I once helped someone with a Biesse program and they didn't even have the facility (or know about it) to start with a dxf. We were so used to CAD and DXF's before CNC, that even a simple rectangle gets drawn in CAD first and then via CAM to code. Result is that we never bother to understand code either.

(Hope you don't mind that I moved the mystery poster to the Market thread. I reckon if a guy doesn't want to give a name and location he has another agenda?)

No problem with moving the mystery poster, I agree if they dont want to be identified maybe we dont want to know them...

Have been scratching around and found the EMC NIST site which has some useful info here it is open source so hopefully there is no problem with placing the link. I realise that it is specifically aimed at the Linux guys but the coding and interpratation seems the same.

New BOB on test
 

I received this recently from CNC Direct here in South Africa to test as an alternative to the other more well known boards available.

At first glance it is a very nice compact well made board with a good finish and it has some interesting features, most notable that it can be used as a full six axis board (obviously at the expense of other general outputs and charge pump output). Overall size is 160 x 100 x 50 (inc supplied standoffs) for the metrically challenged that’s 6.3” x 4” x 2”.

The board is powered by a 7v and 17v (AC) input supplied by the torroid transformer in the background. There are on-board rectifiers and caps to provide 10V and 24V DC (protected by 1amp fuses). The 24V is available to power off board load and as the positive for the 5 inputs (24V – Pin – Gnd). That should supply enough current to keep the switch contacts clean (discussed on another thread) and would work with appropriate proximity switches.

The bank of relays is driven by the outputs of pins 1, 14, 16 & 17 if these pins are not being used as step and direction signals – selectable by a row of jumpers behind the parallel port. Although these relays are rated at 12A, the manufacturer recommends keeping this to about 2amps because of the PCB track limitations.

The board is also capable of supplying a 0 to 10v signal for a VFD but I am not yet sure how to configure this, must be something to do with PWM and ports and pin settings? There is an input for a vari-pot so it is possible to manually override the set spindle speed.

The outputs to the Geckos (would one use anything else :rolleyes:) can supply both +5v and 0v so is compatible with both gnd common and +5v common drives.

Currently the Campbell board is working well in my test setup and I’m not too keen at this stage to go and rebuild that portion of the panel (note to self: must cut back on the time spent just admiring what I have achieved so far – is there a support group for someone with this affliction or does the forum suffice???) however this will definitely form the core of the panel for machine no 2 due to its size and features.

CNC Direct also has a power supply board to simplify the PSU construction and may also be working on an I/O board that has got my interest piqued – must have more inputs… the possibilities of things I can do with more inputs is endless and besides power is nothing without control.

(PS I am not employed by CNC Direct nor do I have any affiliation with the company and I am not endorsing this product but will give feedback to the forum once I have tested it. The decision to use the information supplied is entirely your own)

Speaking of inputs I have managed with only the four inputs to achieve full homing and limits and pause and resume. I have wired the microswitches for Z, Y and X-left in series to one input and X-right to a second input. This works because when you home the machine in MACH it first moves the Z axis until the switch opens, and then backs off slightly, then the Y to the switch and off and then X. When the two X switches open (NC switches) the gantry backs off until both switches close again, then the X-right motor reverses again until that switch opens and then it backs off until its closed to leave the machine homed. The position of the switch ramp for the second x motor determines the squareness of the gantry. The other two inputs I have used for pause and start buttons as Gerald has done.

I still would like to be able to set up a Z-zero plate but have no more inputs, hence my desire mentioned above.

Does anyone know how to set up MACH to be able to do Z-zero with a touch plate of known thickness and how that offset can be fed into MACH so that tool length compensation takes place automatically?

I will not have an auto tool changer so every time a bit is changed the tool must be zeroed which tends to be fraught will all sorts of dangers and frustrations to achieve accuracy.

(mental picture in my mind of a young assistant doing a tool zero on a Multicam but forgetting to place the ground clamp on the tool as the spindle had ceramic bearings – the sound of an expensive solid tungsten tool disintegrating as it tries to force its way through the touch plate is not one you erase from your mind in a hurry :eek:)

I have been working on the design of my angle iron trimming machine and decided to make a wooden prototype to test the concept. It is a combination of Geralds original idea and a sample on J.R.'s thread.

I felt it would be difficult to move a 3m (10ft) length of angle iron past a fixed grinder and still keep it under control. My moving grinder attachment rides on alwayse ball units (a steel ball riding on many smaller balls held captive in a cup). I had originally thought of using normal bearings on edge but was concerned with the tendency that they would have of moving off line if not travelling 100% parallel to the angle iron. With these ball units I will be able to apply side pressure as well as longitudinal pressure.

The prototype was made of some ply I had laying around in the garage so excuse the odd bit of paint and pen marks - I will be making a production model with steel as the ply has too much flex.

