[Arbo]

Finally putting together a new dust boot with brushes... epoxy setting up...

[Arbo]

Bought some felt pads, as I think I'll go that suggested direction with wipers.

And rather than spend time creating a new screen set, I'm going with Gerry's Aqua, slight modifications (get rid of a/b axis stuff and a few other things).

Setting up a mounted piece of copper pipe for the centering routines... plan to use that to mark a constant x,y and subtract out needed distances so my zero is always the same spot. Much easier than the nightmare I was fiddling with.

I said something to a friend about limit switches and how it seems possible they are only good for one use, for if your machine is rapiding out of range, at such speeds switches will be destroyed before the machine stops. He suggested magnetic switches, like for home security on doors and such. Think that would work, or has anyone tried such a thing?

[CarveOne]

Bought some felt pads, as I think I'll go that suggested direction with wipers.

And rather than spend time creating a new screen set, I'm going with Gerry's Aqua, slight modifications (get rid of a/b axis stuff and a few other things).

Setting up a mounted piece of copper pipe for the centering routines... plan to use that to mark a constant x,y and subtract out needed distances so my zero is always the same spot. Much easier than the nightmare I was fiddling with.

I said something to a friend about limit switches and how it seems possible they are only good for one use, for if your machine is rapiding out of range, at such speeds switches will be destroyed before the machine stops. He suggested magnetic switches, like for home security on doors and such. Think that would work, or has anyone tried such a thing?

There have been some builds on the Zone that used the magnetic switch. I believe there may not be fine enough resolution with some of them for accurate homing purposes though. They should work ok for end stop limits.

With the lever arm microswitches you'll need a shallow ramp in both directions that will allow backing up without hanging and breaking the switch. CNC4PC.com has some small roller tipped switches that work well with shallow pyramid shape wood or plastic blocks. The pyramid needs to be just high enough to raise the switch and reliably trip the switch in both directions. Too much lift will crack the plastic case because the short lever is fairly stiff.

CarveOne

[ger21]

As Carveone mentioned, limit switched should ideally be mounted out of the line of fire, with a ramp to activate them that can slide past them.

Not sure if you've seen them, but the Photoshop files for the screen are available for download if you want to modify the buttons or backgrounds. If you don't have Photoshop, I think you can open them with Gimp, which is free. If you need any help, let me know, as it's a bit complicated. I figure I spent over 100 hours working on it.

PhotoShop Files

[Arbo]

I don't think I want home switches, because frankly after playing with this thing for a while, I don't see the point, and I doubt the accuracy of it always being in the same exact spot when homed. I am almost ready to give up on limit switches as well, as no matter what debounce settings I use, they can be falsely triggered, and the machine doesn't go where it's not programmed to go. Yeah, there 'might' be some situation... I just don't see it. Perhaps I'm looking at it wrong.

Yeah, I got the ps files from the mach forums. They open in gimp, but without layers (ie, buttons are all merged down), so not so easy to modify, but I don't think other than moving around some stuff and altering the backgrounds to support it I will be changing much.

[ger21]

If you need some buttons with different text, let me know. I have them broken into separate files, so I can change text pretty easily.

I don't have any switches on my current machine. I use softlimits, when I remember to turn them on, but the only time I've ran into the softlimits is when I purposely want to go past them. They are handy if you're jogging to the far end and can't see exactly where you are, as they'll stop a hard crash. You're right, with a stepper machine, it's only going to go where you want it to go. I home my machine by jogging the X and Y axis up to the hard stops, and refing there. I have my home offsets set to -1, so my 0,0 is 1" from the hard stops. It's quite repeatable that way.

[Arbo]

That's pretty much the way I will be going. I need to look up and see if the 'tool change' location, and soft limits work based on the machine coordinates or the work coordinates. Seems it should be based on machine numbers, otherwise they seem kinda useless as your work coordinates can be ever changing (ie rezeroed).

I think I'm good with buttons, I may change the "Load Program" to "Main Screen" though, but that's easy enough... I'm liking your screen set and it's graphics.

[Arbo]

I pocketed a circle in a piece of wood and set the bit of copper pipe in it, off to the side out of normal work area.

