Messages

21

Mach4 General Discussion / Re: Bridgeport BOSS R2E4 Retrofit

« on: June 08, 2023, 09:36:14 PM »

Hi,
kool. 250 line is 1000 count/rev, so at 3000 rpm the signal rate is 50kHz. The drives you listed are max input of 400kHz, so you could put
better encoders but you can't afford to go too far otherwise you'll not be able to signal fast enough. 2500 line or 10,000 count would be too much,
you could not signal the drives fast enough to get the servo to do 3000rpm, although you'd get away with, just, 2000 line.

I'd suggest a max of 200kHz single ended and 500kHz differential. The max signal rate to my servos is 416kHz, and so I had to use differential signalling, I tried
single ended but it started to crap out at 240kHz.

Still makes sense to te3st the encoders, if one or more are shot you really should know about it.

Craig

22

Mach4 General Discussion / Re: Bridgeport BOSS R2E4 Retrofit

« on: June 08, 2023, 07:39:32 PM »

Hi,
are you 100% sure that they are encoders? Resolvers and tacho generators look very similar but will not work as you might imagine.
Also around 1985 optical encoders were in their infancy, they were expensive and fragile. I think it wise to check on their operation before
you spend money on drivers. Remember these things are 38 years old, you need to check.

Craig

23

Mach4 General Discussion / Re: Bridgeport BOSS R2E4 Retrofit

« on: June 08, 2023, 04:32:24 PM »

Hi,
those drivers you mentioned require the servo to have an encoder.

Have you checked the encoders on the servos? Are they in fact encoders at all? From 1985 they could be resolvers or even tacho generators. Resolvers
or tacho generators will not work with the drive you've mentioned. You need to check....what you don't want to do is get new drivers at $190 each
only to find that what you thought was an encoder is in fact a tacho generator.

Craig

24

General Mach Discussion / Re: New to CNC and Ignorant

« on: June 08, 2023, 04:12:30 PM »

Hi,

But given the OP's spec it may be perfectly suitable.

Quite agree. If however there is the possibility of future expansion and upgrades he could run into the UC100's limitations very quickly. Make no mistake I have nothing
against a genuine UC100, but it would be hopelessly outclassed on my machine. I require nine inputs for Limits and Homes for example. The servos require a pulse stream
of 416kHz to achieve full speed and my C axis requires 466kHz to achieve full speed. The UC100 would just not cut it.

Craig

25

Mach4 General Discussion / Re: Bridgeport BOSS R2E4 Retrofit

« on: June 07, 2023, 08:43:51 PM »

Hi,
I use 750W Delta B2 series servos on my machine, and a number of retrofits that I've done.

https://www.fasttobuy.com/flange-80mm-239nm-ac-motor-driver-kits-with-3m-cable-220v-075kw-cnc-servo-motor-for-cnc-router_p28084.html

They have a 160,000  count/rev encoder, 2.4Nm(rated), 7.1Nm(overload),3000rpm(rated), 5000rpm(max). They are AC servos, so all the bells and whistles. Delta
provide free setup and tuning software, which is a must have if you've had little or no exposure to modern servos. They are $438USD per kit (servo, drive and cables).
They do not require a power supply, they hook direct to the 230VAC line, easy.

You might like to consider that replacing the entire servo and drive might be an easier way to go. Many people have tried to get old school DC servos to run using all manner of different
drives and often encounter either compatibility issues or tuning issues. Buying a new and matching servo and drive obviates those sorts of issues.

Before you spend big dollars on the drives and/or braking units you really need to answer the question ' what is the likelihood that this purchase will adequately drive these servos?'
If the answer is not 100% confident then there is a risk that you'll end up with a sub-standard result....and after spending good money would be extremely disappointing.

I do recognise that its likely more expensive to replace the servo and drive, but the certainty of the outcome is appealing. You may also find some other 'twat' who wants to buy
the old servos and defray the extra spent on AC servos, there is a 'twat' born every minute!

Craig

26

Mach4 General Discussion / Re: Bridgeport BOSS R2E4 Retrofit

« on: June 07, 2023, 06:49:56 PM »

Hi,

How difficult would it be to configure Mach4 so I could use some 20mm industrial push buttons for my Start, Feed Hold, and Stop buttons?

