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H.O
04-14-2009, 04:52 PM
Hello,
I thought I'd start a thread about the Mach3 conversion of my 1986 Abene VHF-3 vertical knee-mill. I've mentioned this project in various threads here on CNCZone and I thought that it's about time I'd start a thread on the subject. The project has been ongoing since December '07 and is still ongoing so I'll jump a little between the past and current, I hope that's OK.

Anyway, I'll start from the beginning. I found the machine on an online advertising site, here's what the photo in the ad looked like:

http://i158.photobucket.com/albums/t110/henrols/1.jpg

What I "fell for" was the fact that it already had been converted to CNC by one of its former owners so ballscrews and servos already existed but it lacked the control - a perfect scenario for a retrofit in other words. After some discussions with the seller I made him an offer and he accepted. This was a bit of a gamble since I hadn't actually seen the machine in person but he felt honest so I went all in....

After quite a struggle with the freight company it finally arrived at it's current destination where it sat during the x-mas holidays '08:

http://i158.photobucket.com/albums/t110/henrols/2.jpg

http://i158.photobucket.com/albums/t110/henrols/3.jpg

Here's a random shot of the "back" of the Y-axis ways and ballscrew after some inital cleanup.
http://i158.photobucket.com/albums/t110/henrols/4.jpg

The machine has a 40 taper DIN2080 spindle, 4.5kW (6HP) with a 12-speed gearbox, dovetail slides on X and Z and boxways on Y. The ballscrews are 32mm*5mm rotating in dual tapered roller bearings. The servo-motors that came with the machine are some REALLY solid Indramat PMDC-servos, you can see one of them here, next to a little Maxon DC servo with a 3600line Scancon encoder that I initially planned to use:

http://i158.photobucket.com/albums/t110/henrols/5.jpg

The X- and Y axis motors are both of the same type, (MDC10.30D) rated at 19A continous, 150A peak, 0.47Nm/A while the Z-axis motor (MDC10.40C) is a little bit bigger, 24A continous, 200A peak and has an integrated break. I did get the original Indramat 3TRM2 3-axis servo amplifier with the machine and the original plan was to get some Pixie P100 boards from Skyko but I found out that they where no longer availble. Besides, the transformer for the original SCR servo amps was single phase 400V (well, two phase really) and I want to be able to run this machine from a 400V/16A outlet.

While looking at, thinking about and searching for suitable a drive I started the design of the powersupply. My motors are rated 2000rpm and to get that speed under full continous load I need ~110V at the motor terminals. Some (quite little actually) of the voltage is dropped across the drives internal resistance and a bit more due to the less than 100% modulation of the drive so I settled for 130VDC. Since not yet knowing which drive I would end up using I designed an energydump circuit that dumps regenerative power in order to prevent overvoltage:

http://i158.photobucket.com/albums/t110/henrols/17.jpg

http://i158.photobucket.com/albums/t110/henrols/18.jpg

This is a double sided PCB with 105um thick copper on each side, it mounts right on top of the two capacitors. In the background of the second photo above you can see the variac and three transformers I used for testing purposes. You can also see the Y-axis motormount. You might also notice that I replaces the original pulleys with new AT5 profile pulleys. The previous pulleys were mounted with keys and setscrews but I went for those "collet-type-thingies" that clamps to the shaft. (I can't find the correct english word for them at the moment)

Quite early I found that there was something wrong with the Z-axis on the machine. The knee is driven by a ballscrew and a 2:1 bevel-gear. However turning the shaft sometimes did and sometimes didn't move the knee - something was slipping. In order to remove the screw-jack for the knee I had to remove the table and then hoist the knee up as high as possible with an engine hoist:

http://i158.photobucket.com/albums/t110/henrols/12.jpg

I removed the screwjack and found the problem. The bevelgear was mounted to the ballscrew with a setscrew that was partially recessed into the screw shaft. The problem was that it was recessed too deep making it more like a small tube or pipe than a solid piece of steel.

http://i158.photobucket.com/albums/t110/henrols/13.jpg

http://i158.photobucket.com/albums/t110/henrols/14-1.jpg

I ended up drilling, reaming and mounting a solid conical pin right thru the gear shaft and screw instead, I hope that will hold up better that the setscrew aproach.


OK, back to the issue with servo-drives.... I'll simply make a very long story fairly short here and say that disregarded Gecko from the get-go due to low voltage, I thought about Rutex but didn't want to go there due to various reasons. I looked and the Viper200, I tried the Mammut from CNCDrive and the VSD-A from Granite Devices. Although I LOVED the VSD-A it simply couldn't supply enough current. When I'm writing this I'm using the HP-UHU and although the motors are still on the bench I beleive that this might actually work.

The motors, as stated earlier, didn't have encoders on them so I had to figure out a way to fit those. The back of the motor had the Indramat logo embossed in it so I took them off, chucked them up in the lathe and turned them "clean":

http://i158.photobucket.com/albums/t110/henrols/6.jpg

I then fabricated three shafts that fits in the internal thread at the back of the motors as well as three mounting adapters that would let me mount various encoders. The little bushing is an mounting aid to help align the adapter coaxially with the shaft when mounting it to the back of the motor:

http://i158.photobucket.com/albums/t110/henrols/7.jpg

The shaft where mounted and secured with LOCTITE and checked for run-out:

http://i158.photobucket.com/albums/t110/henrols/8.jpg

Due to the limited bandwidth of the UHU-chip the nice 3600lines Scancon encoders I had couldn't be used. I ordered up a set of USDigital E7P's and ended up spending another 4+ weeks chasing a noice problem before finally scrapping that piece of s**t and ordered a set of Renco R35i's. With those mounted everything just worked. Here's an overview and closeup of the back of the motor with the R35i mounted:

http://i158.photobucket.com/albums/t110/henrols/9.jpg

http://i158.photobucket.com/albums/t110/henrols/10.jpg

The last photo in this post shows one of the aluminum housings for the encoders that I machined. I made these while the plan was still to use the Scancon encoders so they are a lot longer than needed for the R35i's but it doesn't really matter as there's plenty of room. The groove was originally meant for an o-ring but it turned out that particular dimension, although listed in the catalog i looked in, was a "special" so I made some seals from rubber sheet instead.

http://i158.photobucket.com/albums/t110/henrols/11.jpg

OK, that's it for this first post, more later.

/Henrik.

Jason3
04-15-2009, 07:40 AM
Very nice work so far - the machine looks nice and solid and appears to be in great condition. Those servos are enormous :)

I didn't see the knee lift crank or servo - were those mounted on the opposite side of the knee to the Y axis motor and screw?

This will surely be a very capable machine soon, 40 taper and a 6Kw spindle suggests you'll make short work of some pretty big jobs. I'm looking forward to seeing it come together!

Best regards,

Jason

chich2
04-15-2009, 08:37 AM
Very Nice Henrik. Great machine you started with. Looks like it will turn out to be a good machine. Keep up the post's with all your pictures.

Chich

H.O
04-15-2009, 11:31 AM
Thanks guys! The spindle motor is 4.5kW (6HP) not 6kW as I wrote in the first post - sorry about that. I've also been working in it since '07 and not '08 - sorry about that too....

Before being converted to CNC the crank for the Z-axis was coming out of the now empty hole on the front of the knee. The top of the Z-axis ballscrew is under the round cover that can be seen in the 4th photo and now the driveshaft goes perpendicular to that and comes out on the right hand side of the knee. I'll post a photo of it later.

/Henrik.

samco
04-15-2009, 12:21 PM
Very nice work!!

I am an emc guy - so I might not be welcomed here... ;) I do have a power stage that seems to be working so far. 160v 20a so far. It takes pwm in (up/down)
http://www.cnczone.com/forums/showpost.php?p=592654&postcount=280
(use at your own risk... )
If you could talk this guy into making a modded version of this
http://www.cnczone.com/forums/showthread.php?t=74532
to output pwmup/down.... You could do step/dir.

