[difalkner]

I like your reasoning, Albert. I went with the Hitachi WJ200 - 022SF because it is a far better VFD than the Chinese models and it has far less electrical noise. One thing that I've learned is that Bosch and other companies that tout horsepower ratings for their routers tend to exaggerate their numbers whereas the spindle rating is likely a true(r) number.

My spindle is a 3kW water cooled and yes, it is very quiet and runs very cool. I think the longest job I've run is about 45 minutes and both the spindle and bit were easily handled with bare hands when the job finished. I don't recall the spindle ever getting above just slightly warm.

 

[Albert Z]

Been a few days since my last post. Been extremely busy with work, college visits with my grandson and did I mention that I mentor a teen robotics club. Still I managed to get a little work done on the router.

Finished wiring the VFD electrical panel. The inputs and output wires connect to terminal strips at the top of the panel.

As mentioned in a previous post, the kit did not come with any 30 mm M5 low profile screws. I had to order some and they finally showed up. I finished attaching the wheels to both gantry plates. The bottom wheels are installed with eccentric spacers to permit a tight fit to the rails.

Next I worked on the X-axis gantry front plate by attaching the spacer blocks and 8 mm Acme nut block. I have some concerns about the nut block as it does not seem to be fitting up square to the rest of the plate. I will keep an eye on this and if it becomes a problem I will have to enlarge one of the holes and pin the block to the plate in order to get it into alignment.

I then attached the wheels to the spacer blocks. The wheels on one side are fitted to eccentric spacers for adjustment.

Finally, I have been pondering how to attach the beast of a spindle to the 2060 V-slot carriage. As you can see from the photo, the mounting bracket base is much wider than the 2060 Z-axis V slot. My solution is to manufacture a carrier plate that can be bolted securely to the 2060 with extensions at one end to accommodate the M8 spindle bracket mounting bolts. The carrier plate would be attached with eight M5 screws.

I ordered a 3/16" thick sheet of T6061 aluminum 12" x 12". I drew up the carrier plate in AutoCad from measurements taken from the spindle mounting bracket and the 2060 carrier rail. When my aluminum plate shows up, I'll cut out the part on the robotics club CNC router.

Last night while fitting all the pieces together I realized that the overhang from the spindle mounting bracket is going to interfere with the V-wheel mounting bolts thus restricting the amount of Z-axis travel to about 3". I would like at least 4" of travel and preferably 5" depending on the height of the spoiler board. As the build progresses I will make a determination of exactly how much Z-travel is available. At that point I may opt to buy a longer 2060 carrier and lead screw (250 mm). We shall see as we progress.

 

[Albert Z]

Some Thoughts on Spindle Mounting

If we go back and look at my first post, I attached a stock photo of a complete OX-CNC Router. I you look closely at the photo you can see clearly that the V-rail for the Z-axis is supported by four rollers. Because of the heavy overhung load due to the heavy spindle and mount, it would be highly desirable to have the extra rigidity provided by the fourth roller.

This would seem on the surface to be a straightforward modification. Simply replace the existing 3-hole spacer block with a 4-hole spacer block, add an extra pair of wheels and Bob’s your uncle. Hold on! Not so fast my friends. This is turning out to be a bit more of a slog than I first supposed.

Based on the stock photo showing four rollers, one would think that a 4-hole spacer block would be readily available from one of the on-line suppliers of OX kits. Such is not the case! I have scoured the internet looking for a 4-hole spacer block and have come up with zilch – nada. Oh, there are lots of 3-hole spacer blocks to be had, but no 4-hole, at least not that I have been able to come up with.

The next avenue I explored was making my own 4-hole spacer blocks. The original spacer blocks that came with the kit were fabricated from 12mm x 20mm anodized aluminum. This size is not readily available, at least in small quantities so I opted for ½” x ¾” aluminum stock which is easily obtained at fairly low cost. I drew up the part in AutoCad but ran into another snag. The eccentric adjustment spacer is a precision fit into a 7.13mm hole which is not a standard drill size. Grainger offers a 7.13mm reamer at the bargain price of $176.00. What I don’t want is a loose fit on the eccentric; otherwise I would be better off with no fourth wheel. So that essentially kills the idea of manufacturing my own spacer blocks.

So, how to get that fourth wheel installed without breaking the bank and re-designing the Z-axis? My solution is to buy a 3-hole spacer block, saw off each end and mount it to the X-axis plate above the existing 3-hole spacer block. This way I would only have to drill a pair of holes in the X-axis plate to accommodate the 5mm fixing screws. See the attached drawing for details.

So in order to make these mods I ordered a pair of wheel assemblies, a spacer block, some ¼” spacers, a pair of eccentric spacers and hardware for installation. While at it I also ordered an anti-backlash nut block to replace the one that came with the kit. So now we wait.

