Mill Upgrades – Flood Coolant Part 1

I’m trying to wrap up the documentation for the spindle belt upgrade so I can get it up on wcubed.co, and since spring has sprung I’m also pretty busy getting the yard in order. I did find some time to work on adding flood coolant and tying in the air blast delivery to it.

I’m using a Brute 20 gallon tank with some prospecting sifting screens, and the original 4 GPM coolant pump mounted on a polycarbonate stand to keep it above the coolant level. The manifold is from Automation Direct, and the hoses are standard Loc-Line (one 3/8″ NPT that came with the mill, the rest are 1/4″ NPT). The system is waiting on me to make a drain from the stand into the filters on the coolant tank.

I also have a new drag chain waiting to be installed, which is large enough to carry the coolant line. The Z-axis end stop sensor wire needs to be run down that, as well as the motor cable and the lines mist coolant and air blast, so it should help tidy things up a bit.

Bonus picture: when you have to tap some M3 holes but don’t have a tap holder small enough, a TTS ER20 holder can come in handy.

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An easy guide to making a WooCommerce store

I’m mostly putting this up for my own benefit, as every time I end up doing this I have to relearn like 90% of the process and I’d like to have a reference document.

So, start by picking up a domain name. I like to use Namecheap, but there are a million domain registrars, pick your favorite.

Go download PuTTY if you don’t have it already.

Next, pop over to DigitalOcean. They have a great guide for setting up WordPress on one of their droplets (and a lot of other stuff): https://www.digitalocean.com/community/tutorials/how-to-use-the-wordpress-one-click-install-on-digitalocean. I generally start with the cheapest droplet and will move up from there if necessary.

When you get to the bottom of the page, there’s a section marked “Add your SSH keys”, which you want to do now because it will save you more confusion later. Open up PuTTYgen (which is a separate program from PuTTY, but was installed with it), and generate a key (you should be able to leave the default parameters, they should be RSA and 2048 bits). You will need to save the public key onto the server and keep the private key for logging in.

At some point in here, point the nameservers to the right place. DigitalOcean has a guide here: https://www.digitalocean.com/community/tutorials/an-introduction-to-digitalocean-dns but for Namecheap domains you can just go change the nameservers to “ns1.digitalocean.com”, “ns2…” and “ns3…”.

When you go to log in with PuTTY as shown later in the instructions, you need to use that key. They’ve also written a guide for that: https://www.digitalocean.com/community/tutorials/how-to-connect-to-your-droplet-with-ssh

Don’t forget to save the login settings in PuTTY.

While you’re SSHed into the server, follow these instructions to setup an SSL certificate on your server: https://www.digitalocean.com/community/tutorials/how-to-secure-apache-with-let-s-encrypt-on-ubuntu-16-04

Now your server should be running WordPress and you should have a valid SSL certificate. Go make a login for your site. Note: do not use “admin” — this is a potential attack vector; I strongly suggest using a password vault in general in your life, and in particular using a random character name and password for the site. Remember that anyone who has this login has access to all the data on the site, including the database.

Go to settings, and change the “WordPress address” and “Site address” to the url you got the SSL certificate for. Note that it must much exactly — if you got “xyz.com” you should put in “https://xyz.com”, not “https://www.xyz.com”.

The next step is to add plugins. I am not a guru of WP plugins by any means, but I like:

  • Obviously, WooCommerce. Without this, it’s not a WooCommerce site.
    • WooCommerce Services — supports other plugins.
    • WooCommerce PDF Invoices and Packing Slips
    • WooCommerce Stripe Gateway
    • WooCommerce PayPal Express Checkout Gateway
    • UPS (BASIC) WooCommerce shipping
  • Really Simple SSL
  • Jetpack by WordPress.com
  • Backup WordPress
  • All In One SEO Pack

You’re ready to go — setup products, fine tune your marketing, make whatever custom pages you want.

Mill Upgrades – Spindle Upgrade Part 4

Time to switch the tapered roller bearings (TRB) out for angular contact bearings. The primary benefit is that AC bearings allow higher speeds, particularly when running only with grease. First step was to pull off the seal above the top spindle bearing, remove the nut and pull the spindle out.

I dunno what kinda grease was in here, but there’s certainly a lot of dirt, probably largely as a result of having too much grease. This machine has probably only run for a couple hundred hours, so realistically the grease pack it had now should have lasted a while, and you can see in the first picture that the rollers look pretty clear (the grease forms a thin film on the rotating elements of the bearing).

I didn’t take any pictures apparently, but to get the quill out of the machine, you need to remove the quill retaining bolt (on the left side of the head), then loosen the quill lock. If you have the quill arm that may need to be removed, but as I have already removed mine I’m not sure. I have also already removed the quill DRO and the clamp that holes it

The next step is to knock the TRB cones out of the quill.

I cleaned up the quill face a bit after this, but you can see how much grease was jammed into the rollers and cages when I removed them, and how dirty the inner bore is. Most of the inner bore was hard enough it didn’t come off by wiping, and that stuff I left in there. Whether that was a good choice remains to be seen.

Time to press in the new AC bearings. Note: it would have been a better plan to grease them before doing this.

And back into the machine.