Or switch to emc2 ;) Come on - you know you want to... ;)
rigid tapping anyone?

anyways.. again - nice work.

edit Or - look at the HP uhu drive (duh)

sam

H.O
04-15-2009, 01:30 PM
Hi Sam,
You're more than welcome here! Believe me, I've been following your work with the PWM amplifier, you've done some really nice work with it! Right now, as you might know, I'm going for the HP-UHU drives. After struggling quite a bit in the beginning we (Kreutz, Paul, Irfan, Joszi, me and a few others) seem to have worked thru the small issues that was discovered initially and my drives have been working very nice since then. Again, still on the bench though....

Here's a photo where you can see where the drive shaft for the Z-axis screw will come out:

http://i158.photobucket.com/albums/t110/henrols/19.jpg

Because the shaft is so close to the Y-axis ways the large 60 tooth pulley won't fit without the saddle hitting it on its way towards the back of the machine. This had been solved by using a two stage belt transmision, first 2:1 to get the reduction and then a 1:1 up to the drive shaft. I'll do it the same way but with new mounts, pulleys and belts. Oh, I decided to put some paint on the bare metal surfaces on the side of the knee and sadle so the white layer in the photo is just the primer.

As of today this is pretty much where I am with the actual machine. This weekend I'm planning on lifting the machine off of the pallet and putting it in a somewhat more permanent position where I can actually test and perhaps even use it some time in the future. A lot more work has been done on the control-side of the thing though.

I ripped out what was left of the old control and took the back-plate out of the cabinet so it would be easy to mount all the new goodies:

http://i158.photobucket.com/albums/t110/henrols/20.jpg

Here's a photo from the beginning stages when I was still playing with the VSD-A's. I got a new 400/90V, 4kVA 3-phase transformer that gives me a nice "sturdy" 130VDC:

http://i158.photobucket.com/albums/t110/henrols/21.jpg

You can see a bunch of power resistors in the above photo. Three of them are for softstarting the 4kVA transformer, one is for softstarting the DC-side, one is for discharging the powersupply and two (in parallell) are used for the regenerative braking circuit.

Next photo is a more recent one:
http://i158.photobucket.com/albums/t110/henrols/23.jpg

The VSD-A drives have now been replaced with three HP-UHU, there's a nice Siemens MicroMaster440 VFD for the spindle motor, a C11 breakoutbard, a CUBLOC PLC-board and a few other goodies. In front of the panel is the Smoothstepper and to the left you can see all three motors - it all works :-)


The next photo shows the control panel I designed for this project:

http://i158.photobucket.com/albums/t110/henrols/22.jpg

It features a 17" TFT screen with touch overlay, a nice MPG wheel and a bunch of 22mm pushbuttons. The buttons are interfaced to the CUBLOC which in turn talks to Mach3 over MODBUS, this gives me quite a bit of flexibillity. For example, I've set it up so the CycleStart button only start the program execution if I am on the Program Run screen in Mach3.

I'm also working on my own screenset that will help running the machine with the touchscreen, here a screenshot of the Program Run screen (Auto):

http://i158.photobucket.com/albums/t110/henrols/Auto-Screen_resize.jpg

So, now I've pretty much covered what has been done on the project as of today. Obviously there are A LOT of small things and details but I leave that for later or untill someone asks.

Thanks!
/Henrik.

Adamj12b
04-15-2009, 02:03 PM
Looks Great! I am curious though, What are all the relays and contactors for? I also see alot of din mount devises, but I am unable to make them out in the pictures. Maybe you could do a little youtube video and show us full control?

The console looks great by the way. The 17" touch-screen will be great to use. Is it a resistive or capacitance type touch panel?

-Adam

H.O
04-15-2009, 03:02 PM
Thanks Adam!
Starting at the top, next the VFD is a powersupply used for the low voltage side of servo-drives and only for that. Next to that is another powersupply, 5VDC that powers the "machine side" of the break-out-board, MPG, etc.

Further to the right is the fault-interface for the servo drives. The HP-UHU fault I/O functions much like it does on the G320 - You connect them together and if one drive faults they all stop. The drawback with this is that you don't know which one caused the fault from the start. This circuit and the CUBLOC solves that part for me.

Below the VFD are the contactors, here's what they do:
** Switches power to the VFD
** Switches power to the transformer
** Bypasses the softstart resistors on the mains-side of the transformer.
** Switches the DC between the rectifier and capacitorbank
** Bypasses the softstart resistors for the DC-side.

That's five, the last one is a spare :-) I may have gone overboard with this aproach of cutting and softstarting BOTH the AC and DC side but I want this machine to be as safe as I can possibly make it.


On the right hand side of the contactors is another powersupply, this one pretty much powers everything else in the control (24VDC). Next to that is a timing relay for the softstart and next to that is a phase and voltage supervising relay.

The blue thingie is a Duelco NST-8 emergency stop relay. This is what stops and starts the system, every safety function is connected in series with this and it also supervises the large contactors making it impossible to reset if any of them is stuck closed etc.

Then comes a bunch of relays.... These are mostly for safety and supervision of the system and are connected in series with the E-stop. One relay is for servo motor overheat (thermal switches inside the motors), one is for servo drive overheat, one for limitswitchesby, one for the servo drive fault interface and so on. This E-stops the system in case anything goes wrong while secondary contacts on the relays drives the inputs on the CUBLOC so it can tell Mach3 what is wrong. Mach3 can then tell ME thru the Diagnostics screen:

http://i158.photobucket.com/albums/t110/henrols/diagsscreen_resize.jpg

Another relay is for the Z-axis break and yet another for bypassing the limit-switches. There's a lot of things going on....

I hope that brings some more insight to it.
/Henrik.

Adamj12b
04-15-2009, 03:25 PM
Wow! I guess it wont be able to do anything wrong without you knowing. LOL. How are you controlling the VFD? Are you using the 10V output of the C11 or something else? How about index pulse of the spindle?

Also, The console looks great. Is the computer mounted inside it?

-Adam

H.O
04-15-2009, 04:08 PM
Hi,
I'm sure it can act up just as much as any other machine and in ways I haven't yet thought about. Besides, the more "toys" you add the more stuff is there to fail so it's sort of a balance act. That's why I want to make as sure as I possibly can that it WILL stop when hit the E-stop button.

The VFD isn't fully integrated yet but yes, the plan is to use the analog output on the C11 board. I haven't thought about the indexpulse yet. The spindle speed PID in Mach3 seems to not work that great (judging from messages on the Yahoo-group) can it be used for anything except spindle-speed readout?

No, the computer is not in the console, it's a separate box and will hang on the inside of the cabinet door.

Thanks again for the kind words!
/Henrik.

CNC Viking
04-16-2009, 06:36 PM
http://i158.photobucket.com/albums/t110/henrols/21.jpg
[QUOTE]
You can see a bunch of power resistors in the above photo. Three of them are for softstarting the 4kVA transformer, one is for softstarting the DC-side, one is for discharging the powersupply and two (in parallell) are used for the regenerative braking circuit.
[QUOTE]


Hi Henrik,

Softstart a transformer? Hey, that's just what I am looking for. Sometimes the high current, when flipping the transformer switch, kicks out my cirquit breaker.
I really would like to be able to softstart my 15 KVA 380V 3-phase -> 220V 3-phase transformer. Can you please explain how to do it and what components to use?

http://forumbilder.se/images/ed72009123302fdf3.jpg

/Peter

TOTALLYRC
04-16-2009, 11:30 PM
The next photo shows the control panel I designed for this project:

http://i158.photobucket.com/albums/t110/henrols/22.jpg

It features a 17" TFT screen with touch overlay, a nice MPG wheel and a bunch of 22mm pushbuttons. The buttons are interfaced to the CUBLOC which in turn talks to Mach3 over MODBUS, this gives me quite a bit of flexibillity. For example, I've set it up so the CycleStart button only start the program execution if I am on the Program Run screen in Mach3.

Thanks!
/Henrik.

I am in the design stages of a control panel for my lathe conversion and this is very similar to what I envisioned.
I am thinking 15" screen because of my space limitation, but it is nice to see what other people are doing.

