2X48 Belt Grinder Motor Options

J

Josh Conder

Joined
Apr 29, 2018
Messages
36
Guys I just bought the belt grinder in the link below and I have about a month before it gets to me and I am wanting to get the motor figured out before it gets here. It came with a 1.5 HP, 2800 rpm motor which I did not get because it wouldn't work in the US. So I am trying to figure out what motor would be best since I know 2800 rpm is not a common motor size in the US. Single phase or 3 phase would be in the question, but I think 3 phase only works with a VFD correct? Any help would be greatly appreciated.

https://www.ebay.com/itm/253368776062?ul_noapp=true
 
The original motor would likely have worked fine. The odd speed ( to us in the USA) is because it is 50Hz. It would run around 3200RPm on 60 Hz.

Use a 1.5Hp TEFC C-faced motor.
Single phase will work if you want to use step pulleys.
Far better would be to get a motor and VFD package and have VS at your fingertips. You want a 220/240 volt outlet. You can run a VFD on 120, but it is better on 240.
 
I do have a 220 outlet in my garage so we are good there. I have very little experience with electric motors so that's my problem. Ill have to buy a drive pully to match my motor as well. So you would want a motor with 3000+ RPm as opposed to something on the lower side correct also what kind of frame do you need. Do they sell motors with the VFDs or will I have to buy them separately?
 
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By time you buy pulleys, a shaft, bearings to hold the shaft , and a belt you wouldnt have to spend much more to get a cheap vfd.
 
Spalted said:
By time you buy pulleys, a shaft, bearings to hold the shaft , and a belt you wouldnt have to spend much more to get a cheap vfd.
Click to expand...


I'd prefer to get a Motor/VFD combo, but at the moment I can't find anything online. I'd like to buy them already wired up so I don't have to mess with that. I also don't have a huge amount of cash left after buying that grinder, id like to be around $300 or so for the VFD and motor.
 
My motor came from ebay. nos baldor 3 phase was 85 bucks and I use a teco fm50. So it is doable for 300. Understand that my vfd is not sealed from dust and if dust gets inside it can mess it up. Most just put it in a filtered box or spend alot more money for a good sealed one.
I have saw people talking about cheap Chinese vfds ?? maybe somebody will chime in on those.

Looking at that grinder the first thing I would do is change the arm to one a foot longer so you could use 2x72 belts.
Happy grinding
 
Been using those cheap Chinese VFDs for a few years now and they work just fine. For a 2hp or less Chinese VFD expect to pay around $100 shipped from here in USA. Look here https://goo.gl/7jcYu9 for a selection of 3 ph motors ranging from $150 to $200 range. The 1-1/2 hp 3600 rpm for $142 shipped will work just fine with the VFD. Some folks say the 1800 rpm motor is needed because it's got a slight amount more torque at low rpm than does the 3600 rpm motor. True, but at low rpms you don't need much torque at all because you're doing light touch type grinding, not hogging.

edit: I didn't look at your link until I'd posted. That grinder is a 2X48 and located in Greece, and it says "does not ship to USA". Your profile says you're in Texas?
 
Ken H> said:
Been using those cheap Chinese VFDs for a few years now and they work just fine. For a 2hp or less Chinese VFD expect to pay around $100 shipped from here in USA. Look here https://goo.gl/7jcYu9 for a selection of 3 ph motors ranging from $150 to $200 range. The 1-1/2 hp 3600 rpm for $142 shipped will work just fine with the VFD. Some folks say the 1800 rpm motor is needed because it's got a slight amount more torque at low rpm than does the 3600 rpm motor. True, but at low rpms you don't need much torque at all because you're doing light touch type grinding, not hogging.

edit: I didn't look at your link until I'd posted. That grinder is a 2X48 and located in Greece, and it says "does not ship to USA". Your profile says you're in Texas?
Click to expand...

I contacted the gentleman directly we worked a few things out.

I may go cheap now, probably won’t last long, but it will get me going. May also convince my brother and dad to go in on a good motor and VFD. They were wanting To get get a belt grinder as well. My dad can get motors and VFDs at cost.
 
I know so little about motors and wires too, but figuring out how to wire my set up was pretty easy. I got some help wiring things on this forum too. A vfd is a giant step up over the pulley system.
 
The $100 chinese VFDs are a tremendous value for the money. Many of them are basically clones of Hitachi VFDs IIRC, and are extremely versatile. Actually, they have TOO many features and adjustments for what we really need on a grinder. The main concern is that the cheap ones are open framed, so you need to take some precautions to keep metal dust out, but it need not be complicated. A lot of guys just wrap some filter material around the outside, or stick them in a small cabinet or box.
As for 3 phase motors, if you have a repair shop or electrical surplus, you may be able to find a decent motor for $50 or so. I've seen them pop up on Craigslist occasionally as well. If you want new in box, IronHorse is a decent choice for less than $200.
 
Don't even mess around. You've got 220 where you need it. Get a two horse 1800 rpm motor and a vfd that will allow doubling motor speed. That is a sweet little design that can be easily modified to run 72" belts.
 
If my wife ever lets me have more than half the 2 car garage I will be in business lol. I went for 2x48 for space reasons and less money was a plus.
 
I used to use only 1/2 of my 2.5 car garage.... Now I barely have room to walk in it, much less park a car. ;)

Not to discourage, but FWIW, I think the space savings of a 2x48 over a 2x72 is mostly neglible. Same with a benchtop mill vs a full size knee mill. Yes, they're smaller, use less material, weigh less, etc... but it's doubtful you'd every appreciate any real space savings, especially when you factor in the price and variety of 2x72s vs 2x48s. Most grinders still hang over the front of the work bench the same amount anyhow, so that added "space" is gonna be mostly in the back where you wouldn't use it.
 
Yeah, I’ve got a compatible drive wheel on the way. I just wanted to make sure that the motor would work with the VFD.
 
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