CX601 Milling Machine

[Brian Rupnow]

This thread is going to be a continuation of my trials and tribulations with a new
square column benchtop milling machine from BusyBee Tools in Canada. I had started to cover this mill in my oscillating I.C. engine thread, but I was getting so far off the original thread title that I have opened up a new thread to deal only with the mill. I have upgraded from a smaller version of the same mill, which served me faithfully for six years, but was beginning to show it's age. This new milling machine has more than double the motor power that my previous mill had, and has a Y axis travel of 8 1/2" and an X axis of a whopping great 23 1/2"---(Even though all the brochure and manuals with it claim a 16 1/2" X travel.) The first thing I discovered when I got it home, was that although my old mill moved .002" in X or Y for every graduation on the dials, this new mill moves 0.0025" for each graduation.---Try doing that in your head!!! I have been thinking of a DRO set up for a couple of years now, but didn't want to spend the money. This new mill with it's Bastard travel per graduation has made the purchase of a DRO kit a necessity. I purchased a 2 axis DRO set-up with glass scales from DROPROS in California, and will be installing it on the mill and documenting it here. The second thing I have discovered, is that the R8 shank on the chuck which comes with the mill has a very deep, unusual slot in it, and consequently the "alignment pin" which protrudes inside the spindle was sticking out so far that standard North American R8 shanks wouldn't fit into the spindle. After much hair tearing and screaming at various BusyBee administrative staff, I took matters into my own hands and removed the offending pin with my nasty little cold chisel and Dremel tool.---This was on the advice of some senior forum members who have much, much more machining background than I do. Stay tuned, and I will take you with me on the adventure of installing DRO's, relocating the hard to reach head height adjusting handwheel, and various other modifications in an effort to "Make a silk purse from a sow's ear!!" At this point in time, It has cost me roughly $3500 (Canadian)for the mill, the stand it sets on, a new boring head, and a couple of R8 endmill holders, and a heavy duty "machinery transportation cart" to move the machine around from my garage, thru my office, and into my machine shop. The two axis DRO kit has cost $1000 so far, but I have yet to hear from the taxation and customs people who will want their pound of flesh as well.

 

[Brian Rupnow]

I got up early this morning and modeled the base and column of the milling machine, and all the glass scales, reader heads, and brackets that came with the kit. They are shown here in their approximate positions. I have not modeled in any of the brackets which I will be fabricating.

 

[Brian Rupnow]

It has been a long and much interrupted day, but I have sussed out all the mounts which I will fabricate. --I have to say that the credit for these mounts goes to a fellow over on another forum who has the same mill as me, and mounted the same scales as I am mounting, in Calgary, Canada. He was kind enough to post very clear pictures of his work, and I have used his pictures as a concept for the design of mine.--Thank you, Calgary. The mounts are going to be milled from aluminum. I am about 80 percent of the way there in terms of modeling everything. I still have to see exactly how the scale covers are going to be hung.--X axis is no problem, but the Y axis cover could get exciting.----Brian

 

[Brian Rupnow]

This mornings challenge was to design the mounting brackets for the the guards which fit over the glass scales to keep the swarf and cutting oil away. The guard supplied for the X axis scale will have to be totally reconfigured.--In fact, it may be easier to brake up a new profile than to reconfigure the one that came in the kit. This guard will mount directly to the machined back side of the table. The guard for the Y axis will fit with no modifications at all, and the rear end will be supported by a "tab" coming off the rear glass scale mounting bar bracket. The front will be supported by a small bracket bolted to the top o the new large bracket which supports the front of the glass scale mounting bar.

 

[Brian Rupnow]

The following drawings are going to be meaningless to anyone other than myself. However, I have to make them for myself to work from, and it doesn't cost me anything to post them. As you can expect, fitting metric based scales to a metric based milling machine, using British imperial units ends up giving some very strange and unusual dimensions. This matters very little to me---I have been jumping back and forth between the two measuring systems ever since Canada "went metric" in 1974. Why is everything dimensioned to three decimal places when much of it doesn't need anywhere near this degree of accuracy?---That is a setting on my CAD system, and as long as I know what is critical and what is not, it is MUCH easier to just leave the default dimension to three decimal places for everything. Most of these brackets are going to be fitted to a cast, painted surface on the mill, with an "unknown" radius right in the middle of everything.--All I can do, crude as it may sound, is make cardboard templates from the mill, transfer the template to the semi-finished bracket, and "take my best shot" at filing and fitting.---This isn't really as difficult as it sounds.

 

[petertha]

Hi Brian. Thanks for the PM effort attempt. I've concluded there is something wonky about how links are imbedded (corrupted?) in private messages here. Maybe its a HMEM policy thing. I just see asterisks & link goes nowhere. But don't sweat it, it was more for side interest.

Your DRO retrofit project looks great. One suggestion (assuming your readout box facilitates) is do the Z-axis while you're at it. The wacky graduations you noticed on primary axis is usually consistent on the vertical-Z from what I've heard of many Asian machines. And of course bye-bye to similar backlash & other similar irritations.

 

[petertha]

One more thought while you have the machine disassembled. Most of these type mills have some provisions for X-axis table stops, but generally not the Y-axis. I'm finding I really would like both, but now my ideas are somewhat working around the DRO assembly already in place. Give that some thought while you are knee deep in fixtures, drilling holes & tapping screws.

