BUMP.

Z Axis Origins and Tool Steel Grinding

Just a bump for myself so I can find my way back. Useful info on the thinking and development of the Z axis manufacturing.

This is cool

Tapping with a spindle

Does anyone know if it's some sort of clutch, gearbox, surely the spindle isn't actually being driven at the low speeds required to tap holes?

I watched the video without sound, but the R.P.M. looked slow and it looked like the material was Aluminium.
In my metal machining former life there were 3 types of Tapping holders.

1. Rigid tapping. The R.P.M. and Z axis feed in perfect harmony.

2. Floating holder. The Z was fed into the work at 95% of pitch. A spring in the tapping head compensated for any errors.

3. Holder with an adjustable clutch. Again compensating for any axis drive errors or material chemistry differences..

Yes, it can be done, just like changing tools and setting height or work offsets.

The ongoing process of Design and Development.
How deep are your pockets ? :eek:

This is a floating holder, spindle and feedrate don't have to match exactly as the holder compensates for that and the tap is pulled out.

For rigit tapping it should be a servo spindle which that on the video is not. Just an ordinary VFD controlled spindle.

Tap holders can be acquired and mounted in collet, or like their in video be a part of some type of holder.
More here
http://www.maritool.com/Tool-Holders..._27/index.html

Progress update.
 

I have been pretty busy with paying customers recently so progress slowed.

However, I have made some progress.

I had some problems with rails mainly because I'm not using standard materials. Cutting tests on 8mm angle failed miserably. The discs kept bogging when they got all the way through from friction between the waste material and rail. I had to clamp the waste to keep the cut gap open. It wasn't good the end result was that I spent a day cutting one x rail and wound up with very poor parallelism along the length of the rail. This was without even starting to grind the V.

My wife reminded me what my time is worth to my clients and I bought some pre ground rail.

Now I am mounting the rail to some 3mm angle that I have in stock, but, on the outside to avoid the internal radius on the angle from rolling mill process.

I'm going to double sided tape the rack under the combined thickness of the v rail and angle. Probably a picture is needed to explain, I will add when I get a chance.

I have been working on my controls and have mounted all my controls hardware in the panel and started my loom, it's nice working in my discipline. The loom and panel go quickly.

This last weekend I made great progress on the rails which had been really bogging me down.

Rail grinding just wasn't my thing, I consumed cutting discs way to fast and had problems with the cut diving and that was before I even started on the 45's I used up a lot of time and wasn't happy with the result.

As mentioned above I canned the ground rails and bought v-cap rail from TEA Transmissions The rail arrived really fast, next day.

I decided to use some 3mm angle to mount the v-cap rail on but, again, had lots of difficulty doing a nice job of ripping the angle down and getting a nice neat parallel rail height. I felt much more confident using the bottom of the angle as a rail reference, using the v-shoulder for a reference just wasn't going to work with my poor milling.

Attachment 15083

The gap between the bottom of the rail and main beam is caused by the cutting heat bowing the steel up. When I mounted the v-rail I clamped the mounting angle to the main beam every 300mm and then sat the rail on the main beam and drilled the rails.

Attachment 15084

Here's a photo of the repair I made when the cut I was making dove and gouged out too deep. I just welded the gouge and ground it back roughly.

Attachment 15085

I mounted the rail to the support angle using M4 x 8mm machine screws. I have a box of them from some other project. And I'm really happy with the finished job, 50 machine screws drilled and tapped at 75mm centres on each side. 100 machine screws!

Lessons Learned
The biggest lesson actually has nothing to do with rail grinding. I have read all the arguments on here about rail grinding, watched the youtube videos and think that there's really not a lot new to offer on the subject of rail grinding. I can offer a new alternative idea to v-cap rail mounting.

The real lesson learned is taps. I started tapping with an old M4 taper tap I found in the bottom of a draw, a cheap chinese tap I probably bought at trash and treasure markets, who knows. I use a battery drill to tap holes and try and get the clutch as high as possible and still engage before I shear taps. It's a skill I learned as an apprentice on big construction job where I tapped thousands of holes. Anyway at hole 42, I know because I was 3 holes from the end of that rail, I sheared my old faithful M4 taper tap.

