David Bunch published a new build:

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Thanks for the tip. I will try that next time. Looks like I did not damage the bearings after all. I changed that with a new wheel & bearing and had same issue. I know I did not damage the bearing this time. I changed the screw as the last test & that fixed it,. There must have been a burr on the side of that screw. After quite a bit of adjusting of these small wheels, they still seem a little tight on the Z axis inside that C-Beam. This is the 1st time I have used the mini wheels, but I have used the larger wheels on my Makerfarm i3v 10" 3d printer. I was thinking of changing those screws to M5x25mm Stainless steel button screws, but I only have 4 of them. The button heads might be too high to use, but will see. I might change 4 of them to see if that makes a difference. I am used to using just stainless steel screws on 3d printer builds. Anyone have a good source for Stainless steel hardware, especially ones with same head style as openbuilds? I used to buy mine from Mr.Metric until they dissolved that company.

 

I added the front Y cover plate STL files to the Files and Drawings area of this build. Depending on which STL file you use, you will need to substitute 3 of the M5x12mm screws on each plate for M5x14mm, M5x15mm or M5x16mm screws. I have some extra M5x14mm screws on hand, but would have used the black openbuilds M5x15mm screws if I had some extra of those. I test printed this in 3 different colors to see what I liked best. I will probably use the light blue with Octagram Sprial top/bottom infill that the Prusa slic3r has. I had to add some extra little cylinders to the part to get that pattern centered where I wanted it. Here is a photo of that plate with different colors. The plate is 6mm thick & I recessed the screw heads different heights for the 3 different screw length options. That is the only difference in those STL files. I will eventually make a zip file of all these parts when I think I am done adding plastic parts.

 

I was looking at the Z limit switch location yesterday & discovered the top plate & the carriage both have some M5 threaded holes in them at good locations to mount a Z limit switch that will allow more Z movement. After taking a limit switch cover design I did for my 3d printer a while back, I was able to adapt it to this configuration & loose no Z depth at all. I am using 2 parts, an arm to hit the switch mounted on the front of the front of the Z gantry plate & the Limit switch holder attaches to the top & front side of Reduction plate. I can adjust the design of the arm part to fine tune the height adjustment. I could add a M3 screw to the arm for micro adjustments, but for a CNC machine, probably just print an adjusted arm instead since it is only a 10 minute print. I have about 7mm clear of the top c-beam plates now, 3-4mm is probably the minimum possible. That is a lot better than the 30mm+ the original mounting system gives. The top part probably only needs 1 M5 screw to hold it in place. I originally had 2 mounting holes for the arm also. After I tweak this design a little more and make some x/y cover mounts, I will upload it to thingiverse. I am planning to use these limit switches with the red rollers on them instead of the ones that came with the machine. I am really happy with this design so far. To mount the limit switch to the plastic I am using M2.5x10mm screws with locknuts & M5x12mm screws to mount the plastic to the machine. This idea should also work on any of the other machines that use these same gantry & reduction plate. Think I might also close in the top of the limit switch cover & add an access hole slot thru the back top. I have about run out of plastic parts to design & add to this build, so I might actually have to finish building it now.

 

I realized this morning after taking a look at the drag chain wiring video again that I have the X limit switch & 2020 drag chain tee nuts located in the wrong spot. Always miss something. I have already removed that Y plate once, so it is not difficult to fix that at this point. Guess that is a good reason to use the drop in tee nuts as it is easier to change them. I am designing limit switch covers for the X & Y since I made one for the Z. In doing so, I am going to move the Y-axis limit switch to the top of the C-Beam instead of the side. It will be covered, so it will be difficult for flying debris to hit it. I got my spoiler board from Home Depot today, but they were not able to cut it to my exact 19 11/16" dimension, so I will trim it up on my table saw when I get a good day to do that.

 

I got the tee nuts moved to the proper spots. Taking the Y plate off was a little more trouble than I 1st thought. I also had to take the X-Axis motor bolts off to be able to get the lead screw out of the way to move that side of Y plate out of the way to get to the tee nuts. It was good that I did this as I noticed a couple of the lead screws were not completely tight. The X-axis is still not completely tight, but can't seem to get it any better. Anyone have good ideas to make that completely tight? The latest thing I tried was to hold a channel locks with tape on the jaws against the edge of the lock collar outside of the plate with a closed end 10mm wrench around the lead screw so I would not be tightening against that. I also rotated the lock collar a few times, but have not found best spot yet.

