My baby 15" x 15" machine

[wilfy]

your right acctually.. i didnt look at the prices correctly

so PSU - 480W High Power CNC Stepper/Servo Motor Driver Switching Power Supply 48V10A PSU | eBay
i cant find anything that relates to the 500va i'm guessing that is supposed to be 500w?? other alternative is 600W PSU 48V 12A CNC Power Supply Stepper Motor Milling

drivers - Best Selling! Wantai Stepper Motor Driver DQ860MA 80V 7.8A 256Micro CNC Router Mill Cut Laser Engraving Grind Foam-in Motor Driver from Industry & Business on Aliexpress.com

motors - Nema23 Stepper Motor 3.1Nm x 3

total around £255 is that everything i need or do i need a breakout board aswell for pc connectivity??

[wilfy]

Wilfy I have spent many many hours talking and helping new people to DIYCNC on the phone and via email and THE MOST COMMON (by a long way) single mistake they make is buying the wrong drives and PSU. The TB based boards are one of THE easiest ways to waste money and more importantly time, mainly resulting in frustration and disappointment.

To answer the question regards speed and what's the correct drives PSU to buy then the Honest answer is CAN'T ANSWER.!! . . . . .Until more information is known about the machine and what materials your going to machine.?
I help loads of people either on here on via the phone etc and When I ask folks what they want to machine they generally say "Oh nothing too difficult just MDF, wood, plastic and the Occasional bit of Ali" . . ERmmmm is my reply.?
Whats wrong with that you may think.? . . . . Well it mostly boils down to cutting speeds.!

Given the TB based board and 24V has a crude example.!! . . Out of all those materials you'd think the hard ALi would be the challenge.? BUT in reality given the machine frame is strong enough it will be the most suited to the slow TB based board.? Ali only requires low feed rates and the 24V will probably be ok. This is also why lots of small milling machines and lathes use 24V.
But Wood, MDF, plastics etc require high cutting feed rates so in general require the motors spin faster for longer. There are other things that affect feed rate like screw pitch but in general in these softer materials the motors are working faster. To enable this speed you need voltage and 24V (Excuse the pun) just doesn't cut it and available speed is low and therefore feed rates. Too low feed rates wears tooling out very quickly and leaves a poor finish.
Then you have the workload of the drives.! They are constantly MAX'd out and eventually this takes it toll and in the case of the cheap TB based stuff results in either poor performance in form missed steps etc or has often happens they die quickly by frying themselves.

The extra £100 is worth every penny and will enable a very wide range of cutting capability with the least amount of stress.

thanks for that you replied while i was posting my previous post.. thats explains everything and kind of fills in the missing blanks that i couldnt get my head round.. as it happens using the info jonathan has given me i've pretty much match the earlier price but with the better components

[martin54]

Wilfy, I've put this on your build log rather than hijack the other one. If your looking for a local steel supplier try doing a google search. I have just done a google search for "steel stockholders wigan" and up popped about 4 quite big companies. Probably more if I looked harder but there's a start for you. Guessing any one of them will offer you a better price if you actually go & see them rather than phone up.

[wilfy]

yeah thats on my list of things to do, i did email one company to find no reply, but i'll work out how much steel i need over the next few days and then i know how much i need to order, the other problem is getting someone to deliver it

[njhussey]

wilfy, I'd offer to get the steel for you but by the time you've either courriered it to you or come and collected it (5 hr round trip) you could probably buy it for the same price locally. Plus I can buy the odd thing through work but if they see my buying lots of steel then questions will be asked if you can wait until wobbly orders then I can tack it on, but still got the problem of getting it to you....

[martin54]

You will get a better price if you actually go there rather than email, that's always been my experience so always try to speak to people face to face if I can.
If you can't get it in your own car do you not know someone with an estate or something like that? Just rough cut it on site if the supplier won't cut it for you.
I have a people carrier but all the seats bar the one I need have been removed so really it's small van size. Seats just clip in so if I do have to ferry anyone about I just stick them back in.

[wilfy]

wilfy, I'd offer to get the steel for you but by the time you've either courriered it to you or come and collected it (5 hr round trip) you could probably buy it for the same price locally. Plus I can buy the odd thing through work but if they see my buying lots of steel then questions will be asked if you can wait until wobbly orders then I can tack it on, but still got the problem of getting it to you....

nah it's ok your right i'll find a cheap supplier near here, there is a few places around but i aint got a clue which one to approach.. i've never had to buy steel before :D

i have an estate so can fit 2.5m in one go seats folded down, but thats still 2 cuts needed

[martin54]

Try them all lol, take a list of sizes you need & ask them nicely if they will cut it to length for you, they may charge you a cutting fee but it may be worth it. Even if they won't cut it all to length you may get a couple of bits cut so it fits in the motor.

[wilfy]

hmm been doing some thinking tonight dangerous i know..

looking at the size of the moving parts it now feels when i look at it that everything i've designed i should have a bigger work space.. what i mean is the foot print of the machine is 792 x 700 and yet this produces a cutting area of 385x385 and i'm starting to wonder should i bump up the length of the rails and screws to gain some cutting area... the only down side in this is extra cost which i might be able to come to terms with.

i suppose the biggest decider is at what point do i need to move away from 16mm screws and rails as this will be the limits of the machine for me



i've also added in the green bits for stability... with the above thoughts i'm also thinking of changing the 50 x 25 that supports the y rails to something wide enough so that the whole yellow section can slot in to the blue as at the moment it feels like wasted space that could be better used to shorten the ballscrew and the steel

[wilfy]

infact just a quick look at getting the yellow section to tuck in to the blue i could gain 100mm workable width for the same size screw in just 100mm longer rails so i'm going to consider a slight redesign to make this happen


Edit: i've done it so it's the above with 100mm shorter rails or this one below with 100mm longer rails screw is the same length