OK, no problem jumped in the truck and headed off to Specialty Fasteners for a new tap. I bought two more M4 taper tap expensive fancy Bordo brand name taps. Sheared, Bordo tap no1 on hole 43 and Bordo tap no2 on hole 50. Two taps and only one hole successfully tapped. Raced off to Jaycar and bought 2 more M4 taps, cheap chinese $4 each, and successfully tapped the remaining 52 holes.

I'm sure the Bordo taps are super high quality, they are really hard and have no flex at all the battery drill just shears them even at the lowest clutch setting. The chinese taps flex and twist a huge amount. I can see the flutes twist the width of the flute when the clutch engages.

Finally, a quick YouTube video of my gantry sliding back and forward on the rails. No tuning has been done to shim the double v wheels to the correct centre width, or to shim rail heights, but I'm really happy with the ease of rolling and the sound of the movement.

Gantry and rails first test of movement on rails

Dale, that's a very interesting point. Now that you mention it, I've also had much better luck with cheap taps. Largely, it's when working freehand in soft materials (mild steel and aluminum). Perhaps the advantages of the harder taps show up under more controlled conditions and harder materials.

Sorry to hear of all your difficulties with the grinding. Seeing your skills with the table etc, and reading you've seen all the tricks it really makes me wonder why it became so difficult to grind even the flat part.

I mean, it's still not really a fun job, but with my makita cheap grinder ( 500 watt) held buy the grinder ficture and a good 1mm cutting disc, and the right pressure ( not pressing, just sliding, many strokes before you cust trough ) it went perfectly fine.

You're right Fox. I think I was just too aggressive with the cutting. I found the grinding experience really frustrating and the more frustrated I became with the process the more aggressive I got with it. I'm just really glad I'm past it with my own solution.

Regarding the taps, taps are brittle, common HSS is less brittle than carbide or somehow enhanced HSS taps. So a cheaper tap works better but wears quicker.
M4 are really small and delicate taps so they don't work well with battery drill but you really got skill :) I used M8 tap for hundreds of holes with cordless drill and it was a pleasure.

Good to see another Aussie machine coming together. Hated doing my rails as well, have a heap of spare/old angle as a result. Vee rail is on my upgrade list.

Clean sound !!. Nice hardened rails, the best option.

Hello, you're doing great friend

Has anyone got prices on gas struts I just got quoted $575au and nearly fell over.

AU$575 is a complete rip-off.
You should check-up RS-component site I do remember they have an .AU site.

Dale, no fricken way anyone would pay that much. Go here: http://www.lifteasy.com/ these guys are brilliant and have had my 2 purchases to me within 2 days of ordering over the phone. Total for each plus postage was around $39.00

Just tell them what you want in terms of length, charge and ends and they will make one up for you. I went with one of the 8/18 struts with the ends at 6mm

I've got a deal for you! Only AU$499! Act Now, Today Only...:D Ha Ha

Ok got a gas spring coming Lift easy. $39. Thanks for the tip!

Have a new gas shocks for sale it is a Macmaster –Carr
#9416K181 20 lb will sell for $10.

Thanks Al

Time for progress report
 

Works on MM going really well I'm enjoying the build more and more.

X table is mostly complete except for welding on cable management. I have chosen to paint as I go so that I don't need to disassemble to paint later and this is working out to be a good strategy. I have needed to hit som spots with a flapper disk to weld on a cable bracket here or there but these spots are easily touched up and don't show.

My outside mounted v-rail worked really well. I was worried that the rack would not mount well to the rail/rail mount surface but the 3M tape does an excellent job of catering to minor surface irregularities. It sticks. My rail method did lead to changes in the design.

First the v-rails are all 22mm because that's the height of standard size 3 rail. This is down from the standard ground angle design height of 28mm. And causes clearance problems with the gantry stopper blocks. I shortened my stopper blocks on the gantry to 15mm to allow for Y car clearance above the stopper blocks.

