PDA

View Full Version : BUILD LOG: Newbie First Build 3000mm x 1500mm



psiron
05-07-2010, 09:28 PM
Hi,

I decided to follow the build at www.automatedwoodworks.com (http://www.automatedwoodworks.com/) but change the length of the machine to easily cut 8x4 sheets. I currently cut 15mm plastic sheets using guides and a dewalt 625ek router. I drill lots of holes in each sheet too so im hoping I can eliminate lots of hand work by using this machine.

Originally I was unsure about using timing belts over this distance but after speaking to cross & morse I am happy that by using PU belts and introducing an idler in the centre of the X belt this should work fine.

I have had 2 tables fabricated to enable me to build the machine at home. This will allow me to get the gantry up and running and then allow me to extend the machine once everything is working satisfactory.

As my previous posts indicate, I have no experience in the cnc industry. I have lots of experience using routers by hand but zero using cnc. I have taken the advice from other members and changed the original gantry design as there were indications that the channel alone may twist. The addition of the 100x50 aluminium hollow section has hopefully eliminated the possibility of any twist, it definately has added rigidity that's clear to feel when handling it.

I have decided to use HIWIN rails for the Y&Z which will be with me tomorrow. I have tested the bearings on the 6.35mm bright bar and have to say I am extremely happy with them. There is no play whatsoever in the rails and they run smoothly with zero resistance. Unfortunately they are not my first choice but I had to cut costs somewhere. I will purchase the linear rails if I feel the current setup is causing any problems.

The only thing left to source are the dreaded electrics. The gantry sides have been designed to mount a NEMA 23 motor but I would like to use NEMA 34 if possible. I dont have any experience with the electrics and that's really stressing me out. I will post something in the correct section shortly as I need to get the electrics ordered ASAP now but really could do with some advice.

Anyway, here's my progress, Ill add updates as I progress:

Normsthename
05-07-2010, 11:23 PM
Machine is looking good!

I dont have any experience with the electrics and that's really stressing me out.
Electrics are not that bad once you get your head around them! :smile:
I am not the Worlds best Electrician, but I built all my electrics from scratch

Andy

psiron
06-07-2010, 02:04 PM
Cheers guys,

I have asked for Garys help from Zapp, I need some fool proof wiring and he looks like he's the man!
The HIWIN rails and precision shaft should have arrived today but apparently TNT wouldn't take the long length of shaft so night freight picked them up today so I should see them tomorrow.

My missus is off to London for 3 days later this week so its just me and the machine, ah bliss.................

psiron
06-07-2010, 10:16 PM
Build Update:

Just sourced the electrics with the help of Gary at Zapp.

3 x Power Supplies (PS) Model PS705
1 x SY85STH156-6204B Nema 34 Stepper motor (SY85STH156)
2 x SY85STH118-6004B Nema 34 Stepper motor (SY85STH118)
1 x Uniport Breakout board V2.0 (Uniport)
3 x 2M880N Microstepping Driver (2M880N)

Specification should allow scope for upgraded framework in the future too.

HIWIN rails and drive shafts arrive tomorrow, more pics to follow......

psiron
14-07-2010, 07:22 PM
Hey all,

I managed to test an wire the electrics ok (surprisingly!) and everything seems good. The motors sound awesome I have to say. I have run them upto around 650RPM with no problems so im pleased there wired ok. I run a few programs with mach3 and checked the motors, drivers and power supply for heat, all were minimum however i guess pulling the X,Y,Z could change this!

I have put them in a pc case at the moment which im really not that happy with, I have a control panel from work which I have stripped out and will try to fit them all into that.

I managed to build the Y&Z today, again surprisingly im within 0.2mm and everything slides nice.

I have to re-fabricate some of the gantry side supports as originally they were made to mount 23's and not 34's so thats next on the list.

Once I have the leadscrew and nut from Steve ill finish the Z and get some more images up.