Then I added the following to the end of the 'find center' routine:

	' set x and y so we get a constant zero
	Call SetDro (0, 5.2213)      '  distance from wanted zero to center point
	Call SetDro (1, 25.0722)     
	Sleep(1000)   ' give it time to update before trying to move.
	
	Code "G0 Z2"   ' change this to go to safe z
	
	While IsMoving ()   'wait til it's done moving
	Wend

	Code "G0 X0Y0"     ' go to constant zero
	
	While IsMoving ()
	Wend
	
        DoOEMButton( 1023 )   ' zero machine y
        DoOEMButton( 1022 )   ' zero machine x
        Sleep(1000)
        DoOEMButton(1008)     ' zero x 
        Sleep(1000)
        DoOEMButton(1009)     ' zero y

So once it figures the center point, it set's x and y dro's to a predetermined amount (which is the measured offset from my desired constant zero), moves the router out of the way in the z axis, then moves to what is now the constant zero spot on the table.

Once it get's there it needs to set the machine coords for x and y to zero, so I call the DoOEMButton functions which 'home' those axis. Being that I don't use home switches this just sets the current position to zero.

That of course changes my 'work' coordinates, so I have to re-zero them as well.

Now I am set to start working from there (if I already did the Z zeroing).

Sound reasonable? I figure if something goes wrong I can run the routine to get a base zero again, and then use any offsets I may be using for any given work piece.

I will also make a movable tube as well, which means I'll probably move the new centering button code to a different button.

Oh, and I have the Sleep()s in there as I found without them I got some strange stuff going on at times, or things didn't get updated as needed. Perhaps my machine was getting ahead of itself.

[Arbo]

Getting things cleaned up. Saw the cable carrier thread and may need to find some plastic to cut and make some of those, as I just do the 'dangle' now.

Gerry, some screen shots of how I modified your Aqua for myself. Still in progress (like changing the graphics for the centering stuff which I put on the run screen, and I realized I forgot the G64 led, etc), but i'm currently working with it as the base.

[CarveOne]

Looking cozy in there now Arbo. If you had painted the OSB paneling flat white before moving everything in there you would need to wear sunglasses while working. It really helps to reflect the light you have available and makes the room look larger.

I'll bet those screens really look cool with the room lights off.

CarveOne

[Arbo]

Ok, I was getting the whole thing re-aligned, as I had banged the x and y pretty bad a few times while messing around, and noticed my flat and level surfacing wasn't aligned right (one side of cut raised higher than the other).

No problem until I go to re-tighten the top carriage that runs on the Y axis and snap the bolts. Oops...

Not too bad, new bolts, line it up again. One side up just a bit more than the other, so play in it. Loosen a bit and tap down, same thing, again, other side, again, same thing, more solid taps and it appears I hit it to hard and broke the bearings.

Couldn't find replacements locally (for under 9 bucks a bearing) so I'll temporarily use two from the x carriages wile replacements come in the mail (they are redundant on the x anyway). Bought some big clamps so I can apply pressure to hold the carriages together while tightening to the axis.

Will use them on every axis and ensure I'm all good.

[Arbo]

Re-ran my gcode for the slices of an X-29, this time with a down cut bit.

The thin parts of mdf that broke off before were all good.

Near the end the machine lost it's mind and was trying to drive way out of limits. I will have to investigate to see why tomorrow. I did run the machine for about 10 hours straight, so I'm thinking it was a heat issue, I'll hopefully figure out what happened tomorrow.

Some lessons learned, but what I have will work when glued together, sanded down, and a bit of filler.

Hope to do the other side tomorrow.

[kbone054]

Hey Arbo,

This is my first post on CNCZone but have been watching your build along with many others and am about to start my 2nd build (first was an MDF machine more for trial & error than anything). I feel your design is the simplest for what I am trying to accomplish and have been thoroughly impressed with what you have done.

It will be very similar to yours, except 4' X 8' and I would like to have R & P on both the X & Y Axis.

Just curious why you decided to stay with the screw on your 'Y' and not Rack & Pinion?

