Air drill relay switch bad?

[jdgrahamwaldorf]

I am finally completing installation of my air drill and think the relay switch may be bad. When I do command SO 5,1 then 2 leds light on the drill control board but nothing happpens. If I jump the two red wires in the light green connector then the air drill will work. Does anyone know of a way to check the relay?
Thanks,
John

[richards]

John,
I've been waiting all day for someone who has an air drill to respond to your question. Since no one has and since I don't own an air drill and since I can't find any documentation on the Shopbot web site about the air drill, you might need to provide more information.

Given the fact that the drill control board recognizes Output #5 means that there is a valid connection between those two devices. But, if the relay isn't working then we have to find a quick and easy way to test the relay. I have no idea whether you're describing a Solid State Relay or a Mechanical Relay. If the drill uses a mechanical relay, then you should see the contacts pull in whenever voltage is applied to the relay's coil. If the contacts are opening and closing, then you check voltages on the switched contacts to see if there is actually voltage present. If there is voltage present, but the drill still doesn't work, then we would have to look downstream from the relay to see what is next in line. It's really just a process of elimination. We start at a point where we know that things are functioning properly and then we check things after that point until we find something that doesn't work as expected - then we fix that problem. If that fixes everything, then we are through. If that doesn't fix everything, then we find the next problem and continue on until there are no more problems to solve.

If the relay is a Solid State Relay (usually a 1-1/2 X 1-1/2 inch block of poured plastic with four spade or screw electrical connections available) then the easiest way to check the device is to connect a low wattage lamp to the relay. General practice would have the line voltage (120AC or 24VDC are two common voltages) connected to the SSR's Line connection, so you would place the lamp in series with the SSR's Load connection and AC Neutral or DC Ground, depending on whether you're switching AC or DC. If the lamp turns on, then the SSR is working. If the lamp does not turn on, and if there is voltage present on the two control terminals, and if the SSR has been wired correctly, then the SSR might be faulty.

The same basic rules apply. Start where you know that something is working and follow it until you find a problem. Fix the problem and then continue on until there are no more problems to be solved.

(Hint to Shopbot: Posting a schematic and some basic documentation on everything that you sell would be a really big help when someone is trying to troubleshoot an electrical problem.)

[beacon14]

Not sure exactly what relay you are referring to but there is a short file which is called as a custom cut which is designed to run the air drill. If you just call SO,5,1 the output switch will stay on until you turn it off with SO,5,0 - but the drill only needs momentary contact so the file turns the switch off after .25 seconds, then - and this is important - it looks for an input signal from a prox switch mounted on the drill unit that lets the software know the drill cycle is complete and it is safe to continue with the next command. If you use SO,5,1 in a file the machine will likely continue with the next move before the drill cycle is complete - trust me you do not want this to happen.
I know this doesn't answer your question but you should have this file - if not contact ShopBot - I could not find it on the web site.
Also I have found that if the prox switch on the drill head is screwed down too tightly it will trigger the switch - it might be just my switch but it caused me quite a few problems until I figured that out.

[jdgrahamwaldorf]

Mike,
The relay is 24v solid state. After reading your post I checked the voltage at the coil at SO 5,1 and SO 5,0. At SO 5,0 I have 21v on one post and 0v on the other. At SO 5,1 I have 21v on both posts but the relay is still not activated. I found the tecnical info on the internet (Potter Brumfield T9AS1D12-24) and I believe 21v should trigger it. I will contact Shopbot monday about a replacement.

Dave Everything works fine after the relay so I am sure it is th board

John

[paco]

It might be the board... I believe David as a point; what if you hit C8 (Drill Cycle) with the default configuration setup (no tampering)? Does it work?

[Brady Watson]

The SB drill head uses a separate relay board from the standard CNC control board. Call SB Support on Monday to get you squared away.

-B

[jdgrahamwaldorf]

To everyone that tried to help:

Shopbot was nice enough to exchange my relay board but the problem continued. I started to play with my connections and found that the 24v power supply, the 4G board, and the relay board all need to be grounded together. The wiring diagram that came with the air drill did not show this, assuming that everything would be grounded through the case. I, who learned electronics by building radio shack kits as a kid, did not realize that two boards operating at different voltages could be grounded together. This experience made me think of all the other problems people have had with the ShopBot because of improper grounding. The analogy would be always thinking of the supply piping of the electrical plumbing but not worrying about the drain lines. I hope this helps others who have odd electronics problems in the future.

John