Second the idler roller does not meet the bottom of the rails due to the lower car ride height. The stub axle hits the y car frame. I used a round file to cut a half moon shape into the y car frame. But you could also increase the outside diameter of the idler bearing. I think this might be a better solution but I did not look at buying another bearing because I was impatient to get it working. Interestingly, my pinion and motor shaft clear fine and no mods on the drive side were required.

My gantry had some twist or something. There's no twist on the top where the y car runs but there's <1mm on on corner of the gantry where wheel does not meet rail and you can rock the gantry diagonally from corner to corner. I solved this problem with a round file and slightly elongated on of the wheel axle holes to bring the wheel down to the rail. Now all runs smoothly.

My Z axis went well. I think practice makes perfect and by the time I got to the X I had already gotten into a good groove with the x table and gantry. No mods to Z.

I have mounted all my proxies and started to mount stop/start stations. I'm also working on the motor mounts and setting up the spring loading etc. My gas spring for Z arrived today from easy lift. Super fast as I only ordered yesterday.

I thought I might comment a little on the controls interface relay discussion here. My field controls will all be 24v and I have interface relays in my box. In my experience, in very dirty environments, it has always been good practice to use higher voltages for controls whilst trying to stay away from dangerous voltages. In mining we always used 110v. The reason is that higher voltages are better at 'wiping' clean contact surfaces in contractors and contact blocks for push buttons. OEM equipment with lower voltage controls often suffered from welding contacts due to dirty contact surfaces and were modified to 110v. 12v was particularly bad.i don't really expect the machine and environment but have used this experience to guide my choices.

Lesson Learned
Avoid tuning alignment and fine detail adjustment when tired after having worked on the machine all day. It has been said before by many. I wasted two hours chasing a problem in my x axis rails. And eventually went to bed, the next morning I discovered the problem in my gantry wheel heights almost immediately and had it fixed just as fast.

I'll post some photos next post.

Btw obviously my MM is MM blue and my rails and brackets are machine grey.

Attachment 15139
Painting the MechMate

Attachment 15140
Assembling the sub-components

Attachment 15141
I just realised in this dry fit that the idler wheel is going to foul the y car frame at the stub axle.

An interesting point here. I don't have a lathe and am too impatient to send little bits like stub axles out to be machined. I just used a short piece of twenty mm diameter rod and filed the ends neat. The bearing fitting was a slip fit not a press fit so I rolled the short piece of rod on a table under my bastard file pressing down really hard but avoiding actually cutting/filing the material. This causes the surface of the rod to become knurled and voila, press fit. Don't ask me why knurling makes it work, it just does.

Attachment 15142
I tried to get a photo of the proxy brackets but the afternoon sun was causing problems. This is the best of a bad bunch.

Attachment 15143
Z-axis mounted, and proxy looms starting. I have used NHP Sprecher and Schuh proxies and switch gear mostly. No reason behind this, I just gave my wholesaler a shopping list and he got me the S+S gear. Probably they are doing the best discounts at the moment and they do make great control gear. It's really robust and well designed.You might just be able to see, that I am using a yellow illuminated pushbutton for the stop/start stations. I'm going to run the flashing pause signal out to the lamp. So when running yellow p/b is off and when paused yellow p/b flashes. just a visual indicator if I go away for a cup of tea and can't remember if i'm in the middle of a job.

Also the stub V wheel bosses on the Z axis. Again, I didn't want to send out the little bosses to a machinist. I welded the nuts on the inside face instead of the bosses and am using the nuts as bosses. The nut height is slightly less than the boss height and caused a clearance problem with the little folded tab that hits the Z stopper. So I filed the tab down 1mm and it clears the Z slide.

That's all folks, have fun with your machines.

Dale

Another update
 

Mechanically the machine is complete.

I am now wiring up the machine, and have pre wired my control boards. You may remember, from a previous post, that I bought three switch mode PSU's and a voltage adder board to get my DC requirement for my drives. I have since taken the switch mode PSU's out and made my own simple PSU from a Torroid and some capacitors. I should have done so in the first place but was a bit blinded by everything that was going on at the time with the build and work.

