Cnc group project

#1

Hi there,

I’m really interested in learning more about the CNC machine and I know I have spoken to a few others that have shown interest in learning more about the machine @pip and @Barnaby_Coote has advised he has done some work on the machine already and has access to cutters.

I wondered if there were some people that would be interested in creating a group where we could meet on a regular basis weekly/fortnightly and the aim would be to train ourselves to use the CNC machine maybe by setting small tasks to complete or a group build? I have spoken to 2 people in the last week about setting up some kind of group, but unfortunately, I didn’t catch your name. If you are one of the people I spoke to please leave a comment.

Cheers

#2

The snag is it isn’t so much training that’s needed but also learning to build parts for the machine to make it more useable. Its pretty fragile at present and needs some pretty heavy maintenance fairly frequently.

So I’m a bit worried about intensive use by a large group until we’ve worked out the bigger kinks to be honest. That doesn’t mean we can’t tinker with it but it won’t last long before something major breaks if it runs every day. I went through a few of these problems in the big cnc thread in july which is still on discourse somewhere.

But if more people want to jump on board with improving it or helping with the clarke mill cnc mod that would be great ! It would be amazing to have a decent working cnc in the space.

And yes i can show you how it works if you have a moment in the week !

1 Like
#3

@Barnaby_Coote , what type of parts need replacing? maybe it would be a good idea to come up with a list of the parts required so we can see if we can make or acquire them… I’m also super keen to see how this works so please keep me posted if you are having a tinker session.

#4

There’s quite a few improvements that could be made, the main problem at the moment is the lead screw on the Z-axis which is just a low quality 8mm thread and a plastic nut block. It gets gummed up too easily and you have to remove the whole Z assembly and clean it out quite often. We could replace it with an acme screw and metal block.

Then there’s the beams themselves that aren’t very rigid. We could beef those up to avoid everything flexing when it cuts, which would give us a less jagged and wavy cut and perhaps allow us to cut deeper and faster. For now if you push the bottom of the spindle with your finger, the spindle assembly will flex quite a bit. This isn’t good for making precise clean cuts.

Would be great to replace the wheels with linear bearings and proper lead screws to get rid of any play in the system. The wheel system on the shapeoko isn’t very good, either it jams the motors or it gets too loose depending on how you tighten it.

We could also beef up the motors, get a better spindle, it goes on… Although this isn’t really our shapeoko so these extra bits need to be removed if brendan takes it back.

We also need to finsh the risk assessment for this machine

#5

So do we have a small group interested in getting the CNC functional?

Core tasks include:

fix is the lead screw and metal block?

improve beams by increasing their power?

replace wheels with linear bearings and proper lead screws

risk assessment of machine

Is there a CNCtech group? is there budget to fix this machine? Is it worth looking into purchasing a medium sized CNC machine if this CNC is only a loan? @directors @brendon I noticed the loan date has expired.

#6

I’d love the space to invest money in this but I think the impression was it was a bit niche, ie only a select group were interested and the learning curve was too high to be inclusive with non expert members. And it never really seemed to take off with the directors

looks as if this is gaining a bit more interest though ?

I was suggesting investing about 600-700 pounds on one we make ourselves with a solid steel welded frame, and learn as we go
I could start detailing the budget if that’s something we want to explore

we would need to spend 10 times that for something commercial I think, perhaps a bit much to spend for now ?

1 Like
#7

@directors is this a possibility?

I have also hearrd discussion of a CNC purchase, among a couple of members is this something that would be for the use of the space of a private purchase?

Thanks

Chanelle

#8

If there’s strong interest in this then of course we’ll look at it.

I think having people experiment with the Shapeko can give us a good idea of what we might want in future.

The ‘expert user’ objection was really referring to a full scale CNC machine which has a long and steep learning curve.

#9

The difficult bit is generating the tool paths in the cad/cam software

its a matter of just letting it run after that

#10

I’m very interested in having a cnc machine.
Don’t have much time for it at the moment though.
But full backing for now.

#11

I’ve done quite a bit of experimenting with it now and found it not worth it compared to conventional milling on the micro mill. It can only just manage a feather pass and even then the results are not super clean. You can do some stuff in wood though (if it doesn’t break or jam)

#12

here’s a ballpark budget breakdown:

light machine

  • linear bearing and lead screw kit: £150 (based on the ebay kit the joe found)

  • 3x Nema 23 motors 2.8A kit £54

  • Synthetos tiny G CNC controller £160

  • t-slot table £100

  • spindle with er collet set £240

  • cabling, bolts, aluminium etc £100

  • steel for frame tbd

  • power supply £60 for 24V or 12V for free (we have loads)

  • an arduino

total around £700

uber machine:

  • high torque 3 axis nema 32 kit with drivers (8.1 N.m torque) £350

  • a g-code usb controller system approx £150

  • steel, aluminium and hardware for frame £150

  • spindle and collets £300

  • coolant system (drip wd40 or compressed air or flood) £50-150

  • mdf, sound proofing rubber and perspex for enclosure £150

  • linear bearing kit £150

  • cabling £50

  • t-slot table £100

approx £1300-1500 total

bear in mind we can build the frame with spindle holder and t-slot and then upgrade as we go

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#13

I think this is the moment we accept we have learnt enough and make a decision. If CNC Is always going to be niche and require a bit more operator investment, I’m also if the mind that this might be a machine where a DIY middle ground makes sense. I didn’t start with that view.

1 Like
#14

Thanks for doing that Barnaby. Maybe we need to prove there is demand for it. I can mane leave something at the space for people to sign as there quite a few members who use the space but don’t use discourses. I will put something together over the next week.

#15

tormach do this commercial one
http://www.tormach.com/product-pcnc-440.html
starts at $4950 with many essentials missing

i found an english brand too, was around £5000, i’ll have a look for it again

#16

http://london.craigslist.co.uk/bfd/5874693152.html

3 Likes
#17

Holy :monkey:

#18

and there is this http://london.craigslist.co.uk/tld/5851552303.html

1 Like
#19

Wow. These things make me weep chunky teardrops of desire.

#20

Lets buy it!!!