the head about .1" to put the struts in compression and adjusted the limits so I would not accidentally move up so far that they would come loose. I was planning on putting a dimple for the ends of the struts to rest in as you mentioned, but even my small right angle drill can't get in there to make it, and with my limited testing it does not seem like the ends of the struts are going to go anywhere.

When the time comes to replace the struts all I have to do is override my limit and move the head up until the struts are free and slip the new ones in. I certainly had my doubts about having the struts in the column but so far it looks like it will work OK.

I guess I should have checked here earlier! I just finished drilling and tapping the holes for the Y-axis ballscrew bearing in the base casting. Access is a little tight but I have a good sized hole in the stand which helps a lot. Maintenance will be more difficult, but hopefully it won't require as much since it won't be exposed to coolant and chips.

Here is the large access hole in the base. Plenty of room to work here!

Thanks for the replies! It is greatly appreciated.
I'll see if I can get caught up on post tonight.

Kurt

The Enco I bought is blue kind of like yours. The only date i could see on it was on the motor which states 2011 but that could just be the build date of the motor. It may be next week before I go get it being we have some weather heading our way. I looked through your photos and I am pretty sure I will not go through the beautification mods which you did but I sure do want to do the oiling and CNC mods as soon as funds are available. BTW, My machine came on a stand but I sure like that yellow pine table you built for your. That is some fine looking woodwork from the pictures.

Could you possible get me a measurement? I was hoping to not have to trailer machine home but I think even off the base the mill is just too tall to fit under the camper shell on my truck. With the Z axis moved all the way down what is the total height from the base to the top of the Post? I only have 36 maybe 37" clearance if i want to leave the mill upright. I found that the mill is about 48" tall but that spec had the Z axis fully raised and the motor is pretty tall.

Your CAD model is looking good.
You probably only need 1 strut if your intent is to keep the head from falling when powered off. These dovetail columns have alot more friction than you think, especially due to the cantilevered mass of the head. My IH clone doesn't fall with power off (5tpi ball screw) and I do not have any gas struts. If I loosen the gibs and press down on the head I can make it fall but barely..
Also, to keep the bottom end of the strut from walking around, why not put in a thin plate with a hole to locate the strut, with the outer edges of the plate constraining it inside the column?
For the Y axis - check that the ballnut isn't going to restrict the movement of the saddle away from the column. I recall having to open up that little bit at the front of the base to get even front / rear travel with the ballscrew in place. The ballnut is larger than the original bit from there.

Mike

Mike Hall, the base to column height is right at 43", so looks like it won't fit under your camper. These machines are heavy enough to be a pain to move assembled, but are straight forward to take apart into manageable chunks and is what ENCO recommended. I have moved mine this way on my own and I'm a small guy. For your purposes I would suggest taking the head and column off. A small adjustable wrench will do for the head, you'd need a 12mm hex key for the column. There should not be any shims or anything that will be hard to get back in place.

Thanks for the complements on the stand! It is rock solid and cost all of about $7. I think I got it out of one 2"x10"x10'.

ninefinger Mike, I did consider using one strut but could not figure out a symmetric arrangement to prevent putting a moment on the slide or ballnut mount, though that probably would not mater. I like the locating plate idea for the strut ends, just might have to implement it. Thanks!
I just cheeked and looks like I will need to extend the slot in the base casting to get full travel. I guess I'll pull out the jig saw .

Kurt

Here are some more CAD screen shots.

General view of the X-axis ballnut mount. Note the four tapped holes in the front of the base casting which are for mounting the Y-axis ballscrew bearing.

Underside of table showing method of mounting X-axis end bearing and slots in saddle for allowing some transverse adjustability of the ballnut mount.

Tapped thru holes in end of table pockets for mounting end bearing. I would like to avoid these but they are neat so don't bother me to much.

Some details of the Z-axis parts.

I'll be putting all of the CAD files in this Google Drive folder in the next few days.

https://drive.google.com/drive/folde...1k?usp=sharing

Thanks for looking!
Kurt

As I mentioned in the first post I purchased the the axis motors and ballscrews at the end of the past summer.

After much deliberation I decided to use closed loop steppers. I was originally planning on using regular steppers because they are inexpensive, but I realized that on a machine this size I would need biggish steppers to avoid loosing steps and those are not all that cheap. So I toyed with using servos. The motors themselves are not all that expensive but once I added up the cost of encoders, drivers, belts and pulleys it well exceeded my meager budget. Also I was having trouble designing a servo system that was as compact and as simple as I wanted.

I ended up purchasing the following SuTai brand closed loop steppers and drives from a company I found on Alibaba.

2X NEMA 34 1200 oz-in Stepper Motor w/ 1000 line encoder Model# 86HSS1402
1X NEMA 34 1600 oz-in Stepper Motor w/ 1000 line encoder Model# 86HSS5001
3X 8.2A Closed loop stepper driver Model# HS860

The motors and drives are made by the Changzhou Sutai Electrical Co. and appear nearly identical to those made by Leadshine, they even sent me Leadshine branded software and documentation. The total cost including shipping was about the same as a basic 3 axis stepper kit from ebay, and arrived in about 3-5 days. At first I had trouble getting my computer to communicate with the drives, but costumer service was fantastic and I got the problem resolved very quickly. This was my first time purchasing direct from China, so far so good!

Here is a picture of the motors during preliminary bench test with an Arduino running GRBL. That laptop is my CAD workstation

About ballscrews next..

I decided to go with the standard Chai fare ballscrews with double ballnuts and to use RM2005 on all axes.
The screws are very decent quality, though I may need to replace one of the ballnuts since the races are starting to flake and it is not even in use yet.