I added Sphinx55_AssemblySteps.zip to the files area which is a web page that has time indexed youtube video links of each step of openbuilds video assembly current time indexed. It also has the parts needed at each step. This makes it a little easier to go to each step in the build if you are not doing it all in one sitting. One thing I wish I had done in the beginning was to put the parts of each step in a separate zip lock bag.

 

Thanks for the complement. Guess it is bling with function. I started working on a cover for the top pulleys today. Since there are 4 nice threaded holes in that reduction plate, it makes it easy to attach. I am leaving it open in the back to be able to inspect the pulleys without taking the cover off. That should protect it from debris from the front & sides. The main problem I had with this design was missing the screws that were already on that plate & missing the Z limit switch mount & cover I designed. I am going to print a test print of the bottom part to make sure it misses everything before printing the whole cover. I might be able to slap another sphinx logo on the front of this. This screen shot shows a section cut of this part to check for clearance.

 

That might work. Not sure how I missed that. I might have thought that would be in the way of the router, but looks like there is plenty of clearance & might be a better place for that switch since I am adding that cover. I will look at it a little closer tomorrow. You can't use that top middle hole on the gantry since it is not threaded, but there are 2 other threaded holes, 10mm over & 10mm up from current hole with another threaded hole on the other side of the gantry. Thanks for the idea. I might still just leave it where it is if it works ok, but will see if it is worth moving for me.

 

At first thinking about your idea, I was not sure it would allow me to mount it near the edge & have the wires going out the back. After looking at it on the computer I realized I could. That is actually a simpler design & the switch mount does not get in the way of the top cap. Thanks for the idea. Here is what the design looks like now. I will print it this morning to see how it works.

 

I have a MPCNC I built a few years back & upgraded to newer plastic parts this year which works pretty good for wood, but I have been wanting to cut aluminum plate for a while. This fall I started comparing the Mini-Mill C-Beam & the Sphinx & decided to spend a little extra money & get the sphinx as it seemed like it would be more sturdy. I waited until Black Friday before purchasing it.

Here is what that Z limit switch looks like now. I rotated it so it would be on side instead of the front. It is a bit cantilevered, but since it is such little weight seems like it should be fine. I added an M3 hole in the plastic arm to be able to adjust it without printing another part. Here is a picture installed with the top cover plate just laying in place. I ran out of my light blue plastic & waiting for that before printing the final parts.

I found the problem with the X-axis lead screw being loose. It is apparently loose in the bearing & openbuilds says that is not a problem with accuracy. I made a plastic part to go on the left y-plate with a plastic part extending 2.4mm to hold it tight. It does not rattle now, but not sure how good a long term solution that is. I might try a 688Z bearing recessed into the plastic to see if that works. Here is a screen shot of that idea.

 

I finally had a good day to take the table saw out of the shed to cut the MDF. Home Depot was not able to cut it very accurately which is reasonable. I cut 2 spoiler boards since I had a 2'x4' sheet. The 1st one I cut at 16.5" & 19.625". It fit well but had about 1.5mm gap which will work, but will keep that as the spare or put it on top of the other board. I added 1.5mm to the cut width for each side & that one fits nice & snug. I am weighing each item as I install it as you can see from last photo, this spoiler board weighs about 7lbs 4oz. I have not screwed the spoiler board down yet. Will probably do that tomorrow.

 

I changed the design of the X-axis cover plate that goes on one of the large Y-Plates to be a little more interesting shape than a rectangle. I also tapered the plastic part that rests against the bearing. The top & bottom layer pattern is called Octogram Spiral in Slic3r Prusa edition. I like to use that pattern when it shows up well on a part. I could have put another Sphinx logo on there, but thought that was a bit too much with a logo already on that Y-Plate. Here is the link to a short video showing the loose fit of the lead screw. When the gantry is close to that side, it does not move and openbuilds says this does not affect the accuracy of the machine since the lead screw is snug on the gantry.