:cheers:Nice work Henrik!!!:cheers:

H.O
04-17-2009, 01:37 AM
Hi Peter,
The principle is very simple, when you turn on the power to the transformer you run the current thru a resistor (or three resistors, one for each phase). This limits the inrush current. After a short delay you use a contactor to bypass/short these resistors.

There are different ways to do this and the way to choose depends on the particular application. If you have 3*400+N on the primary side of your transformer the absolute easiest way is to get a contactor with a 230V coil and integrated delay module. I'm using a Telemecanique LC1-D32 contactor with a LA4-DT timing module like in the attached schematic.

I hope this makes sense.
/Henrik.

CNC Viking
04-17-2009, 04:07 AM
Thanks Henrik,

I see, it is just using Ohm's Law for a short period to lower the current peak.

In my case I have L1,L2,L3 + PE, no N so I don't know about using PE for the 230V contactor. Maybe I should get one with a 380V coil?

My machine also has a Power Monitor that checks the 3 x 230V. It "clicks" after a few seconds. I guess it is delayed a little before checking the voltage. This means that I must set the soft start delay shorter than that in order to be "ready for the voltage test" earlier, right?

Can you please advise the specifications and source for the 3 resistors?
What W-rating? etc... I guess they are beefier for a 15 kVA transformer than for a 4kVA one?

/Peter

H.O
04-17-2009, 07:01 AM
Hi Peter,
I would definetly NOT use PE for ANYTHING except PE. A contactor with a 400V coil would work if the timing module can take it. I think that the timing module I used is quite universal and works with anything from 24VDC to 240VAC but I'm not sure about 400VAC. I'm sure they exist though.

Actually, the size of the transformer doesn't make that much difference in this case. The pure resistance in the copperwire is pretty much near zero anyway (which is why you need the softstart...)

I'm using 47ohm/100W resistors (ELFA 60-681-67). This works well because the initial current transient only lasts for a VERY short time (milliseconds) - as soon as current start to flow thru the transformer the magnetic field starts to build and the current decreases - and these wirewound resistors can take massive transients.

A delay of 1s is more than enough.

/Henrik.

CNC Viking
04-17-2009, 08:46 AM
Henrik,

Thanks again.
I checked the resistors at ELFA and they are 100 SEK ea. which is OK.

I will check my power cable to see if it has an N-wire that I can use. if that is the case, I can use 230V for both the delay-relay and the 3-phase contactor that will be required as well.

I have one more question about soft-starting a transformer, but it is about a TIG welder, so I have it in a new tread so not to distroy this thread with welding topics.

http://www.cnczone.com/forums/showthread.php?p=600358#post600358

/Peter

H.O
04-17-2009, 12:52 PM
Hi,
If going for a contactor with 230VAC coil you need to make SURE that the Neutral is connected. Not only in the cable but also in the socket or panel where you connect. If it's not there the bypass contactor will never engage and you will probably smoke the resistors.

You can use a contactor and a separate timing relay it will work the same and might give you some more flexibility. The nice thing about the Telemecanique stuff is that the timing module is mounted directly on the contactor making it a single DIN-rail unit.

/Henrik.

CNC Viking
04-17-2009, 05:59 PM
No worries Henrik,

I built a modern house (2002) and it has all 5-wire electrics. The cable from the cabinet to the outlet for the machine is a heavy duty 5-wire cable with L1,L2,L3, N, PE all connected. But, damn, the machine builder only supplied a 4-wire (L1, L2, L3, PE) 8mm2 rubber cable to the transformer. So If I want to do the soft-start set-up I need to either get 400V relay, delay module and contactor or get 6m of 5-wire 8mm2 rubber cable. It is leaning towards the 5-wire cable and 230V relay, delay module and contactor.
Now I know at least how to do it when I get the right bits.

And the old 4-wire cable is not a complete waste. It can be used for a soft-start setup for a TIG-welder that only had a 3-wire cable. It must have been a "cheap cable" conspiracy back in the nineties. :D

Thanks again Henrik

H.O
04-18-2009, 08:08 AM
Hi,
With the help of a friend I've now got the machine on adjustable feets on the floor instead of on the pallet. Since I don't have access to any heavy duty lifitng gear (crane/forklift etc) I've been thinking about how to actually do this for quite some time.

What we ended up doing was to use two large crowbars to just slightly lift one side of the machine at the time and sliding in a thin piece of well lubricated sheet-metal between the pallet and the bottom of the machine. We then lined up the pallet jack, lubricated the forks and "simply" pushed the machine from the pallet onto the pallet jack using the crowbars and a bit of elbow grease. This gained us access to the four mounting holes in the corners to mount the adjustable feets. The gauge on the pallet jack showed 1200kg (2600lbs) without table, sadle, motors and control-cabinet. It all went smoother than I initially thought, all in all a very good saturday morning.

Next step will be to borrow a machinist level and adjust all the feets so the machine is nice and level. Then it's on to installing the electrical panel in the cabinet.

/Henrik.

contactirfu
04-20-2009, 01:19 PM
SO henrik here you are - I am just waiting to see this work - are you implementing the auto tool changer for this mill -

also would like to know more on the Cubloc thingi you are putting on -

for other folks Henrik has put a lot of effort in getting the HP UHU to work - and a part of the credit goes to him - here are the HP UHU threads one (http://www.cnczone.com/forums/showthread.php?t=61578) and two (http://www.cnczone.com/forums/forumdisplay.php?f=411)

My best to you henrik -

RGDS
IRfan

samco
04-20-2009, 01:24 PM
H.O - is your powerdump circuit up anywhere? Is it similar to Henrik Olsson?

I really like your layout.

thanks
sam

H.O
04-20-2009, 02:01 PM
Hi Irfan,
No, no ATC, it would be pretty hard to implement since it's a knee mill and not a bed mill. It is possible to do but not something I will attempt at the moment.

The "CUBLOC thingi" is a CB405 module (http://www.cubloc.com/product/01_01cb405.php) on a Cubase 40M (http://www.cubloc.com/product/01_03cubase40.php) baseboard. So far it handles the CycleStart, Feedhold and Stop buttons on the console. It interfaces the Reset button on the console so that it not only resets the servo drives and "turns on" the system but also takes Mach3 out of E-Stop.

It will handle the Feedrate override and Spindle Speed once I've decided if I'm going for potentiometers, rotary switches or encoders for the "knobs". It also monitors the system and when something goes wrong it tells Mach3 what (hopefully). Overtemp, limitswitch, VFD fault etc etc.

It also handles one of the, IMHO, weakest points of the HP-UHU - the Fault I/O. As you know, when the Fault I/O of two or more HP-UHUs are connected togheter they all stop if one faults - this is good. But how do you know which one caused the fault in the first place? My little fault circuit and some ladder logic in the CUBLOC takes care of that part.


Sam,
Yes - that is the same circuit. H.O and Henrik Olsson - one and the same person - me.... ;-)

For you and others that might have an interest in it I'm attaching that same .pdf to this post as well.

Thanks!
//Henrik.

samco
04-20-2009, 02:09 PM
Well I'll be.. :)

thanks - I suppose you wouldn't want to share the circuit board? If not - that is ok. Like I said - your layout looks awesome.

sam

H.O
04-20-2009, 04:33 PM
Hi Sam,
I drew the PCB layout in AutoCAD since it was too large for the free version of Eagle. I messed up and swapped pins 2 and 3 of the OP-amp but managed to fix the PCB I made with some surgery and never fixed PCB layout. I also missed adding the top side solderpad for the MOSFET gate - that's what happens when "drawing" a PCB ;-)

So, I'm really not that fond of publishing it since it's not correct but sharing is what this forum is all about so attached is a .pdf that can atleast be used to redraw the layout properly. I'm afraid that's the best I can do at the moment :-(

/Henrik.

samco
04-20-2009, 05:41 PM
Not a problem. Thanks very much.

sam

H.O
04-21-2009, 02:15 PM
Hi,
I thought I'd post a photo or two of the machine now that it's finally off the pallet.
http://i158.photobucket.com/albums/t110/henrols/24.jpg

http://i158.photobucket.com/albums/t110/henrols/25.jpg

The electrical cabinet is remounted to the machine and the panel is now inside the cabinet instead of on my bench.
http://i158.photobucket.com/albums/t110/henrols/26.jpg

Transformer, rectifier, capacitors and dumpcircuit still missing together with the Smoothstepper, computer, encoder isolator board and a few other things. In other words, there's still A LOT to do but it finally feels like I'm making some progress :-)

Thanks!
/Henrik.

tenmetalman
04-21-2009, 02:32 PM
Hello H.O..,
I just stumbled on to your thread this morning, what a great project. and being done in your usual style ! the condition of your shop is amazing ........ made me go out to mine & start cleaning up. the back brought me back to my senses
anyway, keep theis thread going it's great
Paul

contactirfu
04-21-2009, 02:43 PM
Henrik - have you made provisions to add cooling fans to those UHU's - sometimes they get real HOT.

getting all together feels so neat and nice!

and looks like you might be ready to run the axis sooner :)

have fun!

