Well, I'm toying with the thought. Never built anything CNC. Electronics & control options confuse me a bit, but a buddy works professionally with these things, and I can pay in beer.
From wandering all over the Net, the Sphinx keeps intriguing me. Pretty much the original build, rather than a scaling up. A few questions some to mind as I contemplate tho:

• With dual screws and motors on the Y, how dependable are things? Seems like if a motor goes, or something binds, the machine would want to tear itself apart. That's the bad case that comes to mind. Without catastrophe, however, how do you fine adjust squareness of travel?
• Given stock build size, what motors are preferred, say for working aluminum? With 2 on Y, I'd think smaller ones would suffice. Z would seem to benefit from a big one, and perhaps Y as well. I see hefty motors talking 425oz clamping, and others in the 270-300oz range. If bigger is better,,, then OK, I get that. But I wouldn't mind keeping weight and footprint down either.
• Are motors with dual shafts worth having? I was rather wondering if attaching knobs to the protruding shaft could come in handy for manual positioning/adjusting.
• What kind of weight are we talking, for say, a stock build? 50ish lbs? Suspect this is something I'd have sitting on rack shelving, and pull it out to set on a table when I want to play.
• As far as I understand leadscrews,, is there a reason to have chosen a 8*8 2 pitch, versus say a slower 8*4 2 pitch? I'd have thought the slower lead would result in better repeatablity/accuracy... no?
• What sort of accuracy should be a reasonable expectation, of say, the standard build with a Dewalt router? Yes I know, that's a "It depends" answer, but looking for a warm fuzzy to decide what I would cut. Would +/- .001" across a 5" aluminum part be unreasonable?

Dumb/novice questions perhaps.
Too bad there isn't a package of all the pieces set up to buy. I see such for the Ox. Something about the Sphinx seems better to me tho.

====== edits/adds
No responses, so perhaps my questions were dumber than I thought
After several days of reading and poking, some answers and thoughts come to mind.
On weight, I say a mention of 70lbs, but wasn't clear if that was with the added cast aluminum table or not.
More I look at the layout and guess my usage, the less I like the Y and X motors sticking out. Especially the Y, tho. Is there enough clearance for the plates if the Y's were both done with the reduction plates, as the Z was? Shortens up the footprint a bit and leaves me less likely the bang the motors when moving around. Also perhaps, if one Y motor died, I might think the other working one would have the belt shear off, minimizing machine tearing itself apart?

More I consider it, the more I think putting the whole thing on a HarborFreight 30*24 rolling tool cart is interesting to move around in a limited space garage. Tucking the X and Y motors in to stay within that footprint is, thus, even more interesting to keep Murphy at bay.

Mecahnically isolating all the motors from the screws with belts, however, does make me wonder even more about repeatability and accuracy. But I've really little idea how good these belts are too.

 

So I have ordered and received everything off the bom to build a 1000mmx1000mm cbeam cnc. I start assembly of the side rails and realize the instructions call for 4 x 27mm m5 screws. I check my parts and don't have said screws. I start cussing as now I will have to place another order. I plan up the bom again to check and find out there are no 27mm m5 screws listed. I don't think the parts store has them either.

My question, do you cut 30mm to 27mm? Or will 25mm work?

 

You cut. 27mm doesn't exist. The alternative is a 3/16" plate with 25mm, or a 5/16" with 30mm.

 

Cut. When I've had projects when I wasn't sure what lengths I'd need in the end, I just bought lots of the larger size and cut them down. Before cutting, run a nut down the thread up to the head. A longer nut is better than a short nut. After cutting you then bevel the cut end a bit. When all done, taking the nut off will correct the thread at the cut end a littletoo (if needed).
Myself, I tend to use a grinder to chop off. Then chuck the screw head first into a cordless drill (remember, I've got the nut on there), spin it up in the drill and use a file to bevel the end.
Resist the urge to use dikes. You won't end up with a nice round end or threads where you cut using dikes.

 

Just a quick look at the cbeam and lead screws I ordered. Looks like I will have to cut the cbeam to give me some working room on the lead screw. I ordered 1000mm cbeam and 1000mm lead screw. I would think the lead screw would have been cut a little long to give you space for the end caps and coupling. Especially since they were ordered on the same bom. Pretty evident I wanted a 1000mm cbeam linear actuator.

Have any of you used a chop saw to cut the cbeam?

 

Thanks all for the quick replies. I am sure it will all work out. Will update with progress as I start to build.

 

Hello friends,

Just a quick note about my Sphinx, it is up and running for a while now but I've been too lazy to post a pictures of it finished. So, finally, here they are:



This Sphinx is 1000x750mm which allows me to do cuts of 820x585mm without the dust collector, and a little less (on the X-axis) with the dust collector. I did not try to cut aluminium with it yet, until now I only did cuts on MDF (very annoying dust) and plywood.

My next task is to complete the electronics box, not very safe to have 110V exposed Already have the case modeled and will post a picture when it is assembled, hopefully I will complete it next weekend.

Kyo, the Sphinx is a great design, awesome job my friend

Thanks,
Jorge

 

I must apologize, the lead screws I ordered are indeed longer than the cbeam. Not sure how I messed up but I went back with a tape measure and measured each one to 1040mm and the 500 was 540mm.