Hers is a picture of the ballscrews. I had forgotten I made the Z-axis ballnut mount before receiving the screws. More on that soon.

Another view

I have attached my ballscrew drawings for your reference.

I am trying not to get boring with details but still provide enough information, let me know if I should change anything. Also, would fewer or more pictures be better? I have plenty.

Thanks for looking!

Kurt

Disclaimer: Unless your machine is identical to mine (which it is not) and you convert it exactly the same way (which you won't) screws made to these drawings will not work!

Looks awesome, I can not wait to get to this point with my Enco Mill. I guess I should be content with just getting the Mill home first.

What I would like to see is a list of all the components your using on your build. I have been looking around getting ideas of what I would want to use for my conversion and a nice complete list would be great for comparing with other builds or components I may find good deals on. A master list is kind of what I am talking about.

What are the chances I could score the 3d model of the Mill without the CNC mods added? What software are you modeling it in? I am a Autocad user for 20 years and i find it hard to migrate to anything else. I have trouble leaving all those key commands and i find myself getting irritated trying to do simple task in other programs. If you would be willing to share that model let me know. I would enjoy messing around with some ideas for my CNC conversion as well.

Mike

Are these the steppers that you purchased?

https://sutai.en.alibaba.com/product...motor_kit.html
https://sutai.en.alibaba.com/product...er_HBS860.html

Mike Hall,
Per your request I made a drive folder containing my CAD models of all the main castings except the head which I have not modeled yet. They are Solidworks 2016-17 format. I don't know if you can import that format into Autocad, but I can provide them in other formats, just let me know what you need and I can add them to the folder for you.

Below is the link, it should be a sub directory of the folder linked in post #9.
https://drive.google.com/open?id=0B0...W1xaHJwWVpsdDQ

I guess Drive is the best way to share files here. Let me know if it does not work and I'll try something else.

A master list of the components needed for the conversion is a great idea! I'll see what I can come up with in the next day or two. I assume costs should be included as well?

Regarding the motors. Those look like exactly the same ones I purchased, but they did not have them listed like that. I had to contact them to find out what was available. I'm glad to see they have torque curves and more detailed information now. Jinting must have been busy!

Kurt

Kurt, thanks for the files. I will see if i can import them. I just downloaded the free Fusion 360 and I may try to get myself familiar with it as it does have a built in cam package.

Google drive works perfect. Thanks for sharing. Its almost as fun designing parts for a project as it is making them and this will just let me get started now rather than having to measure my machine when it get here.

I got the Mill imported into Fusion 360. So far its got some pretty dang neat features which i kind of like. I may be spending a good bit more time in this software.

Originally Posted by KCJ

Mike Hall,

A master list of the components needed for the conversion is a great idea! I'll see what I can come up with in the next day or two. I assume costs should be included as well?

Kurt

Maybe even a link to where you purchased your components. If you had a good experience with a vendor why not share so we can reward them with more sales. haha

Also did you make your components by CNC or manually? I am not going to have access to any CNC machines until I built mine. I am new to machining just as much as CNC so either way I will be learning along the way. I have a little tiny Craftsman 6" lathe I need to get setup but its just sitting on the bench which it has done sense I purchased it about a year ago.

Something totally not related to CNC but, if your somewhat experienced in machining I would sure appreciate a good basic tool list that would be good to have. I will need to start getting my tooling, clamping, and measuring devices on the way.

I got the Mill imported into Fusion 360. So far its got some pretty dang neat features which i kind of like. I may be spending a good bit more time in this software.

Mike, glad to see the models imported fine! I just might have to give Fusion 360 a try. I get about 100 emails form autodesk each day inviting my to try this or that, but never have tried their CAD. I do use HSMworks for Solidworks which is very nice.

If you had a good experience with a vendor why not share so we can reward them with more sales. haha

OK, when I make up the conversion parts list I'll include links were I can.

Also did you make your components by CNC or manually? I am not going to have access to any CNC machines until I built mine. I am new to machining just as much as CNC so either way I will be learning along the way. I have a little tiny Craftsman 6" lathe I need to get setup but its just sitting on the bench which it has done sense I purchased it about a year ago.

I am making all the components manually. They are all fairly simple and while CNC would make them very easy to make it is not necessary. You should be able to make them all on the mill with only basic tooling and skills, though the lathe may come in handy for some of the parts. BTW, those little Craftsman lathes can be very nice machines!

Something totally not related to CNC but, if your somewhat experienced in machining I would sure appreciate a good basic tool list that would be good to have. I will need to start getting my tooling, clamping, and measuring devices on the way.

I am fairly new to machining, but I would be glad to put together a list of the tools that I fined absolutely necessary. Better yet, if you are ever in the Atlanta area let me know, and maybe we could meet up.

Kurt

SO your in ATL. I am down in Leesburg, GA so only about 3 hours away. Are you possibly a student at Georgia tech or something? I assume your in an engineering program or something? Maybe I should make a trip up someday soon and see your Mill project or whatever else your tinkering on. haha

Mike, I was thinking you were in south Ga!
I just graduated a few weeks ago with a degree in Mechanical Engineering Technology form Southern Poly, which long ago started as a more practical offshoot from GT. Incidentally I was the Engineering Technology Student of the year 2016 for Ga. Right now I am working on finishing up some projects I did not have time to work on while in school, working in the schools nuclear lab, and deciding if I want to pursue a masters or not.

I have some free time so if your in the area I'd be glad to show you around my little shop, it's not anything to write home about, though.

Kurt