The original Ox build uses http://openbuildspartstore.com/nema-23-stepper-motor/ which have a torque of 175 oz-in. If the calculator I've found is correct, that's ~1.23 Nm. So 2.5 Nm should be fine.

 

Hi David,
Just keep in mind that not all steppers are created equally and the advertised torque rating doesn’t tell the whole story.
I found this "article" helpful as it explains a little "stepper motor theory" in layman’s terms.
http://www.cncrouterparts.com/why-s...company-xx-has-higher-torque-motor-p-187.html

For a more detailed explanation read this:
http://www.geckodrive.com/support.html

Hope this helps.
-Nugz

 

Thanks Nugz,
It's obvious I've got a lot more reading to catch up on.

 

DddMan, followed the instructions of that link (especially the ones mentioned in the comments) and hooked up 2 ATX PSU 12V to make 24V. Left some cable extra out to also have 12V from the same setup. So now I have 12V and 24V. Each ATX is good for 25A @12V, which would give 300Watt, but the good thing is that on 24V with the same amperage I will get 600Watt out of them (24V x 25A). That would leave me with about 150Watt available for each stepper, which would only use about 66Watt @ 24V. So, when I'm finished with the recabling and some other pimping of the machine it's time to test this setup.

For me it also turned out cheaper than buying a 24V power supply (about 50% of the prices on eBay, shipping not counted for). Here in Thailand there is no such thing as used and cheap (or for free) ATX's. Either it's broken or reused for a new computer (yes, they still build them here in all kinds of shops, cheap labour heh). So it costed me about $ 37 and an hour or 2 fiddling around.

 

@Prauk I was making some cleaning yesterday and I found two unused 600W ATX PSU that I forgot about My new 3D printers just got some free supplies!

 

Lucky Man! You can also have 3V and 5V of the first one in the line. Good thing is, that if for any reason you want to have 36V or even 48V, it can easily be done by just adding 1 or 2 ATX's in series. Once you've done it, it's dead simple (same as working with 12V batteries and putting them in series to get 24V/36V/48V etc.). Make sure though, that you keep the mains grounding (earth) connected for safety.

The DC side is floating and can be connected to a star grounding in the setup.

My little Up!Plus is working its butts off on a cable chain for the side of the Buffalo, I'm about half way now.

 

I run 70V at 20amps on my larger machine running 960oz Nema 34's and will be running a 48V 20 amp at 3.5amp per motor on my Nema 23 Ox build. The way I have always understood it is the amps help the torque of the motor and the volts more for rapids. Like my 34's are rated at 6amps a piece so my PS is actually underpowering those motors just a bit, now my nema 23's will be on the mark. I run Gecko 203V's btw, the can handle up to 80V each.

 

Lol! Mark I JUST started a conversation with you about this issue. I'm the one who brought this issue to Chris Laidlaw's attention. My Z-axis thru-holes are out of tolerance enough to bind the mounting screws to the point that the second one won't thread in at all. If I try to wrench on it, it WILL cross-thread the block, I can guarantee that. I am using his aluminum V-slot Spacer Blocks. What are the Part Store blocks made from? Maybe they are more forgiving than my aluminum spacer blocks, as I haven’t seen anyone bring up this issue here in the forums.

Now I want that Taller Z-axis plate!
-Nugz

 

I'm still measuring 40.6125mm center to center on the thru-holes in the NEW .dxf file in LibreCAD. On BOTH versions of the Z-axis X plates. Edit- I'm ordering V-Slot Spacer Blocks from the Part Store on the suspicion that it is my spacer blocks that are out of spec with the intended design. The threaded holes are spaced at 40.00mm center to center where I believe they a supposed to be 40.6125mm.:



-Nugz

 

I didn't mean to take All the credit lol...
I told Mark "I received my first report of an issue with the X shaped Z axis plate/Spacer block holes not lining up today".

Tho i did find that the spacer holes were not symetrical on the X plate and did not all line up with the spacer block holes on both the original dxf files and the latest dxf files.
Thanks to Nugz for finding the issue and Thanks to Mark for quickly verifying the issue and starting work on correcting the dxf files!
Chris

 

Lol! Chris, I didn't mean to imply that you were "taking ALL the credit". I'm just trying to figure out why no one else here has had this problem. I'm guessing the Part Store Spacer Blocks are a little more forgiving to being forced into place. That's why I asked what they are made of. Upon further review, the model in sketchup has the threaded holes in the Spacer Blocks ~40.7 center to center (Sketchup Tape Measure" rounds up). The new dxf file has the threaded holes in the Spacer Blocks 40.6125 center to center. This leads me to believe that the problem is actually with my Aluminum Spacers from Chris being drilled/tapped at exactly 40mm center to center. That's the only feasable explanation I can come up with. Can someone with a set of OpenBuilds V-Slot Spacer Blocks please chime in with a center to center measurement of the threaded holes?

