Thanks all for the ideas. For now I will leave it as it is, as Gerald suggested, but in the future I will use Allan's Idea which is the most simple and yet does not confine accessibility.

Greetings to all,

These past weeks, besides a hectic period of work, mostly I managed some other activities.

Bought the whole lot of electrical parts and cables for the next stage.

Bought the computer but have not set it up yet.

Designed a whole new set of power board, 12/5 V board, pwm to 0-10 V and a more compact breakout board (since I have to use two boards). Had them printed on film and made the bare boards.

Attended a one day course for programming the DELTA VFD-E, which I learned how to interface it with external signals. These VFD’s have a lot of potential and I think it is worth learning the plc section of it.

I will be revising the electric schematic which will be posted after completion. Now the VFD will work in two modes, 1- which receives the start and pwm from MACH. 2- a switchover which overrides MACH and gets the RUN and rpm manually, through its detachable mini panel.
I decided on this switch in order to execute the warm up sequence as devised by Mr. Richards without entering MACH. I would not be using the reverse turning, as my spindle is an ER20 collet. Reversing will probably loosen the nut and be quite dangerous. Please tell me of any possible uses for reversing the spindle. The only use I could imagine is for tapping.


Besides, these were the progress made on the machine:

Mounting the racks:
As you have noticed, I use 35mm, M6 screws to hold the rack at a distance from its final position. This provides enough room to strip the double sided tape. For the X axis a middle support is used as well. Then the screws are turned and the rack is elevated to about 2mm below its final position. This facilitates the positioning of the rack and provides a means to once again check the linearity of the rack against the rail. After binding the rails, the screws will be replaced with M6x25mm.
Attachment 7115

Attachment 7114

Attachment 7113

Z plate:
These were the original plates for mounting the spindle.
Attachment 7116

I revised them to incorporate several holes for: attaching a Z echain, bracket for home and limit switch, a moveable dust collector attachment, additional holes for relocating the spindle plate:

Attachment 7117

Attachment 7118

Arrangement for the tension springs.
Attachment 7119

Attachment 7120

Nader: Very nice! Thanks for the great and instructive pictures.

Thanks Joe,
Hope they are helpful.

Besides the VFD and the drivers which I bought, I made two buffered breakout boards and a 12/5 V regulated power supply.

Attachment 7205

I wonder if I could use the 12V for the PWM to 0-10V board for the VFD, as the 12V and the 5V have common grounds. Any comments?


I decided to install an echain for the Z axis which might prove useful in the future; an air hose for a high speed turbine spindle, a water colled spindle or … The size is 25x30mm.
Attachment 7206

Attachment 7207


This is the configuration that I use in my gearboxes. A M12 bolt through a bronze bushing, 13mm high. The gearbox stands clear from the support arm by about 1mm which could be less if i grind the bushing.
Attachment 7208


I tried the standard MechMate 35 turns, 2mm wire, 16mm OD, with elongated length of 128mm, which happened to be unsuitable. While cranking the Z plate down manually, at a point the pinion slipped off the rack. I made a spring with 16 turn, which is very hard to expand and the slipping was eliminated. Now I have to optimize the length of the spring. I suspect this problem is due to slope of the spring and the horizontal vector of the force.
Attachment 7209

Attachment 7210

Here is the detail of the spring assembly:
Attachment 7211

Nader, very interesting build. Please keep the pics coming!

I changed the Z motor spring to 30 turns of 2.2 mm wire, 16 mmOD. Still slipping. Reduced the number of turns to 23 and it works fine.
I guess the below picture shows the fault. The point of effect of the spring is very much near the pinion axis, not providing enough leverage. The spring should be attached farther up.
Attachment 7254

The components and arrangement for the Z axis home and limit switch.
Attachment 7255

Attachment 7256

Attachment 7257

Details of Y axis echain:
Attachment 7258

Attachment 7259

Attachment 7260

Nader, that y-car design (bolted rectangle) was used by ShopBot and it was not a success. The major cure for the weak rectangle was to add a second y-motor. Another cure was to add a plate over the rectangle - link

Gerald,
Thanks for the hint and the link. I studied it but could not comprehend the problem. What was the problem with the ShopBot? What stress condition made it faulty?
Thanks.

Nader,

Your machine is looking really good.

A 5-minute sketch:

Thanks Nils,

Thanks Gerald,
I got the problem. Do you think that welding the rectangle structure members together will help eliminate this problem? I have to say that the square tubes were quite fit to the angles and bolting them was actually a bit hard.

Nader, I would rather not discuss that further. I am trying very hard to concentrate on the MechMate design only.

Dear Gerald

Take it easy SIR, Don't worry about your MechMate design, even you got more questions or 10,000 photographs. Since June 2007, I know what is the Real MechMate Design. And i hopefully everyone also.

Thank you very much for your hard work on the MechMate.

