Router for CNC machine

[martin.pearson]

Contrary opinion: but unless you have prior CNC machine knowledge I wouldn't go used for a first machine.

Having used one (from new) for 15+ years I'd have some idea of what to look for in a used machine, but it would still be pretty daunting if there were a need to do significant rewiring/fixing or configuring of ports and pins without vendor support.

While I wouldn't disagree with what you have said I would add that things have changed a lot in the last 15 years, the help & support available these days makes it far easier to get help & support than it was when you got your machine, still might be a lot to take on though I agree, I didn't have a problem buying an old machine for spares or repair when I first started but then my background probably helped a lot with that.

other than the z90 I cannot see anything else on eBay at the moment That's why I said if you are not in a hurry, machines get listed all the time but they are not always going to suit your needs, it will be a case of sitting & waiting if you go down the second user route lol

 

[Ollie78]

Contrary opinion: but unless you have prior CNC machine knowledge I wouldn't go used for a first machine.

Having used one (from new) for 15+ years I'd have some idea of what to look for in a used machine, but it would still be pretty daunting if there were a need to do significant rewiring/fixing or configuring of ports and pins without vendor support.

This is a valid point.
However, I believe the type of machine Dave is looking at is sort of a kit type thing rather than a turnkey or plug and play solution.
In this case a fully working second hand machine may actually require less setup and assembly.
I found upgrading mine to a uc300 Ethernet motion controller to be reasonably straightforward. Just had to pay attention.

Ollie

 

[martin.pearson]

This is a valid point.
However, I believe the type of machine Dave is looking at is sort of a kit type thing rather than a turnkey or plug and play solution.
In this case a fully working second hand machine may actually require less setup and assembly.
I found upgrading mine to a uc300 Ethernet motion controller to be reasonably straightforward. Just had to pay attention.

Ollie

Are you running UCCNC with it or mach3? I originally set my machine up using mach3 & the parallel port but upgraded to a UC400 not long after & just paid for the UCCNC licence at the same time. I went with the UC400 because I preferred to use ethernet rather than USB, only problem with motion controllers now days is the control software is linked to the motion controller so you need a different licence for each machine lol

 

[Ollie78]

Are you running UCCNC with it or mach3? I originally set my machine up using mach3 & the parallel port but upgraded to a UC400 not long after & just paid for the UCCNC licence at the same time. I went with the UC400 because I preferred to use ethernet rather than USB, only problem with motion controllers now days is the control software is linked to the motion controller so you need a different licence for each machine lol

I am on UCCNC, I bought the uc300 bundle direct from cncdrive in Hungary.
My machine was originally running mach 3 on parallel port but the Pc died so I upgraded, never got much chance to use mach 3 before its death but I like UCCNC.

Ollie

 

[sploo]

Ollie/Martin - I was mostly thinking of "15 years experience" rather than the changes to CNC machines over the last 15 years; but that is a good point. If the used machine is a popular "modern" design with lots of online support then that's a different story. For me a used CNC machine is likely something industrial, from a company that may no longer exist, and will have pretty much zero info online - so obviously that would be a different level of work!

 

[Sporky McGuffin]

Slight diversion - sorry, I think it's relevant - there can be a steep learning curve on these machines. When my K2 caught fire (appalling design of the control box) I learned rather a lot in the process of putting everything right. This is the new control box I made. I do audio visual system design for a living, so built this along the lines of how we build racks. Every connector is available from at least two of RS, CPC, and Canford, and they're all colour-coded. All the soldered connections have heat-shrink or Hellerman tubing over the joints; all the screw-down terminals have bootlace ferrules, and it's all fairly neatly dressed inside.

The Gecko drives (the blue boxes in the middle - these drive the stepper motors) are mounted on PC CPU heatsinks with fans, and all the cables are rated at least 50% over the maximum power that'll go down them.

