New 935 Is Running!

wrmiller said:
I'd actually forgotten how easy a BP style head is to tram
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You mean like how you don't need a set of finely calibrated hammers and shim stock to make the adjustments?
The surface finish on that table is terrible! How are you supposed so see what you are doing when all that light bounces back in your eyes?:cool 2:
 
Question for you guys running a VFD on a BP clone (Mike, Mark)?

How do you disable braking on the WJ200? I made the mistake of grabbing the spindle brake one time and the VFD seemed to fight the brake. Won't do that again. :eek:
 
Bill, in wading through the manual that I have, it looks like the braking is controlled by b09. Setting that =1 may disable the braking, the manual is a bit unclear on this point. Look for ''Free Run Stop"

I hope this helps.
 
Also might help to set your deceleration time to something like 3-4 sec to bring it to a quick stop. If your VFD has the option, you can add an external resistor/choke to help.

With some trial and error you can find the best time; set it too quick and you will get Over Current trips.
 
The manual states that anything under 3 sec. requires a braking resistor like that on my 1340. I'd rather not go that route, but will if I have to.

Jim: I'll take another look at the manual, thanks.
 
WJ200 Free run commands
Free run always active, should program both B091 and B088 as follows:
B091 Stop mode selection = 01 free-run to stop
B088 = 01 Resume from current speed

Or program an input function to give the free run command, so C162-C166 (Inputs 3-7)
11 FRS Free-run Stop = ON input , allows motor to free run (coast) to stop

I often use the latter with a micro switch if one wants to use the machine mechanical brake. So when you hit the mechanical brake, it closes a micro switch which engages an input to give the free run command. If using electronic braking, you can push the VFD a little harder on the braking on a mill without an external braking resistor, because there is less mass (momentum) in the system. Not sure what happens when you start spinning the mill at very high RPM. If one brakes too fast, normally you would get an over voltage error on the bus, because the buss voltage exceeds the programmed threshold which is adjustable to a point. The other factor, braking resistors are cheap, so if you plan on using electronic braking, just get a resistor. Haven't seen a choke used for braking, more for smoothing the ripple on the bus or to tame the voltage switching spikes. Using a braking resistor will keep the VFD cooler, since it will not need to dissipate all the system energy internally, which = heat which is not good long term. Have also used the free run command for tapping on a lathe, and also tied to the lathe mechanical brake. Lots of possibilities.
Mark
 
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Thanks Mark!

I'll give the Free run commands a try this weekend. :)
 
tmarks11 said:
Also might help to set your deceleration time to something like 3-4 sec to bring it to a quick stop. If your VFD has the option, you can add an external resistor/choke to help.

With some trial and error you can find the best time; set it too quick and you will get Over Current trips.
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This is what I did, just played with the setting until I got a value that would not trip it out on overcurrent. I had/have a plan of adding a braking resistor but originally, I just wanted to get the lathe up and running then tackle the braking resistor. However, I have been pleased thus far with it enough that I have not put a braking resistor to the top of my "to do" list. It actually stops quite quick even without the braking resistor.

Mike.
 
Got the EL700 and it's scales installed. Matt at PM says this is a pretty cool DRO. All I know is that it's got a bunch of functions I've never used, so training will be involved. And then there's the touch probe. Never used one of those either. Still have to install the protective shields, but the hard part is done. :)

IMG_0690.jpg
 
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