Here's some photos

Attachment 15174
I bought this fancy wall mount monitor arm and bolted it to the front of the beams. This photo shows Mach3 running, but I haven't got it working with my BOB or ESS yet. I have been playing around learning how to make 'Brains' so that I can get my stop button light on the control stations to flash at different rates for different events. EG. 4 quick strobes and a pause for tool change required, slow 50% on 50 % off for running machine no spindle, Slow 75 on 25 off for running with spindle, Fast flash for manual pause.

Attachment 15175
Another photo of the arm. I'm really happy with the arm and the all-in-one touch screen pc. I have found I never use the keyboard, only the onscreen keyboard and the Mach3 UI responds really well to touch. I am able to adjust sliders and speed and set buttons.

Attachment 15176

Attachment 15177

Attachment 15178
A photo of my pushbutton station. I have used 3 pair shielded instrumentation cable for my pb stations and run them back to a box near the start of the X axis energy chain. I also run the proximity switches all back to the box. I have used connector cables for my proximity switches with the screw on connectors for replacing proxies that get wiped out by accident.

The motors all use VFD cable and the same VFD cable for the spindle. 4 core and shield.

At the box near the X energy chain I have commoned up all the actives and neutrals and parallel stop and resume. I also have the series e'stop links in the box and only run one pair back to my main board.

My umbilical only includes 7 cables:
5 x VFD cables for axes and spindle
1 x 6 pair shielded instrumentation cable for proxies and pb stations
1 x earth single insulated

The 6 pair instrumentation in the umbilical includes:
1w - Active 24v
1b - resume button NO
2w - E'stop safety loop 24v
2b - E'stop safety loop NC
3w - pause lamp
3b - pause button NO
4w - Xa Proxy
4b - Xb Proxy
5w - Y Proxy
5b - Neutral 24v (needed for proxies but otherwise not used)
6w - unused (maybe for homing)
6b - unused (maybe for homing)

When I get a chance I'll draw it up neat, it'll make more sense.

LESSON LEARNED
Always remember to stop and break things back to first principles. You can buy this and buy that, but often it's just as easy to sit down and make what you want from scratch. Particularly with electrical stuff it often looks all fancy shmancy inside with lots of mysterious bits and bobs soldered to incredibly small contacts. Lot's of times if you take the time to break down the circuit and it's purpose, slowly... with a pencil and paper, you will discover it's not all that fancy shmancy electronics after all.

Dale

Looking good.

Some day when I have the time and money I will do a world tour and visit all the MechMates.

Dream on :)

Al, you'll never get finished on that world tour! By the time you get home 10 more will spring up. ;)

I'm digging that touchscreen. Cool.

You are moving right along.

Thanks Pete, I started testing tonight. Just point to points and insulation resistance on all my circuits. Haven't applied any power yet. Also started figuring out my Mach3 io and BOB settings. I have one conundrum, I have setup my estop relay to open the main contactor which drops power to my BOB. This means MACH3 gets left in the dark with IO. I'm assuming it just says ok estop fault. Is it better practice to give the BOB its own power supply?

It can be done either way. You can use it to disengage all energy except the BOB power or kill all energy.

I have just spent the weekend trying to get the ESS to communicate with my Windows 8 Dell AIOPC. I have had no joy, I have come to the conclusion that the ESS and Windows 8 don't talk. Does anyone have an ESS running on Windows 8.

The good news is I have been able to get the ESS communicating with and old MacBook Pro running Windows 7 as a virtual machine under VMWare. I will continue configuring on the MacBook Pro until I either downgrade the Dell to Windows 7 or figure out a solution for Windows 8 to operate.

The best news is I can communicate with my ESS! YES, I'm right now configuring my IO. I have test run my spindle. It's noisy when it gets up to 400hz ~11K RPM. It's also very exciting watching it spin up. I have not installed a braking resistor but am definitely going to do that. The spin down time is a bit scary under e'stop conditions.

Well time for me to get back to my IO config.

