Hi from Glasgow

[Doddy]

Agreed with the ER11 chuck. If you struggle to find a UK supplier then I could throw one in in the post....



...though I had one bad experience of boring one of these for a mate with a similar designed PCB router (the shaft is hardened - I tried heat treating it but with little success) - I'd see this as letting someone else experiment with a solution.

You may find that you have run-out on the spindle motor as well - the biggest problem you're going to face is all the float in the system - from bushes through to the spindle to get the resolution that you need for PCB without smashing end-mills (I prefer the 0.3mm end mills to the v-cutters, but if you look at one of those endmills wrong you'll snap it).

Having wasted the weekend investigating toolchains I'd be interested in hearing what software you're using for this.

EDIT: Having just been over to eBay - plenty in the UK. I'd seriously recommend getting a couple of pillow block bearings and creating your own spindle, driven by belt from the existing spindle motor - then you can manage the runout and end-float easier than inheriting from the motor.

[bartdietrich]

Agreed with the ER11 chuck. If you struggle to find a UK supplier then I could throw one in in the post....

Hi Doddy,

Sorry for the delay, got caught up in the 3D-printing-face-shield-frames-for-health-workers thing and then completely forgot about this forum!

Thanks for the offer but I'm not even sure what that picture is of or how I would go about attaching this bit to my setup. It looks quite long anyway, it might not fit between my spindle and the bed. Here's a picture of the business end of my machine with a ruler for scale. It's quite small:

You may find that you have run-out on the spindle motor as well - the biggest problem you're going to face is all the float in the system - from bushes through to the spindle to get the resolution that you need for PCB without smashing end-mills (I prefer the 0.3mm end mills to the v-cutters, but if you look at one of those endmills wrong you'll snap it).

Run-out on the motor is possible although that is about the only thing on the mill that looks and feels like it might be ok. The motor shaft doesn't feel like it has any play and it looks like it's spinning cleanly. Or at least cleanly enough for what I want to use it for. Although obviously that's very difficult to judge by eye. The problem is that there is no way to attach the chuck to the motor shaft in a repeatable centred way: the two grub screws allow all sorts of tilted orientations because the motor shaft is thinner than the inside of the chuck. Do you know of any chucks with some kind of reliable attachment systems?

Also, you say you prefer 0.3mm end mills to v-cutters. I have what was described on eBay as 30 degree 0.3mm end-mills. Because their tip is a V-shape I thought these were V-cutters?

Having wasted the weekend investigating toolchains I'd be interested in hearing what software you're using for this.

Well, I still use what probably most people who have just got into this use: FlatCAM for creating the G-code from Gerbers or drill files and then Universal G-Code Sender to send it to the mill. They're both free software. Can't tell you whether they're any good or how they compare to other software packages. These are the only ones I've ever used! They seem to work well enough although I'm finding the most recent version of FlatCAM to be quite buggy.

EDIT: Having just been over to eBay - plenty in the UK. I'd seriously recommend getting a couple of pillow block bearings and creating your own spindle, driven by belt from the existing spindle motor - then you can manage the runout and end-float easier than inheriting from the motor.

Do you mean plenty of ER11 chuck/collets on eBay? I'll have a look but the ones I've seen so far are all for bigger machines. As for the building my own belt-driven spindle, I'm not sure that can be done while keeping the whole thing to a reasonable size that will fit on my mini-mill!

Bart

[Voicecoil]

The problem is that there is no way to attach the chuck to the motor shaft in a repeatable centred way: the two grub screws allow all sorts of tilted orientations because the motor shaft is thinner than the inside of the chuck. Do you know of any chucks with some kind of reliable attachment systems?

Bart

From this statement it sounds like the problem is the attachment bit of your chuck - to have any chance of good centering the hole that the motor shaft goes into is going to need to be an extremely snug fit. I've had a wee search and like you not had much success with finding an ER11 chuck with a 3mm shaft entry. I did however come across one or two motors with ER11 chuck fitted that look like they might fit your machine on the Bay of fleas for quite reasonable money (£18....25) - might that be a way to go?

[bartdietrich]

From this statement it sounds like the problem is the attachment bit of your chuck - to have any chance of good centering the hole that the motor shaft goes into is going to need to be an extremely snug fit. I've had a wee search and like you not had much success with finding an ER11 chuck with a 3mm shaft entry. I did however come across one or two motors with ER11 chuck fitted that look like they might fit your machine on the Bay of fleas for quite reasonable money (£18....25) - might that be a way to go?

Indeed, I don't think my current chuck is worth me spending any more time on trying to fix it. What keywords did you use for the eBay search? Can you post a link to one of the results you found? The ones I've seen all seem too big. I need a motor of 29 mm diameter and the mounting holes need to be 22 mm apart. Since I don't have the capability to machine my own motor holder I am pretty much stuck with the hardware that came with the mill. I'm toying with the idea of getting a Ooznest WorkBee milling machine. I could use that to make a motor holder for a different size motor for the PCB mill (not just for that, it would complement what I can do with the 3D printer and would come in handy for work too), but that's just a vague plan for sometime in the future. So for the moment I'm stuck with that size of motor for the PCB mill. Speaking of which, any opinions on the WorkBee?

Bart

[Doddy]

Indeed, I don't think my current chuck is worth me spending any more time on trying to fix it. What keywords did you use for the eBay search? Can you post a link to one of the results you found? The ones I've seen all seem too big. I need a motor of 29 mm diameter and the mounting holes need to be 22 mm apart. Since I don't have the capability to machine my own motor holder I am pretty much stuck with the hardware that came with the mill. I'm toying with the idea of getting a Ooznest WorkBee milling machine. I could use that to make a motor holder for a different size motor for the PCB mill (not just for that, it would complement what I can do with the 3D printer and would come in handy for work too), but that's just a vague plan for sometime in the future. So for the moment I'm stuck with that size of motor for the PCB mill. Speaking of which, any opinions on the WorkBee?

Bart

If only you could find a forum where people had such machines that could cut something for a different sized motors :(

Don't let the diameter unnecessarily constrain you. I would offer some assistance but I've... erm... had a bit of an accident with my mill and am waiting a delivery from China. Just don't throw a lot of money at that machine.