However, building this took a LOT of swearing, several hundred pounds, and the use of two other CNC machines - one to cut the panels, the other to make all the connector and breakout PCBs. My point overall is that a CNC machine is one of the highest maintenance tools you can own, and you have to be prepared for the ongoing spend. I've also got a couple of grand of software and that's not the expensive end of the market.

 

[sploo]

When did you get your K2 (originally)? The incoming control board with the parallel port looks different to mine.

Also - those Geckos look like the more modern G320X servodrives. Mine came with the older G320, but my 4th axis (DIY added later) uses a newer G320X.

Your wiring is certainly neater than mine!

 

[Sporky McGuffin]

I bought it used. Good spot - that was a new breakout board, I think from diycnc. I replaced all the Geckos and two of the HEDS encoders. You may already know but the G320X aren't actually a drop-in replacement for the G320 (despite what it says on the Gecko site). If you're using optical encoders (as the K2 does) you have to add a capacitor at the encoder and two resistors at the Gecko. That indifference is hidden in an obscure technical note in a locked filing cabinet in a sub-basement toilet of the web site.

I also completely recabled the machine at the same time. The original runs to the steppers were about right for 10% of the power the steppers can pull. K2 were a bunch of bodgers!

 

[sploo]

I bought it used. Good spot - that was a new breakout board, I think from diycnc. I replaced all the Geckos and two of the HEDS encoders. You may already know but the G320X aren't actually a drop-in replacement for the G320 (despite what it says on the Gecko site). If you're using optical encoders (as the K2 does) you have to add a capacitor at the encoder and two resistors at the Gecko. That indifference is hidden in an obscure technical note in a locked filing cabinet in a sub-basement toilet of the web site.

I also completely recabled the machine at the same time. The original runs to the steppers were about right for 10% of the power the steppers can pull. K2 were a bunch of bodgers!

Yea, I added the cap and resistor combos to my machine.

BTW (pedant mode enabled - sorry ) it's running on servos rather than steppers. You can get hybrid steppers with built in encoders, but I assume yours will be running the DGM 24V servos that K2 were using in the early 2000s?

I do note that a lot of CNC vendors are now using steppers even in higher end machines (well, higher end than my K2). Back in the day it seemed that steppers were for the cheap stuff and servos were where it was at for the better machines. I don't know if the stepper technology has moved on in the last 20 years or whether it's purely down to volume reducing the prices, but it does surprise me that the servo motors haven't caught on.

 

[martin.pearson]

Slight diversion - sorry, I think it's relevant - there can be a steep learning curve on these machines I don't think this is really a diversion, it's very true & I don't think a lot of people realise just how steep it can be if you are new to both CNC machines & the type of software required to use one.
Not sure I agree fully with what you have said about it being one of the highest maintenance items you can own, your experience with the machine you bought was really down to poor design & manufacture by the company more than anything else, unfortunately, there were quite a few companies like that knocking about & I guess there probably still will be but it is easier to research a machine online now & many companies have their own forums from what I have seen. You could have rebuilt your control box for a lot less than you actually spent, but then again you could have spent a lot more, I think that is possibly a difficult balance to get right & something someone without any experience should be doing on their own. I think your point about it being an ongoing spend is very valid & I am guessing a lot of people wish they had known that before buying their first machine, someone mentioned on a forum I use years ago that you should buy your second machine first & that has always stuck in my mind lol
I guess there is more that can potentially go wrong so from that point of view they may be higher maintenance & people often upgrade entry level machines so there is definitely no end to the amount of money you can spend on them lol
There are free software programs available but as I said in another post most people will invest in software for one reason or another & you are right in saying that it doesn't come cheaply, in fact depending on what you want to be able to do & how quickly & efficiently you want to be able to do it the software can cost many thousands of pounds lol I have never found a one size fits all software for anything that I have done so have a range of different software & try to use the strengths of each but it can be an expensive way of doing things.

