I built an X2 hybrid mill here (http://www.cnczone.com/forums/showthread.php?t=29650&highlight=rodm1954)
a couple of years ago and sold it twelve months later. I CNC'd an X3 in between but I have regretted selling the X2 ever since. It was far more rigid than the X3 so I got to thinking why not build another.

I have been collecting parts for quite a while now and got the last bits from Hoss this week. I have to give a plug here as Hoss has been fantastic helping me out with parts and his machining is something I aspire to. His rates are very good and it is a no fuss service so anybody thinking of using him I can highly recommend.

The final details of this machine are far from set in concrete and it will evolve rather than be meticulously planned. I don't have the patience for drawing everything out and prefer to have challenges along the way - good excuse hey. :)

The column will be a chunk of 200mm square RHS and Z axis will be 25mm four way linear rails mounted on 50 by 25 solid that I will mill flat after fixing to the column.

The compound table is a KT179 and it was the best quality table I could find. The cheaper models do not have a drain around the perimeter and I will be using flood on this machine so that was important to me.

The spindle will be an X2 with R8 taper and I have already fitted the belt drive kit to it – nice and quiet. I also have a 2HP 3phase 24,000 RPM water cooled spindle and VFD. I am thinking of being able to swap between the two but would like some feedback on this.

I have some 5056 drivers, 497oz dual shaft motors, 48 volt power supply, smoothstepper and C10 breakout board for the electronics. To house all this I have an electrical enclosure that I will play around with.

I will use Roton ballscrews and double nuts on X and Y and Hoss’s Z axis assembly.

I will build this from the ground up and incorporate a steel stand and enclosure in the design.

The build will be slow as I am still completing a gantry router but I thought I would chuck this up here so that the collective knowledge might offer some suggestions.

Forgot I have included a jpg of the laser cuts parts I have on order. Two column braces, base plate and plug for the column cut from 10mm steel plate.

Hi Rod,

Where did you get the table from? A local supplier or did you import it yourself?

I especially like the swap spindle capability with the 3 phase high speed spindle - I am considering that for my X3 actually - I've had my eye on the spindle/VFD HomeShopCNC carries. I recall following your thread - it was very interesting - I think you've got a solid background and concept so I think you'll make easy work of it and it'll come out a charm. Good luck and have fun!

Greg

Hi Tumutbound,
I got it from McJing. These seem to be sold more in the European market.

Here (http://www.optimum-maschinen.de/fileadmin/blaetterkataloge/optimum_GB_2008/blaetterkatalog/index.html)

Page 58

Hi Greg,
Trails of the spindle are impressive. Very quiet as well so that is always a bonus.
I think you have hit the nail on the head - having fun is what is it about and sure beats watching TV.

Should be a good one to watch!

BW

I agree with Bob:cheers:

Hi Rod,

Will this complement your X3 or be a replacement?

I've been considering doing something similar to my mill since your last mill build as the column is VERY poor to say the least. You've probably already considered this but what do think about turning the table around and having the Y axis stepper inside the column out of the way? Do you think cutting a hole in the steel box for the stepper would compromise the rigidity of the column? Another possible issue might be dissipating the heat from the stepper motor. I'm probably just unnecessarily over complicating things but it would be so nice to have that stepper motor out of the way.

John

Hi John,
I will keep the X3 as it is running well and as everybody knows we all need two CNC mills. :eek: I have a mate that says two are good but three is better.

You certainly are a lateral thinker. For me I will keep the motor out in front where it can be serviced easily. Room is not an issue as I can make the enclosure any size at this stage and the covers I put over the X3 motors have provided good protection with flood coolant.

Keep the ideas coming.

I also have a 2HP 3phase 24,000 RPM water cooled spindle and VFD. I am thinking of being able to swap between the two but would like some feedback on this.

Hi Rod hows tricks, making progress I hope.

Any way I have been thinking about your spindle and wondering how much stick these can take milling aluminium? As you have one in hand what's your opinion or have you not had the time to investigate? If your too busy with other things I will try to get more info else where and let you know what I find out if your interested.

Regards,
John

Hi John,

I have only bench tested the spindles but I loaned one to a mate and he has had very impressive results. So much so he kept it and brought me a replacement. :)
Here is his comment on the spindle and the material was aluminum.

The first test was a 20mm circular pocket, 2mm deep, 0.25 depth of cut, 40% stepover, 3 flute, 1/8” carbide cutter. I started at 600mm a min and ended up limited by the acceleration on the router, I saw the feed rate get up to 3.1m/min. It cut really well. Finish was spot on. On the cuts faster than 2m/min, I noticed that the circular pockets became a little oval shaped. Not sure if this was cutter flex (I was using stupid long cutters) or Mach’s constant velocity code.