Extra Play with Sphinx 55 X-axis Lead Screw

 

I screwed the spoiler board down today. I clamped it first to make sure it would not move as I wanted to pre drill the holes. I tried it without drilling first, but drilling a hole about 1/4" in helped a lot. I only have a B&D 12v cordless drill, so probably not as powerful as some people use. I also did the first 3 steps of the wiring & think I finally have the X,Y & Z limit switch covers the way I want them. The Z-axis I went back to my original idea of mounting it on the top, but changed it some. It just did not seem sturdy enough coming off the middle front screws. If I mounted the limit switch in the middle, it would have been sturdy enough, but I wanted it on the side to keep the wires out of the way. I did have to get my soldering iron out today. 2 of the leads on one of the 4 conductor wire for soldered together. It was easy to heat those 2 leads up & separate them. I also noticed while installing the LED ring that there was not another 7' 2 conductor wire as shown in build video, but mine was longer at 13'. That is the only 2 conductor wire left in my kit, so that must be it. When I route the wires, I will probably realize why it is that long. I was hoping to finish this build by the end of the year & I might make it. I weighed the machine with the spoiler board added & it is now 34lbs 11oz. I took the router & p/s off before weighing it. There is probably 2 or 3 oz. of plastic parts on there though.


My test prints for the X & Y came out good, so I am going to reprint them in the light blue I have been using. I was able to get the full X & Y width with these limit switch holder/covers. Here is progress photos of the X,Y & Z. I fine tuned the height of the Z carriage arm with the M3 screw & then reprinted another arm with correct height without the screw. I had to leave the top cover off to be able to manually turn the pulleys. I used a 2mm high shim to make up for the top cover plate so the switch would be at same height when I put the cover back on.

 

Not going to finish it today & do not want to rush the electronics portion of this build. I needed to print my plastic electronics case which is what I based this Plastic Addons build log on to begin with. That is probably a 6 or 7 hour print. I put one of the limit switches using the limit switch plate that came with the kit beside my plastic limit switch holder & I really only gain 9 or 10mm of space in case someone is wondering about that. I still like the plastic versions better since they hide and cover the switch & wires more. I will not be able to tell how much cutting space I actually have until powering it up with the router attached, which should be this week. I decided to use the limit switches that came with the kit instead of the ones shown in my photos with red roller on lever. The ones in the kit have the lever closer to the switch mount. I did have to drill out the switch holes with a 7/64" drill bit to use M2.5 screws. I used M2.5x12mm screws with locknuts to secure the switches to the plastic parts. If I had some M2x12mm screws, I would not have had to do that. Just realized I could have put a sphinx logo or text on the bottom of that case that faces the front of the machine, but not going to reprint it since it is going well & over an hour into the print.

Here is what that case should look like.

 

My case design printed out really well. Since I thought about adding the sphinx name & logo to the case after well into the print, I decided to make a 3mm thick additional face place to put on the bottom of the case. I am now at the point to connect all the wires to xPro. That will be tomorrows task. Here are photos of the case.

 

I finished most of the wiring today. Attaching the wires to the xPro board was the most difficult part of the build for me. Those screw connections with the small wires were very frustrating. I still have to make the connections to the PS & go thru the wire tie portion of the video. The Y limit switch wire did not have much slack in it. After I power it up tomorrow & go thru the initial testing I am considering shortening up some of those wires. Being at the bottom of the case where it is completely open those wires would probably drag on the table I put it on if I have to slide the machine. I might redesign that case again to add a wall on that bottom side. I decided not to add the sphinx face plate to the back as I did not like the way it looked. For mounting the xPro & fan, I used a little longer M3 screw with plastic shims & locknuts. I like using locknuts rather than the t-nuts. Seems like they will not budge over time. I mounted the board with screw head from the outside & the locknut on top of a plastic shim on the board. You can see them in 1 or 2 of the photos. Here are some photos of my mornings work. Anyone have some good suggestions for stripping the wire ends & tinning them better. I have a pretty good wire stripper, but the smaller wires do not work as well.

