Setting up Fadal rigid tap

Setting up rigid tapping isn’t hard per se, but finding the right set of instructions was more difficult than I expected. ITSCNC and FadalCNC both have a ton of Fadal manuals and technical instructions, if you’re ever looking for info on your machine. For rigid tapping, ITSCNC has two helpful manuals: rigid tapping installation guide, and spindle drive installation guide.

The rigid tapping guide is not necessarily that useful if you already get the Fadal control scheme, as there really aren’t that many cables involved in setting up the whole system. But the settings changes in the spindle drive installation guide are really, really helpful (some more obvious than others). The big one is that your spindle will not run at all unless you change the control signal the inverter expects from 0-10V to +0-10V. The rigid tapping EEPROMs open both the forward and reverse relays, and use the full range signal to get faster spindle reversal (I assume, anyway). There are a bunch of other drive parameter changes described in the installation guide to get it working 100%.

Getting coolant set up

When I picked up the Fadal, one of the big upgrades I was looking forward to was easy to use coolant. I had bad experiences with coolant on my PM940: coolant growing stuff, limited pumping power and coolant volume for flood coolant, and poor efficacy from MQL/mist coolant. The Fadal enclosure and coolant tank solved most of those problems.

Picking a coolant is a game that even most of the seasoned vets on Practical Machinist don’t seem to have a good recipe for. I went with Trim Microsol 690XT because quite a few members of PM reported getting long life and no issues with smell or rust.

I mixed in a 5-gallon bucket, and checked concentration with a refractometer, to confirm it was in the 10% range, the poured the bucket in the coolant tank (which was already cleaned — I also replaced the coolant hose). For some people concentration alone isn’t the best indicator, at least according to some of the applications engineers for these products. Hard water or pH imbalances causes issues, the details of which are over my head.

Now the real issue starts once you have the coolant mixed and in the machine. That problem is the way oil which is mixing into the coolant, and which allows the growth of anaerobic bacteria that make the coolant smell (and presumably reduce the lubrication qualities of the coolant). I bought a NexJen 1500 oil skimmer, which uses a pump and float in the tank, as well as a small separate tank to actually skim. I hooked this up to standard 120V household timer, and it runs for about 1.5 hours every day, based on the results I initially achieved running it for several hours.

The Fadal makes some money

The first batch of parts off the Fadal — a rerun of some parts I made on the PM940 last year. So much easier to run (because of the ATC and better repeatability), and definitely valuable for helping my figure out my workflow and starting to optimize programming and running the machine.

The softjaws hold two parts in each of three operations. First, cutting one end to length; then cutting the other end to length and surfacing the curved surface; finally, drilling holes and putting in countersinks. All edges are deburred in the machine, which I haven’t done before (because without an ATC it meant manually changing another tool in, when I was already standing there and could do it by hand while the 3D surfacing was running). The only real learning experience there was implementing a trace toolpath to go around the top of the curved surface, which worked out nicely.

The other learning experience here (possibly re-learning, since it’s been so long since I did this on the PM940) is that it’s easier to leave a lot of extra material while saw cutting  to make up for angled cuts and poor surface finish. I left an extra 1/8″, turning a 1.25″ part into a 1.5″ part, but that took my defect rate from ~50% down to 0%. All of which goes to say, it’s probably better to just have a good saw.

Setting up the Fadal

A quick test piece (circle diamond test, I guess, although the standard is usually circle diamond square, with some counterbores and other features in there).

img_7637.jpg

For setting fixtures and tools, nothing beats Aaron Gough’s macros: https://www.practicalmachinist.com/vb/cnc-machining/fadal-toolsetting-system-doesnt-suck-304132/

The 88HS control is pretty straightforward, and while it may not be the prettiest or quickest interface, it’s definitely easy to pick up and navigate through quickly. The fixture and tool setting utilities are great (and that much better with Aaron’s macros), and the onboard Gcode editor is decent as well. Get used to hitting the space bar.

If you’re using Fusion 360, the post is set to output in Format 2 (Fanuc compatible), so make sure your machine is set right (guess how I realized that…).

I’m trying out  lots of new tooling, and as part of that I ran side by side comparison of SK16 holders from Maritool and Shars. I measured 0.0004″ runout on the Maritool holder and 0.0005″ on the Shars holder (both using a Maritool collet, and a 1/4″ carbide blank). Given that the Shars holders are 2/3 the price of the Maritool ones, the difference seems worthwhile. The collets themselves are the same price from Maritool or Shars — I’ll keep buying them from Frank. One thing that is different is the size of the tightening slots in the collet nuts. The Shar’s ones are pretty small, and required modification of my wrenches with a grinder.