I would never have run a 1/8th cutter at 3m/min for fear of snapping it off so the results are very impressive by my standards. The speed he ran the spindle was 24k. It was a water cooled 800 watt spindle. If the X2 head with a belt kit was not so quiet to run i would skip it and just run a spindle on this mill. I cut jobs late at night so stealth mode is necessary for me. :)

I haven't started this project yet as I am finishing off a gantry router - wrong gantry spindle. :confused:
Maybe in a coupla three weeks I might get going on the mill. Build for router is here
http://www.cnczone.com/forums/showthread.php?t=71219

Thanks Rod,

I'm thinking I may go for a 3Kw (4hp) :eek:as I'd like to make some money with it. Do you think this mill build could handle that much power (rigid enough) as I may go a similar rout with my mill. I know I would need bigger steppers or servos? I am also considering a much bigger mill but could do this convention for less money.

I hope you don't mind all my questions,:)
John

Hi John,
I encourage questions and comments as this is how we learn.

I am not an engineer and polish a seat with my bum for a job so take what I say in this context.

I think that the reason we play with machines this size is because we can afford to do it for a hobby. Steppers and off the shelf steel sections are relatively cheap but they are limiting.

Rigidity can be achieved with structural integrity but you also need mass to absorb the resonances. I haven't tried any of the polimer cement products but this might be an option for a fabricated steel structure. Without something to absorb those resonances I think you are pushing it uphill. Commercial machines are made from cast iron for a reason.

If you want a production machine then servos are the real option particularly if you have built mass into your machine. This adds considerably to the cost and the complexity for a home builder.

These are the thoughts of a shed tinkerer so be gentle but by all means disagree with anything I have said. :)

Further to the last post the spindles are quiet but do introduce a very high pitched resonance of the type that magnifies easily.

This was in the back of my mind when writing the first post.

I agree with all your comments :)

I believe cast iron is the way to go and am considering alternatives. What I've been looking into (just started) is buying something similar to this http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=150329263186&ssPageName=STRK:MEWA:IT&ih=005 , heavier column machines can be had and will look into scrapped ones, they are cheap and numerous. I'll strip the unnecessary parts and build my mill into it. Another possible alternative is a scrapped milling machine.

John

Now you are talking. :)
I live in Perth which is a very remote capital city in the world so I envy you for having access to machinery like that. I love old iron and nearly had a divorce for paying a premium for an old hand operated shaper. Not really but it makes for a good story. :)
I do agree with you than getting old iron and converting it to CNC is probably the most cost effective way you can go. The older stuff is made from good quality castings that are properly cured, over engineered, probably have outlasted a couple of operaters and will still take a hammering. If only those machines could talk.
I don't think you can go wrong with this concept.

There I go again taking your thread on tangents but I appreciate your comments :)

I look forward to more updates on your build and will let you get on with some work.

Any old iron? :wee:

John

RodM & “OLD”,

You are “right on” with your comments on Gray iron.
Love the stuff, But; hate to machine it!

If you are in an area where the absence of a foundry is a handicap,
I suggest you try using Polymer Cement, since you mentioned it..
The material is used for concrete counter tops.

It is easily cast and makes for a very fine, heavy machine base.
You can also reinforce it using painted rebar .
Used this technique on some rain gutter basins, they turned out OK,
considering I made a quickie pattern and had some surface blemishes
due to air bubbles. I used pre-mixed cement & an acrylic polymer product called JASCO "Cure-Seal".

There are several, more scientific comments on the subject here on the Zone.

Keep up the good work!!

Hi CNCfun&games,
I am not getting notifications by email anymore from this site so sorry I missed your post. Thanks for the heads up on the polymer cement and I will definately try that in the column.

I have my gantry router running now and need to do a little finishing off and then I will start this project.

Picked up the laser cut 10mm thick plates today. Laser technology is fantastic - the dimensions are perfect, cut is clean and straight, tight corners and no slag.

Photo shows the two column braces, base table and a plug for the column.
I am itching to get started on this but as I said I need to finish off the other machine first. Maybe in a week......

There is a lot of traffic on this site. This thread was burried eight pages back.

Finally the mill has started.

