New Vevor 2HP 82" belt grinder

I have been wanting a belt grinder for a few years, and I finally went for it. A VFD-controlled three-phase 1.5kW (2HP) TEFC motor driving an 82" belt, and I’ll do what I need to to put a 72" belt on it because that’s the size I can get in the belts I want. It was about $1K.

I have some work to do, but less than if I built it from scratch. The ebay images weren’t particularly accurate but I don’t think they were misleading. (For example, the arm sleeve is no longer made with a bolted-on top section; it’s either extruded or welded, I didn’t try to figure out.)

Shipping

It was advertised as shipping from New Jersey, but was actually shipped LTL freight from California, so it was not a quick trip. I hope that the shoe prints on the case were from the stock from which it was assembled and not because the case was being used as the floor on the trip across the ocean…

The unit was intact inside the crate, which was sturdy, and used folding metal clips to hold together:

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It comes with one sheet of paper of “instructions” that tell you to read the instructions, and not much more. You had better know how these things work.

Power

It is advertised as a 120V unit. I was intrigued; I’d expect to want 240V to drive a three-phase VFD. Turns out it ships with a 120-240V transformer in a box. The VFD has a euro-style plug without a ground pin, plugging into a receptacle that supplies a ground but without a pin to connect ground. Not awesome.

I’ll probably eventually run a 240V outlet and wire it directly, including a ground wire. But 12A @ 120V is OK; my shop outlets are 20A.

It says to try to keep grinding dust out of the VFD. Well, yeah. Turns out that the VFD has a control panel that can be removed form the case and remoted through an ethernet cable. This means that the VFD can be mounted away from grinding dust, and the mostly-sealed control panel mounted near or on the unit.

The VFD did come pre-programmed correctly for the unit, as far as I can tell, and included the instruction manual for the VFD, with plenty of detail including RS485 modbus protocol information in it. Might be a nice VFD to keep in mind for other projects to be honest!

Condition

Things looked pretty good, everything packed well in the crate, until I got it up on the bench.

Every wonder why your import tools are covered with thick grease? Here’s your answer for a tool that sadly wasn’t so protected!

I treated all the surface rust with Corrosion-X to stop the rusting.

I missed getting a picture, but the 200N gas spring also had a lot of surface rust.

The welding on the table looks worse than my welds. I’m not sure yet what I’ll do with the table, but I’ll probably do something for precision angles for grinding HSS blanks for my lathe.

Accessories

The wheel looks fine, though I expect rarely to use it.

The concave grinding rack had something that looked like salt on it but was actually not corroded.

Mostly I expect to use the flat platen. The platen and at least upper roller are not square to the machine. This looks like more work:

The platen is graphite coated. I’ve ordered a 2" x 6" ceramic platen liner to replace it and will add a safety shelf when I install it:

It came with three 180grit aluminum oxide unidirectional belts. I’ve ordered a pack of various grits of Red Label ceramic bidirectional 72" belts. I’ll see which grits I use most of and buy more of those belts as I find need. I’ll also find out whether I need to modify the unit at all to fit 72" belts.

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WOW! that is a “seriously” grinder!!!

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This video describes possible modifications to fit 2x72" belts:

I’ve also seen mention that some folks have just skipped the tracking wheel and tensioned it by pulling the arm and locking it against the belt, but I don’t want to do that; I want tracking control. :relaxed:

The only endmill I had long enough to fix the off-square table mount was a large “corncob” roughing mill. It didn’t leave a smooth finish, but it’s at least true. Their welding jig was so off-square that I had to remove 1mm from the side that interfaces with the arm to make it square.

I can measure the other, untouched, side later for how many degrees it was off square. But at least now it mounts square after facing that side in the mill.

The edges of the table appeared not to have been dressed. The edge was raised and dinged, and the laser-cut tab wasn’t finished. Took a few minutes of careful filing to properly fettle the table.

I think that the mounting hole for the upper roller is not straight; I don’t think it’s just a bent screw. I’m thinking about turning new shoulder bolts on the lathe that will be strong and register the shoulder on the platten arm to make them run square. I’ll have to look through my round stock for the right pieces for that work.

The angle brackets that mount the platen just aren’t 90° angles. I think I’ll try to bend them square in my vice; they are thin enough already that cutting them thinner to square them is probably a bad idea.

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This particular comment (#104 in a monster thread spanning years) is probably the best place to start with why I’m doing this…

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The tracking wheel and driving wheel were both specified as 4" but that’s not right. The tracking wheel is 5" nominal (about 125mm) and the drive wheel is about 220mm.

The platen is specified as aluminum but is fortunately actually steel (10mm thick).

I managed to carefully bend the platen brackets from 85° to much closer to 90°

I removed the upper wheel and confirmed that the screw was not bent in shipping; the screw hole is just not straight. But it’s so far off straight (2°) that my shoulder bolt idea won’t work. All I can think of is to bore it out and pressure fit a bushing in and re-do the hole straight.

