Starting to design out my build, looking for critique

[AndyUK]

Well... I have been inactive for a while now, I guess... But a certain event that might entail additional customs charges for the parts that I want to source from Britain, is pressuring me back into activity :D

You've got till the end of Jan - I'll give you good odds on that :)

Now I did not do nothing all this time, but I did get a plan going for the power lines. As mentioned before, I have someone with more experience than me in the field help me with the selection of specific parts, so the plan is just for the power connections, not the data lines. These are to be specified when the parts are fixed (Also, logic level stuff is more my expertise, so I can more easily deal with all of that on my own, while I am more concerned about getting all the higher-voltage lines done to spec).

Looks good - Although read the VFD manual about switching it on and off with a relay - mine specifically says not to. I'm hoping UCCNC will drop the spindle enable when it receives an E-Stop command, but have yet to test this.

I'm also planning to use FA/FB/FC for a fault signal feedback from the VFD to the UC300eth - I figure I'd rather use this function for stopping the CNC when the spindle faults (and therefore stops rotating) than running the water pump - which can just be run continuously anyway. I don't like the idea of the spindle stopping and then the CNC trying to force the bit through stock.... that sounds like a bad situation.

I also already got a hold of a couple parts: The person helping me has access to some old parts that are not used anymore, so I already have a 24V PSU, all the connector blocks and wiring that I could ever need, as well as a transformer and the fuses.

Cool. Also look for an electronics cab which will help you start placing components etc. I used Tempa Pano - rather cheap, but not perfect quality.

What I am looking to get in a more time sensitive manner, is the UC300eth controller, as well as the steppers mentioned in the above post and the AM882 drivers to run them. The drivers and controller have already been discussed in this thread, but it is the motors I am still a bit unsure about. They were chosen under the constraints that were brought up, but I might have overlooked something.

Don't forget to look into breakout boards. I really like my UB1. May as well buy them at the same time. Why is the UC300 time-sensitive? Usually its best to get the mechanicals in order and built before starting to buy the big ticket electrical components - you never know whats just round the corner in terms of new models, and you'll end up ticking away your warranty while you're still building.

On a different note of mechanics: I am pretty much ready, at this point to start buying parts, like the alu, the plates and the rails. I actually already have one of the rails here. And since there does not seem to be anything to change in the design, I will probably proceed with that, as soon as the electrical part is signed off on by the council of more knowledged people here :) And I guess, once I start buying, it is finally time to open a build log thread.

Looking forward to it! :)

[Chrono]

You've got till the end of Jan - I'll give you good odds on that :)

Looks good - Although read the VFD manual about switching it on and off with a relay - mine specifically says not to. I'm hoping UCCNC will drop the spindle enable when it receives an E-Stop command, but have yet to test this.

I'm also planning to use FA/FB/FC for a fault signal feedback from the VFD to the UC300eth - I figure I'd rather use this function for stopping the CNC when the spindle faults (and therefore stops rotating) than running the water pump - which can just be run continuously anyway. I don't like the idea of the spindle stopping and then the CNC trying to force the bit through stock.... that sounds like a bad situation.

Guess I really need to take a better look... With the F-Terminals, and with the whole schematic to be honest, I took a look at JoeHarris' build and for the most part copied it over, and slightly changed it to fit my setup. Thanks for making me aware that that might not be the best option. Time to dig out the datasheet.

Cool. Also look for an electronics cab which will help you start placing components etc. I used Tempa Pano - rather cheap, but not perfect quality.

Yep, already got that covered. Most likely my helper will be able to source one for cheap, that is excess or old stock.

Don't forget to look into breakout boards. I really like my UB1. May as well buy them at the same time. Why is the UC300 time-sensitive? Usually its best to get the mechanicals in order and built before starting to buy the big ticket electrical components - you never know whats just round the corner in terms of new models, and you'll end up ticking away your warranty while you're still building.

Looking forward to it! :)

The urgency was more from the time of writing, since I did not know, at the time, that I would have till January, and these are the parts I need to get from the UK, since they are massively more expensive here.

