Hello from Grenoble

[lewiss66]

Hi,
I've been having an interest in CNC for few years to make little parts for my motorcycle and decided to pull the trigger on a SIEG SX2.7 bought recently from Arceurotrade. This will be a long process for me since I don't have yet the money to upgrade it to CNC but really pleased with this little milling machine even though I got already to major problems out of the box. If you want you can watch some videos I made on youtube:



https://www.youtube.com/watch?v=aD6VgfeqZC0

[mekanik]

Hi lewiss66
Welcome to the forum, looks like something is bent, i would contact the supplier, item has to be fit for purpose and that isn't.
Regards
Mike

[lewiss66]

Ok Thanks I contacted them and waiting for their reply for the spindle. I may have to take it apart myself...

[Doddy]

Welcome, Lewis.

Re. an earlier question, elsewhere, on the back panel on the Z column - have you checked the exploded diagrams on Arc's site (spare-parts)? It's admittedly not very clear (it doesn't include the two bolts that are there). This is one area I've modded on mine - there's only one bolt there now (had to cut part of the casing to fit the Z-axis motor mount). My machine is bolted to my bench and levelled - if you struggle to get the cover off I can unbolt to investigate but I expect it'd be easier to check yours?, feel free to ask if you do need me to take a proper look (I'll have to unmount some of the control boxes that are bolted to the column through holes I drilled and tapped into the column for this purpose). I can't remember any significant problems working on the Z column.

This is a (poor) image of the back of mine when I had it in bits (with new ball screw/nut and a limit sensor)

http://www.mycncuk.com/attachment.php?attachmentid=25779&d=1557694115

also,

[lewiss66]

For whoever is reading this thread I'm talking also about my second problem which is my motor that is acting up.

Actually I removed the two top screws and the cover came off at the top only but got stuck at the bottom, then removed the two bottom screws at the back of the cover but still doesn't want to come off. It could have been simpler if my mill was on the bench but unfortunatly it's still in the crate. Yes I was not expecting to buy it that soon and haven't build the table. But I wasn't not expecting to have those two problemes right at the checking when I got the mill.
So It could just be the cover that rub against the bottom plywood of the crate but I have not much room to access and if someone knew what screws to unbold that would help me to get into it directly without contortions :)
Anyway I just received from Arceurotrade the motor control board so I might have to push the heavy crate anyhow to install it ...

[Doddy]

Anyway I just received from Arceurotrade the motor control board so I might have to push the heavy crate anyhow to install it ...

Motor Control Board? More problems? You show the spindle binding with the spindle belt removed - so I thought this was just a mechanical issue with the spindle?

[lewiss66]

Yes the first problem is the spindle binding. The second one is the motor acting up and that's why I'm trying to remove the back cover. (I made a video on each problem)
The video of the motor faillure:

https://www.youtube.com/watch?v=AzIPPOLdAK0

[lewiss66]

Hey Mike,
So do you recall removing any screws underneath the collumn when you took off your cover?
By the way, thanks for introducing me to this great Forum.

[Edward]

27663



Electronics with lids removed.

[Doddy]

Hey Mike,
So do you recall removing any screws underneath the collumn when you took off your cover?
By the way, thanks for introducing me to this great Forum.


No problem - easier to give advice on here than YouTube - and there's a clever bunch of blokes on here.

Re. bolts, when I can find time I'll.... oh!, wait....


27664

That's the base of the Z column - bolt on low left and low right. Don't take the bolts off the bottom plate - that's the filter mesh :)

EDIT: OP - sorry, re-read your earlier post - and you've found the two bolts on the lower part of the column. I really can't recall any problem removing the shroud on the Z-column, but if you're working inside the packing case you're giving yourself problems. As you can see the column shroud contains all the electronics and cabling that will restrict movement/removal of the shroud - you really need to get the machine out of the crate to continue sensibly.

I have a problem taking mine off further because I've drilled and tapped a number of holes to mount junction boxes etc to the column - they'd have to come off first.

[Doddy]

Electronics with lids removed.

Oooer, Edward - can't recall if we've spoke about the SX2.7 before now - currently I'm still on manual spindle control - have you found any alternative? (you're obviously using the standard speed controller).