The RPM is misconfigured on the VFD (though I don’t know by how much) and I’m curious whether I could change the parameters so that it actually displays SFM which I care about more anyway.

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Sorry to hear that your bargain was not such a bargain with all the work you are having to do to make it usable. In the end I know it will be better than the expensive ones and you will know every nook and cranny of the machine!

OK, setting P143 is number of poles. It’s set to the default 4, with an allowed range of 2–10. By shooting a video with 60RPM commanded, I could see that it made about 18 revolutions in about 10.4 seconds, rather than the commanded 10.4 revolutions. That’s pretty close to half the commanded speed, and there is obviously an integer number of poles in the motor!

Looking at the motor data plate, I see “TYPE YS90S-2” and the “-2” part of the type means that it is in fact a two-pole motor rather than the four-pole configured.

220mm diameter is just over 2 feet circumference, about 27.2 inches.

This means that when displaying 60RPM, it should actually be going 120RPM, giving almost 230 SFM or 45 inches per second.

So if I leave it configured this way, I’ll know that 75% of the displayed number is a good approximation of inches per second. :relaxed:

Later…

I realized that telling it that the motor has 5 poles should display 48RPM by my math, so I tried it.

Changing the configured number of poles does not change the RPM reading at all. I tried 2, 4, and 5 and it didn’t change the RPM reading.

It turns out that it’s actually an asynchronous motor, so the frequency doesn’t directly control RPM, and the VFD can’t sense actual RPM via back-EMF.

The frequency doesn’t matter. It apparently varies the voltage with the frequency, and it has a mode for displaying the AC voltage it is providing. I have not validated this with a multimeter.

So I’ll just give up on measurement for now. :relaxed:

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The major source of delay in acquiring this was determining whether to design and make my own from scratch. :relaxed:

I did send support at vevor dot com a request for a replacement for the malformed part that is not trivially repairable. I’ll see what they have to say.

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It was 1.5° off square before I milled it:

The wheel is about 2° off square:

Vevor support asked for pictures so I sent them some. I’ll post updates with what they say.

The 72" belts arrived today and as expected don’t quite fit without some modifications. I’ll wait to approach that until I hear back from support on the platen arm bracket replacement.

While waiting on the 72" belt adjustment and the platen ceramic glass, I actually used the provided 180 grit belts today… To touch up some 3D prints in PETG before gluing them together.

I may be the first person in history to buy a belt grinder for lathe tools and then inaugurate it with 3D printed plastic. :smiley:

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The correct socket for that europe schuko plug would have a ground pin (or a ground spring on the side) and this plug is usualy used for 240V 50Hz AC.

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@cprezzi yeah, I’ve definitely seen those when I’ve traveled on your side of the Big Pond. :relaxed: I thought about turning down a piece of brass to make a ground pin but decided I’d just rather not use the transformer at all.

They offered $60 to compensate. I don’t know whether a typical knifemaker would have the tools to use $60 to fix it, but I do know how I want to fix this, so it works for me.

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Thats the better solution, for sure :wink:

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My restocking abilities aren’t quite up to ToT’s, so I won’t just untap and undrill the hole and start over, even though I have enough filler and mill scale in the lathe tray otherwise.

I’ll have to do something different.

The platen wheels are mounted on M12 x 1.75 screws. The thread in the upper mounting hole is a bit chowdered. I should be able to center on the existing hole, run a 1/2" end mill through to get the hole straight, then drill 37/64 and tap M16 x 1.5.

Then on the lathe I can make a threaded bushing. I have some 1" 1117 CRS stock I can use for this.

That narrower section at the end will have the matching M16 x 1.5 thread externally, and the part will be drilled through 13/32" and tapped M12 x 1.75 to match the bolt that carries the wheel. I can loctite the threaded bushing into the bracket, and the shoulder will help carry the load, so this is perhaps ultimately better than the original design.

Of course now I find that a 37/64" drill (which I have) is the right size for 75% thread engagement recommended for aluminum, and 19/32" (which I don’t have) would provide the 50% thread engagement recommended for steel. If I have to, I can get out the boring head, but I’m hoping that a merely 10mm deep hole and plenty of cutting fluid will get me through. And I’d prefer to have the max thread engagement possible for strength.

Meanwhile, my glass platen bearing surface is on the way, and my 72" belts are here and waiting for me to also work out how I want to modify this to work best.

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Both the refund and the glass platen bearing surface have arrived.

I have realized that the threaded bushing won’t work with the lock nut holding the bearings on the wheel, so I need to think about it a little bit more. I have found replacement brackets on eBay for $30-40. It looks like they are all threaded 1/2x13 so I need to re-check the threads on my existing axle; I only checked metric because of other metric hardware.

I’d like to be able to trade speed for torque, so I’m thinking about also getting a smaller drive wheel, closer to what was actually specified for this machine. These are about the same price, though I’m going to have to dislodge the screw mounting the existing drive wheel before I can confirm the bore (more carefully than the thread!) and order an additional drive wheel.

