4th Axis work continues
 

Here's a quick video of my 4th axis in action today. Slowly getting it tuned. Still a few issues/glitches to iron out, but getting much better.

https://vimeo.com/342147786

Ted

Well done Ted

impressive;);););)

Spindle cooling system failure
 

Almost had a catastrophe! I was running a long 3D finishing pass on my 4th axis while I was at my design computer doing some CAD work. I got up and walked around the machine and just glanced down at the water reservoir. There was no splashing in the tank from return water! The return line at the top of the tank was empty! The coolant pump was not running. I used my e-stop for the first time in production! Quickly checked temp of spindle and it did not feel any warmer to the touch than normal, so I suspect the pump had failed just a short time prior.

Now motivated, I threw together a quick water flow alarm with a flow sensor I had bought earlier meaning to put one together sometime. With just a very, very loud alarm. Checking the pump, the inline fuse had blown. I replaced the fuse and tested it and it seemed okay. Reset the machine and started running again. Not five minutes later, the alarm went off and scared the bejeesus out of me. I assumed my alarm hardare/software was faulty, but sure enough, the pump was not running. I did a feedstop and then spindle stop and checked everything out. The pump I was using was a Rule 12Volt inline pump that was really overkill as far as volume and pressure goes. Looks like the backpressure caused the impeller to slide up the motor shaft and jam against the housing. I've got a couple of different ones on order right now. This made me think, though, what if I was out of the shop when this occurred, what would have happened to my spindle? So I put together some hardware/software to monitor the flowmeter and do an automatic feedhold and spindle stop if wanted or an e-stop if preferred. It will sound an audible alarm first for a few seconds and then, after a programmed delay, it will issue the feedhold and spindle stop to my bob through a couple of inputs or it can be set to do a full e-stop. I'm putting a display on it right now so that it will show the measured flow rate as well as alarm status, battery voltage (it has a battery backup) and the voltage of the incoming 12v power brick that powers it. If it's own power supply fails, it switches over to the battery backup and gives a quick audible alarm every few minutes and an alert on the display. The battery pack would actually run it for a day or so, so it will just give the audible chirp until it sees the battery pack voltage starting to drop and it will then go full alarm and send the stop commands.

Not sure what everyone else is doing to monitor their spindle cooling, and I am sure there is a commercial product out there to do this. If my spindle had a temp sensor built in, I would probably just use that, but mine doesn't, and monitoring the water flow should catch a problem before the spindle starts to heat up. If anyone wants the info on what I put together, just PM me. As soon as I get everything finalized and tested, I'll put some documentation together for it and will be happy to share.

Ted

Again, very nice work. Glad you were "present". You might consider one of these to monitor and "alarm" on your spindle over-temperature

Thanks, John. As much as I like to make my own boards, for that price, I can't pass it up!

Ted

Spindle coolant monitor prototype
 

Got a prototype flow monitor put together and starting to test. Ignore the wiring mess, I'm a professional, and that is a professional grade nest of wires! Trying to calibrate the flow sensor, but it may not be that important, except for spotting trends. I have the software logic working, and it will drive 2 pins on my bob for feedhold and spindle stop, but it is a long run from my water reservoir to the bob, so we'll see if the 5v signals are good enough.

Ted

Not enough sleep!
 

So, I have been tinkering with the spindle coolant flow meter (if anyone can think of a cool acronym, let me know!). As typical, I keep thinking of cool new stuff to add. Ended up adding a bunch of I/O lines to the design, for future features if nothing else. I was up late last night, finishing some honey-do stuff, and got back to this project. Everything has to fit on a 100 x 70 single sided PCB, and I am doing a photoresist etching with resist film and the negative being printed on my inkjet. So I can't do very fine traces with this setup and it requires some post Kicad work in Gimp to clean it up. Anyway, it is a time consuming process, especially when tired and late at night. Finally got it printed, exposed, developed and etched. Looked great! Went ahead and drilled the tiny holes for the components and couldn't stop myself from going ahead and placing the components and soldering it all up. Then went to bed. Got up this morning and mounted the board in the enclosure and started wiring it up. Then I realized what I had done at 2:00AM. I had inverted the image and everything is backwards. Pin 1 on the ATMEGA chip is actually where pin 28 will be when I plug it in. Doh! I am an idiot. Reprinted, re-exposed and re-developing it right now. Sigh...