By the way, you have an email from me! I have another project for you. I want a taller Z-Axis X-Plate as posted by Mark. Warm up the spindle on that CNC machine of yours, you have work to do!
-Nugz

 

That's great ... the taller front X plate. It will help myOX reach down deep ... probably not all the way to the bottom shelf or floor (over 20" !), but it should have a much firmer grasp of the tool end for the 6" or so I need for making mold bucks (R/C truck bodies).

Will there be a longer spacer block to go with it as well ?

Now I'll have to get one of those and take myOX apart yet an other time ...

But I'm also working (in my head still) for a "better" gantry design for the deep reach. A new build in the making ...

 

That would be a great addition to the Part Store. I don't care for the multiple spacer solution personally.

 

I have only had one complaint about spacer blocks fitting the x plate from digger but not sure if he was using open builds spacer blocks or not.

I milled another set of blocks from the provided file on open builds parts store and they line up Perfect to all of my plates.

I just sold a kit that has them in it and the buyer has a set of OB spacers also.
I will ask him to compare the two for spacing

 

The V-slot spacer block drawing that was on this Openbuilds OX CNC site in the r3 zip file on 4/27/14 is 40.00 mm on both sides of the center hole... (see attached)
I assume the parts in the Openbuilds store are made to this Openbuilds drawing.

 

That's the source of the problem Chris. You are making Spacer Blocks that do not mate to the X-plate that you are also making. The error is in the Spacer Blocks. Like you said, the CAD file was on the site but is no longer available. All I'm trying to do here is find the source of the problem and correct it. I'm not trying to place blame. This is all Open Source and we are an Open Community. We are working from each-others work and mistakes will sometimes happen.
Your parts are, otherwise, beautifully machined, and obviously accurate to the file. I don't mean to come off harsh, but if that file is wrong you need to take the steps to correct it before sending more bad parts out.
-Nugz

 

We found another minor issue with the same X plate drawing a couple months ago and corrected it... I'm sure we will get to the bottom of this issue too soon.

 

The X plate drawing is correct to the Sketchup model. I already told you where the problem is. The Spacer Block mounting holes have to be drilled and tapped exactly 40.6125mm center to center. Go into Sketchup, tear apart the Ox model, and measure the distance between the threaded holes in the Spacer Blocks. -Edit for future reference: Chris and I got to the bottom of the problem and he graciously stepped up and made me a new x-plate and spacer blocks at no cost to me. He even gave me a free upgrade to the new taller X-Plate design for my troubles. Well played sir, well played.
-Nugz

 

Hi Mark,

Can you please upload the v-slot spacer block file you are using now for the Openbuilds store parts so we can help see if this current minor issue is with the X plate drawing or the spacer block?
Thanks,

Chris

 

What would really help the situation is to always have the latest release of the plate designs and any other components up to date on the files available here. There was, apparently a lag at one point as well as files which are now 'missing', ... It is Open Source/Hardware, so anyone going off the 'original' has to make certain they work off the latest and greatest release. It is not like the base design is changing every day.

The current files are for release '80' (yesterday's date included in the file name, if memory serves me right). It includes the taller front X plate. I would like to think these will be the 'base' design for the OBPS official version as it will give the option for better Z support.

These files should probably be a "ressource" rather than tacked on the OX design. As a ressource, the versions would be tracked better. The files should not get confused. The community should also be able to follow ('watch') for any updates as they are released. Anyone making a custom version should be doing the same. After all, the plate design is Open Hardware (CC SA ...) If some 3rd party just 'cut' base design plates, they just help out those who can't make their own plates or want a different material than the soon available OBPS.

The third party or custom plates, as an example, should state which release they are based on and what changes they introduced, if any, so one can make am informed choice of whether to go for (what will become) the 'original' or the 3rd party / custom design. This should include any corrections/adjustments they can make to the 'original'. It should be part of their value-add since there will always be room for improvements ... especially in the DIY/Maker area. After all, we are potentially on the bleeding edge with some of the designs.

