[Cret]

And yes, I realise the table won't have full Y axis movement with the current setup here.
I might stick the 3 plates bolted together onto my bandsaw to get them level with the mill casting but I'm not concerned about that just at the moment.

[Cret]

Ok, it's on at last!
Attachment 245266



Next thing is to refit the saddle, then try to get the alignment correct so that it turns all the way from end to end without any binding.

[Cret]

I've put the saddle back on to test it now and see if it binds at all or is correctly aligned, but I can't get a pulse to the steppers now for some reason. I've wired everything back as it was before, and started up Mach3, but when I hit reset, open motor tuning, and select Y axis then press the cursor arrows to move the motor manually, nothing happens and I can't detect a 5v pulse arriving at the driver board at all from the break out board with my meter at all. (either on the step or direction terminals).

Not sure why this would be. I think I've overlooked something but no idea what! It's possible the parallel cable isn't communicating but not sure how best to check. Any ideas?

[hoss2006]

The motors aren't going to move with motor tuning open, make your adjustments, click save settings and close the window.
Hoss

[Cret]

Really? How dumb of me - I could have sworn I had that open last time but I guess not. It's ages since I tried it though.

Me goes off back to the garage to try again - thanks Hoss!

[Cret]

Well I'm a little ashamed to admit what the failure was (other than my brain of course), but it was somewhat more fundamental than that.
I was right in thinking along the lines of a communication failure involving the parallel cable at least.

I'd plugged the parallel cable into the break out board, but rather stupidly made the classic mistake of making an assumption it was still plugged in at the other end as it looked like it was.
It wasn't.

Doh! Running now, and running quite nicely I'd say! So worth the effort, blood, and silly mistakes/embarrassment.
Thanks for the help Hoss.

So the saddle seems to move nicely without backlash that I can notice at this stage (I'm sure there must be some).
I need to fit the X axis on now and figure where I was up to with that. Then start considering how to convert the Z axis (goes off to look at your site again.......)

[Cret]

Et voila:
YouTube

[Cret]

Now we're in business! X and Y axes are now armed & fully operational, running on bearings, and seemingly smooth enough too. No idea how I'm doing the Z axis yet.
Time to get researching (goes off to look at someone's website....)

Attachment 245284

[Cret]

I have got an idea now for the Z axis that I'm going to do it at the right side of the column, using a 400mm ballscrew (as below), and I'll knock up the necessary brackets for this. My mill already has a DIY airspring conversion that may or may not assist in reducing the amount of grunt necessary for Z. My steppers are 435oz so I'm unsure if it's necessary to gear it down like your machine hoss with the combination of the airspring and motor that I've got?

1pcs Antibacklash Ball Screw 1605 L400MM C7 BK BF12 2pcs 6 35 10mm Couplers | eBay

It'll take a few weeks for the ballscrew to come from China once I've ordered it, so I can set about trying to make some brackets. I always find that sort of thing a lot easier to plan when I can see with the having the ballscrew there in front of me for instance but I can improvise with a stick or something!

I'm planning on the ballnut being captive on the milling head. There's space above the mill whereby I could add the motor direct on the end of the ballscrew but after seeing pics of machines like yours Hoss I'm not sure if I need to get belt & pulleys. If I do then I'll need to get ones that match the bore of the screw end which have set screws or something I suppose.

I'm a little unsure about the ballscrew dimensions in relation to the end support blocks though. That set says it includes a BF12 and BK12 which presumably are for 12mm shaft, but I'm sure those ballscrews only have a section at one end that's 12mm, and 10mm at the other, which would mean you can only use one of the included blocks and the other would need a spacer or something to use it. And that would be a bit silly....

More investigation needed I think!

I'm interested though to get thoughts on whether gearing is necessary or not with my setup. Cheers guys!

[Cret]

Actually, after a bit more looking, this ballscrew looks a much better bet as it includes a nice housing for the nut to help attach to the milling head for the same money basically.
Plus it says BK10/BF10 which makes more sense re' the sizing of the end supports. I think I'll order this, then the question over attaching the motor either directly or with pulleys is the next thing to decide.

End machined CNC 400mm SFU1204 ballscrew + ball nut nut housing bracket + BK10 BF10 end Support + 6.35x8mm Flexible coupler-in Linear Bearings from Industry & Business on Aliexpress.com

This is a 12mm screw rather than 16mm, but will that matter at all? I can pay more to get the 16mm version if need be but not sure if it's needed or not.

*Edit* I bit the bullet and ordered the 16mm version as I found for the same money I could get the bigger size but with slower delivery. Can't argue about the value for money!

In the meantime while I wait for that I can start to think about how I'm going to house all the electronics (will see if I can find a spare PC tower perhaps), and I might start pondering trying some sort of 2D exercise (a bit like engraving) to try and get the hang of the software a bit.

[Cret]

Update - the ballscrew/nut and the end bearing blocks plus ballnut housing block thing came today so I'm really excited now to get the hardware together for it.
I need to make 2 adaptor plates to sit beneath the bearing blocks, as they're wider than the column is thick, so won't attach correctly without adaptors. Should be easy enough.

I've removed the handle for moving the mill head up & down, along with the fine feed assembly. I have some thickish L section aluminium that should suffice for now to attach the ballnut housing to the mill head.