Electrical Cabinet

Meanwhile, I got started on the electrical cabinet by installing the exhaust outlets at the top of the cabinet and the fans in the bottom of the cabinet. The fiberglass reinforced plastic is tough as hell on saw blades. Completely destroyed two blades cutting the holes for the inlet and outlet.

 

[jw2170]

Great to see how this build is progressing, Albert.

 

[Albert Z]

Not much going on in the shop these past few days. Been working on the electrical panel layout and component placement. This will determine where to put the penetrations for the cables to the stepper motors and limit switches.
Referring to the attached drawing (sorry if it’s cocked a little), the toroid transformer, 10,000uF capacitor and 50 amp full wave bridge comprise the 36 volt power supply. The transformer is double wound with each winding rated at 7.5 amps. I am wiring them in parallel to increase the overall capacity to 15 amps.

In the upper right hand corner are the auxiliary power supplies. There is a 24 volt power supply dedicated to the RMHV3.1, another 24 volt supply for the contactor coil located on the VFD panel and a 12 volt supply for the fans. These are DIN rail power supplies and take up very little room in the cabinet. (See photo).

I used conventional terminal strips for the 36 volt DC and 110 volt AC distribution.

For the control wiring I decided to use DIN rail terminal blocks. These are quite convenient to use since all you have to do is strip the end of the wire, insert and snap shut for a solid connection. The ID for each terminal block corresponds to one of the wires coming from the DB25 connector except for the 24 volt RMHV3.1 power which goes directly to the DIN mounted power supply. In the process of laying out the connections for the terminal block, I realized I forgot to include the separate 12 volt supply and ground connections for the probe and limit switches. I will have to go back into the control box and add these.

Happy Thanksgiving everyone and thanks for watching my thread.

 

[Albert Z]

Continuing on from my previous post, I have spent quite a few hours working on this project with not a lot to show for it. Nevertheless I have been soldiering on with most of the time spent on mounting the electrical components to the sub-plate which will get installed in the electrical cabinet. A good bit of time was spent putting labels on all the terminals. In addition, I installed the DB25 connector into the side of the electrical cabinet as well as the 4 connectors for the stepper motors.

I got tired of waiting for the spacer block that I was going to partition (see post #23) so I took one of the existing spacer blocks and cut it up in order to prove the concept. Seems to work pretty well - now I just need the other spacer block to finish the Z-plate assembly.

How are we doing with the budget?

Way back in post #1 I estimated the cost of this project to be $2000. Every project manager has to track expenses vs. budget so this is where we stand to date:

OX CNC kit $514.86
CNC Controller $291.50
Electrical Cabinet $143.99
Spindle & Accessories $262.99
Stepper Drivers $ 84.76
Misc. Elec. & Mech. parts $396.97

Total Spending $1695.07

 

[jw2170]

I like following your posts, but starting to get a bit too technical for this old brain.... LOL

 

[Albert Z]

Been a busy week, but I finally got all of the mechanical parts I need to get on with the build. I installed the new spacer block and anti-backlash nut on to the front plate of the X-axis assembly. I test fitted the Z-axis 2060 V-slot and everything looks good. I adjusted the eccentrics so all the wheels turn and the 2060 slides up and down without binding.

Next I attached the NEMA 23 stepper motor to the X-axis gantry back plate. This was followed by joining the front and back plates together with the rollers and appropriate spacers sandwiched in between.

Next we moved on to the Z-axis assembly. Here is where we ran into a bit of difficulty. The Bill of Materials specifies the spacer between the motor and the end plate to be 40 mm. However, when I assembled the unit this resulted in the motor coupling hitting up against the end plate. I took everything apart and measured the spacers and found that they were only 38 mm long. To solve the problem I used three 1 mm precision shims to increase the distance to 41 mm. This gave me 1 mm clearance between the coupling and the end plate.

Next I attached the motor assembly to the Z-axis 2060 V-slot. Then I slid the X-gantry assembly onto the Z-axis V-slot and threaded in the Acme lead screw into the flexible coupling. Then I tightened the coupling and brought the lock collar up against the bearing and tightened it as well. To finish off the Z-axis assembly, I slid the lock collar and bearing on to the lead screw and then attached the bottom plate to the 2060 V-slot. I adjusted all the eccentrics so that the Z-axis assembly moved freely when turning the coupling by hand and that all the wheels were contacting the V-slot.

Now it was time to move on to the X-Axis gantry assembly. The X-axis gantry consists of three aluminum extrusions: two 2060 x 500 mm and one 2040 x 500 mm as well as two side plates with NEMA 23 stepper motors attached. I started by attaching one of the side plates to the aluminum extrusions. Next I slid the X/Z gantry assembly onto the aluminum extrusions as well as sliding in some T-nuts for attaching the reinforcing corner brackets. Next, I attached the other side plate as well as the reinforcing corner brackets and we now have a complete X-gantry assembly. Before going any further I will check to make sure everything is square and plumb.

