operation cnc

[alex wight]

kingcreaky, before using the actual material, and possibly making an error. Try cutting it on mdf ir ply ect, to see if your correct then go ahead and cut the actual material, with the knowledge of knowing that your not going cock it up. Saves on grey hairs as well lol. Well done tho, now you can sleep till you have to do the same again lol.

[WandrinAndy]

For me however, this very plate has wasted more brain cycles, sweat, and most importantly self-doubt I cannot help but stand back an admire its sheer beauty. Its elegance...

Its literally taken me two nights... looking at it, measuring it, measuring again. Aligning the pillar drill then repeating the process again and again until I ultimately grew the nuts to trust my measurements, and simply start drilling.

To me, Its perfect. Bobby D! boys...

I can totally relate to those kinds of feelings! In the absence of a good woman, it can even provide sweet dreams for a night or two!!

Sad but true.... Lol

[kingcreaky]

happy new year all.
back at work today. what a blur the past week has been.

Didnt get as much done on this project as Id hoped. Spare time at christmas isnt what it used to be since we've had our first child. (18 months ago)

But did get some done.

[njhussey]

Looking good! You've done more than me over the period, I was away all over Christmas so nothings happened :( Still best pull my finger out as only got 2 weekends free this month to work on my one.

[kingcreaky]

bit more done... just taking my time... checking and checking again before drilling. and LOADS of tapping (thinking about training misses to do it)

the gantry is now made; the bottom rail is only loosly bolted (need some shorter bolts)

its only sat on the slider plates, as to bolt it to them it needs to be assembled in place..

top rail just sat on top loosly

[JoeHarris]

Looking good! Got a stick welder for Christmas so just learning - seems I have one of biggest learning curves on here and being left painfully behind by you guys! Looking forward to seeing it live! Tapping for me is still fun - guess the novelty will quickly wear off?!

[kingcreaky]

Sounds very rude referring to people by their chat handles, I apologise in advance.
Within JoeHarris's build log, JazzCNC points out that its not possible to get long belts in 15mm HTD flavour.(I also noticed this) His solution was to span the long length with a different flavour belt.

(to be fair, probably the best solution). My plan was a little more un-thought out... My vision was to have dual steppers.. I had read in other build logs regarding the issue of missed steps but I hadnt really realised what this means... and disregarded it with a 'il worry about that later' attitude. The other reasoning behind this question is I ultimately would like to go down the spinning ballnut route ala Jonathons build. As Ive had the fear of god put through me regarding whip of the screws.

However ive just read your post on JoeHarris's build thread the following
**

No it doesn't go away but if the digital drive has a feature to monitor stall detection and send an alarm signal like the AM882 drive do then it's possible to use this to informthe control software to stop the machine and therefore the other motor before any damage is done.!! . . . . You'll still have lost steps and run out of position slightly but no damage is done.

**

I have bought these motor controllers
Cheap CNC! Wantai 4 PCS Stepper Motor Driver DQ860MA 80V 7.8A 256micro CNC Router Mill Cut Engraving Grind Foam Embroidery-in Motor Driver from Industry & Business on Aliexpress.com
(4) of them

Although I have a bob, it was one that come free with the above, I intend to buy another one when I have time to research the best one

Its mentioned above, the problem over missed steps is less significant if you have stall detection.. but I bet the above (cheap) drivers dont have this... ive looked but dont really understand what im looking at. What would you do?
1.)scrap idea of two steppers, and have an arrangement similar to that of the grand master above.. (im favouring)
2.)keep the dual motors (as I have all the gear to hand) where there is one stepper for each of the two screws (the gantry is quite heavy!) but I guess this may entail buying the motor controllers to replace the above?

I genuinly hope this isnt a stupid question.

[Swarfing]

You can get open ended belt in any width up 30mm in HTD flavour. I used 5M HTD15 on my build of the reinforced polymer type. This works great but out of choice doing it again would stick with screws.

[Jonathan]

2.)keep the dual motors (as I have all the gear to hand) where there is one stepper for each of the two screws (the gantry is quite heavy!) but I guess this may entail buying the motor controllers to replace the above?

I would keep the two steppers with the drivers you already have. I don't consider one stepper stalling and twisting the gantry to be an issue, since once you've set up the motors properly they will not stall. If they do stall then clearly having the stall detection feature is excellent, since it can prevent any damage, but the motors have no reason to stall so to me it's protecting against something that wont happen anyway. You also have more input power, since there are two motors, unless you use a reasonable size Nema 34 motor if just using one. With either system you always set the motors up such that they will never stall in normal operation, so you don't have to run it slower with two motors to play safe since if either configuration stalls it's set up wrong. Since you already have the drivers and motors(?) it doesn't really cost much to try it and plenty of people use either system. I don't have problems caused by having two motors.

Jazz will now vote for option 1.

[Kerryfisher]

Coming along nicely KC, I'm researching building a plasma table, thanks for some good info along the way, good luck with the rest of the build.