RGDS
IRfan

the4thseal
04-21-2009, 03:41 PM
this machine looks great. is there any more info o the machine? it looks very interesting, never seen before,

samco
04-21-2009, 03:49 PM
That is one sexy machine!

sam

CNC Viking
04-21-2009, 04:28 PM
OK Henrik,

Tell them which country and city they come from!!:cool::cool:

H.O
04-22-2009, 01:29 AM
Paul,
Thank you! I like to keep it tidy, especially when "showing off" ;-) The machine isn't actually in my small shop at home, it's in a garage that I'm borrowing. Make sure you get back to your project soon too!

Irfan,
Yes, I can add a fan hanging from the top of the cabinet, blowing air down over the drives or on a bracket from the side blowing air up across the heatsinks. I'll see what's needed when I get it running.

the4thseal,
It's a Swedish machine made by Abene Machine AB (http://www.abene.se/engelska/home). This particular machine is a 1986 VHF-3 that started its life as a manual machine but was later converted to CNC by a former owner. It has a 1200X300mm table (47"X12") with four T-slots and a 6HP ISO40 DIN2080 spindle with a 12 speed gearbox, 44-2000rpm. The sidemounted head can be tilted and set to any angle between horizontal and a few degrees past vertical (10° I think - but I'm not sure right now).

I'd be happy to answer any questions you might have.

CNCViking,
I just did ;-)

Thanks guys!
/Henrik.

the4thseal
04-22-2009, 04:50 AM
it just looks beautiful. i would love to play with a machine like that....i am used to bridgeport type stuff, i am attracted to unusual machines.

H.O
05-02-2009, 11:06 AM
Hi guys,
I've made som slight progress in the last days....
I decided to mount the Smoothstepper inside the PC instead of on a DIN-rail in the cabinet. Had to machine the brackets for the D-Sub connectors because I'm using a low profile PC case but it turned out quite OK.

http://i158.photobucket.com/albums/t110/henrols/30.jpg

http://i158.photobucket.com/albums/t110/henrols/31.jpg

I managed to get the ballscrew and table back on the machine, had some problems aligning the screw with the bearings because the bolts that holds the ballnut are obviously under the table and impossible to reach without disassembling. I managed to get it OK but I still have some binding at one end of the travel.

I also got the transformer mounted in the cabinet, routed part of the cables for the incoming power and managed to get the X- and Y-axis servos mounted.

http://i158.photobucket.com/albums/t110/henrols/32.jpg

Have a good weekend!
/Henrik.

contactirfu
05-02-2009, 01:59 PM
Henrik - thats a lot of progress - I like the covers you have made for the encoders, even I just about finished wiring my Mechmate router - ouch - the back hurts - but the there was light at the end of the tunnel - so quite happy - when are you planning to run the axis - have you wired your proximities yet?

RGDS
IRfan

BobWarfield
05-02-2009, 06:40 PM
Very nice project, Henrik.

I don't see Abene's very often in this part of the world. Looks like an extremely nice machine.

Best,

BW

H.O
05-04-2009, 01:58 PM
Irfan,
No, no proximity switches yet and I don't think there will be any. The machine came with some nice and sturdy Balluff switches (see attached photo) so I'll use those. There's three switches in each "enclosure" so I can set up on for home, one for hard limit (E-stop) and one for "soft" limit. (Or I'll just use the soft limit feature in Mach3 but I don't know the current Smoothstepper status on that one.) I would like to get hold of some new cams for the switched though...

Bob,
Thank you!
It's a quite common machine over here, probably not on par with Bridgeport over at your end but still ;-)

I've personally never used one but it's supposed to be a good machine and they have looked more or less the same since the 60's so the design has to have some merit. The one in the attached photo is from 1964 and looks quite like mine which is 20+ years older. The factory does refurbishing of old ones too, they are doing it a hell of a lot better than me though, see the other attached photo...

I'm looking forward to powering it up, it's WAY overdue....

/Henrik.

H.O
05-24-2009, 09:33 AM
Hi guys,
I think it's time for an update. I've got a few things done the last couple of days and things are looking quite good at the moment.

I've mounted and wired everything for the powersupply and powerdump circuit, that part is now done.

http://i158.photobucket.com/albums/t110/henrols/34.jpg

I've also mounted the control panel and wired it to the cabinet and connected the motors and overtemp switches:
http://i158.photobucket.com/albums/t110/henrols/33.jpg

http://i158.photobucket.com/albums/t110/henrols/35.jpg

I also soldered the connectors back on the encoder cables after having to cut them off in order to get the cables thru the botton of the cabinet. I found some nice shells that allowed me connect two cables nicely without too much hassle.
http://i158.photobucket.com/albums/t110/henrols/36.jpg

http://i158.photobucket.com/albums/t110/henrols/37.jpg

Finally I got the computer mounted to the inside of the cabinet door and temporarily connected for some testing.
http://i158.photobucket.com/albums/t110/henrols/38.jpg

http://i158.photobucket.com/albums/t110/henrols/39.jpg

Everything powered up as it should - no smoke, no sparks :-) I got the belts on X and Y just to see if it moved and it did - IT'S ALIVE... :-) One problem noted though, there was quite a bit of vibration when running the Y-axis at anything but extremely slow. It seems as if the ballscrew stub is either slightly bent or there's something going on with the bearings. I'll have to investigate it further before knowing what's going on there.

Still a ton of things to do but it feels quite good to finally see it move.

/Henrik.

contactirfu
05-24-2009, 10:57 AM
Henrik - thats a lot of progress - any video's?

are the UHU's making any heat?

is that keyboard from Deal Extreme?

RGDS
Irfan

H.O
05-24-2009, 11:26 AM
Hi Irfan,
No, no videos, not much to see really, I just jogged the X and Y at diferent speeds for a few minutes. I don't have my limit switches wired (or mounted) yet so I don't wan't to run it 'full tilt'. The drives were cool but again, I only run for few minutes so it doesn't say much.

I got the keyboard from a friend, don't know where he got it but I've seen them available in online-stores etc. It works and it's water tight but that's the only good thing about it - it's really not a great keyboard...

/Henrik.

Larken
05-25-2009, 08:03 PM
Thats a really nice mill. Can't beat swedish steel.
Did it have a ATC ?
How about an automatic oiler ?

H.O
05-26-2009, 01:54 AM
Hi Larry,
Thanks! It does look like it is in really great shape, obviously I haven't run it yet so I don't know what may sneak up on me though. It is 23 years old after old....

There's no ATC, just until recently I had never even seen a knee-mill with ATC. I now know they exists so I'll have to investigate exactly how it is bing done. Not that I'll be doing it right away - if ever.

There is an automatic oiler, that's one of the thins I have left to do. I need to replace some of the lines and wire it up to the control. It's just 230V power and a level-switch so that part should be a piece of cake.