That is dead easy. You say you are using an ESS but do not say what breakout board or boards you are using. You'll need one spare input for each button you wish to use.
Ten buttons, ten inputs.

I am also looking at the DG4S-16035 High voltage servo drives and probably the BRKC-180 braking units. from CNC4PC. The current drives are rated 140VDC and I am not sure what the performance would be with a drive limited to 80VDC. And besides, I already have the higher voltage DC supply in my machine...

You don't say what the servos are? The servos will usually have a recommend max voltage, and that's what you should aim for. If you supply a lesser voltage the servo will still
work but never get to it maximum speed.

As a rough guide, lets say your servos are rated to 2500rpm at 180V, and you have only a 80V supply then the servo will get to about 80/180 x 2500=1111rpm. The torque should remain the same
its just that the servo will not go as fast until or unless you provide a higher voltage.

Craig

27

General Mach Discussion / Re: New to CNC and Ignorant

« on: June 07, 2023, 06:34:25 PM »

Hi,
only a few shortcoming of the UC100.

First is has a max pulse speed of 100khz, usually enough for steppers but not really enough for high resolution servos.
The UC100 has the equivalent of one parallel port output, ie 17IO's only. OK for the most basic of machines but you need more IO for anything bigger
and better. The ESS has 51 IO's, and the UC300, the bigger brother of the UC100 from the same company has 85 IO's.
USB is more prone to electrical noise interference than Ethernet. I would not recommend the UC100 for a plasma table which are always noise prone.

Craig

28

General Mach Discussion / Re: Clicking RESET on screen turns DROs to zero

« on: June 07, 2023, 05:59:10 PM »

Hi,
if you want to jog around in the middle of a job then hit <Feed Hold>. The machine will stop, but you may notice a very short delay, that is Mach
consuming the last of the trajectory data that's already been issued. Typically the delay is 0.2 to 0.5 seconds, so hardly noticeable. Now that the machine
has stopped hit <Stop>. This stops the Gcode program and releases the Code interpreter/trajectory planner to Mach. Now you can jog around or do as you require.
If you now want to restart the job that you previously stopped you'll have to use <Run From Here>. You really need to read that closely, then read it again and then
a third time!. It works but has caused more crashes than any other feature of Mach. There is a procedure and you MUST FOLLOW IT EXACTLY or you will have trouble.

Craig

29

General Mach Discussion / Re: Clicking RESET on screen turns DROs to zero

« on: June 07, 2023, 05:28:51 PM »

Hi,
its been a while since I used Mach3, I now use Mach4, which is very similar and that's is what happens when you RESET the machine.
This causes a crash stop, whatever moves in the motion buffer are aborted, and consequently Mach no longer knows where it is.

Try using <FeedHold>. It stops the machine but it consumes the last of the movement data in the motion buffer and so when it stops it knows
where it is. You can hit <Cycle Start> and the machine will carry on. You actually have to stoip the job if you want to jog, ie you cannot jog
around while in FeedHold.

Craig

30

Mach4 General Discussion / Re: EZ-Router and Mach4

« on: June 06, 2023, 05:27:45 PM »

Hi,
yes, Mach4 can do as you require.

When all said and done Mach3 is a Gcode interpreter and a trajectory planner.
Mach4 is a Gcode interpreter and a trajectory planner.

Where Mach4 differs is the manner in which the program is constructed, its highly modular. It has a highly editable GUI. It is vastly better equipped to
be customised to a certain machine with a much more robust scripting environment. It has a PLC which is many times faster than Mach3, and it has
a PMC module equivalent to 'Brains' in Mach3, but can operate across different sections of Mach4 unlike Brains in Mach3.

https://www.machsupport.com/forum/index.php?topic=42891.msg278176#msg278176

Don't get me wrong Mach4 is a steep learning curve.

Mach4 all but requires an external motion controller. There are six different manufacturers of motion controllers that are Mach4 ready. Iuse and recommend an
Ethernet SmoothStepper ($195) by Warp9TD, but there are others, both cheaper and more expensive.

Craig