Once they're done (just off to do these in a minute), I need to mount the Z stepper.
I've had no input on whether the 435oz stepper with air spring combo is going to be fine directly driving this assembly, or if it really has to be geared, so I'm just going to attach it direct and try it.
Only one way to find out I guess.....

[Cret]

BTW Hoss, if you happen to read this, I see from the pics on your page there's no coolant tray under your machine - do you run without coolant and is this ok to do?

99% of the time it'll be aluminium or maybe plastic I'll be milling, so I'm not sure if this is a necessity or a nice to have?

[hoss2006]

BTW Hoss, if you happen to read this, I see from the pics on your page there's no coolant tray under your machine - do you run without coolant and is this ok to do?

99% of the time it'll be aluminium or maybe plastic I'll be milling, so I'm not sure if this is a necessity or a nice to have?

I did the typical spray bottle machining early on and made a mess everywhere, chips do fling about whether you run dry, mist or flood.
I pretty soon built an enclosure to contain it all and get the benefit of flood.
Projects 8
number 13 here.
FAQ
Hoss

[Cret]

Thanks Hoss, I hadn't seen the pages with the enclosure like that. Wow, that's impressive!
I'll have to figure something out.

Well I got the Z axis mounted now, I just need to make a bracket for the stepper to be held on, then in theory it's all electrical and software to be done from there.
Getting pretty excited now I must admit!
Attachment 247480

Once the machine is up and running I think the first jobs beyond testing etc will be to create nicer hardware for mounts and so on that I've had to make temporary bits so far. It'll be a really pleasing project to upgrade all those bits and know everything is then really solid. Can't wait!!

[Cret]

Ok, so the Z axis is now fitted, and I just about have the stepper attached.

Here's the bits at the top of the Z ballscrew and its a bit of an awkward shape to fit the stepper mount to.


So I took a few measurements, got on sketchup, and 90 minutes later had this white ABS spacer block done, which fits perfectly and allows the stepper mount to sit on top nicely:



It's not actually bolted down yet.

I also stripped out an old PC case as a housing for the PSUs and drivers etc.
Had to drill out some rivets on the case and unfortunately the bit snapped and the remaining sharp stub decided the palm of my hand would make a good target to plunge into.

So I decided that would suffice for last night!

[Cret]

Right, everything is secured on the Z stepper now.

The case for the electronics is coming on now too. I'm hoping that tonight I can get the rest of the wiring finished and try plugging it all in - will be a tense moment!



One thing I'm not sure about on the wiring side of things is that I want to run Mach 3 on a little touchscreen netbook I have, and it has no parallel output socket. I've bought a USB to parallel cable, but I've no idea if this will work as intended and connect up happily to the DB25 BOB.....

I really hope so, otherwise I have to re-locate my main garage computer and that will be a right pain.

[hoss2006]

Right, everything is secured on the Z stepper now.

The case for the electronics is coming on now too. I'm hoping that tonight I can get the rest of the wiring finished and try plugging it all in - will be a tense moment!



One thing I'm not sure about on the wiring side of things is that I want to run Mach 3 on a little touchscreen netbook I have, and it has no parallel output socket. I've bought a USB to parallel cable, but I've no idea if this will work as intended and connect up happily to the DB25 BOB.....

I really hope so, otherwise I have to re-locate my main garage computer and that will be a right pain.

No it won't work, you'll need a board with it's mach 3 plugin made to work with usb like a smoothstepper to connect to your bob.
Hoss

[Cret]

Bugger, thanks for saying though Hoss.


I've ordered a 5m parallel cable so I can hook up to the pc on the opposite side of the garage. Would much rather have the machine next to the mill though so I can see them both at the same time.

I might buy a smoothstepper eventually but a bit too skint just now.

[Cret]

Well I managed to get everything hooked up to move all 3 axes moving with manual keyboard commands, which is good, and the newly fitted Z axis appears to work nicely.

HOWEVER.....

There's some strange gremlin behaviour going on and I'm not sure why.
This applies to all 3 axes - sometimes they work fine, other times they will only move one way (ie regardless of the key you press, the axis moves the same direction).
It seems unpredictable - one moment an axis is fine, the next it will only move one way.
On Mach3 the correct values are showing so it is recognising that you're changing direction but not always recognising this at the motors for some reason.

I've checked the wiring all through and all seems secure enough. The wiring all seems to be the right way round too, and I guess the fact it is functioning correct 'some' of the time means it must be correctly wired configured, but why would it be behaving erratically like this? So close to having a working machine!!!

Appreciate any suggestions! Thanks

[Cret]

I've read that wiring faults or interference can cause this sort of behaviour after some searching.

I can't find any issue in the wiring re' connections etc, and while I could accept say one of the wires having a fault that shows when it moves with the axis, not all 3!
So it could be interference.

This has never happened previously when I've tested each axis alone, and has only happened since I've combined them all inside the PC case, where it has mains cables, power wires from PSU to drivers, stepper wires, and signal wires from BOB to drivers all in fairly close proximity. I don't think I have any suitable shielded cable to try replacing this stuff on the signal wires but are they (direction wires) most likely to be the problem causing this?