I have searched but am unable to find Ahren's Rack and Pinion system being used on both axis. Anyone have any ideas, suggestions, or links to show somebody's build that used R & P on both x & y?

I am using 8020 material and like the compatibility of Ahren's parts.

I am assuming the y would be built just like the x and just like the videos on Ahren's site, but I am concerned about the Z Axis being too heavy on the router side and potentially being 'lop-sided' (if that's the right word)

Any thoughts would be greatly appreciated.

thanks.

[ahren]

Sean at www.freecncplans.com has built a machine with the R&P drive on both X and Y, and a couple of people with Joe's machines have modified them to use the R&P on both axes. There's really nothing about one drive system over another that influences the stiffness of the machine -- it's all about the bearing system. If anything, since the R&P requires the extended carriages rather than the regular ones, the Z will be even stiffer.

I think Arbo went with the screw on his gantry because it was a shorter travel, and given that the mass of the Z is not that great compared to the whole gantry, the speeds are comparable. For a shorter axis, the screw drive is slightly more economical.

Best regards,

Ahren
www.cncrouterparts.com

[Arbo]

Yes, as Ahren said, I went with the screw because it wasn't a huge span, so I didn't see any issues with keeping that one a screw.

I believe CarveOne is also retrofitting his build to use the R&P on his Y axis, so you might want to look for that one.

If I used it, I'm not sure how I'd go about it. I wouldn't want to go with a y rail less than 6 inches... Hmm.. perhaps I'd have a spacer to raise the y axis the 1 1/2 or so so that the top of the y rail only went about 1/2" above the y 8020, and mount the R&P up there. (so the stepper would be pointing up, and the setup would be right behind the z axis.. if you can visualize that)

Paul

[Arbo]

Oh, if you go that way, you do have to plan for the extended carriage (and the R&P will stick out a bit from one side of that carriage) when figuring out your desired usable Y vs the require length of the Y between the X rails.

[CarveOne]

Yes, as Ahren said, I went with the screw because it wasn't a huge span, so I didn't see any issues with keeping that one a screw.

I believe CarveOne is also retrofitting his build to use the R&P on his Y axis, so you might want to look for that one.

If I used it, I'm not sure how I'd go about it. I wouldn't want to go with a y rail less than 6 inches... Hmm.. perhaps I'd have a spacer to raise the y axis the 1 1/2 or so so that the top of the y rail only went about 1/2" above the y 8020, and mount the R&P up there. (so the stepper would be pointing up, and the setup would be right behind the z axis.. if you can visualize that)

Paul

You are correct that a wide carriage will be needed and a 6" rail is what I expect to change to if I do the screw change-out to R&P on my gantry. I already have the rack and the pinion drive on hand for potential use sometime next year. The wide carriages will reduce the travel to less than the 49" that I have now with the narrow carriages on the Y axis. Maybe I can figure a way around that during the gantry redesign effort. Note that my machine is different from Arbo's and other machines using Ahren's products in that my rails are vertically oriented on the X and Y axis and no 8020 extrusions are used. These motors are mounted horizontally. I will have no issues with the Z axis other than to bolt on the wider Y carriages.

My priority right now is to get the machine to run with what it has on it asap. The Y conversion has to wait. I'll be doing some conversion planning during the winter though.

CarveOne

[Arbo]

Well, I opened up my pc out there to clean it out, considering all the MDF cutting, it wasn't too bad. That's good.

I really don't like the bristled dust boot. They are so stiff they can add undue pressure to the whole system. How do you guys set yours up? I fix my height so the bristles are at the same left as the tip of the router bit. I dunno, it just seems my very first one worked the best.

[joecnc2006]

Kent on my forum has designed a great dust shoe, he did allot of research and testing and found the brushes that work and are flexible enough to use. he added an extra 1" row on the inside to prevent the brushes from bending into the dust hose, and also it clamps to the router, and the bottom section is held on with magnets, he did a great design and works the best i have ever tried. He now sells them to our members. I have the Hitachi and he uses a Porter cable. With the removable brush section it is really easy to change bits.

[Arbo]

Promising, just tried to register, guess it's only open to folks who have bought your plans?