Ross77
15-07-2010, 03:04 AM
looking very good in orange but not liking the z axis arrangment........for the umteenth time mount the blocks back to back and let the rails move up an down. I know its only a plasma but good design is the same same in all languages :smile::smile::smile:

Normsthename
15-07-2010, 11:40 AM
not liking the z axis arrangment........for the umteenth time mount the blocks back to back and let the rails move up an down. I know its only a plasma but good design is the same same in all languages :smile::smile::smile:
Not sure what you mean........
I am going to be building a new gantry for my machine very soon so I would like to know what is the best design to use :smile:

Andy

ecat
15-07-2010, 01:01 PM
mount the blocks back to back and let the rails move up an down. I know its only a plasma but good design is the same same in all languages :smile::smile::smile:

I think what Ross77 is saying is: mount the z blocks on the z support and the z rails on the carriage. Your current z configuration has the rails on the support and blocks on the carriage. I'm sure there are pros and cons but I don't know enough to comment.

Impressive build anyway, nicely done :)

Ross77
15-07-2010, 02:37 PM
I think what Ross77 is saying is: mount the z blocks on the z support and the z rails on the carriage. Your current z configuration has the rails on the support and blocks on the carriage. I'm sure there are pros and cons but I don't know enough to comment.


Yep thats it. (just re-read my comment and it dose seem a bit hash :eek:, I only meant it as a suggestion and not insisting thats it has to be done that way:whistling:)

As it is when the spindle/torch is at the top of its travel it will need a long drop down plate to make it lower than the gantry. Which will put a lever arm on the bearings and a torsional load on the beam,


pros; reduces loading on bearings and torsion on gantry, lowers the C of G, no long plate to flex......need I go on.....:tongue:

Cons: extra weight on the ball screw and motor if mounted on the rail side, which is easily solved, cant really think of any

As its plasma and using linear rails then it shouldn't be a problem, until the day when you decide to convert it to a routerlol

psiron
15-07-2010, 02:57 PM
Not sure what your talking about there fellas??? This aint plasma and I havent discussed changing the Z axis with anyone either??????

Ross77
15-07-2010, 03:27 PM
Not sure what your talking about there fellas??? This aint plasma


Ups got mixed up with another tread. me bad :redface: that'll teach me the check all the posts and not just the last one:heehee:



I havent discussed changing the Z axis with anyone either??????


I know I was just suggesting that you might want to think about changing it. :naughty:

psiron
15-07-2010, 04:42 PM
Ha ha, no worries.

Im sticking with it for now, seems to work ok on the original build and I dont know enough to change it at this stage.
Ill post some videos when I finally get the machine up and running. Im still waiting for the belts and pulleys to be confirmed from the supplier which is a right pain in the but.

GeorgeD
15-07-2010, 05:55 PM
I must say,that ally that has 10mm stamped on it sure looks like 19mm to me rather than 10mm.

This is gonna be one big bu**er of a CNC:naughty:

GeorgeD
15-07-2010, 06:29 PM
Far be it from me to question Gary at Zapp Auto...but those powe supplys are 5amp peaking at 7 and the motors are in the range of 6/6.5 amp,Drivers 8amp a piece

Will the motors be stepped down below their max amperage and will you have the power supplys connected in parallel?

Just being curious:whistling:

psiron
15-07-2010, 06:43 PM
Garys advice was to set the drivers to 6A and connect the 156 in parallel. The 188's only have 4 wires so no parallel.

irving2008
16-07-2010, 01:36 AM
The 188's are parallel by default. And the power supplies are fine, the peak driver current is 6A, the average current is a lot lower... 66% is a good rule of thumb...

Did Gary suggest one PSU per driver, or paralleling all PSU and driving all three drivers together? I'd consider going the latter route as it gives more overall headroom as its very unlikely all 3 drivers are running peak output simultaneously..

psiron
16-07-2010, 12:02 PM
Yes Gary advised the latter, PSU wired in parallel.