I was reading Hoss's thread on the X2 freak looking for some inspiration and I got to his articulated head (the mill not Hoss :) ) and the lights turned on. I was going to make the two spindles interchangeable by removing one then bolting the other on.
If I make a couple of disks that can rotate through 180 degrees very similar to a tilting head on a mill then I can mount both spindles parallel to each other but in opposite directions. Spin the head through 180 degrees and the second spindle is ready to go. It will mean that each spindle will be off centre but if I mount the compound table over by the offset of the spindle then that is covered.

The photo shows one of the disks I wil turn up this weekend. I am not sure if it needs the outer registration as it might be adequate to just spin it on the centre pivot. There will be slotted holes and bolts to secure the two disks. Advice or comments???

Love the 2 headed monster idea!

Sounds like a good idea Rod...at least until the toolchanger is sorted :D

Russell.

Nah, toolchanger gotta do one change in advance on the head that's flipped up while the other one is machining. That way you never stop machining, you just rotate the head and keep going!

LOL,

BW

Heh yeah even better :)

Or we could build Rod a toolchanger something like this :

YouTube - CNC Brother TC32 B QT-Fast tool Change

This may add a month or two to the overall build though...:D

Russell.

That is really quick - I couldn't see the tool changing at all.

Hi Rod,

Interesting idea for a twin head and would save all the hassle of removing and replacing those spindles. Don't see any negatives other than the extra weight to rapid and cable management.

I think adding the EG to the column is an excellent idea and well worth the time from what I have been reading. I'll take it you will be adding another tube inside the column and not completely filling?

Got my "old iron" btw :wee::D

John

Hi John,
Like all my machines I have a concept in my head and it will evolve rather than be meticulously planned. I am tossing around a couple of ideas about the column and not settled on anything yet.

I like Bob's 2 headed monster quote and have been racking my brains on a name for the machine based on that.

Have to see a photo of your machine - anything on the zone yet?

Evening Rod,

As they say “two heads are better than one” and I'm sure you will get some interesting names for your machine from other members. :D

I have nothing on the zone as yet but have just bought an old mill to butcher http://www.lathes.co.uk/harrisonmiller/index.html .

Looking forward to more updates on this build :)

John

Hi John,
It is 8:00 am Sunday Morning here. You are tempting me with more names there. :)

I will probably go with a Nema34 for the head to help with the extra weight.

A fine looking machine - I assume you are just going to use the knee and table and add a vertical head or did yours come with a vertical head? Intersting that the table can swivel too.

I was just being polite and forgetting it's an international internet world, it's actually 1am here :tired: (insomniac)

I am thinking about jacking up the machine,loosing the knee altogether and fixing some linear rails to the column to slide the head on. I did get a vertical head with it and its a 30int with some nice Timken bearings so I may modify it for my spindle.

Having said all that I may keep the knee. Obviously I need to give it some though before committing myself. :rolleyes:

John

I am a night owl too. :)

Sounds interesting with a few options on the design. At least you have a heavy base to work with so chances are in should work well for you.
Hope to see some progress down the track.

Hi Rod,

Made any progress?

Hi John,
No progress yet. :o

I have run out of shed space for another machine so it has been put on hold for a while.

Reality check has also made me rethink the dual spindle. I have a gantry router (see photo) with one of the spindles and have been cutting aluminum plate with that. My goal is to make a quiet machine that I can operate at night so I am going to make it easier on myself and just run the X2 head and if I find it necessary do the dual head at a later date.

I think there is some logic in there somewhere.

Thanks for the update,

You have too many toys anyway, or that’s what I’d be told lol.

How would you compare aluminium plate milling on your router compared to your mill? I’m considering building something similar to the attached picture for ali work and keeping the Harrison for the steel jobs. Hot rolled tubes filled with EG or Portland in a rubber casing.

Do I hear shed extension and do you get the “I never see you” comment with the late evening tinkering?

Very nice router btw and it’s a shame your on the other side of the globe as you could have stored it in my workshop to make more room.:D

Any way will catch you later on this one,
John

Hi John,
I'll even admit to having too many toys but at least I use them and no I won't consult with SWMBO for her opinion as I have a fair idea of the response. :)

I can't expand the shed as there is no land left. I already occupy half the garage as well and have a couple of machines parked under the patio with covers on them. I keep looking upwards hoping for a couple of sky hooks for temporary storage. :)

The gantry routers cut plate well but the finish is not a good as flood coolant on the mill. Biggest problem with the gantry routers is cleaning up the swarf as it gets spread far and wide with the higher speed spindle. I can cut higher feed rates on the gantry router and I always limit myself to 1/2 mm depth of cut on any of my machines. I fugure it is better to go faster and shallow cuts than the other way around as it puts less strain on the machine.