Nobody, will change my mind " Gerald D is my hero"

I not worried about the MM design (and it is NOT perfect), I am only worried about what will happen to my free time and this forum if I start discussing other designs.

I personally agree with Gerald. If I were in his place my answer would be the same. It is not fair to introduce various designs and ask him to comment. Gerald was very considerate to note a fault in my machine. I myself, have to improve it with my mindset on my own design (which somehow I did).

Details of X axis echain: after the echain a sheet metal duct is installed. A perforated plate has been devised to carry one end of the flexible cable hose.
Attachment 7494

Spindle and its mounting plate installed.
Attachment 7495

Starting the electrical
 

The cables I use. From top to bottom:
Common ground signals cable (except for the motors), i.e. Estop signal (pin10), Pause, Resume, Zset, Home X1,X2,Y,Z,B and GND.
Spindle cable.
Motors cables.
Microswitches routing and Limit Switches/Estop 12VAC cables.
Attachment 7496

I started with the cabling of the machine, soon to notice I have to clear up the matter of the control panel, regarding its entries and exits. So I left the cabling and will attend to that after completing the panel.

As you may have noticed, there are no free walls inside this workshop in order to hang the control panel. Also I might be moving this machine to another workshop. So some flexibility should be considered and I have to make a portable one.

Ordered a 500x700x220 mm control panel. Upon collecting it, I noticed he made a mistake and made it to 500x800x220 mm. He gave me a discount to the initial price for his error. All for the better! Now I can install the VFD inside the box.

These are the panel and the support structure.
Attachment 7497

Here are the sequences for its preparation.

The first step was to locate various components inside the box with minimum voltage interference, considering the routes for the cables, interfacing connectors and input/output devices, and also their location outside the panel walls and door. Also the path of the cooling air to the VFD, the drivers and the transformer should be considered. Metallic plates might be even necessary to channel the air flow to the desired path. I tried different layouts and this was chosen:
Attachment 7498

The next step was to mark the location of the ducts and other components, inside the box.
Next I measured different components dimensions and draw and printed them on paper. Glued them on each panel surface, center pinned and drilled them. Holes larger than 16 mm were cut by hole saw. Sizes: 19, 22, 25 and 43 mm are usually the most common for preparing a panel. For 120 mm fan a 114 mm hole saw should be used. All cuts were done by hand drill.
Attachment 7499

All holes were deburred both from inside and outside, as this is really crucial. This is one side completed:
Attachment 7500

Two rectangular openings should be made. 1- for VFD’s mini keyboard. 2- for the parallel ports.
Here is my method for making rectangular opening on the control panel.
Cutting is done with the remainder of the cutting disks used for cutting the rails. These depleted disks have reduced diameter and work better in short distances. A diagonal cut helps to separate each tab easily. The rest will be finished by filing.
Attachment 7501

Attachment 7502

This is the double LPT port interface:
Attachment 7503

Here are the views of the completed bare box.
Attachment 7504

Attachment 7505

The transformer is quite heavy and will be backed by this U channel. The angle will support the other end of the flexible cable hose. Therefore, for moving the machine, the only tasks to be done are to disconnect the connectors, the earth wire and this angle iron. Then the control panel can be moved independently.
Attachment 7506

The auto air filter and its assembly components. Two off will be installed. One just above the VFD and the other one to provide air for the drivers.
Attachment 7507

Wiring diagram update
 

The following changes have been reflected in the new diagram:
Some errative colour coded wires are corrected.
The preliminary wiring of the VFD and the 0-10V board are added.
Another Estop switch added on the panel.
There amy be other revisions.

For DELTA type-E VFD the following programs are to be done:
MI1 -- 02.01 = 2 (external terminal, keypad start/stop disabled)
MI3 -- 04.05 = 8 (operation command selector = external terminal)
MI4 -- 04.06 = 19 (operation command selector = keypad)
MI5 -- 04.07 = 22 (source of second frequency command)
DCM -- 02.09 = 4 (source of 2nd frequency command = digital keypad potentiometer)

Also.

AVI -- 02.00 = 1 (source of 1st master frequency)

The attached file is a zipped .dxf file

Attachment 7536

Wiring of the control panel
 

Here will be the stages of wiring the control panel as I progress.

Prior to starting, the box was vacuum cleaned and cleaned with a damp cloth. No traces of drilling chips.
Placing and securing the cable ducts inside the panel:
Attachment 7537

These are the consumables normally used for wiring.
Attachment 7538

The wiring operation will be divided into 4 stages:
The 220VAC stage, the VFD stage, the drivers stage and the breakout and interface stage.