Oh my! A lesson re-learned. I'm still impressed with your perseverance.

Spindle coolant flow monitor up and running
 

Finally had time to finish the monitor and get it in place for testing. Ran a series of tests where I stopped the water flow and it engaged the feedhold and spindle stop correctly. It also monitors the incoming ac for the coolant pump and it properly stopped everything when I manually killed the pump power. It will also issue an estop to the bob (not the high voltage e-stop) if it has issued a feedhold and spindle stop but still detects ac to the pump, just in case the spindle stop did not work. Running some production runs now and keeping an eye on it. It's going to take a while and a lot more tests for me to feel comfortable walking away from the machine.

Ted

First class!

So is there a microprocessor in there somewhere?

There is an ATmega328PU microcontroller running it. I have a drawer full of them from some previous projects and are very simple devices. These are the microcontrollers that many of the Arduino line of devices are based on, so you can use the Arduino IDE to program them. There is a limited number of I/O lines, but enough for this project. The good thing about using a microcontroller for this kind of job is that I can keep tweaking and updating this software. I included an SD card interface, so the software can capture and save data for things like spindle run hours, average coolant flow rate, etc, I just have to add the functionality to the software. Fun project.

Ted

More 4th axis shenanigans
 

Needing to run some cuts for testing the flow monitor, I tried out some detailed carving on a 3D surface with compound curves. Using .25mm tapered ball nose bit, smallest I've used yet. I expected it to snap at any moment, but it made it through just fine.

Ted
https://vimeo.com/345093710

Classy! I'm running out of superlatives.

And, I learned something new from your schematic discussion (thanks for sharing). I hadn't thought of using the Arduino IDE with my own circuit. What a great idea.

So have you considered adding a temperature probe (like the K-type) with appropriate microcontroller to your configuration? Oh, and with your data logging capabilities...

Thanks, John.

Yes, I have thought about that, and I added the inputs to the pcb and connector to the chassis when I built it. I also have the probe I'm going to use. I ran out of good, shielded 2 conductor cable, but have some on order and will install it as soon as it gets here.

Also, learned a good lesson this morning. Just because Vectric gives you the toolpath for your mill of choice, doesn't mean that your collet is going to clear the sides of your profile. Time to buy some longer ball mills! ;)

Ted

Been spending so much time with the 4th axis, I haven't put down a real spoilboard. Time to fix that. I'll have to look up the drawing specs, but I think i remember them calling for 6 bolts per crossbeam, so 48 holes to drill and tap. I also started looking real closely at my rails for being parallel and coplanar. My x-rails are about 2 mm off from parallel right now which is well within the adjustment range of the bolts holding the rails to the main beams. I seem to remember a method of using wire cable with a sag chart to shim the rails true, but I don't remember what the best method was to get the rails at the same height. Feel free to chime in if you've done this! I'm too old to reinvent the wheel.

Ted

Spoilboard
 

First bolt in spoilboard. 47 more to go. This is going to be a Guinness kind of day. I've got 2 M8 taps/bits. Think I'll get them all done with just those 2 taps? Probably depends on the Guinness to work ratio! :D

Ted

First tap broken at hole 23. Guinness ratio still way too low!

Ted

I assume you are using a "good" taping fluid like Rapid Tap. I was given the advice to use such a product 10 years ago when I built my MechMate #26. I, mostly, used Harbor Freight (cheap) taps. I didn't break any taps.