I am using a Ryobi angle grinder as its what I had available but then it comes with a hidden advantage. The gear head has metal threaded bushings that were originally used to mount the guard, this makes it easy to mount to the holding plate. It has three M4 threads and one M5 thread. I have used SS cap screws to mount the holding plate.

The four set bolts allow me to adjust the height of the cutting disk off the table as well as allowing me move it higher to mount a grinding disk to polish the top of the cut angle iron.

I dont like that bit of cutting disk exposed at the back so the production model will have a modified holding plate to cover the disk.

I did not have a sample piece of angle iron at hand so I have shown the assembled unit next to a length of timber instead.

Don't try to cut deep, I found this out the hard way. The cut will heat up and the 1/16" disc will suffer loss. The first 12' rail I cut down took about 4 disc, the second took almost as many. When I started the 8' rails I worked smarter by taking longer faster passes. The 8' rails took 1 disc each and a lot less time. Go easy when the disc cuts through, this is another place where you use up a lot of disc.

Yes, you don't use a grinder like a table saw. A grinder touching red-hot metal just chews up the disk. Use an oscillating motion that moves the disk to cold metal all the time. (Those chop-saw cut-off grinders are terrible at chewing up disks)

Beautiful craftsmanship Alan. I like the idea of moving the tool rather than the angle iron. I moved the iron and it was a real bear. I started out cutting the 8 foot pieces in case I screwed one up it would be cheaper to replace it. When I started cutting the 12 footers, I switched to a new silicon spray and it ended up creating a gooey mess that actually made it harder to push the steel. I didn't figure that out until I had cut for a couple of hours. I just assumed the 12 foot lengths were much heavier than the 8 foot lengths.

Gerald

While doing the countersinks on the y car end plates and gantry carrier plate (10 20 454) I noticed for the first time that the two carrier plates are bent up the same - not mirror images of each other. Will this cause a problem?

I know one of the other guys had the same problem but couldn't find that message to see the answer so sorry for the repeat question.

Jeesh, you should find yourself a new supplier! ;)

No problem with "handing" those plates. I drew them handed originally because I believed at that time I would be drawing wiring harnesses down to the last 10mm. This "mistake" is only going to affect which gantry tube you might use to pass the cable through . . . . if you run the cable up along the spring.

Which reminds me...do try and install the motors with their cable entry pointing down so that dust falls out. We have already destroyed the bearings in 2 stepper motors due to dust ingress.

Naah - He's too valuable :rolleyes:

I received these this morning from Superior Bearings, thanks Rick.

Quality looks very good and the price was extremely reasonable. The price of the complete package with shipping to South Africa was less than what I could get the V-tyres turned for here in Cape Town, and that was using ductile cast iron, it would have been more had I had the wheels turned from special steel and then hardened with the possibility of distortion etc. It would be cheaper if I could do them myself, but I dont have the equipment.

Overall a very good deal.

Rick was a late discovery. I went down the DIY route when the local BWC/Hepco agents wanted about $60 per size 2 wheel. ("Star Pneumatics" or someone like that)

Spent the day at work today (as I have been last 3 weekends) doing major maintenance and cleaning on our auto spray machine so progress has been slow (not to mention financial constraints) but I have managed to weld up the Y car in the interim - pics to follow

If you want help with welding the table, my welder guys would be happy to help. They take on "private jobs" which they are allowed to do in their own time on my premises - they know how to read my drawings :)

Thanks for the offer Gerald, but its the steel purchase thats holding me up, not the welding ability (I used to be a coded mig welder - certification since lapsed) and I know your drawings so well by now, I could probably draw them from memory...:D

Progress - AT LAST
 

I am sure Gerald and the rest of my online friends had given up on me as there had'nt been a post for some months, but things are moving forward again...;)

Collected all the nuts, bolts, washers and other fasteners on friday - all in for R135.00 (about $20.00).

I have had some more laser cut parts done: Cable tray parts, grinder skate, cutter skate (my design), stiffening closures, upper strut bracket and hold down swing plate. Laser cutting and bending for these parts (11 items) R815 ($113) which is a bit steep, but as I dont have an established relationship with the laser cutters, they tend to rip the ring on the bending charging about R40 per bend. Guys with established business with them pay in the single figures for bending :eek:

Welded up the gantry today and tested the angle cutting jig on a piece of offcut 60x60. - works like a charm. I am hoping to cut down the two angles for the gantry tomorrow and then start on the bevel grinding.

I made some mods to the grinder skate to fit my Ryobi grinder but it has ended up putting the grinding wheel in a different position to the standard item, this means I have to drop lower to the angle to get the full grind. I may just extend the slots so that the grinder holding plate is able to move further across. ( this means I will also have to extend the cut out in the base plate as the grinding wheel will foul the edge) - pics to follow...

Alan,
Glad to see your back on the wagon! Nice rail cutting tool...I sure bet it glides nice.
Sean

Hey Alan,

I never gave up on ya. I spent over 2 months working on my skate design (we won't talk about that any more) and a gantry crane, and people thought I had given up. Never happen!!