 

[Sporky McGuffin]

BTW (pedant mode enabled - sorry ) it's running on servos rather than steppers. You can get hybrid steppers with built in encoders, but I assume yours will be running the DGM 24V servos that K2 were using in the early 2000s?

You might be right - I'd assumed steppers because they "sing", and the encoders are bolted onto the ends.

You could have rebuilt your control box for a lot less than you actually spent, but then again you could have spent a lot more, I think that is possibly a difficult balance to get right & something someone without any experience should be doing on their own.

Hard to call; initially I'd thought it was just a blown Gecko which is painful but not ruinously expensive, but then found the BOB had gone too, and two encoders. At that point I decided that the grown up approach was to bin K2s effort and make something reliable and serviceable that wasn't going to catch fire again.

 

[martin.pearson]

Oh I agree with you 100%, unfortunately, that's often the way with electronics it seems, one component goes & takes out a bunch more in the process lol
Point is it was their bad design & workmanship that led to the problem in the first place, if they had done the job correctly then you wouldn't have had to fix it.
What I meant was that when it comes to upgrades & making changes its hard to know exactly where to start & how much to spend without some kind of experience, you could spend a small amount & see a big improvement in the machine or you could spend a lot of money & see very little improvement as making one change is just going to reveal the next weak link.
I take it you have never had any real problems with crabbing on the machine with it having a single centre lead/ball screw on the x or y axis to me it would be the y axis but I know a lot of American thinking was that the x axis was the longest axis from what I have read.

 

[sploo]

You might be right - I'd assumed steppers because they "sing", and the encoders are bolted onto the ends.



Hard to call; initially I'd thought it was just a blown Gecko which is painful but not ruinously expensive, but then found the BOB had gone too, and two encoders. At that point I decided that the grown up approach was to bin K2s effort and make something reliable and serviceable that wasn't going to catch fire again.

Yea they (the servos) definitely sing; all part of the PID tuning between the motor and the encoder. You can adjust the tuning on the Gecko to improve things (though I've never entirely eliminated it).

I've had... mixed... experience with the Gecko drives. They're pitched at the upper end of the cost/quality scale, but I had one fail shortly after the machine was delivered. K2 sent me a replacement. Years later another died, and Geckodrives replaced one for free under their "stuff happens" program. An electrically savvy friend took a look at the original bad drive and found some failed solder joints (which he fixed by reflowing them). I suppose it could be blamed on K2's design of the control box, but regardless it has left me feeling a little burnt.

I once heard the analogy that servos are like sports cars (fast but temperamental) and steppers like tractors (slow but reliable). Given that the cutting speed on hobby level CNC machines is limited by the machine rigidity and spindle horsepower I'd probably use steppers if I were ever to build myself a new machine.

 

[Sporky McGuffin]

I take it you have never had any real problems with crabbing on the machine with it having a single centre lead/ball screw on the x or y axis to me it would be the y axis but I know a lot of American thinking was that the x axis was the longest axis from what I have read.

No mechanical issues at all. To me that's the X because (a) I started with it o make guitars, and that's how I lay them out in CAD, and (b) I stand at the long side.

Yea they (the servos) definitely sing; all part of the PID tuning between the motor and the encoder. You can adjust the tuning on the Gecko to improve things (though I've never entirely eliminated it).

Gotcha. I sit corrected/better informed.

 

[Ollie78]

@Dave the woodworker
Just been looking on ebay randomly saw this one, might be up your street

https://www.ebay.co.uk/itm/cnc-rout...2349624.m46890.l49286&mkrid=710-127635-2958-0
Ollie

 

[Dave the woodworker]

@Dave the woodworker
Just been looking on ebay randomly saw this one, might be up your street

https://www.ebay.co.uk/itm/cnc-rout...2349624.m46890.l49286&mkrid=710-127635-2958-0
Ollie

The QueenBee pro I believe, is from the USA and is modelled on the workbee. They seem to have bought out the pro inorder to introduce improvement to the original Queenbee. Probably not too different from the killerbee from Portugal but delivery costs from the USA will be much more.