Thanks, John. Yes, I use Tap Magic and a cordless drill. When I think of all the hand tapping I did as a kid, with no tapping fluid, I can only shake my head. I broke that first tap because the drill torqued out of my hand. Two wrist surgeries ago, that wouldn't have happened! :) That was the only casualty, however, and the deed is done. On to gluing the second piece of MDF down today. I have lured some family/friends over with promises of grilled food and beer, the suckers. They are going to help me get this finished.

Ted

Looking good! And there's that 4th axis again. I wish I had thought of extending my X rails so I could add a 4th axis like you did. I did configure a space in my control box for the 4th axis driver.

Well, so much of my work is at the lathe, it was natural for a rotary axis to be high on my list during the planning.

I did get the table surfaced. However I would not recommend doing that without functional dust collection on the machine! I have worked with MDF many times over the years, and have even routed it before. But... the amount of dust this thing made when surfacing was unreal! I ended up leaving the machine to it and waited for it to finish to come back. It took me half the night to blow out my shop! I do have a dust collector for my shop mounted outside the shop and it works well for my other tools. I just haven't had time to make the pipe/tubing runs up for the beast. Big mistake! I'm making the time this weekend (assuming the expected bad weather down here leaves me alone) to get it done. Anyway, the surfacing went well and I have a pretty flat surface now. Still trying to decide on clamping system. I have some t-track I can lay down, or maybe just route some t-slots in the spoilboard itself.

Ted

Well done.
Coming along nicely.

MDF, yuk!!!!!!!!!!!

Reference the clamping, I used T nuts.
I made a couple of cam clamps.

Thanks, Al. Yep, MDF = Double Yuk!

The good thing about my dust collection is that it is outside my shop in a small outbuilding, so I don't have to worry about fine particulates escaping through any filters in my shop, and it is much quieter.

I also built a shop air filter that hangs from my ceiling with 6 high volume PWM fans. It sounds like a server room when it spins up to full speed. :) It runs through a MERV 13 filter, and is pretty good at getting dust down to 1 micron, and about 50% of particulates down to .3 microns. Of course, it is centered on the MechMate and is right in the way of where I need to stop my horizontal pipe run and drop the vertical flex hose down to the machine, so I've got to get up there and move it.

So, Al, do your cam clamps apply pressure down from the top of your work piece or from the side?

Thanks,
Ted

The cam clamps apply side pressure.
I use them when surfacing a workpiece.

I thread in a couple of short M8 studs at the rear so they are below the finished thickness and tighten the clamps.
This allows a clear run over the work.
When profiling I use a hold down clamp.
Hope this helps.

Thanks, Al. Yes, it does help.

Finished my dust extraction setup last night. Made up a steel post that mounts to the top of the Z stiffener and holds the hose up above the energy chain so that it can drape down before it turns up towards the ceiling. Looked like that was Gerald's recommendation. Seems to work well. I was somewhat concerned about it applying bending force to the Z axis, but I'm not seeing any issue so far. I bought the cheapest metal dustshoe I could find and had to cut it and re-weld it to make it fit into the Y-carriage. I plan on making one out of acrylic or mdf with magnetic mounted brushes to allow easier collet access, so I didn't want to spend too much on this one.

We are having a lot of mains power outages today with Hurricane Barry practically on top of us, so I'm not running the machine. Taking the time to do some design work and further researching laser options. I have been really happy with the cheap laser I bought to test with, and I want to get a higher quality, higher power and PWM controlled one in the 5 to 7 watt range.

Ted

Started fabricating a better dust shoe. The cheap one works great for 4th axis, but too tall for my shorter mills. This is the first milling that I have done where I had to hit measurements. Drew this up in Sketchup Pro and brought it into Aspire, then cut out this prototype. Can't tell you how ecstatic I was when I measured that opening that slides over my 80mm spindle! Yes! :)

Ted

I know the feeling. You're almost afraid to make that first accuracy measurement. Because, if it's not correct, it's totally your problem...you have to fix it...can't call the manufacturer's Support Desk, YOU'RE the manufacturer. So, congratulations, you've done a lot of things RIGHT.