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The idler wheel bolts in the arm are indeed 12mm x 1.75, not the more common 1/2x13, and the idler wheels run on 6201Z bearings, which have a 12mm ID. The bolt is a shoulder bolt with a 12mm flat shoulder through the length of the idler wheel, threaded only past the wheel.

The motor shaft is 24mm with an 8mm keyway. It’s really tight; I haven’t managed to remove it yet. I don’t really have a large enough puller. I’ve tried striking the back with a soft deadblow hammer while rotating it and I’ve moved it maybe 10mm out of about 50mm (hard to measure in situ). I need to rummage through the scrap pile and see if I can make a puller…

For this replacement drive wheel, I’d have to open out the keyway to 8mm (~5/16") to fit it in place:

This one has the right keyway, so I ordered it:

I think that if I open up the existing drive wheel to a tight slip fit and add a keyway fixing set screw I’ll basically be able to change gears to choose between speed and torque.

The more I think about the hole, the more I think I’ll just use a press-fit bushing with no shoulder for my first attempt, and if I don’t like the result I can still do the fancy threaded option.

I have some 1" x 2" steel stock to make the safety shelf for the platen liner.

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I marked the location of the motor on its stand, removed it, and used my hydraulic press to push the motor out of the wheel.

This stackup looks crazy, but it didn’t show any propensity to wobble. It of course came crashing down when the motor came free, but as you can see I was holding it up to keep things intact.

The shaft was indeed a tight interference fit. It’s not clear to me that it needs to be a tight interference fit when it has a 8mm key. Before I do anything to the 220mm wheel that came with the unit, I’m going to see what the 4" wheel I ordered is like. I’ll also try that before I do any adjustments for 72" belts, because the smaller drive wheel will give me about 7" of the 10" I need.

I’d have to do a lot to do a skim pass on the inside of the bore. I’d have to surface the face plate that I bought for my lathe (it’s still rough right now), mount the wheel and indicate it as perfectly as possible with a tenths indicator, and then take the lightest pass I possibly can with an polished insert in my carbide boring bar.

It’s quite possible that I’ll mount the 4" drive wheel and keep the 220mm as-is until such time as I discover a need for it.

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Crooked idler repair appears to have been successful.

I clamped the bracket arm in my mill vice and held up the end with a machinists jack. Centered on the hole the best I could and plunged a 1/2" end mill through it to get a straight hole.

Then I found some 5/8" stock. That gives me 1/16" on each side to hold threads. But I don’t have an undersized 5/8" reamer. I had a choice between the fast way of turning larger stock down to oversize to use with my 5/8" reamer, or the slow way of making a custom hole with the boring head on the mill.

Of course I chose the slow way, by way of practice for when I really need to hit an odd dimension.

I skimmed the stock with a ground insert about 1" long. Then I turned a section about 1/2" long about .0015 thinner, and then about 1/4" about .005 thinner than the main section. I parted off just barely into the full width section to make a go/no-go gauge. Then I drilled half an inch deep 13/32" and tapped as far as I could with an M12x1.75 taper tap, and parted it off the thickness of the plate (about 10mm).

Here are the gauge and the partially-threaded bushing:

You can probably just barely make out the two lines on the gauge where the diameter steps are.

I then used the boring head to get close to the plug size, and then crept .002" until I could fit the .005" undersized section, then .001" at a time until I could just barely fit the .0015" undersized section into the hole.

I used the hydraulic press to press the bushing into the newly-bored hole, and then finished tapping.

As you can see, I don’t have a de-roughing tool for putting mill scale back on. :grin:

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Very nice. I know you are unhappy about the lack of quality, but how long would it have taken to build one? And besides, YOU are a craftsman and having tools that work exactly the way you want them to is part of your craft… If Dewalt made it, it would be half plastic, if B&D made it, it would fall apart in three weeks. And if Delta made it it would cost twice as much… Enjoy the process.

Oh, but I’m not unhappy. :+1:

I’m considering this to be a mostly pre-assembled kit that cost less than making it from scratch, which was the other serious consideration.

To buy something I would have expected to cover all my needs out of the box would have been closer to $3K. That would have come with a higher-quality motor and VFD of course, as well as a completely different, high-featured guide table. But I would still have possibly expected to have to add the ceramic glass platen liner and safety shelf myself; I don’t know that anyone ships those off-the-shelf.

I am being clear about the faults I found in part so that someone else who reads this can judge whether this is a level of quality they will be satisfied with as a starting point. There are plenty of people who could go into this with eyes wide open and be satisfied!

I would definitely suggest to buy it with a credit card in case you have problems and aren’t satisfied with the resolution offered. But I will say that support at vevor dot com responded within hours with a request for pictures, then again promptly with offer of partial refund, and when I accepted it they applied it promptly to my card.

If I had it to do over again I would make the same choice.

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