operation cnc

[kingcreaky]

your a talkative bunch on here arent you!. :-D

Anybody able to point me in the right direction of a thread that details information about wiring this gear up.... and a base set of configuration jumper settings etc? I am genuinely very confused!

the drivers and breakout: Wholesale Product Snapshot Product name is Cheap CNC! Wantai 4 PCS Stepper Motor Driver DQ860MA 80V 7.8A 256micro CNC Router Mill Cut Engraving Grind Foam Embroidery

Also as the parrelel cable is only about 1.5 meters long... and the computer is about 3 meters (crow flies, 6 meters cable run) from the machine shall I put the control circuits next to the computer then have LONG wires to the steppers / limit switches... or... perhaps put the breakout board near the computer and have LONG cables from that to the drivers and power supply (which is at the machine) your opinions will be very welcome

also... what cable is good for long runs; I like the idea of like multicore sheilded wire; id got car trailer wire in mind but it appears its only rated at 7amp which is no use I guess?

box of chocolates in the post to anybody who helps me :-/

[mocha]

They're all too busy building! :-)

I'll claim the chocs tho, "CY" is the evolved option of choice for cable that has floated to the top, have you seen how bad trailer hookup wire gets after it's been used for a while? not good! For loads of info on wiring and the laws of electrickery, have a search through some of Irvings' posts... all that thee seeketh thou shalt surely find! :-) dig up the stuff on earth practices especially.

Right, back to Sketchup for me!

[Tom]

Hello kreaky,
Good to see bits turning up.

About your cable Qs. I would put the control box near the PC. The voltages in the parallel port cable are low (3.3 or 5v), whereas the cables from the drivers to the motors are high (80v or so by the look of your power supply) so will travel better. You WILL need shielded motor cable. I had terrible problems with low voltage limit switches tripping due to interference before I added shielded cable. My motors only run at 37v too (from memory).

[blackburn mark]

I see "you lot" mill out these sexy pocketed aluminum peaces of art. take a photo stand back and say 'that'll do'. I dunno glue? bluetac? nails?

Winner!

shit!! you didn't hang about
you'll be standing behind a wall wincing your eyes and pressing the "ON" button in no time :)

[Lee Roberts]

Looking good King Julian (look he's a lady !!!)

Yea shielded cable from the start and short cable runs when you can.

.Me

[kingcreaky]

Right then gents

a productive day... Good friend of mine lent me the use of his unit... which was invaluable square warm space with all the kit to hand to make the job of making the frame easier.

Not to mention a fork-lift to load it onto the trailer to bring it home!. My god its heavy.

60x60x4 box & 60x100x5 box

Very pleased with my welding.. Proud enough to upload a piccy. Got so used to welding on crappy tin underneath cars welding nice clean think steel was a dream!

and finally; back to my comparably dark and dingy untidy workshop.


"I have a new crown"

[Lee Roberts]

Looking good Julian, looks like your mates unit is the business!

Welding up cars made of tin....I hear that, how comes you dubbled up on the top rails ?

EDIT: Scrap that question just went back to post #31 for a recap !

.Me

[kingcreaky]

ok taking on board jonathons comments; ive redesigned Y gantry to bring Z closer. feelings on this?

ive also taken the sound advice of a very nice chap; who pointed out I should add some extra bracing at the top to reduce resonance; At present I can only guarentee space for the yellow peace... I need to think of a cunning place to put one at the other end. the obvious place would be between the two 60x100's however that is going to be RIGHT in the way

Ive also added the red-blocks... the idea of this is to support the bed bolts further. Its suspected the bolts will move and the bed will constantly go out of true. Therefore the idea of these is to re-inforce.

however, ive since had a brain wave.. stand back. the idea of the multiple holes on each leg is so the bed can be lifted and dropped. well... how about instead of the small red peaces; I have 6 metal peaces pre-cut same length per height adjustment... so imagine the red bit going all the way down to the horizontal cross bracing.. only drawback to this idea is that I need 6 bits per desired hieght; but the advatage is the plunge force onto the bed is directed down onto the horizontal beams (which in the drawing are represented as 30x30; when infact they are 60x60x4's


eagle eyes amongst you will also notice ive switched the Z screws round (so the belt and stepper is at the other end).

anyway; been building cnc all day yesterday and new shed all day today (long story) in the freezing cold; Time for a beer and to fall asleep in front of the telle

work tomorrow.. dredd.

Who can I Pay to supply cut and machine all ali plate bits for the Z and Y this side of xmas? none of them are complicated no pocketing. just straight cutting (well straighter than me and my angle grinder can do!)

[kingcreaky]

Hi All.
Im aware that mounting the ballscrew behind the face is a compromise, however. Based on the gear ive got here I cant pocket therefore this is my final gantry design.
The gantry is made of two 60x100x6 Ali Box Sections bolted together.

The Y face plate is 160mm wide

before I spend a sh*t tonne of money with Aluminium Supplier | Aluminium Stock | Aluminium Warehouse (excess £200) on ali; can somebody tell me any good reasons why this wont work (it maybe revised at a later date once the machine is made)

also; do you think ecocast is necessary for anything other than the front plate... for example the top & bottom bits and the back plate can surely be 6082?

thanks in advance for the influx of replies...


^^ or... turn it round? so the Y plate is at the back?

[Jonathan]

Make the 4 joints on the Y plates the other way round, otherwise you can't adjust the vertical spacing of the Y-axis bearings to account for any error in the box section dimensions.

You don't really need eco-cast for these parts, so long as you use cut aluminium plate not flat bar since the error on plate is tolerable when you're only using round rails.

Edit: You could also make the plate on the back thinner as it doesn't contribute much to the overall strength.