Sooner rather than later I must get back to the electrical wiring, but in the words of Scarlett O'hara " Tomorrow is another day"

 

[Albert Z]

While checking to be sure that everything is square and plumb I identified two problems. One of the issues involves mounting the spindle, which I will address a bit later. However, my immediate concern is that the Z-axis is not plumb. I spent a couple of hours measuring and thinking about the problem and I believe I have identified the root cause.

Using a machinist’s square I checked the plumb of the left side spacer vs. the right side spacer. First the left side. I pushed the straight edge up against the spacer block and observed whether or not the base was sitting squarely on the work plate. Indeed it was as I could not discern any gap whatsoever between the base and the work plate. Note that the bubble is just a touch off center to the left. This is shown in the following photo:

Next I moved to the right side and repeated the procedure. Here is where things began to get a bit sticky. I slid the machinist square along the work table until it just contacted the spacer block. I immediately observed that the base of the machinist square was still firmly on the work table but the bubble had shifted considerably to the right.

This was certainly an indication that the right spacer block was not square and perpendicular to the work table. But by how much was the question. Next, I moved the scale until it contacted the entire spacer block. Then I observed the relation of the base to the spacer block, there was a significant gap as shown in the next photo.

So where do we go from here? One option is to scrap the entire project and take up basket weaving or needlepoint. But that isn’t gonna happen!

Here’s what we’re going to do: Dis-assemble the whole bloody works and find out why the left side spacer blocks are cocked out of plumb. Fix the problem and I’ll get back to you.

As far as the spindle mount goes, my original thought was to machine an adapter plate to attach the spindle mount. But that would not work because of interference with the spacer mounting bolts. I decided to order a totally different spindle mount and we will see how that works out. Talk about project cost creep!

Meanwhile, I’ve got a bit of electrical wiring to deal with.

 

[TimPa]

looking pretty good, enjoying your build, thanks for posting it!
on the spindle mounting plate, you can "design in" some adjustablity for tramming the spindle (oversized/elongated holes?). typically, one axis is trammed by loosening the mointing screws and shifting the spindle until perpindicular to the table. the other axis is trammed by inserting shim material strategically where needed between the spinle and mounting plate. probably a good idea to get it close now, then do a final check later when you get it all assembled and locked down.

tramming is easiest done by bending a 1/4" rod into a z shape. insert one end into a 1/4" collet. rotate the rod around so you can see where the rod is closer or farther from the table. hope i described it well enough, i'm sure there are utubes about it.

 

[Albert Z]

Acknowledgement

Thanks for the input Tim. I’m not quite at the stage where I will do actual tramming, but I will use your input when I get down to the final tramming and leveling. One quick question: Steelers or Eagles?

Progress

This is going to be somewhat difficult to describe, even using photos; but I will give it my best shot.

I completely dis-assembled the entire gantry, then proceeded to re-assemble it step by step. This time, instead of tightening the bolts as I went along, I left everything loose and only tightened everything at the end when it was square and level. Also, I alternated the tightening sequence so that one side or one sub-assembly would be torque balanced as I proceeded. Another significant change in the re-assembly process involved the Z-axis support rollers. I will try my best to explain.

If you go back and review posts #23 and #28 you will see that I added a 4th support roller for the Z-axis spindle support. If you look carefully, you can see that the spacer blocks for both sides are machined identical; that is they are machined with 7.12 mm openings for a 6 mm eccentric spacer. Aha! But the instructions provided say to use a 6 mm aluminum spacer on one side and a 6 mm spacer on the other.

So, I removed the 6 mm aluminum spacers and replaced them with the 6 mm eccentric spacers. Now I had some adjustment available when I wanted to tram my router. Each eccentric provides up to 1.25 mm of linear adjustment, so if I adjusted the eccentric 1 mm on the right, I could compensate 1 mm to the left and thus adjust the perpendicularity of my spindle. Jeez, I hope that makes sense to whoever is reading this!

OK folks, here is the bottom line: after re-assembling the entire gantry, and incorporating the techniques mentioned above, everything is within 0.5 degrees of perpendicularity which I expect to correct when I do the final tramming.

And now, if you don't mind, can we get back to the electrical wiring?

The inclinometer images represent the top of the Z-axis stepper motor, the X-axis gantry rail, and the base that the entire assembly rests on.

 

[Albert Z]

It's Beginning to look like a CNC Router

I was on a roll today! I started by fitting the gantry assembly to the 2080 x 750 mm side rails. These side rails sit on top of two 2040 x 494 mm cross pieces at each end of the base assembly. The "X" and "Y" rails are joined by a special end plate that you can see in the photos. In hindsight I should have made a drawing of these end plates because I cannot find them anywhere from the usual sources on the internet.

