Another new router project

[ZipSnipe]

Looking good, my only concern is the size spindle motor(That heavy blue PacificScience motor). I would watch for deflection maybe use a laser pointer in the spindle to shoot you a reference point on the table before you mount the motor,. Then when you go to mount the motor check to see if it( reference point) moved. I cound,t tell from the pics if you got the z axis mounted to that top gantry flat beam. If not maybe fab a bracket for that spot. Otherwise keep up the good work.

[acondit]

ZipSnipe,

Actually, that heavy blue PacificScience motor is now mounted on my 9x20 lathe as a variable speed mod to my lathe. My router spindle is a PorterCable router. The blue motor on the top of my Z is a Superior Electric Stepper. And after I get the limit switches installed I am going to have to do a lot of checking about deflection. All of the thompson bearings are ball bushings and I am thinking about replacing them with something like the frelon bushings if there is deflection attributable to the bearings.

Alan

[acondit]

I used Igus B15 Energy Chain for the Y-axis wiring. The applications tech at Igus helped me figure out which size to buy and how much I needed. I would have bought way too much without his help. You only need enough to start at the middle and travel to each side Plus the curve. I would have probably bought enough to go from the front to the back plus the curve. I still need to fasten down the loose wires.

I also used Igus Energy Chain for the Z-axis wiring, both where the Z-axis travels on the Y-axis and the Z-axis itself. I found a good buy on a couple of pieces on eBay.

I probably need to use some spiral wrap to neaten up the motor wiring.

Here is the AC plug for the router spindle. I haven't decided whether to coil the router's cord around the router or shorten it up. I am leaning towards just coiling it up so that I don't have to have an extension cord anytime I want to use the router by itself.

Alan

[Halfnutz]

Great going Alan, the cable carriers really add a professional touch, and they are nice 'cause they're the smaller size, perfect for a router. I am really interested in your optical switch, what a great multi tasking little DIY, I bet the boards or a kit would sell well, very cool. With a nice paint job youl have a machine that looks like you spent 3-4 grand. Any more details on that switch would be great! I'll check your website.

[acondit]

Halfnutz,

Thanks for the compliment. I see now why people often build more than one router. I have learned a lot in building this one and have some things that I would (will?) definitely do different on another one.

I have gone through four iterations of circuit boards on the limit switch to get to one that I really like. I have about a half dozen of them and I want to do some testing before I even consider trying to sell them to someone else.

Alan

[acondit]

I am thinking that I will save my optical switches for Home(s) and use mechanical switches for the limits. It will be easier to create a serial loop of NC switches with the mechanical ones.

I am thinking about mounting the two X-axis limits like the one I show in the picture. I will have to drill the tab on the gantry and put in a pan head machine screw as an adjustable stop.

What do you all think?

[acondit]

As I was starting to install the limit switches, I discovered that the x-axis was going the opposite direction that I expected when I jogged and the z-axis was homing down instead of up.

I am running emc2. Both problems turned out to be easy fixes. I found a message in the emc forum where someone else had the same problem of the axis moving the opposite direction to that expected and the solution was an easy edit of the ini file. The homing of the z-axis was also an easy fix. I had set all three axii to home to 0 and I just had to change z to home to max-z.

[moonlighttech]

Hi Alan -
I've visited your web page. Very nice, like the good work you've done with your CNC router. I love the limit switch! I designed one very similar to show the status of a vacuum valve. You do PCB's too? I also noted you might be on multiple forums? I gotta ask, how do you find the time!! Are you busy or what! Okay, I'm impressed! Maybe I should stop playing Hoyle card games (my clock indicates It can bend space and time) and focus!! I must have that tilt foundry!

I have always preferred non contact limits. I've even designed DC motor controllers that sense end of travel load currents. One of my favorites (that you don't need) is just a glass encapsulated reed switch with a rare earth magnet. You move whichever is the easiest. I use the micro style SPDT type so it can be normally open or closed, high or low. I imbed it in a 5 min epoxy block if it's mounted above the surface or I route a small slot and bury it flush to the surface. The magnet is .125 dia and .187 thick and it gets imbedded flush as well. It makes some people nervous when they can't see the limit and can't hear the click. I like it.

I tested repeatability on a single stage with 1/4-20 acme leadscrew and a dc motor control (not relay). As the switch position moved the stage stopped within 6 microns, about .00025 which is pretty good for a home position. If you implement a backup and creep manuver it might improve even more. I couldn't do that then. The reed snap may vary that much too, I don't know. A PM DC motor has cogging but it's alot coarser than a stepper which depends on it. The elimination of the DC motor and gearing to drive the leadscrew might result in better repeatability by stopping on a higher resolution cog of sorts.

I've been doing other things than CNC for the last few years. Things have changed. There used to be an outfit called Digital Design in Florida that had a program called Z-Trace which outlined gerber files into G-code. I think they're gone. Any suggestions? A better way?

Looking forward to your progress and comments!
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[acondit]

moonlighttech,

I am officially retired. I have a problem in that I am much better at starting new projects that getting them completed. I have enough projects started to probably keep me busy for a year without starting anything new. I am trying to turn over a new leaf and get several of my ongoing projects completed.

I have been designing (in my head) a case for my optical limit switch that would allow it to be activated by a plunger from either side (like the limit switch on the X-axis of some mills). I really like your idea for a magnetic limit switch. Magnetism works through dust. How is it affected when machining steel or cast iron?

I have my circuit boards done commercially.

[moonlighttech]

Alan,
I'm sure any magnetic particle near the magnet would be attracted to it. My guess is that it would blurr or spread the field and change the switch point. The physical location is the determining factor. I would probably mount the reed switch for X somewhere least affected, say the leadscrew nut, and keep the magnet at the extreme ends. You could use 2 reeds wired to indicate both ends or just a state at each end of travel. The other stages are higher and affected to a lesser degree. Again it's the physical mounting. I don't have a complete answer. This is one of those challenges I'll face when I do my machine. I hate to say they won't work or the mounting difficulties pass the point of being realistically worth the effort just yet but it may be so!
This is also coupled to another design challenge of protecting the bearing rods or rails. I guess "up, up, and away!" actually refers to a rod or rail mounting location!! Just as "put it where the sun doesn't shine" is for mounting magnetic reed switches!! Sorry this is my best answer but I haven't done it yet. Who knows, the answer may be rubber boots, or a lip over a ledge, even additional magnetic attractors to filter a specific area. Is gravity your working friend?. I beleive there is a usable solution. You may already have one!
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[Mr.Chips]

Originally Posted by acondit Well, I figured out how I wanted to do the Y-Axis motor mount. So here are some pictures with the motors mounted on the X, Y and Z axii (Latin right) and the Z-Axis mounted on the machine. I still need to finish the power supply and controller setup. Then I will need some help on getting the software working. Alan

Say is that a Bill P design Cyclone Vacuum in the backfround of Post #33? It is a perfect parterner for the dust maker CNC. I will be building one soo also.

Hager

[acondit]

Originally Posted by Mr.Chips Say is that a Bill P design Cyclone Vacuum in the backfround of Post #33? It is a perfect partner for the dust maker CNC. I will be building one soo also. Hager

Pretty much. I bought the cnc cut cyclone parts from a gentleman in Colorado. I bought a 2hp ShopFox (Grizzly) dust collector and married the two together.

It really does a nice job. I use it more as a huge vacuum than a dust collector. I have a twenty foot hose on it and it reaches most places in my shop.

Now that my router is almost done, it may begin to see more use as a dust collector.

Alan