I actually wanted to ask about BOBs, but completely forgot. As far as I understand, they step up the controllers signals to 24V and handle isolation between the electronics and the controller? The UB1 looks great, but the price is another 200€ on top (on that note: Where did you buy your BOB, if I may ask? I can only find a couple shops, some of which sell it for twice as much as others)... if only i had a schematic, then i could just roll my own :D

But you are right, it makes more sense to get the mechanical side figured out first... And since that setup is ready to go, I guess it is time to clean up the workshop and get the space cleaned out that I want to put the router in. Then order the alu, sheet metal and the linear motion equipment and put that together, before moving on. One step at a time.

Regarding the linear motion: With both the 25mm rails and the ballscrews, I have the choice between HIWIN stuff and "mainland china" rails with "C7" ballscrews. The difference is 670$ to more than 1000$... Are there any verdicts on the quality of the chinese alternatives?

[JAZZCNC]

As far as I understand, they step up the controllers signals to 24V and handle isolation between the electronics and the controller? The UB1 looks great, but the price is another 200€ on top (on that note: Where did you buy your BOB, if I may ask? I can only find a couple shops, some of which sell it for twice as much as others)... if only i had a schematic, then i could just roll my own :D

Don't skimp on the BOB it's just as important as the controller and the single most troublesome part of any machine when it's done on the cheap.
The UB1 is good BOB, thou i'm not keen on the spring loaded terminals but other than that it's well made and very capable.
I've seen Many electronics geeks try to Roll there own and 99% fail resulting in wasted time only to buy one in end.

Regarding the linear motion: With both the 25mm rails and the ballscrews, I have the choice between HIWIN stuff and "mainland china" rails with "C7" ballscrews. The difference is 670$ to more than 1000$... Are there any verdicts on the quality of the chinese alternatives?

You can get Hi-win from china and the ballscrews are Ok for the money. They also sell C5 if you want little better.

You don't need 25mm rails for machine this size and it will actually negatively affect the machine compared to 20mm rails because of the extra inertia etc the motors will have to deal with. These may seem little negative things but together they add up into large negative which affects performance.

Regards the VFD it will damage the VFD eventually by switching it off and on thru a relay. It's also not safe due to capacitors causing a delay in it powering down.

Not looked at the schematic too close but will take a look. The schematic Joe used mostly came from me so should make sense..

[Chrono]

Don't skimp on the BOB it's just as important as the controller and the single most troublesome part of any machine when it's done on the cheap.
The UB1 is good BOB, thou i'm not keen on the spring loaded terminals but other than that it's well made and very capable.
I've seen Many electronics geeks try to Roll there own and 99% fail resulting in wasted time only to buy one in end.

Got it. Makes sense to me... There are just too many variables for me to try and get it on the first try, and on the second I would likely be overshooting the cost of the UB1 anyways.

You can get Hi-win from china and the ballscrews are Ok for the money. They also sell C5 if you want little better.

You don't need 25mm rails for machine this size and it will actually negatively affect the machine compared to 20mm rails because of the extra inertia etc the motors will have to deal with. These may seem little negative things but together they add up into large negative which affects performance.

I have checked again, and as it turns out, my memory was wrong... I was already planning on using 20mm rails, and that is what is in the CAD model. I am planning to get them from china, but HIWIN vs china rails are still 300$... Would that be worth it, or are the chinese ones good as well?

Regards the VFD it will damage the VFD eventually by switching it off and on thru a relay. It's also not safe due to capacitors causing a delay in it powering down.

Not looked at the schematic too close but will take a look. The schematic Joe used mostly came from me so should make sense..

Got it. So the only E-Stop for the VFD then is the mains switch and the internal E-Stop signal, I am guessing?

[AndyUK]

Where did you buy your BOB, if I may ask?

I got my UC300eth and UB1 as a pair from CNCROOM.com in Thailand. They are the designers of the UB1, so are very helpful when you have questions. As you say, not the cheapest (and they label correctly so you will be stung for the full correct amount import duty) but the quality of the product is high, and the delivery was very fast considering the distance (less than a week).

I also purchased my UCCNC licence from them rather than direct from CNCDrive (because no VAT) - but do it separately so its not on your invoice for the UC300 and UB1. You'll need the serial number of your UC300 so wait for that to arrive first.