Thanks!
/Henrik.

nhatson.elec
05-31-2009, 02:21 AM
Hi Sam,
You're more than welcome here! Believe me, I've been following your work with the PWM amplifier, you've done some really nice work with it! Right now, as you might know, I'm going for the HP-UHU drives. After struggling quite a bit in the beginning we (Kreutz, Paul, Irfan, Joszi, me and a few others) seem to have worked thru the small issues that was discovered initially and my drives have been working very nice since then. Again, still on the bench though....

Here's a photo where you can see where the drive shaft for the Z-axis screw will come out:

http://i158.photobucket.com/albums/t110/henrols/19.jpg

Because the shaft is so close to the Y-axis ways the large 60 tooth pulley won't fit without the saddle hitting it on its way towards the back of the machine. This had been solved by using a two stage belt transmision, first 2:1 to get the reduction and then a 1:1 up to the drive shaft. I'll do it the same way but with new mounts, pulleys and belts. Oh, I decided to put some paint on the bare metal surfaces on the side of the knee and sadle so the white layer in the photo is just the primer.

As of today this is pretty much where I am with the actual machine. This weekend I'm planning on lifting the machine off of the pallet and putting it in a somewhat more permanent position where I can actually test and perhaps even use it some time in the future. A lot more work has been done on the control-side of the thing though.

I ripped out what was left of the old control and took the back-plate out of the cabinet so it would be easy to mount all the new goodies:

http://i158.photobucket.com/albums/t110/henrols/20.jpg

Here's a photo from the beginning stages when I was still playing with the VSD-A's. I got a new 400/90V, 4kVA 3-phase transformer that gives me a nice "sturdy" 130VDC:

http://i158.photobucket.com/albums/t110/henrols/21.jpg

You can see a bunch of power resistors in the above photo. Three of them are for softstarting the 4kVA transformer, one is for softstarting the DC-side, one is for discharging the powersupply and two (in parallell) are used for the regenerative braking circuit.

Next photo is a more recent one:
http://i158.photobucket.com/albums/t110/henrols/23.jpg

The VSD-A drives have now been replaced with three HP-UHU, there's a nice Siemens MicroMaster440 VFD for the spindle motor, a C11 breakoutbard, a CUBLOC PLC-board and a few other goodies. In front of the panel is the Smoothstepper and to the left you can see all three motors - it all works :-)


The next photo shows the control panel I designed for this project:

http://i158.photobucket.com/albums/t110/henrols/22.jpg

It features a 17" TFT screen with touch overlay, a nice MPG wheel and a bunch of 22mm pushbuttons. The buttons are interfaced to the CUBLOC which in turn talks to Mach3 over MODBUS, this gives me quite a bit of flexibillity. For example, I've set it up so the CycleStart button only start the program execution if I am on the Program Run screen in Mach3.

I'm also working on my own screenset that will help running the machine with the touchscreen, here a screenshot of the Program Run screen (Auto):

http://i158.photobucket.com/albums/t110/henrols/Auto-Screen_resize.jpg

So, now I've pretty much covered what has been done on the project as of today. Obviously there are A LOT of small things and details but I leave that for later or untill someone asks.

Thanks!
/Henrik.

Could you share the screen

thanks and regards

tenmetalman
07-12-2009, 08:24 AM
Henrik, What's the current status of your project ? I've missed Your updates. Your work is fabulous
Paul

H.O
07-12-2009, 09:21 AM
Hi Paul,
Thank you for the compliments and sorry for the slow progress and lack of updates. The current status is pretty much as in the above post. I have fabricated some parts for the Z-axis belt drive and fiddled with a few other things but no real progress yet. It seems I have some excessive backlash on the Y-axis that I can't seem to figure out where it's coming from so I'll have to investigate that as well.

Soon I'll have a couple of weeks vacation and I'm planning on spendning some time on the project then. I'll come back with updates when I have something to show.

How's your project going? Did you get the powersuply sorted properly?

/Henrik.

tenmetalman
07-13-2009, 12:27 AM
Henrik,
My project is dead in the water for now. I was running into so many problems that I had caused by not taking enough time with each & every item that I striped all of my added wiring, pulled the drives boards and intend to start from scratch. this time I'm going to mount the drives so as I can attach & bundle wires correctly. Also draw readable schematics as I go.............
summer's here & I've been using my free time working on my "88" Supra Turbo. I've pulled the engine/trans assembly, striped the engine & am awaiting pistons & misc. parts by cleaning & painting everything in sight. I've got the engine bay squeaky clean so I"m cleaning all the engine parts, again after pressure washing with the intent of using high temp paint to make it look as nice as possible.
Paul

CNC Viking
09-03-2009, 07:25 PM
Hi Peter,


Actually, the size of the transformer doesn't make that much difference in this case. The pure resistance in the copperwire is pretty much near zero anyway (which is why you need the softstart...)

I'm using 47ohm/100W resistors (ELFA 60-681-67). This works well because the initial current transient only lasts for a VERY short time (milliseconds) - as soon as current start to flow thru the transformer the magnetic field starts to build and the current decreases - and these wirewound resistors can take massive transients.

A delay of 1s is more than enough.

/Henrik.

Hi Henrik,
How are things with this nice Abene-project? I hope that you managed to get some job done on it during the summer holidays.


I am about to order the soft start stuff for my transformer now.
I have dropped the idea of switching to a 5-wire cable and will instead use a 400-230V, 200VA transformer (Elfa 55-066-84) between two of the phases to drive the time delay relay (Elfa 37-554-05) and the 230V coil for a 3-phase 400V, 15kW bypass contactor (Elfa 36-245-66). The power resistors will be 3 x 47 Ohm / 100W Arcol HS solder type (Elfa 60-681-67).

Some more questions about the power resistors though, before I buy and install:

1. Why 47 Ohm and not 100 Ohm to get an even softer start?, or would that be "starting over again" with a large trancient shock after the bypass kicks in?

2. Do the resistor terminals get hot, I mean is it OK to solder with normal soldering wire to the leads? Or is it better to crimp the leads to the resistors solder tabs? After all, it is a very short duration we talk about, so I guess they stay cool.

3. What size leads should I use between the power resistors and contactor? 4mm2? 6mm2? or.....?

And thanks again for borrowing your thread :)

/Peter

H.O
09-04-2009, 02:23 AM
Hi Peter,

1) I used 47ohm because I had them already, you can use 100ohm if you like but it's not necessary, basically you have 2*47ohm across 400V so the current will be limitied to 400/94=4.2A.

2) No, the terminals won't get hot if the bypass contactor kicks in as it should. If for any reason the contactor doesn't activate the resistors will get hot though - very hot.

3) The current thru the resistors is ~4A which means 1.5mm² would be more than enough but you really should do the wiring with a wire gauge matching the main fuse you have in the machine, I'm guessing 6mm².

I can't seem to find 37-554-05 on ELFA but as long as it operates on 230VAC you should be fine. What was the power rating of the transformer you're softstarting again? Just make sure the contactor can handle the power + some margin to be safe.


Not much have been done on the Abene project. I've found I have conciderable backlash in the Y-axis and I've tried to figure out where it comes from but so far haven't made much progress. Anyway, babysteps....I'll get there eventually.

/Henrik.

CNC Viking
09-04-2009, 05:19 AM
Hi Peter,

2) No, the terminals won't get hot if the bypass contactor kicks in as it should. If for any reason the contactor doesn't activate the resistors will get hot though - very hot.

I can't seem to find 37-554-05 on ELFA but as long as it operates on 230VAC you should be fine. What was the power rating of the transformer you're softstarting again? Just make sure the contactor can handle the power + some margin to be safe.


Not much have been done on the Abene project. I've found I have conciderable backlash in the Y-axis and I've tried to figure out where it comes from but so far haven't made much progress. Anyway, babysteps....I'll get there eventually.

/Henrik.

Thanks for the quick feedback Henrik,

2) If the contactor fails to activate, and thereby fail bypassing the resistors, I guess the Power Monitor will detect the low voltage and trip the main power switch a second later.

Sorry, I mis-spelled that Elfa No for the time delay relay. The correct No is (Elfa 37-544-05). And for the 400-230V / 200VA transformer the correct Elfa No is 56-068-84 and not 56-066-84 that I stated earlier by mistake. I hope that the 200VA should be enough to drive the time relay and hold the contactor activated continiously.