The problem with buying off eBay is you have no warranty and as this person selling is not a company you take a greater risk. Also the price is quite high. I would expect it to be much lower for a private sale, but thanks for letting me know.

 

[Dave the woodworker]

Have really enjoyed the discussion on this thread but for me personally, I am not really after an all singing all dancing CNC. I wish to make simple wooden signs using an CNC and other tools. The speed of the machine is not important to me so I have purchased the killerbee for about £850 not including a spindle but includes the power supply as I will start off with a router and free software until I have learned how to use the machine. I will decide on the controller in due course once I have explored the options a bit more. I will of course have to pay UK vat but the delivery cost should be around £35. We shall wait and see as Brexit could screw this up a little.

I would have gone for the British Workbee but all those wheels has put me off and it definitely would have less stiffness than the Killerbee. Also the killerbee is cheaper.

 

[Ollie78]

Have really enjoyed the discussion on this thread but for me personally, I am not really after an all singing all dancing CNC. I wish to make simple wooden signs using an CNC and other tools. The speed of the machine is not important to me so I have purchased the killerbee for about £850 not including a spindle but includes the power supply as I will start off with a router and free software until I have learned how to use the machine. I will decide on the controller in due course once I have explored the options a bit more. I will of course have to pay UK vat but the delivery cost should be around £35. We shall wait and see as Brexit could screw this up a little.

I would have gone for the British Workbee but all those wheels has put me off and it definitely would have less stiffness than the Killerbee. Also the killerbee is cheaper.

No worries, I just remembered this thread when I saw it and thought it was quite good as pretty much a complete setup with spindle and everything.

I am sure the Killerbee will suit your needs, it has removed the worst aspect of the workbee and its clones, the rubber wheels on extrusion.
Does it come with a motion controller? if not I seriously recomment the CNCDrive AXBB ethernet controller with built in breakout board and UCCNC as probably the best value motion control system out there.

For free software Fusion 360 hobby version is still great despite people complaining about it having slow rapids etc. A very powerfull software with design and advanced CAM in one , however not the best for v carving.
I use vectric vcarve for that, its not free but is worth its money I think.
Carveco is another alternative which looks good but monthly subscription at 3 different levels.
I had a free engraver called textgraver that worked ok.

Have fun with your cnc. Its addictive.

Ollie

 

[Dave the woodworker]

No worries, I just remembered this thread when I saw it and thought it was quite good as pretty much a complete setup with spindle an everything.

I am sure the Killerbee will suit your needs, it has removed the worst aspect of the workbee and its clones, the rubber wheels on extrusion.
Does it come with a motion controller? if not I seriously recomment the CNCDrive AXBB ethernet controller with built in breakout board and UCCNC as probably the best value motion control system out there.

For free software Fusion 360 hobby version is still great despite people complaining about it having slow rapids etc. A very powerfull software with design and advanced CAM in one , however not the best for v carving.
I use vectric vcarve for that, its not free but is worth its money I think.
Carveco is another alternative which looks good but monthly subscription at 3 different levels.
I had a free engraver called textgraver that worked ok.

Have fun with your cnc.

Ollie

Thanks Ollie, I will have to wait a couple of months as they are extremely busy. They have just moved to a larger warehouse and have taken on more staff. It would not surprise me if their prices go up which is why I have made a decision now.

Meanwhile I have been looking at YouTube videos and purchased secondhand books, ( the old fashioned way of learning). I have one by a man who made his own CNC and then turned it into a manufacturing company. Shapeoko. As you may know already, they are now on version 4. His book is full of useful information to a beginner like me. He states in the book that he is still learning but that is part of the enjoyment of a woodworking hobby come small business.

 

[Dave the woodworker]

What I fine amusing about a number of videos on YouTube is the number of personalities that you see unboxing their new toys, all sorts, and then nothing more on how they get on with the item ever again.