[Edward]

Ho Doddy, I converted one of the first ones to come in, so that's a while ago. But I haven't done anything about the spindle control yet. I am tempted to swap the motor for a Delta servo or similar, preferably with a motor frame that will fit inside. Or maybe I will find something slightly more powerful with higher revs, but I haven't found anything viable for a reasonable price yet.

[Edward]

Doddy, are you using a secondary e-stop button to stop everything, including PSU to XYZ motors, controller, etc? This is what I am doing at the moment. I just found that the mill e-button carries the 240V mains L and N straight from the socket.

[Doddy]

Doddy, are you using a secondary e-stop button to stop everything, including PSU to XYZ motors, controller, etc? This is what I am doing at the moment. I just found that the mill e-button carries the 240V mains L and N straight from the socket.

Mine now just carries the Live. I've re-purposed the second pole of the E-Stop to send a control signal back to the control electronics. I don't look at the E-Stop to provide isolation from the mains - I look at it to effectively take power from the spindle-motor - good enough for shed-ware.

EDIT: But if you had a mains relay you could slave an E-Stop signal from the returns from the E-Stop control.

[Edward]

The way I am going to do it is to have an outside 12A relay that will feed the mains to the mill. This is the equivalent of pulling the plug out of the mill socket, but done safely with a relay. And the same relay will also control de 24V e-stop circuit, etc. The mains input will first go through a Schneider double pole Mcb.

[lewiss66]

Thanks to both of you for the info about the back cover. At the moment I don't have any lift to move the crate unfortunatly and with the Covid19 can't rent anything. Will keep posting my progress status. I will probably first start working on my spindle binding issue. I'm waiting for Arceurotrade to contact me tomorrow to give me instructions. Wait and see...

[lewiss66]

Hey Mike,
When you were talking about your spindle lock problem, you said a far-east R8 tool holders don't engage the anti-rotation nipple inside the spindle. Could you show of picture of this type of tool holder?
Thanks

[Doddy]

I have maybe a dozen toolholder, some give me no problem, some - mainly the ER32 collet holders that I bought from one Chinese vendor on eBay give me all sorts of gip.

27693

View from under the spindle, looking up - you can just make out a round nipple just before the taper inside the spindle. That is, I understand, intended to engage with the keyway on the R8 collet.

27694

This R8 collet holder is problematic... If I offer it into the spindle properly aligned there's no problem, but if, as I tighten the draw bar the tool holder rotates (not difficult) then the spindle binds and becomes stiff to rotate. I can only release the tool holder by rotating it until it aligns again with the nipple.

This second toolholder (all silver) ...

27696

...doesn't have this problem (I cannot rotate this more than a couple of degrees when it's seated in the spindle, before I tighten the draw bar). You can see the keyway extends much closer to the taper on the tool holder.

I had tried manually re-cutting the keyway on a couple of spindles with some success.

EDIT:

From what I can see I think it's the depth of the keyway cut into the tool holder. Particularly with the arc at the end of the keyway as the depth reduces. At this point the tool holder can revolve and "jump" the nipple out of the keyway.

[lewiss66]

Ok I see. Thanks
Are you sure it's not due to some tool holders not compatible with our mill?

[Doddy]

Apart from the 5/8" drawbar (and not the alternate 12mm size) unless I'm wrong, an R8 is an R8 - I'd expect it to fit.

Whether it's the tool holder that's out of spec, or the machine, I'm unsure.

From previous conversation you demo'd without a toolholder installed and still had a binding spindle so clearly it's not the toolholder that's at fault with yours. I think you also demo'd without the belt from the spindle to the motor - the motor was erratic but very low speed - I guess 10rpm (default from start on a Sieg) so I wouldn't expect the motor to be super-smooth at that RPM.

[lewiss66]

One question about the Column of the SX2.7.
Do you know if it has the same column as the X2.7?
Thanks

[lewiss66]

One question about the Column of the SX2.7.
Do you know if it has the same column as the X2.7?
Thanks

[Doddy]

I don't know.

I thought, but only thought, that the X2.7 and the SX2.7 were different only in the electricals / high torque motor, drive, control box and electronics. The spares break-down on Arc's website indicate they are at least substantially similar. But "know" - no, I don't know.