My transformer capacity is 15 kVA and the main users are:

Spindle Motor: 5,5 kW / 7,5 kW for 30 min.
X-axis AC-servo: 1 kW
Y-axis AC-servo: 1 kW
Z-axis AC-servo: 2 kW
4:th axis AC servo: 0,5 kW
Coolant pump: 0,9 kW
Tool changer: 0,25 kW
Some add-on gizmo's, lighting etc...: max 1 kW
If everything is in use at max rated power at the same time, the total load would be 14,15 kW.

So I guess it is OK to select the 15 kW rated Omron J7KN-32 3-pole contactor (Elfa 36-246-08) with 230V coil. Damn, I did not get many numbers right in my last post. It must be the lack of oxygene to the brain in the middle of the night... or lack of brain capacity alltogether.:D

Do you know anything about these Omron contactors? I would hate to get one that has a humming noise all day long.



Re. your Y-axis backlash, I guess it can be anything in the mechanical chain.

Do you have the encoder on the ballscrew end?

It can be encoder to ball screw coupler, encoder mount, ballscrew thrust bearings, thrust bearing nuts, thrust bearing mounts, ball nut, ball nut mounts..... Keep us posted on the progress

/Peter

H.O
09-04-2009, 10:48 AM
Hi,
Yeah, the power monitor will most likely kick in if the contactor doesn't activate - that's a nice thing! Hopefully there's enough delay to let the softstart do its thing.

I've no personal expereince with OMRONs contactors but they generally produce good stuff so I'm sure you'll be OK with that one.

200VA for the 400/230 transformer sounds way more than you need if the timing relay and contactor is all you're going to power with it. The specification of the contactor says 17VA for the coil. I can't find any info on the timing relay but it won't be much. A 50VA transformer should be plenty.


As for the backlash.... The encoder is on the motor but right now the motor isn't even on the machine. I turn the screw manually and there's a couple of degrees(!) backlash. The ballnut is an adjutable type and I've tried tightening it more than I'm comfortable with. The screw was then really hard to turn but the backlash was still there. I then headed for the ballscrew bearings, (two tapered roller bearings) and tightned up the preload nut on those, now I had to struggle to turn the screw but the backlash was still there.
Despite this I'm leaning towards the bearings and I'll take a closer look at it next time. New bearings I can manage but I'd hate to have to get a new screw....

It MIGHT also be the connection from the ballnut to the saddle but that is a really sturdy piece of cast iron and I can't really see it flexing or rocking that much. I'll keep you posted....

/Henrik.

CNC Viking
09-04-2009, 06:54 PM
Hi,

200VA for the 400/230 transformer sounds way more than you need if the timing relay and contactor is all you're going to power with it. The specification of the contactor says 17VA for the coil. I can't find any info on the timing relay but it won't be much. A 50VA transformer should be plenty.


As for the backlash.... The encoder is on the motor but right now the motor isn't even on the machine. I turn the screw manually and there's a couple of degrees(!) backlash. The ballnut is an adjutable type and I've tried tightening it more than I'm comfortable with. The screw was then really hard to turn but the backlash was still there. I then headed for the ballscrew bearings, (two tapered roller bearings) and tightned up the preload nut on those, now I had to struggle to turn the screw but the backlash was still there.
Despite this I'm leaning towards the bearings and I'll take a closer look at it next time. New bearings I can manage but I'd hate to have to get a new screw....

It MIGHT also be the connection from the ballnut to the saddle but that is a really sturdy piece of cast iron and I can't really see it flexing or rocking that much. I'll keep you posted....

/Henrik.


Hi,

So I don't have to calculate for the contactor's "rush current" ( 115 VA) when it activates, only the hold current (13VA)? In that case I could possibly settle for the 60 VA version which is just above half the price.

From what you say about the backlash problem, I personally suspect the fixation of the bearings either at the ends or the ballscrew housing on the saddle. Is that housing a part of the saddle casting, or is it bolted to the saddle? Can you squeeze in there and take some pics at the ends / ballnut areas? I get more and more curious about your issue here.

/Peter

H.O
09-05-2009, 03:21 AM
No, you don't have to worry about the inrush current of the coil, the 60VA transformer will work just fine in this case. Or you could build a soft start for the softstart.... just kidding ;-)

The part that connects the ballnut to the sadle is bolted to the sadle, I'm attaching the best photo I have from when it was taken apart. There are 4 screws and two dowel pins holding the two parts together. I wish I had taken a photo with the covers removed but I didn't.

If I can't find anything wrong with the bearing I'll have to go back in there but it means I have to tear the X-axis apart again and removing table..again...but if that is what it takes then so be it.

I'll try to stick the camera up inside the knee next time, hopefully I'll be able to get a picture of how it looks.

Thanks for the interest, keeps MY interest up as well!

/Henrik.

CNC Viking
09-05-2009, 04:03 AM
The part that connects the ballnut to the sadle is bolted to the sadle, I'm attaching the best photo I have from when it was taken apart. There are 4 screws and two dowel pins holding the two parts together. I wish I had taken a photo with the covers removed but I didn't.

If I can't find anything wrong with the bearing I'll have to go back in there but it means I have to tear the X-axis apart again and removing table..again...but if that is what it takes then so be it.

I'll try to stick the camera up inside the knee next time, hopefully I'll be able to get a picture of how it looks.

Thanks for the interest, keeps MY interest up as well!

/Henrik.


Looking forward to more pics and progress for you (hopefully without having to lift all those heavy cast iron chunks). BTW, what happens if you remove the bearings at each end, grab the ball screw and just push/pull to see if something is rattling in there? Just my 2 cents...

Soft start parts will be ordered from Elfa asap. The setup will be installed inside the transformer case. Will post pics and story when it's done.
Thanks for your insight and guiding.

/Peter

H.O
09-05-2009, 10:46 AM
Hi,
I just spent an hour or two on this backlash issue. I put the belt drive back on and adjusted the preload on the bearings to a "comfortable" level where turning the screw felt smooth and even. The backlash is roughly 0.07-0.1mm (5-6° turn on the screw) which is a bit more than what I feel is acceptable.

I managed to snap a couple of photos which are attached here. Photo 1 shows the Y-axis screw and ballnut from below and photo 2 shows the same thing thru a hole in the front of the knee. You can see that the part connecting the nut to the saddle is quite sturdy so I don't think it's flex there - might be in the actuall connection to the saddle though but I don't think so.

The third photo shows the bearing assembly. I can't feel any slop or backlash when pushin/pulling/rocking/wiggling on either the screw or the bearing assembly after "disconecting" it from the machine as in the photo. The bearing on the other end of the screw is a simple radial ballbearing supporting the screw.

I'm still leaning towards the bearings but now when I look at the photos I come to think about the ballnut and how it is secured to the piece connecting it to the saddle. I haven't touched those screws but perhaps it's just as simple as these not being tightened properly....hmmm....need to take another look tomorrow.

At least I powered up the machine today and had it run some G2 G3 moves which was a bit of motiviation booster. 4m/min rapids, (should be able of a bit more after som further tuning) not VMC teritory but fast enough for me and this machine, i think.

Does anyone have any pointers towards info on belt tension. I'm running AT5 belts and I'm trying to find out how much tension to put on them. They make quite a bit of noice when tightened.

Thanks!
/Henrik.

CNC Viking
09-09-2009, 05:16 PM
Hi,
I just spent an hour or two on this backlash issue. I put the belt drive back on and adjusted the preload on the bearings to a "comfortable" level where turning the screw felt smooth and even. The backlash is roughly 0.07-0.1mm (5-6° turn on the screw) which is a bit more than what I feel is acceptable.

I managed to snap a couple of photos which are attached here. Photo 1 shows the Y-axis screw and ballnut from below and photo 2 shows the same thing thru a hole in the front of the knee. You can see that the part connecting the nut to the saddle is quite sturdy so I don't think it's flex there - might be in the actuall connection to the saddle though but I don't think so.