There is room for all three : the "original" (one stop shopping was missing the plates), 3rd party (get different material, ...) and 'custom' plates which can add features or bling (anodized in different colours, support for extra wheel on front X plate for a more stable Z, etc.)

The Plates I got off Chris back in ... sometime late summer now, work fine but required some tweaking of the eccentrics for the Z wheels to do their work. The base design ("original") WAS later updated, partly after my comments and observations. It brought the 2 columns of wheels a tad closer inwards so eccentrics would not be pushed to their limit. 3rd party suppliers seem to have followed, some waiting for delayed updated files and others making the updates to their own design.

Some will welcome the possibility of buying the 'standard' base plates right along the rest of the parts - one source shopping. But many will still go for the 3rd party/custom plates for various worthy, at least to their eyes, reasons.

In any case, now I have to see if I get the new front X plate from someone, probably Chris to keep style with my other plates, or if I wait until I get my own completely different style out of my head, unto SketchUp and somehow cut to test.

 

Can you make these official ressources, instead of in posts and builds ? It would make tracking versions easier, or should, for all.

 

I have made many standard and custom plates for many builders, including for example, sets of side plates 3" taller in Z, for more Z travel.
I always base my plates on the latest drawings available in the FILES section that day. I only make plates after getting an order, and if I get the order by noon, I usually can make the plates and ship them by 8pm (when my main post office closes).
This zero inventory means I am always shipping the latest and greatest, and they are always shipped 2-3 day USPS Priority mail.
For example, I just now received an order for tomorrow and they will be Rev 80 plates.

Chris

 

Due to the issues with files being shared I am now only going to have my files listed and shared in the OX AI build log .
The reason for this is simple and where I think the real problem lies.
No mill is the same, especially a hobby one.
If someone was to take my file and simply mill it, I can be 100% sure it's not going to be the same as one I mill.

Any issues with my provided plates please contact me and I can correct the issue as they have nothing to do with OB other then being my own rendition of the OX files.

I have only had one complaint and still am not sure what blocks where used.

I would like to get my hands on a set of OB blocks for test fitting my plates before shipping as I use a milled set that fit fine but my whole goal was to have my plates work with all OB parts.

 

I still need a set of Aluminum Spacer Blocks that work with the X Plate that you made for me. Should I be expecting them in my mail box soon? -Edit for future reference: Chris and I got to the bottom of the problem and he graciously stepped up and made me a new x-plate and spacer blocks at no cost to me. He even gave me a free upgrade to the new taller X-Plate design for my troubles. Well played sir, well played.
-Nugz

 

Yep.

 

And that's part of your popularity, from what I gather from reading around. I've got your plates. Wished I knew about the taller plates earlier ... unless they came about after my order and observations. Posting such alternatives as ressources, even without files, might of attracted my attention. Then again, back then I didn't know much of anything. Like I said a few times earlier, there is always better ... It's part of evolution as well as particular needs, but also seeking it out as in learning - me, or designing - others.

As I have realized not too long ago, partly through the posts regarding the spacing of the holes for the Z wheels on the front X plate, the posted files aren't always up to date (apparently there was earlier discussions about the spacing of the holes on the X plate) and, even if they were, can't necessarily be taken as gospel / perfect either as an other situation surfaced only days ago - mainly confusion amongst all versions of the plates and their hole spacing in general. Nothing being show stopper, it is just more confusing for some than others.

So, yes, it is good for OBPS to step to the plate and put some order. Getting into the plate business after all this time might not be the 'best' way since it only throws in yet an other possible variation. Releasing a clean set of reference files along with those plates would. But I'm confused as to the latest files, which have the larger front X plate and what OBPS will be selling for plates ...

It would be nice to get everyone on a clean slate, especially if all plate sources state the version they have based their product on (with the release number). As a ressource, I think, it would be easy for anyone to go double check. Of course, if like me not so long ago, the option might not mean much without some details of what the newer version brings. Something like the taller front X plate might not be for everyone. Would that be a 'fork' off the base design ? We can't expect OBPS to manage or produce/sell all likely 'forks'. So the 'forks' become ressources on their own from whom ever 'created' them ...

Just my 2 cents.

OBPS is the domain of Mark (and his team)... It might not satisfy everyone's needs or wants. But it certainly is a good place to be for learning and building one's own design.