The 220 VAC wiring stage:
The relay and terminal blocks mounted on the DIN rail and tag numbered. Please note the spacer under the rail for ease of wiring (idea from Gerald).
Attachment 7539

All other components related to this stage are mounted in their respective places.
Attachment 7540

This is the space I made myself to start with the wiring.
Attachment 7541

The 220VAC stage completed. All wires tagged according to the drawing:
Attachment 7542

Mounting the VFD and connecting the feed wires. Mounting the transformers:
Attachment 7543

Attachment 7544

Fastening the transformer from behind.
Attachment 7545

Mounting the 39VDC module:
Attachment 7546

thats actually good organized work - I am so ashamed :(

Nader

You´re the MAN!

Connecting the drivers
 

Connector side of motors wiring:
Attachment 7725

Driver side with separate grounds for motors wiring:
Attachment 7726

Arrangement of the motor/driver wires:
Attachment 7727

Preparation of wires between the driver and the DC power supply.
Attachment 7728

Attachment 7729

Placing the drivers and its wiring. Duct covers removed to show the routes better.
Attachment 7730

Attachment 7731

Details of power supply connection. To avoid clutter around the driver, the second set of ground wires are connected on the power supply side, rather than the driver side.
Attachment 7732

Attachment 7733

Spindle UVW connection:
Attachment 7734

Connection route of the VFD switchover switch and the mini keypad to the VFD. Another Estop is also routed through this cable duct.
Attachment 7735

Mounting the 5/12 VDC power suppy:
Attachment 7736

The PWM to 0-10V board is still under development, therefore I have to run the spindle in manual mode. Upon completion, I will start a separate thread for it.

Here are a set of carbide bits, newly bought. Although I was told that they are usually used by stone cutters but they work outstanding on MDF. On the other machine, a 6mm diameter tool cuts 6 mm depth per pass @1700 mm/min without any deflection in the tool. I have not tested them beyond this limits but I suppose they have the potential for more. Wall faces are smooth with acceptable tool marks.
These are 5,6 and 8 mm shanks.
Attachment 7737

These I have bought to test the 4th axis. 6mm shanks:
Attachment 7738

Nader, nice panel layout. Ideally those drivers should be mounted vertically so that the heat can dissipate off the fins of the heatsinks. as they are now you might get hot air pockets collecting under each heatsink. I know you are going to have fans on the case but I doubt much air will move through there. Of course it also depends on how much heat those drivers will generate - it might be of no concern - perhaps Mike Richards could weigh in here, he has far mor experience with these kind of layouts.

Never mind, I see above you have considered even putting in baffles if required - it would help if I read properly before commenting. :o

Nadar,
I second Alan's concern. The drivers might be just a bit too closely spaced to encourage air flow. I not an expert in this as well, it might not be a concern if the drivers never heat up.

Alan, Ken,

Thanks for your comments. You are both right. To tell you the truth, my first layout was that the drivers were arranged vertically, drawing air from above, but in order to have isolation of high voltage to control voltage, and also to have access to the microstep setting dip switches, I had to place them upside down. I just didn't like the idea to read the texts on the driver upside down!!

In the previous machine, the motors were wired unipolar. They actually worked with very little heat generated. The motors were 3 Amps. Now they will be 4.5 Amps and wired bipolar serial (except for the 4th axis which will be wired bipolar parallel) and I am not aware of their behaviour, but we'll see how it goes.

After finishing the panel (which you will see in the next post), I noticed that baffling might not be a feasible idea, but as you may have noticed there is a space between the VFD and the drivers, just above the 5/12 volts power supply. I could add a couple of 12V computer fans if the temperature builds up.

Finishing the control panel
 

This is a single connector that incorporates: Estop signal, Home (X1,Y,Z), Home X2, Home B, Pause, Resume, Zset and a common GND.
Attachment 7751

All the wires that will lead to the breakout boards:
Attachment 7752

Breakout boards are installed and wired.
Attachment 7753

Connectors between the parallel ports and the breakout boards are attached.
Attachment 7754

Den of snakes, i.e. the grounding hub. Two more wires will be passed. 1- the 6mm wire from the machine, 2- the wire that goes into the earth.
Attachment 7755

A thorough vacuum cleaning was in order to remove any residue of snapped wires. This is the panel almost finished.
Please ignore the yellow/green wire that goes from the transformer secondary to the ground. It was an aweful mistake and will be replaced by the negative line, just after the bridge to the grounding hub.
Attachment 7756

Air filters installed:
Attachment 7757

Pictures of the work. Nameplates will be attached later.
Attachment 7758

Attachment 7759

A 60 mm cable duct attached to the panel chassis (with double sided tape) which will carry the cables to the other side of the panel.
Attachment 7760

Nail varnish on M3 nuts and screw ends on the back of the panel to restrict their loosening.
Attachment 7761


Next step will be wiring the machine.

Nader, As clean as one can do…. you’re the guy:)
Very inspiring for many !
Thanks for sharing those. Amicalement, Robert ;)

Nader, that came out professional! Good Job.

Robert, Claus,
Thanks. These works are inspired by your and others works in this forum.