IMG_7705.JPG

So far I’ve been running exclusively Maritool carbide tools (mostly AlTiN coated) on mild steel. The 3″ face mill seems nice (MSAP series), although I haven’t pushed it very hard yet. I’ve been using Maritool solid carbide tools for years, and I’m very happy with the 1/8-1/2″ roughers and finishers. Everything runs so much quieter in the Fadal than on my old mill, which is great. I’m looking forward to using the two larger (1″ and 2″) Korloy Pro-X mills I’ve picked up for aluminum, and have a project cooking for them now. I’ve started to wear gloves 100% of the time because I have super sweaty hands and even putting oil on some of the tool holders didn’t prevent my hands from wiping enough away and depositing enough sweat to start some rusting.

Despite my previous assertion that the machine has rigid tap, it was in fact not set up to use it — it was missing the two EEPROMs on the spindle control board, but everything else was there and ready to go (spindle encoder, rigid tapping capable inverter, encoder cable back to the rigid tapping capable spindle control board). This machine came out of a shop with at least four other Fadals, and it looks like someone grabbed those EEPROMs or even the whole board and swapped it out with another machine. I was really stumped when it just wouldn’t run a G84.1 cycle — the machine would get to the line shown below, sit there, and then crash out of auto to manual without any errors.

Setting up and fixing the Fadal

Not sure where that month went. Got a lot done though. This post is a bit of a stream of events because I wrote the 1st half a couple weeks ago.

Since the machine was dropped off I’ve installed a Mistaway unit and a NexJen oil skimmer. I’m working on finishing up the air compressor installation, but a new 1/2″ line has been run around the garage for it, and the air dryer is just waiting for it to be hooked up.

The outside of the machine and even most of the drain pan/enclosure had been kept fairly clean, and was delivered without too many chips (but with a substantial coat of what appears to be way oil, unless they were running an oil based coolant).

So far, it looks like there is a lot on this machine that’s in good condition:
1. Everything (electrical) runs.
2. Spindle runout looks good (need to run a tenths indicator on it now), and spindle feels well lubricated and smooth.
3. Oil lines are intact and working.
4. -5A controller.
5. Rigid tapping.
6. Y and Z ways are clean (except for back few inches of Y ways, which have rust).

The Y-axis ways look good, even if chips were packed absolutely everywhere. I can’t imagine how long this went without cleaning: the chips were packed in between the ways by the bottom of the saddle to the point no more would fit.

I’ve gone through the machine as much as I can without air or taking off structural components, taking a look at backlash and spindle runout. The bad:

1. Way covers are beat up and rusty, nothing that can’t be fixed as far as I can tell though.
2. The table is out 0.0065 over the X, 0.003 over the Y. Everything slopes down from the back right corner, front left corner is lowest.
3. The ends of the X-axis ways look bad. They seem to be functional, and the Turcite on the X-axis is in good condition.
4. Backlash settings on the machine were X 8, 10, 14; Y 18, 20, 20; Z 20. I haven’t confirmed these across the range yet, but my initial numbers at the center of X and Y were 0.002 and 0.0035″ respectively. The X sounds like it has a bad bearing (but maybe that’s cast iron dragging where Turcite is gone?). I’m gonna go through and start checking couplings and stuff, then replace bearings if that doesn’t help.

I wonder if the oil lines were plugged for a while or something. They’re working great at the moment.

Time to check under the table and see what the Turcite is like there. Some photos show the original attempt to pick up the table, but I ended up just tilting it up. It’s not the least safe thing I’ve ever done, but certainly not the recommended method.

Turcite was in great condition on the table itself, I even poked at the strips with a scraper and didn’t get anything off, so I’m confident they’re still in good condition. The gibs and straps were anything but though, the Turcite fell right off them. New Turcite and Waylock is in the mail to replace those.

The other thing that needs dealt with is the backlash, so I pulled the X and Y ballscrews so far, and ordered replacements for all three axes (gonna get X and Y back in before pulling Z). The bearings and seals were full of some serious gunk, and the coolant line evidently had run long enough that it rusted out the screw where the seals were. I cleaned it up a bit, but the corrosion is pretty deep. Not a critical surface, so it probably doesn’t matter long term.

The Y-axis is fun to get out…especially how I’ve got it up against a wall (just enough space, thankfully).

img_7295

Got some nice iron dust out when I used the press to push the seals out of the bearing housing. Also found out the main power cabinet filter was totally clogged while pulling out the Y axis, so I cleaned that up.

I also picked up some new tools: a 7×12 bandsaw and a Makita cordless impact wrench (critical for getting the bearing retaining nut off the ballscrews — didn’t take any pictures of it). Played with the bandsaw yet cutting some wood, but it hasn’t made any metal chips yet, and I need to mix some coolant for it.

img_7242

And replaced all the Y and Z way wipers.