The third photo shows the bearing assembly. I can't feel any slop or backlash when pushin/pulling/rocking/wiggling on either the screw or the bearing assembly after "disconecting" it from the machine as in the photo. The bearing on the other end of the screw is a simple radial ballbearing supporting the screw.

I'm still leaning towards the bearings but now when I look at the photos I come to think about the ballnut and how it is secured to the piece connecting it to the saddle. I haven't touched those screws but perhaps it's just as simple as these not being tightened properly....hmmm....need to take another look tomorrow.

At least I powered up the machine today and had it run some G2 G3 moves which was a bit of motiviation booster. 4m/min rapids, (should be able of a bit more after som further tuning) not VMC teritory but fast enough for me and this machine, i think.

Does anyone have any pointers towards info on belt tension. I'm running AT5 belts and I'm trying to find out how much tension to put on them. They make quite a bit of noice when tightened.

Thanks!
/Henrik.

Great pics Henrik,


Ball Nut fixation:
I look at pic 1 and see something that to my eyes look like a stack of washers between the ball nut support housing and the saddle. Lower left side in the pic. Any chance of that arrangement not being firmly secured to the saddle? You mentioned that you will go in there and check that anyway.


Ball screw end bearings:
On OEM VMC's I think you find mostly angle contact ball bearings at the thrust side (normally the servo side) and normal ball bearing at the other end. I recall you mentioned that you have 2 conical roller bearigs at the thrust end. I take it that you are pre-loading these against eachother in order to eliminate any axial play and that you have secured the package firmly in the housing (console).

Motivation Booster:
Congratulations to the sucessfull circular interpolations, and keep up the good work....:cheers:

H.O
10-03-2009, 11:10 AM
Hi guys,
No progress on the Y-axis backlash issue yet but today I had the spindle running for the first time since I got the machine, 22 months ago.... I ran the VFD's quick commissioning guide and had it running in less than 10 minutes, very smooth silent. Only ran it for a minute or two between 5-15Hz as I'm a bit low on oil in the gearbox, need to get some and top it off. Once I have the basic functionallity I'll tweak the settings, switch from V/f to sensorless vector, add the breaking resistors etc.

I've also got the Z-axis motor and the intermediate belt transmision mounted. I still need to fabricate the support bracket for the shaft coming out from the bevel gear but that's pretty much what is left until I have all three axis done. Then I need to mount the limit-switches...

TOTALLYRC
10-03-2009, 12:52 PM
Hi guys,
No progress on the Y-axis backlash issue yet but today I had the spindle running for the first time since I got the machine, 22 months ago.... I ran the VFD's quick commissioning guide and had it running in less than 10 minutes, very smooth silent. Only ran it for a minute or two between 5-15Hz as I'm a bit low on oil in the gearbox, need to get some and top it off. Once I have the basic functionallity I'll tweak the settings, switch from V/f to sensorless vector, add the breaking resistors etc.

I've also got the Z-axis motor and the intermediate belt transmision mounted. I still need to fabricate the support bracket for the shaft coming out from the bevel gear but that's pretty much what is left until I have all three axis done. Then I need to mount the limit-switches...


Keep up the good work.
I think you are going about it the right way, a little at a time.
As I type this I have mine running in the background. It is nice to have the machines be part of your multitasking strategy.

Mike

tenmetalman
10-05-2009, 01:06 PM
Great Project, you started with a very good piece of iron that will be on heck of a cnc. keep us supplied with pictures, gives the rest of us things to aspire to
Paul

CNC Viking
10-05-2009, 05:25 PM
Who would have thought it would be anything else than smooth and silent with this machine? What will be your min / max speeds?

Henrik, keep up the excellent work!:cheers:

H.O
10-06-2009, 01:26 AM
Thanks!
The gearbox allows 12 speeds between 44 and 2000rpm with the motor running on 50Hz. I don't know what's the limiting factor here, gearbox, motor or spindle bearings but 3000rpm (75Hz) shouldn't be a problem - I think.

3000rpm isn't that much, one possible way to get more is to change the ratio of the belt drive between the motor and gearbox, but again, although I beleive it can handle it I don't know for sure.... :-(

CNC Viking
10-06-2009, 06:47 AM
Or you could use a speed-increaser. It is just like changing a tool. No doubt they may be less stable, add runout etc., but it is an easy way to get high rpm's.


Check this for an example:
http://www.bigkaiser.com/kpt_pdfs/Profit%20Maker%20Tools.pdf

H.O
10-06-2009, 11:33 AM
Problem is they cost quite a lot. Used ones goes for ~$1000 and up on EBAY, I can only imagine what a new one costs....

I think I rather get one of those Chinese spindles and make up a sturdy mount for it. 8000-24000rpm, 4kW including inverter for $650. With todays exchange rate that's around SEK6500:- including VAT and shipping. But that's another project....

protman16
10-07-2009, 10:29 AM
Thanks!
The gearbox allows 12 speeds between 44 and 2000rpm with the motor running on 50Hz. I don't know what's the limiting factor here, gearbox, motor or spindle bearings but 3000rpm (75Hz) shouldn't be a problem - I think.

3000rpm isn't that much, one possible way to get more is to change the ratio of the belt drive between the motor and gearbox, but again, although I beleive it can handle it I don't know for sure.... :-(


Most 60Hz motors can run at 120Hz without issue. I am sure the 50Hz motor you have is rated for 60Hz as well. The bearings will not be the limiting factor, but maybe the gearbox will.

CNC Viking
10-07-2009, 05:38 PM
HO,

What about bolting a spindle motor (laying horizontal) on the right wall of the gearbox, empty the gearbox less the pinion, and connect the motorshaft with the pinion of the right angle gear. Is that right angle gear 1:1?

Just brainstorming, but you never know......:)

Jason3
10-07-2009, 06:47 PM
Henrik, do you anticipate doing much work with very small cutters on this machine? I'm just curious - I find most of my work is usually between 800 and 2500 rpm on the turret mill, and wondered whether it's worth the risk of damage to the gearbox and reduction in lifespan of those parts for an incremental increase in speed?

It would be a shame to have to replace what are obviously very nicely made gears and likely expensive bearings for little gain - I'd suggest that if taken care of and not abused, the spindle should last many, many years.

I think the auxiliary spindle for higher speed work is a great idea - maybe even an ATC capable BT30 spindle? I know of somebody who built their own, it was nearly finished too :) Maybe you could have another go at fixing the issue with the drawbar on that one and put it to use here!

Best regards,

Jason.

CNC Viking
10-08-2009, 04:09 AM
I was thinking of a rather careful modification by merely replacing that wall with a steel plate that would act as a flange plate for the new spindle motor and then carefully remove those gears and shafts that would interfere with this new direct drive. Always possible to return back to original state.

I think that the speed limiting factor with such a modification may be if the spindle has preloaded conical roller bearings. But if one think it is revable to say 4-5000 rpm that would definitely be nice for those alu jobs. If the spindle does not like that, what about upgrading by converting to angle contact bearings at the nose and standard bearing at top?

Or maybe a completely new independent spindle replacement with an ATC cylinder right above it and side-step belt driven motor would be an option. Then I guess that horizontal tilting will no longer be possible.

But I would never use a 30-taper spindle on this rigid machine. BT 40 as a minimum.


EDIT: But hey, now we are slipping into high $$$$ territory again...

H.O
10-08-2009, 01:06 PM
Hi guys,
I appreciate all the ideas but for now I'm going to concentrate on getting it running as it stands.

According to the drawings I have the spindle has tapered roller bearings but there's no saying what type number etc. Looking at SKF, figuring an ID of 60mm and an OD of 95mm the reference speed in this range is 4800-5300rpm and the limitng speed is 6700-7000. Using the VFD to speed it up to 3000rpm (75Hz) likely won't be a problem but when I try it I'll keep an eye on the temperature in the region of the bearings.