 

I see you have the sketchup file for the whole thing, but do you have the full fusion file?

 

Kyo

My first build and I chose yours, but I have a question. The z axis shows a belt reduction in your build videos but the bom that I ordered from shows both pulleys the same size. What are the correct parts?
I'm also upsizing to 1000 x 1000. I may need to find a wider gantry plate for the z axis since I will be using a 1.5 Iva water cooled spindle motor. (65mm). I ordered 2 of the openbuilds clamps to attach it to handle lateral stress.
I'm also toying around with the possibility of using linear rails and v wheels and possibly going to steel on the heavy load bearing wheels.

Any thoughts? Looking forward to your comments.

Should begin the build within 2 weeks, waiting on parts and anodizing all aluminum.

Thanks

Daryl Eden

 

Well,,, I am still contemplating
So,,, you are coming out with something new and improved? Gives me something more of a reason to procrastinate then Well at least on that front, as perhaps I get around to converting my lathe over to a variable speed DC drive.

Yeah, would certainly like the motors tucked away as much as possible, just to not have them protruding. The X looks like the belt setup on the Z would work. Y's perhaps too, if only to the outside on the Y rails.

Was hoping a buddy of mine could get some time in his shop to do the plates, out of 7075. But economy is good and all the machines are running flat out making real money for them I was hoping to do a little engraving soon, as was the first thought on me cobbling together a CNC myself. I can probably get my buddy to to a few minutes on a machine for that. Still like to have my own toy tho, but have to wait fo rthe stars to align.

I noted you have a v3 casually mentioned on the side plates, supposedly with some mounting slop for using dual thread blocks, instead of the antibacklach type. Seems a much better thought, especially if you left the slot cutout between them, to have more thread engaged and be able to tune out backlash easily, without taking anything apart

 

This actually raises a question I had. Using the dual anti-backlash nuts, is it necessary to have the backlash adjustment on it? I noticed the blocks are tight with the adjustment tab and actually rib on one of the wheels. With two blocks I don't really see the need for the adjustment tab.

 

I don't have the adjustment nut tightened down on mine, but I have noticed what might be backlash when my bits get dull. Not sure if this is actually backlash or just a normal side effect of using a dull end mill. It's particularly noticeable when boring aluminum (holes end up slightly oblong and smaller than requested). Usually a second pass will open them up.

 

@Kyo I build myself one of these and it seemed to be functioning well, however, I seem to be losing steps (if possible?) on one of my Y axis. I'm trying simply to level the waste board, about a minute or so into the job one of the Y motors seems to miss steps or something to that affect temporarily. Always the same Y. I've replaced the driver, the motor, and checked all the connections. Any idea on what could be causing this??

 

Thanks for the reply Giarc. It turned out to be a power issue. I hooked up a spare PSU i had laying around to the driver in question and it's been smooth sailing since!

 

@Kyo I just had a quick question about wiring up the drivers, did you find that one way was better than another? I'm just about to that point on my build and before I commit one way or the other I just wanted to check because I don't believe in your videos or posts you lean one way or the other. Thanks by the way for the great documentation on this build, it has helped me a lot!!

 

Kyo, do you use the Arduino Uno Screw Shield with your current system or wire directly into the Uno?

 

what is the cut area of this setup ?

 

Hi Kyo. Massive follower from Australia. Love your work, thank you for all of your contributions and information. I am just about to embark on marking a Sphinx with a few modifications. I am going to construct a customized welded steel frame for the base to gain a little more 'Z' height (removing the 20x60 frame) and perhaps structural integrity. Was just wondering, with the X-axis, would the increase to a 1000mm long cbeam actuator be too much for the 1/4 inch (6mm) aluminium plates? Is it too much of a span? I have seen it a couple of times and I know it has been mentioned but I just wanted to know your thoughts. I would like to increase the width (X-axis) but keep the length (Y-axis) at the standard 500mm?

Any thoughts would be greatly appreciated! I will post updates all through my build with pictures for you. If you have any thoughts/notes on the frame (seeing it will be completely custom built) I would love to hear/see them! I am great at constructing these things and can work with many materials but the engineering side I really need to gather from experts. As I say I will keep you posted throughout my build integrating any of your thoughts.

Thank-you very much,
Chris

 

So I have the Sphynx extra tall plate kit from Chris. I have all the parts and have begun assembly on the 1000mm x 1000mm C-Beam. During assembly I realized I may like it better if I mount the router to the Z c-beam and use the actuator to raise and lower the entire actuator/router. This way I wouldn't have to worry about height as much. The c-beam would not basically control the maximum height of whatever I am carving. I tried to turn the c-beam around and unfortunately there were only 2 holes that lined up on the OB double wide gantry plate and the Chris Laidlaw gantry plate.

My question is, is there an OB plate that will work with the Chris Laidlaw plate set that will do what I am trying to do?

Picture is from an OX build but it shows what I am to do.



Thanks,
Steve

 

I thought about that after I put it all back together. I may actually do that but was thinking it would be nice having more wheels on the outside for support as well.