Well, I guess it’s a mill upgrade…

More like a replacement I guess — a 1998 Fadal 3016, which came out of liquidation sale at Honeywell’s former satellite waveguide plant in Long Beach, CA. This machine had a long trip here:

  • Moved to a rigger’s warehouse in California.
  • Picked up on by an air-ride flat bed (took three tries on the truck to get it right…sometimes it’s best to deal with people in person).
  • Driven 2,700 miles to another rigger’s warehouse in central NJ.
  • Delivered to my house (took roughly 2 hours from the time they arrived till the time they left).

So, pictures broken up into sections, starting with delivery to the rigger’s warehouse in NJ:

Showing up at the house on a rollback truck, which was super cool. This is probably the smallest rigging operation I’ve ever been involved with, but I’ve never used a rollback before (because normal people get their industrial machines delivered to places with loading docks and forklifts).

They had to carry the machine about 300 feet down the road (note that it weighs around 4 tons — and the forklift it’s on is another 6-8 tons). This whole part was done at <5 MPH, but everyone driving was surprisingly courteous. Note how low he has the machine, especially coming into the driveway. That was done incredibly slowly, and the machine was visibly rocking on the forks due to the bump!

There was a break in photography here for about 20 minutes as I crawled around on top of the machine disconnecting things so that it would fit through the doorway. The garage door itself was braced so the whole thing was flat to give us as much room to play with as possible.

IMG_6952.JPG

Partway there, one of the riggers is setting up the sliding pads that go under the machine here.

Woops, turns out 10k+ pounds on this side of the driveway was not a good plan. You know what’s harder than getting a machine through a door with 1″ to spare on each side? Doing it while the forklift is settling into the ground. Still, nothing some QPR can’t fix.

Showing how tight a fit this thing was. This doesn’t quite show the final position, which was far enough in that the garage door opens and closes fine without running into any of the tall stuff on the machine (which isn’t even reinstalled in this picture).

Inside of the electrical cabinets are super clean, and the machine is setup basically how I hoped (there are a lot of options that could have been left out).

I’ve been running pneumatic and electrical stuff, setting up parts of the machine, and cleaning it out for the last few days but haven’t been taking pictures while I’m going. Pushing for power on and first cuts by 4/19 (waiting on a few critical electrical power items, namely a transformer and a rotary phase converter, but I’m also moving my compressor to a new tank and setting that up).

Mill upgrade plans

After a loooong time mostly away from the shop (a job hunt, a new job…then another new job) I had been considering selling the mill and moving onto some other projects. After sitting down and really looking at the whole picture, I realized that the mill will help me complete these projects quicker, but it’s gotta work better than it does now. Holding a thou with this thing is basically impossible, so the question at this point is how much better can I get it. There are a few things that aren’t quite right:

  • Backlash:
    • X: 0.002″
    • Y: 0.002″
    • Z: 0.006″
  • Spindle perpendicularity (to table): currently off by about 0.001″/1″ (about 1 mrad or 0.000017°). This doesn’t sound like much, but with a 2.5″ face mill it’s very noticeable on a single pass.
  • Z-axis perpendicularity (to table): unknown at the moment.

The testing looks like this:

  • Put indicators on X-,Y-,Z-axes and ballscrews simultaneously (one axis at a time)
    • Determine if screw is able to move independently of axis structure.
      • If so, need to pull screw and repack with larger balls, or order new ballscrew and nut.
    • Determine if mounting block is moving relative to saddle.
      • Need to reinstall screws with Loctite.
  • Measure Z-axis perpendicularity
    • Put indicator in spindle and 123 block on table, determine if movement is perpendicular.
      • Shim column or rotate head to achieve best perpendicularity.
  • Measure spindle runout
    • Measure runout of taper
    • Measure stack-up by installing TTS holder with ground rod in it
  • Test higher spindle speeds, up to 10k RPM
    • Measure top bearing temperature and noise, compare to previous values

So the first step is to resolve these, then do some further testing. This will not only give me a more useful machine, but also is helping me think through issues on one of the projects I’m working on.