Well, I'm not going to disassemble this puppy just to take measurements and make a drawing.

Next, I added the 454 mm long piece of 2040 above the 4954 mm long pieces (the photos tell it all better than I can describe). It's important to mention that you have to plan ahead in order to avoid dis assembling later just to add some "T" nuts. So, I inserted 3 T-nuts into the top of the 454 mm 2040 for attaching the spoiler board, two additional T-nuts in the 494 mm section for attachment of the router to the plywood base, as well as the T-nuts required for the triple L-brackets.

Finally, I added the two 2080 x 710 mm Y-axis spoiler board supports and base frame stiffeners. These were secured to the 2040 cross pieces with triple L Brackets as shown in the photos.

During the entire assembly process, I was constantly checking the assembly for squareness using machinist squares and calipers. When I was satisfied with the squareness and alignment i tightened all of the fastening screws.

Mechanically, I see five major steps to accomplish going forward:

1. Install the timing belt mechanical dive system
2. Mount the spindle
3. Mount the spindle cooling system
4. Install the spoil(er) board
5. Fasten the router to the table base

Tomorrow I am off to Lowes to buy some MDF. I promised to help my grandson with his physics project, and I may (not promising) get back to wiring the control panel.

I want to emphasize once again that the instruction set that I am working from is NOT the same machine that I am building. However, it is a helpful guide as I slog through this process.

Until next post...

 

[difalkner]

Looking really good. Kinda cool seeing one without any dust on it but they'll get dusty pretty soon once you begin using it.

 

[Albert Z]

As promised, getting into the wiring of this puppy. First, I finished all of the openings into the electrical cabinet and installed the rocker switch, the fuse holder and the IEC electrical power connector.

All of the external connections other than the DB25 will be via 4-pin aircraft connectors. I mounted these on the side panel below the DB25.

A good deal of time was spent crimping and installing the contacts into the DB25 making sure that they matched up with the connections to the controller.

I wired up all of the 110 VAC connections to the 12V and 24 V power supplies. Still need to tie all of the grounds together.

 

[TimPa]

looks like you are having great fun! and doing a really nice job at the same time. thanks for posting. there is light at the end of the tunnel!

 

[Albert Z]

Thanks Tim,

You're right, I'm having a ball doing this project but I'll have more fun making sawdust!

 

[UglySign]

@Albert Z Hey Al... your avatar. I've seen it before. What movie?
Looks like Burgess.

 

[Albert Z]

The Movie is Dr. Strangelove: Or How I Stopped Worrying and Learned to Love the Bomb It was released in 1964

The actor in the avatar is Peter Sellers playing the role of Dr. Strangelove. In the movie he also played the roles of RAF Group Captain Lionel Mandrake and President of the United States Merkin Muffley.

Produced and directed by the incomparable Stanley Kubrick.

 

[UglySign]

The Movie is Dr. Strangelove: Or How I Stopped Worrying and Learned to Love the Bomb It was released in 1964...

OK... seen that on youtube a couple years back. Now Yoohoo wants you to buy or rent it. No thanks.
But thanx for the info!

 

[Albert Z]

Spoiler Board

Went down to my local Lowes and purchased a 4' x 8' sheet of MDF. Took two of us to get it off the shelf and over to the cutting station. It yielded five pieces of spoiler board 17-7/8" x 29-1/2" enough for a lifetime (mine anyway).

Set one of the pieces into the router and it fit perfectly!

Electrical Control Cabinet

Meanwhile, back in the electrical department:

• Finished all 110 VAC connections
• Finished wiring up the 36 VDC bus and distribution
• Wired up the 12 VDC connections for the cooling fans
• Wired up the 24 VDC power connections for the RMHV3.1 controller
• Completed all of the connections from the DB25 to the distribution blocks on the DIN rail
• Completed all of the wiring into and out of the stepper motor controllers

Next I took my DVM and checked for any short circuits as well as continuity from the distribution blocks on the DIN rail to the DB25 as well as the stepper motor controllers. I plugged in an IDE power cord and connected the controller box to the electrical panel via the DB25.

Without any further procrastination I flipped the power switch on and...

Voila!!!

The fans are running, the stepper motor drivers are energized, the RMHV3.1 controller is energized and sees no faults.

There is much more to do. I have to wire up the limit switch outputs as well as the spindle control outputs. Then, after testing, I have to re-locate the electrical control panel to the router cabinet base. Then, connect the stepper motors and make sure we have proper rotation.

Meanwhile we still have to address the 220 VAC side and the spindle VFD.

So here are some pics from a rather exciting week for an electrical geek: