Now this 3 phase mill can run from single phase (regular 220v plug), it stops in 0.5 seconds thanks to electric braking, and it also reverses, which is something it was not capable of before.
In addition to the old gearbox speed changer, speed can also be varied with a pot (0-60 Hz).
All of the above make this machine more desirable.
Ignoramus7041 wrote in news:-
7OdnWrc6MOucAfXnZ2dnUVZ snipped-for-privacy@giganews.com:
Ahhhh! Ventilated electronics enclosure mounted below the table of a metalworking machine tool.
Yes, good point, I was going to put a cover above it. Have not gotten to it yet.
iDo you know if the company is still in business for parts?
My Arboga radial arm drill broke the power down while doing a 3" hole this summer. Its on my winter repair list.
Karl
Do you know what broke exactly?
I looked and could not find their website, I suspect that they were bought out by Wilton (WMH tool group).
i
Seriously big pending fuckup. That VFD needs to go on the BACKSIDE of the mill column.
You are going to get chips down into the top of it in its present location and all the magic smoke is going to come out of it.
At the very very least..put a horizontal thin plate aprox 1" above the upper vent grid to protect it from shit going down the grid.
Trust me on this. It WILL happen.
Gunner
Whenever a Liberal utters the term "Common Sense approach"....grab your wallet, your ass, and your guns because the sombitch is about to do something damned nasty to all three of them.
Yes, I will put some sort of a thin plate over it asap.
Good catch Gunner. I actually thought to do it, then completely forgot.
I am reluctant to put it on the back, it will make it hard to program.
i
Nope, I just engaged the power down and it wasn't there any more. Means you got to stand there and push down by hand - sux on a deep large hole.
Karl
This makes me hope that it is something simple, some intentional weak link. Maybe there is some roll pin that is purposely made to break under excess load.
i
Very likely, being able to talk to somebody that knows this machine or having an assembly drawing would be worth its weight in gold.
Karl
You already have a "remote control" that sets forward/off/reverse and speed, right?
A simple Form C toggle switch and a pot in a tiny little box mounted somewhere on the face of the machine.
Right?
Ive got a number of mills with the VFD mounted in boxes on the wall Behind the mill, with the simple control device mounted on the head.
Its not rocket science, and it makes the machine safe, secure and unlikely for the magic smoke to come out.
And its quite easy to simply change the wiring on the existing power switch to run directly to the VFD and the head switch (I didnt check) control the VFD, rather than the 3ph power directly.
Gunner
Whenever a Liberal utters the term "Common Sense approach"....grab your wallet, your ass, and your guns because the sombitch is about to do something damned nasty to all three of them.
Yes
Exactly.
Well, yes, but it is an on/off switch, and I need a forward/reverse switch.
Anyway, I did put a cover over the top of the VFD last night, it should be fine as is.
i
Chips are far too clever for a simple cover to work for very long, unless the cover is so tight that airflow is blocked. One can cut the leakage rate down with some fine-mesh metal screening, but even that isn't perfect.
Real factories often put the VFDs in a closed metal box, precisely to protect the VFD from factory dust, dirt, chips, gasses, et al. And from confused button-pushers, but that's another story.
It's easy to build a remote-control box for a VFD, which is mounted up high on the wall, behind the mill, out of the chip impact zone. Put the VFD's displays at eye height and programming (a rare activity) is easy enough.
Joe Gwinn
Lets hope so. Though I suspect, based on my years as a machine tool mechanic in commercial machine shops...that it wont blow up until the new owners uses it for more than 30 days...or maybe not. Shrug...
Gunner
Whenever a Liberal utters the term "Common Sense approach"....grab your wallet, your ass, and your guns because the sombitch is about to do something damned nasty to all three of them.
Indeed. Well said.
Whenever a Liberal utters the term "Common Sense approach"....grab your wallet, your ass, and your guns because the sombitch is about to do something damned nasty to all three of them.
I have a TECO FM-50 for a 2HP Bridgeport. A pot and on-off switches in a separate box would be a lot more convenient. What are typical specs for a potentiometer for one of these? Something I could pick up at Radio Shack or do I need to order on line? Under what section of the manual would you go looking for specs if it's something that varies by manufacturer and model? I only read enough of the manual to get my mill up and running so I could play with it. Now that I've had it for several months, it's time to make improvements.
RWL
Your VFD manual does not seem to say what the rating for the pot should be. Mine said, IIRC, that it should be between 1k and 10k. I used a 1k pot because I have a few of those. 5k should work well. You can call Teco and ask to be sure.
If you want a pot and an on-off switch, then you can buy a pot with a built in switch, those are widely available. They have two contacts for a switch and three for a pot, usually they click and turn off when fully turned counterclockwise. So you can wire that switch to turn off the current when the switch is off, and turn on and ramp up the frequency as you turn the knob clockwise.
Now if you want a pot and a forward/off/reverse switch, then you need to have them separately, pretty much.
It is really up to you as to what you want, for instance whether you want to power tap on the mill.
Radio Shack could be pricey, but the easiest option of all. Most likely you need a 5k pot.
i
Look in the wiring diagrams and it should show you what value the pot is supposed to be.
Generally....0-5k...some are 0-10k, others are different.
This is not something to guess at.
If you do..you will never get it going fast enough...or ever get it going, or ever get it going slow enough.....
Gunner
Whenever a Liberal utters the term "Common Sense approach"....grab your wallet, your ass, and your guns because the sombitch is about to do something damned nasty to all three of them.
Typical pot is a 5K or 10K linear pot with a 2W power rating.
As for the switch -- make it a SPDTCO (Single Pole Single Throws Center Off) switch so you can use it to select forward stop or reverse. (It might be good to have one of the locking toggles with the pull-to-release handles, so you can't accidentally go from forward to reverse when you really want to stop.
There should be wiring diagrams for how to connect such switches, as well as ones for using three push buttons (forward, reverse, and stop). For the latter, a red mushroom actuator for ths top switch with a locking mode so you have to twist it or pull it to reset the stop. That way, you just bring your hand up and slap it to stop in an emergency.
Enjoy, DoN.
Yes -- but these are common ratings.
Hmm ... that effect would be more if it were being wired and used as a rheostat instead of a potentiometer. Normally, the VFD has three pins for use with a pot. One is common ground, one puts out 10V or 5V, and the third connects to the wiper. Usually, the output voltage is capable of sufficient current for 1K, 5K or 10K, and what really matters is the voltage which the wiper returns to the control input, which should cover the same range with any reasonable value of potentiometer. Go really too high, and you are likely to pick up noise which will cause the speed to vary a lot at mid range settings. Go really too low, and the 5V or 10V output can't provide enough current, and the voltage will be too low so you can't get enough speed. But anything from 1K to 10K should be fine -- with values beyond that possibly encountering problems. But it is not a critical value.
Enjoy, DoN.
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