I'm being nosey - why that particular question?

[lewiss66]

Ok, I was just reading a comment on the video of CT's X2.7 mill:
https://www.youtube.com/watch?v=BhlwHcUE078
When tkarlmann asked to CT about his point of view about his column and CT replied that it was awfull...and he showed this photo:
https://ibb.co/qgfr952
It appears at the end of their comments that it's not clear if the SX2.7 and X2.7 share the same column.
That was my concern...

[Doddy]

Ah understood. I think the comments from CT, earlier were:-

"hour glassed dovetails on the Z axis,"

Okay, that would be a bit of a deal-breaker. I understand different importers do some level of their own QC, or have at least established a quality control with the OEM. Arc may have done some of this (though for a low-end mill like this - and please remember I do have one, I'm not having a pop) - there's a limit to how much time they'd spend on it. In my experience - I've had no problems at all with the dovetails on Z, though I'll admit to not having measured them. I don't see any significant movement at different heights. If I get chance I might DTI it just to check.


"rough areas in the casting,"

None seen on mine o the machined surfaces. As for the rest of the casting - unless it's structural then who cares?

"a few small voids here and there in the casting,"

Not noticed. At least not enough to worry me, and I did get pretty intimate with the column. I've drilled more holes than there were voids, certainly!

"and most holes and pins seemed to be hand drilled and tapped as they were all over the place"

Yes, and this is the pain-in-the-arse - the dowel holes are almost certainly hand-drilled - I was trying to transfer all major holes onto paper, to measure and transfer into components into Fusion for CNC conversion and - yeah, no rhyme-no-reason other than being eye-balled/hand-drilled. But the main mounting points are, from memory, accurate. It's the work of a couple of minutes to measure yours. At the end of the day it just means that any conversion you have to measure twice, cut once. If the dowels worry you then drill and taper-ream new dowel holes once you have end-plates in place (from memory the only pins were on the end plates).

[Doddy]

Just another point - there's a Seig Facebook group where someone has a seig spindle-controller mod that takes 0-10V / Directionk signalling for CNC conversion. Very similar in design to other boards for other Seig machines. I found that too late for me (particularly as I'd trashed my BLDC controller) and I'd replaced the spindle motor with a servo.

[lewiss66]

Ok, Good to know your point of view and thanks a lot for your quick and clear response.
Now I'm reassured...
Maybe it could be possible to weld the left over holes in the cast iron to keep the strengh even Just a stupid statement here :)
I've heard also that so was thinking about adding a vertical plate at the bottom in beetwen the open side of the C shape column to strenghen the cut for steel. Well, maybe overkill for hobbyist.
Do you mind providing the link of the facebook group project?
Thanks

[Doddy]

Don’t know about links but just search for the group name “Sieg Machinists User Group”, there’s very little traffic in there but what there is appears to be comprehensive

[lewiss66]

Got it! :thumsup:
https://www.facebook.com/groups/560605051411947

There is another one:
https://www.facebook.com/groups/940071046173484

[lewiss66]

Doddy,
Good idea to replace the spindle motor with a servo. Speed is all it needs to cut aluminium!
But you are seing that servo motors are able to run with this 10V board?
Looks like there won't be enough voltage for a big spindle

[Doddy]

I think I’ve managed to confuse you, I mentioned the 0-10v controller to support easy integration with the existing bldc motor controller provided by the Sx2.7.

The separate case for me is, having blown the controller I’ve replaced that with a servo and controller, and the controller could take 0-10v speed demand from a BoB, for sure. Although I choose to use step/dir signaling instead. Same end result though, easy integration with UCCNC

[lewiss66]

Ok,
Seems very good info here.
Onestly, I'm falling behind of what you've achieved so far to CNC it!
But I'll be very interested to see if you have made some kind of reporting videos or photos on it.

[lewiss66]

Hi Jaket,
you said: "Clutch: Offers the freedom to move the table by handwheel or powerfeed."
That's a handy solution to keep the mill as original!
Wonder if you can still run this setup without the need of a mecanical clutch...maybe electronics system?