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Smart Brown 1024 vfd conversion

beckerkumm

Hot Rolled
Joined
Aug 5, 2014
Location
Wisconsin Rapids WI
I'm doing more work and planning to convert my 1024 to vfd control. The S and B operates with three small momentary forward, reverse, stop buttons. While I could reuse them, they are small and tend to be easily bumped when shifting the lever for the Matrix clutch. There is not enough room for three 20mm buttons. I am thinking of going to an IDEC ARN three or four position monolever switch. Up and down would be forward and reverse and right and left are both stop. The stop positions would be maintained so the lever couldn't be easily bumped and engage the lathe. The forward and reverse could be momentary or maintained although momentary might be my preference. I could also source a lever that automatically locks in the center neutral position but that feels like it could be a pain more than a gain.

Any better ideas or any flaws in the plan? I usually am full of flaws. DaveDSCN3860.jpg DSCN3861.jpg
 
Any better ideas or any flaws in the plan? I usually am full of flaws. DaveView attachment 299052 View attachment 299053

Why not go for similar ergonometrics to late-model Schaublin manual, or any of several modern "teach-in" hybrid style lathes?

Put a sort of "joystick" on the carriage apron so it is always in the same position for your hand - operator stance - relative to all the other most-used hand controls - regardless of where the tool is, anywhere along the cut.

I easily found "hexane" elastomer oil-proof condoms and "slap down" lift-covers in clear and several colours to fit common toggle switches - lighted ones, if you want fancy - for "enable" and "run" for my DC drives. EStops are common as well.

It isn't hard to rig an armoured flex conduit for the low-power control wiring, carriage to back (passed under the bed, that part in stout steel tube if need be ) or to either end of the lathe.

All the conductors I need work over a CAT5 stranded ("patch" grade) 4-pair data cable, common RJ-45 plugs to stock punch-down blocks to go off to the DC Drive control TB. Very little to "invent". Easily replaced components. Cheap enough. Proven performers.
 
Looks like you are overthinking this.

Why not replace the buttons with ones having deeper shrouds and make a new L shape clutch shifting lever so the operating arc is shifted round about 30° or 40° taking your hand well clear of the buttons.

I imagine there is room for one of the small "build a switch" systems where you choose your button style and hook contact sets on the back. A little spendy but easy to set up with a good choice of shrouds. Or, if there is enough thread on the switch mounts just make your own, longer shrouds. I've seen a thickish plate bored for button access simply bolted on where the buttons go used as a quick and dirty solution to a similar problem in a different context. Worked but looked horrible.

Clive
 
Good points. the thought of a single purpose lever vs the three buttons seemed fairly easy and convenient but not necessary. The existing buttons are momentary so I could just keep them and wire them to the vfd. There is a coupling nut to change the arc of the Matrix lever so that really isn't as much a problem as an excuse. Is there a problem with using the existing buttons? They look to be in good condition.

The idea of putting a joystick type lever on the apron rather than on the control panel is interesting and probably a better idea. I can get the lathe running normally and add the additional single lever switch later. The S and B apron has an L shaped front cover at the top front of the apron so mounting something could be worked out. Thanks, Dave
 
Only potential issue I can see with the existing buttons is that they have many years of use with 220(?)Volt control gear in an oily machine shop environment behind them so contact resistance may be higher than a VFD control input likes. Probably fine if you clean them up but when I comes to low level electronics control, like a VFD, I like nice new switches designed for that purpose. One potential "when the shop gremlins are feeling frisky" problem out of the way.

If my 1024 VFD is anything to go by Smart & Brown didn't do low voltage controls!

Clive
 
My switches actually had 600v running through them. Back to sourcing switches that fit or replacing with fewer. There are some neat looking 19MM switches that might fit. I was in contact with a place that had them but didn't pursue when I got the joystick idea. Dave
 








 
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