2X72 Grinder, 2HP 3Phase Motor with 3HP VFD

A set of drawings that I will be working from. Ignore metric threads as originally I was headed that way. The bearings where in imperial so I switched over and mostly in my head. It's an incomplete set but anyone could work from them using parts described at begining of thread. The motor plate has to be confirmed so no holes that plate. Missing the complete idle aligner. Going to have to figure out what to do there with bearings, spring or shock absorber. At the end of building the redlines will be included.
 

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Haven't given up, just taking a long time. Rather use my "facility" a little at a time rather than never.
My welding is getting.. ah.. better? Grinding takes forever with so much build up. It is so far functioning as intended regardless of my underwelming performance with a cheapium plasma cutter and aluminum oxide grinding disks, , minus the motor of course. Remember that I am building this grinder to help in my grinding a straight edge. So don't laugh too hard. Ad bad as some of the supposed to be straight cuts are, the important sections work flawlessly.

Next construction step is to weld cross braces between the vertical support plates, weld up and add the aligning wheel bar assembly, and weld on the motor plate.IMG_20201115_01.jpgIMG_20201115_02.jpgIMG_20201115_03.jpgIMG_20201115_04.jpgIMG_20201115_05.jpg
 
A lot of work! My welding requires a lot of grinding, then Bondo, then primer surfacer, then thick enamel.
I've thought about getting a plasma cutter but don't do much welding. Are you happy with the one you got?
 
That is one stout grinder frame!

I've seen trailer hitches that were wimpier.

-brino
 
A lot of work! My welding requires a lot of grinding, then Bondo, then primer surfacer, then thick enamel.
I've thought about getting a plasma cutter but don't do much welding. Are you happy with the one you got?
I have a 200 dollar touch start Cut40 off of Ama... I can't say it was the worst 200 dollars I have ever spent. It will blow a 20amp circuit breaker easily, though I made a special cable and dual outlet to hook up to the 50amp total 1ph 240 on the Ranger. I still need to get the air/amp ratios right. I have trouble on the the 1/4 and 5/16 plates. As soon as the consumable gets fudged then the cutting gets harder. That 8inch channel on the bottom was a pain to cut. The way I figure it, if I am going to get too much grinding sparks right at me I would rather direct them down. Though beware of your shoes. I have pants with a hole at my crotch from the grinder sparks and holes in a shoe from the molten metal. Which area is more important, humm. I have since got a leather apron/chaps. I still forget to change steel toe shoes when I think "am not really going to do to much."

That is one stout grinder frame!

I've seen trailer hitches that were wimpier.

-brino
Ah.. thanks.
I reduced the length of the dual beam pivot attachment to about 6 inches, due to using material that I had. I worried about excessive virbation being that it was extended unsupported so far out. So I beefed them up to 2x2x1/4 and am adding a clamp towards the end to wedge those beams together. I want over kill rather than under kill so there is no kill on me. Oh, I did see someone on the tube using 2x2 solid bar. Now I thought that was over kill.
 
Got delayed due to winter and funds. Just finished the electrical control boards that were outside of my area of expertice. Powered by 24vac coming from the VFD electrical enclosure. Once the SPST rocker switch is thrown, 24vac will go back to the contactor in the VFD enclosure and startup the VFD. The control box will house the potentiometer, a LED display for Feet Per Minute (maybe), a LED lit NC momentary switch, and two NO momentary switches and three leds. When 24vac is switched ON a LED will light along with the LED Display. Press forward or reverse by one of the NO momentary switches and hold for four seconds until the "RUN SET" LED comes on and at this time the motor should start to run. If the buttons are pressed and held long enough the motor will not come on. This should help in two ways. One is that accidental starts should be diminished and additionally give some time for the motor to break before trying to change directions. Once running the two NO switches become inactive and only the potentiometer can be adjusted and the NC STOP momentary switch be engaged. One LED will display reverse when lit and the LED lit switch will show when power is going through the circuit. Will update with schematics as soone as I place all the values I actually used into them.
 

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A little spikey. In therory this is how it is supposed to work but in actuallity there is a brief period, maybe like 500 milliseconds, that the REV switch can be released prior to the "RUN SET" LED lighting and it will be operating in FWD mode. I have changed resistor values to increase the delay and it ALWAYS happens just prior to the RUN SET. This would indicate to me that REV coil is de-energized but there is still a current/voltage available to finish the time delay. That is why the RUN SET is there, so you KNOW when it the switch has occured at which point the FWD/REV NO switches are disabled and you can let go.CAP.PNG
 

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