As long as there's nothing wrong with the head or gearbox I'm reluctant to mess with it so when the need for speed arises the most likely way to go will be the auxillary spindle. As some of you may know I also stumbled across a 40-taper spindle with drawbar a while back, in the back of my head I've been toying with the idea of making a new head with that spindle...but that's just a fantasy right now.

The BT30 spindle will, someday, end up on my small machine - with or without the automatic drawbar. I'll make sure to revisit that project when I'm 'done' with this.


First thing first though - get this going and hopefully fix that Y-axis backlash without having to buy a new ballscrew/nut.

I'm almost done with the last piece for the Z-axis drivetrain, what's left is to bore the 47mm pocket for 6204 bearing and drill and counterbore three holes for the screws that will hold it to the machine then the Z-axis should be done as well.

/Henrik.

CNC Viking
10-08-2009, 03:37 PM
We are just winding you up a bit.:D We know that you can, and will, do an awful lot of work with it just as it is. Let's revisit the spindle issue when / if you feel that need for speed.

Re. your Z-axis. How heavy is that knee? Is it counterweighed, or does your servo have to carry that load when going Z-? Here your vise, workpiece, everything that is placed on the table is also added to the Z-travel's load.

H.O
10-08-2009, 05:14 PM
Hi,
I don't really know but when I had the table off I estimated the weight of it to around 150kg, I'm guessing the knee casting is another 250kg, the Z-axis motor is 25kg, let's say 500kg (1/3 of the total mass of the machine) all in all. Then add 100kg for vise and work for a total of 600kg.

I've priced a pair of 1000N gas struts from Aditech (http://www.aditech.se/pdf/Broschyr_Gasfjadrar.pdf) to help counterbalance the knee but I'm going to see if I need them. Here's my reasoning:

The Z-axis servo drive can just barely run the motor at it's continous rating of 24A but let's be conservative and do the calculations with a bit of margin, say 10A continous. The motor has a torque constant of 0.47Nm/A making the torque at 10A 4.7Nm. The total reduction between motor and the 5mm pitch screw is 4:1 for a total torque of 18.8Nm.

Unfortunately the dual belt transmission and the bevel gear reduction isn't the most efficient, let's say overall effeciency is 40% so 7.5Nm at the screw.

7.5Nm / (0.005m / 2 / PI) = 9425N of linear thrust.

So, in theory (and if my math is correct) this means that at 10A the motor should be able to accelerate the knee at almost 0.6G neglecting friction and inertia of the motor etc. If I get 1/5 of that I'd be more than happy. The drive can supply 25A.

It's another I'll have to wait and see kind of thing, hopefully I'll have an answer this weekend :-)

/Henrik.

H.O
10-10-2009, 11:07 AM
Hi,
Major milestone passed today! All three axis run under CNC control for the first time... :-)

I started by finishing the Z-axis belt drive parts and got it mounted on the machine:
http://i158.photobucket.com/albums/t110/henrols/CIMG0928.jpg

http://i158.photobucket.com/albums/t110/henrols/CIMG0929.jpg

Made a short video of one of the first testruns. Still needs some finetuning of PID parameters, speeds and acceleration and belt tension I think but all in all it looks like it might work out. YouTube - Abene 1

I also replaced the oil in the gearbox and run the spindle up to 2000rpm without problem. However, after running the spindle I could see thru the oil-gauge glass that the oil was full of air-bubbles, is this something I should worry about?

Still a boatload of stuff to take care of but at least it works! Whooohoo ;-)

tenmetalman
10-10-2009, 10:28 PM
H.O.,
Air entrapped in the gearbox oil is fairly normal. As long as the oil continues to circulate, lubing & cooling the bearings & gears it should be OK. if it foams out of the breather than I'd change it. What type of oil did you use ? Good Quality Non detergent would be best. in one of my conventional horz. mills the oil goes from the normal light see through brown to off white foamy in the sight glass at anything above 1000rpm. in fact I've had problems with some water contamination in the gear oil when the machine sets. when I purchased the mill from a state college it was low on gear lube. I added non detergent 30 engine oil to fill it. almost a gallon I think. I start the spindle & let it run an hour or so to warm the machine & oil and the water vents off as vapor with out any further problems. not the best situation but I've yet to have any further problems. You could use the lightest differential lube if your concerned. it will have high shear strength & anti foaming additives and be able to handle the gear tooth faces & bearings. in my application the oil is lubing the spindle bearings as well as the gears & gear shaft bearings.
Your pictures & video are great, keep up the good work ! whats the status of the excess backlash ?
Paul

rokag3
10-10-2009, 11:26 PM
in gear box we use a grade of oil that make foam in purpose this is the nice smell caracteristic of this type of oil .the goal is to reduce the amount of energy spend in the oil insure a complete lubrification even in the upper part of the gear box avoid use of oil pump (the moving parts insure a good distribution and a thinner film

H.O
10-11-2009, 05:01 AM
Thanks guys!
I don't have the exakt type/name of the oil right now but the label said Machine tool slideway and gear oil - or something like that. I guess everything is as it should then.

The Y-axis backlash issue is unfortunately still unresolved....

Piobaire
11-02-2009, 05:24 AM
Thanks Henrik that you've blowed new life in her...
Excellent project work !!

Best regards
/Thomas (former owner)

H.O
11-02-2009, 11:48 AM
Oh, nice to see you here Thomas, and thanks for letting me take her over!

It's been a long stretch (even longer than I expected) and have set me off on various sub-projects but I'm getting close to call it a working machine. Basically what is left is the home and limit switches and reconnecting the central lubing system, lines and electrical and some sheet metal covers for the belts etc (if I can't reuse the old ones)

I would love to find the cause for the Y-axis backlash though, was that something you noted or did you never had her up and running with the old control?

Thanks again for posting, I'm glad you liked what I've done!

/Henrik.

Piobaire
11-02-2009, 02:00 PM
You've done a tremendous good work, Henrik. I'm very happy that she finally got some attention. Mechanically the machine was like new, but the old Anilam controller was a bit "untrustworthy".
The backlash should be no problem to take care about. The bearings are or should be tensioned towards each other in the front bearing house and the backside is floating with a single groove bearing. It the ball screw is tightening up correctly, the backlash is in the nut and the nut has adjustable pre-tension. Set it to about 2% - 5% pre-tension but it’s not easy done assembled. Disassembly it and pre-tension it, also check the ball screw nut fastening to the nut bracket if something happened there.

When you’re finished with the Abene, I have a stranded Harrison M400 project just waiting for some attention. Check Blocket.se...

Thanks again my friend !

/T

H.O
11-02-2009, 04:23 PM
Thanks Thomas,
I've preloaded the bearings (new ones) so hard I could barely turn the screw and I managed to access the preload adjustment on the ballnut thru a hole on left side of the knee and tightned that up really hard as well just to see what was going on. It did reduce the backlash slightly but there was still quite bit left.

What I haven't yet checked is the nut/bracket connection - I'm hoping for some loose screws there but I haven't touched it so I don't know. Next step will be to remove the screw and see what I can get from that. I'll get there eventually ;-)

CNC Viking
01-12-2010, 06:58 AM
Happy New Year HO!

Man, is it cold around here? Well it was much colder last week. I hate to waste time on snow showeling, car de-icing and such.

Anyway, Bambi came by this morning which was nice...
http://forumbilder.se/images/5022010125612d2a6.jpg


Just checking in to hear about current status. Any progress with Y backlash?

H.O
01-12-2010, 12:09 PM
Hi,
Cold indeed, today however we have temperatures on the correct side of 0 again, still about 25° to cold though :-)

No progress on the backlash, the machine is (unfortunately) in an unheated garage so I can't really run it or work on it when it's as cold as it's been lately. I think I will try to rip the screw and nut out and see what I can see - after re-checking the retaining bolts for the ballnut. Will keep you posted!

Nice photo BTW!
/Henrik.

Khalid
07-25-2010, 09:22 AM
Any progress.. test samples HENRIK!!

H.O
07-25-2010, 12:57 PM
Unfortunately, no. Progress on the mill is seriously slow at the moment - non existant to be precise. I'll get there eventually and when I do I'll keep you posted.

/Henrik.