 

I put my final notation on the build tab of this buildlog. I will add any further info to this discussion thread. I researched stripping small gauge wires today and came across this helpful page Working with Wire I have a pair of Klein wire strippers I bought from Home Depot awhile back that go up to 22 AWG, but they will pull a strand or few off when stripping the 22 gauge. I started to order a pair of Klein 22-32 AWG Stranded Wire strippers, but then found & ordered this pair of Hakko Professional Quality 20-30 AWG Wire Strippers - CSP-30-1 Think I will practice on the long LED wire to start with and this will give me the opportunity to become more proficient with this task. I weighed the machine with everything attached & comes out to just under 44lbs. My X,Y,Z limits were a little less than the video show. Mine are X330,Y310 & Z85. I will have to set back the electronics case a little to get the Y distance bigger which will be easy to do. I plan to shorten up all the wires when I get the new wire stripper. I am going to revisit my electronics case design now that I see some things I would like to change that I could not see until putting it all together. I used the openbuilds control software to setup the grbl settings & the initial tests. I have an Etlcam license, so will probably use that when I am finally cutting on this machine. One thing I noticed when bundling those wires in the case is that fan blade can easily hit them. That is one really good reason to shorten those wires.

 

That is high praise coming from you. Thanks. I am printing a couple of corner brackets to move the electronics case back 20mm. I have a couple of 2020x250mm & 2040x250mm I can use. I will start with 2020 to see how that works.

 

I solved the problem of the 2020 X-axis dragchain hitting the electronics case. I started with a couple of the 2020 corners printed from https://www.thingiverse.com/thing:105900 & used a short v-slot 2020x250mm to set the electronics back. I then went a little further to raise the electronics case above the table 20mm by using a 2040x250mm instead. That also solves my problem of the wire tied cables dragging. I just need to bundle them a little better, add a ledge or maybe just use the original openbuilds back for it which has some places to wire tie it. Not sure which method I will use just yet. I am going to make a 2040 corner to cover the end of the top of the 2040 extrusion.

I also noticed when moving the gantry around that the Y-axis limit switch wire could easily get pinched if the Y-axis moves all the way back. I am going to relocate that wire to bottom of the C-Beam instead of the top as is shown in the video. Since the Y-plate does not extend down that far it seems like this will solve that problem. In doing this I was going to pull the spade connectors off the switch rather than the more difficult way of undoing them from the electronics board & realized the spade connectors would not go thru the slotted opening I made, so I redesigned that cover to have a bigger opening. That helped me to see a problem in my limit switch cover design.

 

I added V2020_90_Rev2.stl & V2040_90_x2_Rev5.stl to the files area if someone wants to use these 3d printed parts rather than metal corners. They seem to be strong enough for this purpose. As I said in an earlier post, these files I will eventually just put into one zip file. I worked on redesigning my electronics case today & shortened it 40mm as well as adding some more wire tie loops to the design. I am using openscad for the design, but I am thinking of moving my design process to fusion 360. Here are some photos of my progress. One photo shows how much I increased the wire access hole to allow for the spade connector. The slot was large enough for the spade connector, but it could not get around the tight corner on the X or Y cover. It is straight back on the Z cover, so I am not planning to change that except make it a little longer. I used M5x10mm screws for the plastic corner connections and seems sturdy enough. The last screen capture shows my current electronics case design. I put 3 sets of wire tie loops at bottom & top to keep the cables away from the fan & also changed the wire tie locations on the sides to the bottom of the case instead of the top of the openings since the wires come in the opening at the bottom of the case. I am printing the back fan mount 1st before printing the much longer bottom print.

 

I published the limit switch covers & reduction plate cover on thingiverse today. The reduction plate cover & Z-axis limit switch mount covers should also work on the openbuilds mini-mill or any machine that uses that reduction plate & double wide gantry plate combination.

The cover can be found: Cover for Openbuilds Nema23 Reduction Plate by GeoDave
The X,Y & Z limit switch mount covers can be found: https://www.thingiverse.com/thing:3342477

 

Thanks Alex. I did forget to publish it. That is what I get for adding to projects at the same time to thingiverse. The link should work now.

 

I added the 2 STL files for the electronics case to the File and Drawings tab. Not sure when I will get around to putting that on thingiverse. The files are Hull_Side_Rev58.stl & BackFanMount_Rev11.stl . The weight of the case is around 5oz & took me close to 8 hours to print using variable layer heights & 80mm/sec print speed. Here are a couple of photos showing it attached to the machine. I still have shorten all my wiring.