Now, I put way more grease than necessary because I forgot to grease them before, and my hope was that some excess would move under gravity in the top bearing, and that I would force some through by hand in the bottom bearing. I also wiped away a lot of the grease after running the spindle at 500 RPM for a little while to warm things up and spread the grease onto the balls. You’re only supposed to fill about 1/3 of the open space in the bearing (according to SKF, who should know), however ultimately the grease will convert to a thin film and coat the bearing, and any real excess will be forced out, particularly at high RPM. Excess grease will hold onto dirt and potentially migrate back into the bearing which isn’t great. If the space confines the grease in the bearing it will also cause excess heating, even if it’s clean.

Here’s what they look like after a few hours of running. I ran the spindle up to 7k in 500 RPM increments over the course of 5-6 hours (I was working on other stuff around the shop, the only rule I had was that I waited at least 10 minutes to measure temperature, and if I had already measured noise then I confirmed the measurement).

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The noise produced with the AC bearings is lower than the TRBs, although the modified motor and spindle pulley mounting may be a factor in that. Both are way better than the geared setup, which ran at 85 dB at 3k RPM.

One interesting thing to note was the peak around 6k RPM — some sort of resonance frequency perhaps. I remeasured that point going up and down several times to confirm, but it really does get quieter if regardless of whether the RPM is reduced or increased from there.

Spindle bearing temperature

Both bearings are in a good temperature range for the application, and there’s certainly head room to run the spindle faster. I’ve gotta scratch my head some more about why the smaller bearing is hotter.

Time to pop the seals back on and try out ripping some aluminum.

 

 

Mill Upgrades – Spindle Motor Part 3

The new spindle motor and pulleys are finally installed and working (and all the gearing and oil is out of the head).

As you can see in the picture below, I ended up with two cap screws to hold the spindle pulley in place. This is because I did a poor job on the bore and the pulley had 0.020″ runout. I just added the second cap screw and got it to within 0.002″, which really reduced the noise level.

The next step is to run the spindle up in steps and see how the temps look. It’s currently running the stock bearings, but I do have replacement angular contact bearings that are good up to at least 8k RPM with grease.

After that I want to try out some commercially available pulleys as I put together the BOM and instructions for the plans I’ll be selling.

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The biggest benefit by far is the difference in noise level. It now makes 77 dB at 3k RPM, compared to 85 dB with the gears in place.

Mill Upgrades – Spindle Motor – Part 2

Running into many more roadblocks than expected on this. I missed some critical factors when planning the installation of the original motor and as such had to recut the motor mounting plates (which required reinstalling the original motor and all the head gearing), and I’ve been distracted by working on the air compressor.

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I finally got around to testing the upgrade VFD, only to discover that it’s throwing a ‘low DC bus voltage’ error, which probably means something inside is not working right. I couldn’t get it working again and a replacement is $1k (I paid much less for mine on Ebay, but there don’t seem to be any floating around there now). I confirmed the motor worked with my Huanyang VFD, but I don’t trust one of those enough to make it permanent. Also, the cast iron motor I have is crazy heavy (100 lbs), so both for ease of installation and Z-axis acceleration a lighter motor is a plus.

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I went out and bought a used Baldor EM3610T (3 HP, two pole, 240V, steel banded case) on Ebay, and had to wait a few days to find out which face mounting kit was correct (according to Baldor, the 35-1325GLD, the 35-1325 will work too but the color doesn’t match). Finding C-face kits can be a pain and I strongly suggest you buy a motor which is sold with it already installed, like the CEM3610T.

I also bought an LS (formerly LG) VFD from Wolf Automation. There are a lot of good options for cheap single-phase drives in this horsepower range, including Fuji and Delta.

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The motor and VFD have been tested and are working, just waiting on the face mount to show up. The VFD is currently running the original 1.5 HP motor. Once the new face mount shows up it’ll be time to pull the head back apart and mount the new motor.

Compressor Refurbishment – Part 5

Time to clean everything up. I pulled the rusty valves apart (after cleaning the outsides up), and they range from not rusty at all to very, very rusty inside.

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The inside and top sealing surface of the crankcase cleaned up. See that tub next to it? That sludge was inside before. Yuck. I’ve already cleaned off most or all of the old gasket at this point.

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Here’s what the old gaskets looked like (I mostly removed them with a razor blade and a plastic scrubber).

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Installing the new gasket at the other end.

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And all back together.

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After flipping it on, there seems to be some knocking in the valves and the hydraulic pressure is low. So a little more work to get over the finish line.

Shars 440V 4″ Vise Review – Part 2

Got the Haimer in the spindle and off we go. Note that nothing here is statistically significant and the equipment being used is really not the right stuff (a Faro arm, or at least a large surface plate and a good indicator, would be a better choice but aren’t available), so take the results as you will. This is good enough for the work this machine does, and to confirm I’ve spent my money less poorly than I would otherwise.

Jaw alignment: measured at 0.0005″ off over 4″. I got the fixed jaw flat, zeroed out the indicator on the left side of the moving jaw, and got the reading shown below on the right side.IMG_3098.JPG

Parallelism (to spindle): 0.0006″ over ~5″. The bed drops away on the side further from the spindle. I will admit that it’s just as likely this is the machine. I didn’t have a piece of ground stock to test it lying around.

Clamping displacement: 0.000″. Unclamped and clamped shown below.

I’m happy with it so far, time to drop in some soft jaws and make some parts.