Finished up on the X and Y cable chains last night. I'll post pic's tonight.

All the discussion about limit switches, homing ... Man, I can't wait to get my MM moving. :)

Keep the pictures coming. It's looking good guy !!

Looking good Alan!!

This Alan bloke is a perfectionist. I just noticed in his photo of the V-rollers, he has turned all the Superior Bearing logos in the same direction!!! :eek::eek:

Thanks Guys, I hope Doug doesn't mind the shiny blue paint on the rail cutting tool :D

Thanks for the compliment Gerald, that comes from my years doing product photography and pack shots. (other people just think I'm APITA)

That rail cutting tool does move sweetly, I have just closed the holes in the top of the ball bearing units to stop the grinding dust getting in there.

Right, the post of Official MechMate Photographer has just been filled!
To earn your keep you need to tell us how you get your lighting and focus so good. :)

I don't know if I can afford the travel fees and per diem to bring him here! :D

How about a "group buy", spread the costs over the country and I get to see it all ;) :D

Hey, he didn't get the job of Roving Official MechMate Photographer - that's on my portfolio. :mad:

Lighting: try to balance the flash with the daylight or use daylight and reflectors only - flash tends to blow out the details if not controlled properly. When taking pics after dark I have a 85w CFL (= 500w) above the work station that gives a nice even light which I then balance with the on camera flash (i.e. turn down the output of the flash)

Focus: no tricks there, just focus 1/3 in, use the smallest apperture possible and if necessary use a tripod to eliminate camera shake (the biggest cause of fuzzy pics). I take all my pics into Photoshop, resize and apply unsharp mask to help bring out that extra bit of detail.

Thanks Alan,

I'll start working on the lighting. My pictures do need some work.

If Alan agrees, for daylight light, avoid direct sunlight (too many shadows on machinery). Overcast day is ideal.

I actually wrote a comment about the fact that you even painted the skate but changed my mind about posting it for fear that you might take it wrong. :) I can already see indications that I'm not going to want pictures of my machine on the same forum with the one you build. :rolleyes:

Doug,
Don't worry, when my pics start coming in you will definitely feel good about yours. :)

Ditto, here as well.

Skate assembled
 

Here are some pics of the mods and final assembled grinding skate.

I modified the mounting position to suit the Ryobi grinder, it attaches with those cap screws into metal inserts in the gear head. That gear head bearing holder is plastic so we will have to see the long term wisdom of my decision. Because of that mounting position, the plate sits proud of the grinder body so I extended the shape around the back to cover the grinding wheel. The recess in the plate is to mount it as close as possible to the grinder and also helps it locate. (I have the same arrangement on the cutting jig). To attach the bearings I used countersunk cap screws and just machined most of the head away to make a very low profile fastener and its still plenty strong enough.

The second shot shows the skate assembled with the bearings. I am using the Superior Bearings cam bushes here, but have also made shorter versions to hold only one bearing if necessary.

The next two pics show the skate in working position on the rail - I still have enough space below the bearing bolts to drop the height of the rail closer to the required spec, its currently sitting at 28mm on that test piece.

The last one shows my hand position when testing the contraption - one hand on the body near the switch and one hand gripping one of the height adjusting bolts. I am considering welding a nut to the outside edge of the grinder holding plate to mount the handle that usually fits into the side of the grinding head. This will, I think, add just a little bit more control and comfort. :confused:

Yep, that's what mine looks like too!
I found if I kept my left hand on the center [(in a glove:) ] and my right hand on the aft (cord end) it had great balance.
I also added threaded handles to the "studs" sticking up at a 45 Deg angle and it push and pulled well.
* NOTE *
I also recommend zip tieing the cord to the top side of the grinder. I knicked my jacket on the cord and required a little "e-tape" repair.

Alan,
Also, on the vertical adjustment bolts don't forget to round them over on the bench grinder. The lead on the threads wants to try galling the top of the rail. I replaced my bolts with Bullet tipped hex head cap screws after the Beta test.

NICE WORK......Is that polish residue on your hand from manicuring for the photos :D

Have fun grinding...it's a Hoot!

Alan, did you buy a new grinder to make these pictures? :cool:
Man, looks like we have the beginning here of the official Mechmate manual comming to Amazon soon! Wow great pictures!
The parts also look nice :)

Stefan

Okay Alan, it's official, you're banned.:D

I know of a bloke in Cape Town that would like to borrow your grinder!

JR, can you see what you started here. Everybody, blame JR for this! :D

That can certainly be arranged, lets just hope I dont burn it out doing the rails :eek:

Alan, you win the award for the nicest pictures! Keep them coming, please. I am enjoying them.

Paul

wow superb, nice pictures, i just whait for my laser cut parts for the skate, i've got the roller and the grinder.