Wiring the Hypertherm interface cable
- Aldenflorio
- Topic Author
- Offline
- Platinum Member
Less
More
- Posts: 389
- Thank you received: 15
11 Jan 2023 14:43 #261578
by Aldenflorio
Replied by Aldenflorio on topic Wiring the Hypertherm interface cable
7i76e. I don’t have any of the hardware yet. I am trying to make sure I have absolutely everything right with my wiring and my configuration. Since this side of the machine doesn’t come naturally to me I don’t want to do what I’ve done in the past and wing it when I get the materials.
I’m trying to keep it just asking here, though I know I have a lot of annoying basic questions.
I’m trying to keep it just asking here, though I know I have a lot of annoying basic questions.
Please Log in or Create an account to join the conversation.
- tommylight
- Away
- Moderator
Less
More
- Posts: 19380
- Thank you received: 6489
11 Jan 2023 14:50 #261580
by tommylight
Replied by tommylight on topic Wiring the Hypertherm interface cable
For Mesa 7i76E, pin 14 to +24V, pin 12 to input.
No need for resistor.
No need for resistor.
Please Log in or Create an account to join the conversation.
- Aldenflorio
- Topic Author
- Offline
- Platinum Member
Less
More
- Posts: 389
- Thank you received: 15
11 Jan 2023 14:54 #261582
by Aldenflorio
Replied by Aldenflorio on topic Wiring the Hypertherm interface cable
Attachments:
Please Log in or Create an account to join the conversation.
- rodw
- Away
- Platinum Member
Less
More
- Posts: 10711
- Thank you received: 3534
11 Jan 2023 21:18 #261624
by rodw
Replied by rodw on topic Wiring the Hypertherm interface cable
The use of a pullup resistor is discussed int he qtplasmac docs.
The current passing through the 7i76e (from an input to ground) is way below the minimum current of the internal Hypertherm relay so not using the resistor could see oxidisation build up on the relay contacts and result in intermittent operation over time which will prevent you from cutting.
The resistor allows some current to bypass the 7i76e to ensure that the minimum current of the relay is respected.
The current passing through the 7i76e (from an input to ground) is way below the minimum current of the internal Hypertherm relay so not using the resistor could see oxidisation build up on the relay contacts and result in intermittent operation over time which will prevent you from cutting.
The resistor allows some current to bypass the 7i76e to ensure that the minimum current of the relay is respected.
Please Log in or Create an account to join the conversation.
- rodw
- Away
- Platinum Member
Less
More
- Posts: 10711
- Thank you received: 3534
11 Jan 2023 21:19 #261626
by rodw
Replied by rodw on topic Wiring the Hypertherm interface cable
This is bad advice. Read up on it in the qtplasmac docs and follow one of the recommendationsNo need for resistor.
Please Log in or Create an account to join the conversation.
- tommylight
- Away
- Moderator
Less
More
- Posts: 19380
- Thank you received: 6489
11 Jan 2023 21:49 #261635
by tommylight
I really do not know how to reply to this, you are putting me in a very bad possition with this behaviour.
I have over 20 of CNC plasma machines on daily use that never needed a resistor or wetting or whatever, you have built 1.
You putting it in docs and insisting on it does not make it true, and it should not be there, but it does not break anuthing so i never insisted on removing it from the docs.
Not nice.
Replied by tommylight on topic Wiring the Hypertherm interface cable
This is bad advice. Read up on it in the qtplasmac docs and follow one of the recommendationsNo need for resistor.
I really do not know how to reply to this, you are putting me in a very bad possition with this behaviour.
I have over 20 of CNC plasma machines on daily use that never needed a resistor or wetting or whatever, you have built 1.
You putting it in docs and insisting on it does not make it true, and it should not be there, but it does not break anuthing so i never insisted on removing it from the docs.
Not nice.
The following user(s) said Thank You: snowgoer540
Please Log in or Create an account to join the conversation.
- snowgoer540
- Offline
- Moderator
Less
More
- Posts: 2391
- Thank you received: 782
11 Jan 2023 23:28 - 11 Jan 2023 23:34 #261640
by snowgoer540
Replied by snowgoer540 on topic Wiring the Hypertherm interface cable
For what it’s worth, I don’t use the wetting resistor or capacitor either with no problems.
Last edit: 11 Jan 2023 23:34 by snowgoer540.
The following user(s) said Thank You: tommylight
Please Log in or Create an account to join the conversation.
- rodw
- Away
- Platinum Member
Less
More
- Posts: 10711
- Thank you received: 3534
12 Jan 2023 00:51 #261646
by rodw
Replied by rodw on topic Wiring the Hypertherm interface cable
It is bad advice becasue it does not reference the documentation. There is a chapter about this issue.
linuxcnc.org/docs/devel/html/plasma/qtpl...html#qt-contact-load
Let the user make up his mind.
There have been enough people caught with this issue on the forum to add a component costing a few cents for a defensive circuit design.
Sure, he may never have an issue if its left out but its a very painful place to be if it bites.
linuxcnc.org/docs/devel/html/plasma/qtpl...html#qt-contact-load
Let the user make up his mind.
There have been enough people caught with this issue on the forum to add a component costing a few cents for a defensive circuit design.
Sure, he may never have an issue if its left out but its a very painful place to be if it bites.
Please Log in or Create an account to join the conversation.
- Clive S
- Offline
- Platinum Member
Less
More
- Posts: 2241
- Thank you received: 476
12 Jan 2023 09:44 #261674
by Clive S
Replied by Clive S on topic Wiring the Hypertherm interface cable
I have built 2 machines so plus 2For what it’s worth, I don’t use the wetting resistor or capacitor either with no problems.
Please Log in or Create an account to join the conversation.
- rodw
- Away
- Platinum Member
Less
More
- Posts: 10711
- Thank you received: 3534
12 Jan 2023 10:48 #261678
by rodw
Replied by rodw on topic Wiring the Hypertherm interface cable
The thing is plasma machines don't last forever so you might have several cutters on your table over the years. I've had 2 and will probably be running a third shortly. These machines might have different characteristics so for the sake of 10c, why not do the job properly? By the time you need it you will probably have forgotten the possible cause is the shortcut you took years ago..
Its nothing about the table you build or how many you've built. its the plasma cutter you use.
Its nothing about the table you build or how many you've built. its the plasma cutter you use.
Please Log in or Create an account to join the conversation.
Moderators: snowgoer540
Time to create page: 0.193 seconds