 

[Brian Rupnow]

This machine has a built in digital Z axis readout, that can be reset at any point and changed from metric to imperial at the touch of a button. I did a thread a long time ago about adding y axis stops to my old CT129 mill, and they worked really great. I just don't remember how to find the thread.----The thread I was trying to refer you to was the h.o.b.b.y.-m.a.c.h.i.n.i.s.t. forum. the post was by a fellow called bmw rider.---Brian

 

[Brian Rupnow]

First DRO bracket and shame faced admission of Dumb-Assity!!! The first bracket is finished and the power of this new mill is just awesome!!!---The Dumb-Assity------Well----I don't have DRO's yet, so the drilling and counterboring of 6 holes required a great deal of calculating, counting, measuring, and twiddling dials----and Guess What! I have been trying to convince everyone for three weeks now that the table moved 0.150" for every full turn of the dial and .0025" for every graduation on the dial. I was only half right. It's true about the graduations on the dial being worth .0025" of table movement for each graduation.--I was stone-wrong about the amount of travel for one full turn of the dial. It isn't 0.150". It is 0.125". Of course, this still doesn't let me make the calculation for table travel in my head like the old mill with .002" movement per graduation did, but I feel really dumb about reporting the travel per full dial revolution wrongly. Sorry guys. Put it down to encroaching old age and too much new stuff at once.---Brian

 

[petertha]

I have been trying to convince everyone for three weeks now that the table moved 0.150" for every full turn of the dial and .0025" for every graduation on the dial. I was only half right. It's true about the graduations on the dial being worth .0025" of table movement for each graduation.--I was stone-wrong about the amount of travel for one full turn of the dial. It isn't 0.150". It is 0.125".
http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/FIRST%20DRO%20BRKT.%20001_zpskuftqtki.jpg.html

I was trying to figure that out but let it go. I thought maybe you had a metric but that didn't add up either. Sounds like you have an 8 TPI lead screw? 1 rotation advances 1/8 = 0.125" A 100 dial graduation would yield 0.00125". 50 grads yields, 0.0025". Neither are very nice round numbers to work with.

If they were sourcing Imperial lead screws, a 10 TPI would make life easier. 1 rotation advances 0.100", 100 dial grads would yield 0.001" exactly. I've always wondered about this, maybe some mechanical/strength reason. Oh well, DRO will make this a moot point.

 

[bazmak]

If thats the case brian then its logical to make new dials,but dont think you will need them with the digital scales

 

[AlbertdeWitte]

Hi Brian

Thanks for sharing. I have a similar machine and find your article very interesting, having thought about doing a mod on mine as well. I also need to do the Z axis at the same time. May I use your methods please

Regards

Albert

 

[Brian Rupnow]

Albert--that is why I post them--so others around the world can use the information.---Brian

 

[dsage]

Hi Brian:

This may seem to be a silly comment but before you mount anything, have you checked to be sure the DRO's indicate a positive direction in the desired (conventional) direction of table movement? I only ask because my dro's, - which are not at all the same - are mounted in a similar fashion except the X unit is on the front of the machine. Which would make it read backwards to your's. And it reads properly. So I assume it may be backwards if mounted on the back. Of course it depends on a lot of things but worth a double check.


Sage

 

[Swifty]

Hi Brian:

This may seem to be a silly comment but before you mount anything, have you checked to be sure the DRO's indicate a positive direction in the desired (conventional) direction of table movement? I only ask because my dro's, - which are not at all the same - are mounted in a similar fashion except the X unit is on the front of the machine. Which would make it read backwards to your's. And it reads properly. So I assume it may be backwards if mounted on the back. Of course it depends on a lot of things but worth a double check.


Sage

You may find that there is a DIP switch somewhere to fix this if it occurs.

Paul.

 

[Brian Rupnow]

The instructions with my DRO's indicates that there is a setting in the electronic readout somewhere that lets you change the direction of "read".

 

[dsage]

That's good. No such thing on mine and it had to be taken into account when I mounted them.

Sage

 

[petertha]

When I was comparing DRO boxes, a lot of them including clones & knockoffs seemed to offer many standard features - flipping plus/minus direction regardless of encoder setup, imp/metric conversion, center finding between 2 same axis edge points, recalling stored settings, bolt circle type calcs, even compensation curves. Many boxes can be readily swapped for mill or lathe work so that DOC (depth of cut) on a mill is re-processed internally to yield more convenient 'diameter' on a lathe cross slide channel.

I've heard of people successfully marrying scales of one brand with clone boxes of another. Don't try this without research, just saying it kind of infers there are probably some standards the encoder brands communicate positioning. Maybe this is related to cloning or maybe adopting some defined protocols? Anyway, I sure like DRO's. Makes amateur machining a lot more enjoyable.

 

[Brian Rupnow]

Another one bites the dust!! I have one more bracket to build that doesn't fit against the curved surface of the milling machine. It is probably the most complex shape, but doesn't have to be fitted by trial and error to the cast mill surface.--And yes, after milling two brackets, I am finding those .0025" graduations to be just as hard as I had expected to work with. Its easy to take out the 1/8" increments, because they are one full dial turn. Then you have to divide whatever is left by .0025 and count graduations---and many of the graduations you want to hit fall somewhere between the graduation marks.--I did have a stroke of good luck, in that while rooting though my box of aluminum cut-offs I found sufficient stock to make all of the brackets.

 

[Brian Rupnow]

Third bracket finished.--Why that little area that looks like some material is missing between the two bolted together brackets?---That my friends is an "oops"!! It is only about 3/32" deep on the one corner. I just don't understand why, when I make an "oops" it's always on the part that will show the most on an assembled machine.--Probably repayment of some horrible thing I did earlier on in life.--Will leave it there to remind me to be humble. I have to hang up my machinsts hat now and put on my carpenters hat---Have to fix a piece of furniture that got dropped on one corner during a move. I had my painters hat on early this morning. Wife has threatened dreadful consequences if I keep getting up at 5:00 a.M. and running machines that wake her up. Paint brushes are very quiet----