In addition, I’m working on upgrading to LinuxCNC. I have a computer which is being setup with it now (slowly but surely), using Mesa hardware (7i76 and 6i25). I’ll note here my comparison of control upgrade options:

  1. Upgrade to LinuxCNC ($300)
    1. Buy Mesa 7i76+6i25
  2. With steppers including encoders ($720+):
    1. New steppers (~$50 each)
    2. New encoders (~$65 each)
    3. Design and manufacture or buy mounting bracket ($??)
    4. Convert to LinuxCNC using Mesa 7i76+6i25+7i52 (~$370)
  3. With direct servos ($1780+)
    1. New servos ($240 each)
    2. New servo drivers ($218 each)
    3. New mounting adapters for motors ($??)
    4. Convert to LinuxCNC using Mesa 7i77+6i25 (~$300)
  4. With servos and pulleys (1:3 or 1:4) ($1200+)
    1. New servos ($150 each)
    2. New servo drivers ($138 each)
    3. New mounting adapters for motors ($??)
    4. Pulleys and belts ($??)
    5. Convert to LinuxCNC using Mesa 7i77+6i25 (~$300)

Finally, I’m whipping up an oil mist eliminator because of the crazy amount of oil mist that comes from using the minimum quantity lubricant system. This seems easier than completing the modifications I made to get flood coolant (and will probably be valuable with that system should I go to it, anyway).

Mill Upgrades – Fixed Tool Changer 1

I’ve tested several tool finger designs for the fixed tool changer (eventually to be used on the rotary tool changer), and while I don’t have a final design yet I thought I’d share some data.

The goal here is to ensure retention while minimizing required force to grab the tool. These are PLA, but the production version will likely be Nylon. In the case of this fixed tool changer, the retention required is primarily going to be determined by the maximum speed of the table, which is 100 in/min. For the rotary tool changer, there may be higher accelerations, particularly at the end stops.

Using a postal scale and slowly increasing pressure, I measured the force required to insert into the different designs. They are all the same basic geometry with some minor tweaks (except for #2, which is flat):

Design #1: 11 pounds. Tapered in both Y and Z  along the X-axis (which you can imagine as a line that splits the finger symmetrically).

Design #2: 12 pounds. 2D, flat sheet. Distorts significantly while trying to insert the tool holder.

Design #3: 15 pounds. Tapered only in the Y direction along the X-axis.

Design #4: 11 pounds. Added two additional bending locations and tapered in the Y direction, but this time the taper goes outwards instead of inwards.

Design #5: 21 pounds. This was my original design.

Now, some of you may be saying, “why didn’t you just simulate this and save yourself a lot of time?”. Let’s take a look at the results of a simulation on Design #4.Rev 4 tool holder body v4.png

This is showing the total deformation with 11 lbs of force applied. The force location might not be quite right, but that’s not critical here. Notice that maximum deformation is 0.005 mm — in other words, 5 microns. Now that amount of deformation is nowhere near the required deformation to seat the tool holder in the finger (approximately 4.25mm).

The first point of error in comparing these is the scale (and my measurements which are probably somewhat subjective). A better method for this would be using a setup where values could be pulled directly off the load cell, preferably with some tunable power source pushing the tool holder (like a pneumatic cylinder).

The other major factor is that these parts are 3D printed, so they deform more easily. Simulating 3D printed objects requires playing some funny games with things and is overall not that fun, so physical testing is easier and more straight forward.

Mill Upgrades – Air-Over-Hydraulic Drawbar Part 1

I spent some time reorganizing the shop after several weeks of pretty much total inattention to it. This included finally building a keyboard mount so I can now reach it while close enough to the mill to reach/look in (really handy when indicating stuff in). Not shown are the grinders and other welding supplies sitting in a large plastic bin and nagging me to come up with a real storage system on the wall.

I also made some real progress on the power drawbar. Most of the structure of the system is ready to go. I’m using an air-over-hydraulic system, with an Enerpac cylinder and a 33:1 pneumatic to hydraulic booster. Below you can see the system. The pneumatic valve is in place on the manifold, I still need to wire up the relay, and then I need to figure out the Mach3 side of things. I do think those parts will go quickly.

IMG_3989

I also have the materials for the new drawbar, but haven’t completed the new drawbar clamping nut, or figured out exactly how I’m going to setup the mechanical components to keep the Bellevilles centered on the drawbar and the drawbar centered in the spindle.

Not pictured is the two attempts at the mounting plate for the hydraulic cylinder assembly — the first was for fit testing and some critical dimensions were off just a little, the second I cut the wrong size stock and didn’t realize till a while into it. Hopefully attempt three will do the trick.

I also did some work to design a fixed ATC assembly I can use once the hydraulic drawbar is installed. This will be a good opportunity for me to test software as well, as I’m sticking with Mach3 for the time being (with the next stop most likely being LinuxCNC, although it’s possible I’ll go for Acorn Centroid). I’ve already started on a new screen set for Mach3 which includes an ATC, and expect that will be for sale at the same time the ATC is ready.

Fixed ATC Assy v4.png

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 tip: 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.