Planning - Bridgeport Interact 1 linuxCNC Retrofit

Yes I think I'll get one of the cheap China VFD's 5hp single phase. Also I'll probably be getting a cheap Buck DC step down.

But now I have a more immediate issue.

I just ran 120v to my 24v system! :S Blowing my resistor on my "bread board" and taking out my CFU1 fuse, good thing those blew, but I might have taken out a 24v relay or two. Not sure yet.

My "y" axis limit switch was partially dissembled. Wire# 26, and a unmarked wire going to my "z" axis upper limit switch, Those two had 120v. I HAVE not made any changes on this limit switch since I received this machine. The way I connected these wires was to #26 to 95 and the unmarked [#25?] to 65. [Limit switch pin 1 and 2] I guess you can now say I know I was wrong

Im guessing I had 24v going through wire #95. And the way the switch is wired I did not realize I had 24v on the other side of the switch. I need 110v to pass through my limits for the joystick. I tested this by just connecting my #26 and the unmarked wire together. Voltmeter had 120v on each wire, prior to me connecting them. (I had my enable on a on/off switch) after connecting them I could "turn off my enable switch" and use it as a momentary switch as designed.

I was correct that it was what I needed. However I screwed up my wiring in my "y" limit switch box.

I sure could use the help figuring this wiring out of my limit switch.

Here are some attached photos.

I removed the blown resistor located on the 2nd leg from the top. Anyone can you tell what size it is? Looks gold, black, black, brown. I'll check the tables for the 4 banded resistors and see if it makes sense. [Edit: its a 10 Ohms 5%, Watt's unknown] suggestions?]






The lower wire #65 is where i ran my wire out. I made the mistake of not disconnecting it first. Perhaps I missed something, or I was connected elsewhere. I'm going to disconnect it an try to ring it again, to figure out the unmarked wire number.

image missing http://i346.photobucket.com/albums/p431/swill008/2015-11/1F7BEA49-C0B6-4C95-A6DE-303016C25AFA_zpshbnvawds.jpg

I attached a highlighted wiring diagram of what I blew and connected. "blown.pdf"






After further studying the schematics I think I should have just tied these wires together, I don't see how they could be tied into the limit switch. Either way sending 120V into this switch will send 120v into the 24v system. Suggestions are welcome.

cncnoob1979 wrote: I removed the blown resistor located on the 2nd leg from the top. Anyone can you tell what size it is? Looks gold, black, black, brown. I'll check the tables for the 4 banded resistors and see if it makes sense. [Edit: its a 10 Ohms 5%, Watt's unknown] suggestions?]

Well, given that resistor cost is minimal, just assume it dissipates all it can at the applied voltage.

P = V2/R

So, 120V = 1.4kW
24V = 60W

OK, so don't assume that

It looks like a 5W, but if you can read the bands it might be OK.

In your first picture Terminals 1 and 2 are normally closed contacts and terminals 3 and 4 are normally open. Wire 65 should be common since it's jumpered and wires 95 and 80 would be your signal wires all should carry 24v. These are home switches right? You should have 2 more switches on other axis with wires 94 and 79 and another switch with wires 96 and 81.

The schematic suggests you should have limit switches where wires 23,25, 26, 123, and 27 would be connected carrying 120v signal. There should be 1 limit switch for the x and one for the y axis and 2 on the z axis, in addition to a home switch for each axis. Is this correct? If you don't have limit and home switches on each axis you'll need to figure out what you do have and redraw the schematic. Given this configuration there is no way to use the limit switches as home switches or vice versa without changing some IO hardware

Andy,

Yes I'm thinking between 5 watts and 10 for the resistor... or just replace it all with the buck step down transformer. Would be easier to just replace the resistor tho. Cant believe I was such a dummy! lol



kornphlake79,

I'm trying to figure out the wiring on my limit switches now. Each one passes a reference signal as well via 24v and the limits are 120v. Hence the reason I was trying to figure out the y axis before I tried to kill the machine. [Well I guess I did kill it!]

These wires were in this limit switch prior, I'm sure of it. I just don't see how it was wired. The wire #65 should only be carrying 24v current and the two wires not wired in, are 120v, so I'm not sure how I can wire these. However I do believe that someone has taken the limit switch relay from this box. The relay box can carry two switches internally and there is only one installed. I think it was robbed? Not sure yet.

I missed the part about using the VFD to run a 3 phase spindle motor with single phase power. Good luck with that, 5hp is kind of the tipping point where you can or should use a VFD to convert single phase to 3 phase. As a general rule you should derate the capacity of the VFD when converting from 1 to 3 phase, for a 5hp motor your VFD should be rated for 7-10HP 3 phase. The Chinese units may claim to be rated for 5hp and single phase, but there is a reason it's hard to find VFDs with a recognizable name brand rated for single phase at 5hp, and when you do find them there is a reason the VFD cost a couple times more than an equivalent VFD that only operates on 3 phase.

I know people have used the Chinese VFDs and they do work, but I'm not sure for how long, or how well. There is a good chance those inexpensive drives can't supply enough current to the motor to reach the rated capacity. Since your machine has the capability of mechanically varying the spindle speed, you might consider a phase converter and idler motor instead of a VFD, unfortunately that means you'll have to manually adjust the spindle speed, but that's not a huge deal since you'll be manually changing tools anyway.