Lesson Learned:

Be patient grasshopper, be patient.

Dale

Emergency Mode Active Output Help?
 

Hi Folks,

Can anyone point me to some documentation on how to take the "Emergency Mode Active" (EMA) screen signal to an output?

I want to use the EMA signal in my hard controls. Ideally I want something similar to the System Hotkeys OEM triggers except for outputs from system status.

Thanks in advance.

Dale

PS: I also want to make an output into a "one-shot". Is this possible?

Hey Dale, I don't think you need a braking resistor, the spindle stops within a couple of seconds which is way less time than a regular router. The resistor is just another unnecessary expense IMHO. As far as the other I definitely can not help you there although I understand what you are asking.

Asked and answered, Brains are the answer to both questions.

See http://www.youtube.com/watch?v=O8V7dZy02og for a good primer on Brains.

For more information on oemLED see also http://www.machsupport.com/Mach3Wiki...title=OEM_LEDs

OEMbuttons see http://www.machsupport.com/Mach3Wiki...le=OEM_Buttons

Well folks, I am very pleased to announce that as I write this my machine is surfacing its own table top. I'm just cleaning up the top I have used as a work surface for the past months before I glue down the spoil board.

The biggest thing I can't believe is how quiet it is. I don't get any squeal from the drives or that high pitch hum. I get more noise coming off the wheels on the rails.

I'm still playing around with settings. I have the drivers set at 64 microsteps and with 40 tooth gears on at the moment. While i'm learning i'm not so interested in setting rapid records or anything I just want nice clean calibrated cuts for now.

Lessons Learned.
I'm sure you are all going to laugh but although I initially set up my A drive as the X slave on the right hand drive correctly and had some great fun making my axes go this way and that, during commissioning I made changes in Motor Tuning to the X axis but forgot the A axis. I went to test my new Steps Per and the machine groaned and shuddered and crabbed. I checked my settings, rechecked, checked my notes, reset my X back to my original settings. Drove the X all good, made changes... Groan shudder!!! Agh I redid this little process back and forth over and over checking and checking and checking before I realised I needed to change A (X slave) every time I change X. Traps for new players ;)

Will post some video tomorrow.

Dale

Hi, need some help. My computer went to sleep and lost ethernet traffic to the ESS. I was having a cuppa at the time and actually saw it when it happened. I have recovered the program and restarted the job, no problem there. But, I am very concerned because when the ESS lost its connection to Mach3 it didn't fail the charge pump. This meant the axes stopped because they didn't have any new step and direction signals but the spindle kept on spinning.

Lost ethernet connection should fail charge pump and cause the BOB output interlocks to come on.

Anyone seen this behaviour before? Is there a setting somewhere?

Dale

Dale,
You may want to check you settings on the smooth stepper plugin.

Watchdog:
- check value for ESTOP timeout. Max value of 3.1 seconds will trigger an estop
- check FEED HOLD setting, If controlled by Mach or Smoothstepper. If by smoothstepper, it looks at the watchdog setting and triggers an estop. If by Mach, I may only do what you observed - which was mach stopping running the file, but spindle kept going.

...I'll do some more reading later to see if I see anything else to look at.

Cheers.

Thanks Sean, much appreciated.

Dale,
( I am pretty sure you have already done this )

Also, go and turn off the SLEEP settings on the PC.
Interestingly enough, it's mentioned in the MACH manual due to how Mach takes over the Kernel of the PC during the run of the routine. The idle / sleep of the PC does a lot of bad things to CNC software.

Dale, as far as I know the charge pump only works in parallel port mode and has no effect with the Smoothstepper.

In my control box I have a safety relay that controls the e-stops, if anything bad happens it closes everything down but leaves my 126 & ESS active to handle the report backs. You might want to look into that sort of thing.

Dale.
Ref your twin axis motors X and slave A.

Just wondering why you used a slave.

On my machine, the twin gantry motors are under control of 1 axis output.
One of the motors is wired so it rotates in the opposite direction to the other.
There is only one set of values to change.

You probably have your reasons for using a slave.
Just wondering.