Thanks, John. That is EXACTLY how I felt! :)

Look what came in the post today! She is all logo'd up. Now it feels complete. 3465 days from my first post. Man, I had no idea what I was getting in to!


Ted

That's a beautiful sight. Hey, Mike, time to award a Serial Number.

Short video on some more wine goblets being shaped on my 4th axis. This wood was pretty wet, and I tried the cheapest .5" end mill I could find for the rounding passes. Left a lot of spaghetti behind! The 8mm ball nose took care of it though, on the roughing pass. These goblets have a 3D witch on a broom on them. I don't think I'll turn down the stems as small on these multiple goblet blanks, as I started to get some chatter from the wood flexing. Probably better to leave the stems thicker and turn them to their final diameter on the lathe, or just keep the blanks shorter.

Noise warning on the video!

https://vimeo.com/350087969

Ted

Ted,

Cool build. Love the rotary axis!!

You get Serial Number 131!!

Mike

Ted,

Congratulations for earning Serial Number 131. Here is the Update Builder's Log with your entry added. Please let me know the cutting dimensions of your table including the Rotary Axis extension. Also, let me know any changes you want to make to your entry.

Woo Hoo! 131 it is! Had to wake my wife up to tell her. Probably not the smartest thing on a Saturday morning! ;)

I can't even begin to adequately express to everyone how grateful I am for this forum and all of the support I have received over the years. Thanks to you all.

John,
The cutting dimensions are 2620mm x 1340mm, including the 4th axis. The 4th axis can handle a 1200mm long piece between centers with a 200mm diameter. All other info is fine in the Builder's Log.

For general info, and anyone interested, I'm running a 2.2kw water cooled spindle with Sunfar E300 VFD. PMDX-126 BOB, PMDX-107 Spindle controller and two PMDX-133 motherboards with five Gecko 203V Drivers and a Warp9 Smoothstepper (ESS). Running Mach3, on Windows 10, with 2010 Screenset. WXHC wireless pendant.

Funny story... my wife was complaining last night about yet another UPS package that was delivered to a neighbor by mistake. I thought to myself, we really need a bigger street number sign. 30 minutes later it was done with the MechMate. How cool is that? Happy wife, happy life!



Ted

Congratulations #131.
Now the fun starts.
#114.

Ted,

Thanks for the dimensions. Your entry has been updated.

Thirty minutes from idea to sign...now that's a TOOL!

Regarding the additional information about your build, we try to keep the log entries to a single line. But, the extra information you provided is great. For those building or adding to their MechMate the additional information is permanently part of your build thread. You may get follow-up questions for years to come...that's how this forum works.

Little bit of 3D work
 

Still rocking and rolling on #131. Here's a short video of a 3D carving done on a Mahogany Apothecary top.

Standard Aspire Gryphon clipart.

6mm roughing.
2mm ball nose finish pass.
Run-Time: Forever! Still figuring out best toolpath strategy for these 3D files.

https://vimeo.com/363168659

Ted

Looking good Ted.

I rough out with a 1/2" cutter steeping down in Z.
Finish 0.75mm taper ball nose.

Last one 400x300, 20 deep.
Rough out 1 hour.
Finish 6 hours

Custom 8 sided mug
 

Very nice, Al, and thanks for the info.

Got a custom order for a large 8 sided beer mug (130mm x 230mm) with 3D skull and crossbones. Here are a couple of videos during the process:

https://vimeo.com/366243007

https://vimeo.com/366241555

If anyone wants to see the type of stuff I normally make, you can check out my still under construction website: https://angryroostergoblets.com/

Ted

Speaking of my enclosure temps in another thread. I found this morning that letting the shop get down to 3C certainly helps keep the drivers cool!

Ted