Vevor 11lb/5Kg Jewelry Tumbler

[chaosdsm]

After viewing liveoak's thread on this tumbler, I thought I would give it a go.  I liked the idea of the auto-reversing feature, though not sure if it's just gimic, or actually helpful.  

So I want to coat the inside of the drum with truck bed liner. It's not going to stick very well to the high gloss finish that it comes with, so I decided to run 4 pounds of mostly unused small ceramic media DRY in the tumbler to basically sand-blast the insides of the drum. It worked quite well, the inside now has what looks exactly like a sandblasted matte finish.

I've seen several comments on youtube and other places about it being too fast, so I broke out my Olympus, setup my tripod, and did some slo-motion capture. Video capture was at 120 frames per second, which means I'm able to get very accurate RPM readings after a bit of math!

The speeds on this thing are kind of weird.... 1 & 2 are very close to each other 3 IS in-between 2 & 4, and 4 & 5 are also very close to each other, so close that I re-shot speed 5.... and oddly enough, with wash water in the mix (heavier drum) it actually spun faster.

I also found something odd.... when running in auto reverse mode, reverse runs about 15% faster than forward.... I'll be contacting Vevor tech support about that to see if it's normal or not.

[chaosdsm]

One thing I was disappointed in... the round door instead of a hexagonal door as shown on the Amazon product page. I contacted Vevor tech support about it, and only the 6.6lb/3Kg version comes with the hex door.

This basically leaves space for small particles of grit to get stuck in and not easily come out. But this will basically be a stage 1 tumbler only anyway.

It's also a lot smaller than I thought it would be. It's 5% larger diameter as my 3lb Nat Geo drum, and barely over twice as wide, plus 4lbs of small ceramic media filled it half way.

[chaosdsm]

Here's my Nat Geo 3-speed tumbler for comparison:



EDIT: Just as a data point, the Nat Geo full drum as shot in the video weighs 3lb 13.35oz

[chaosdsm]

For now, I'm just using this as a stage 1 tumbler due to the speed of the tumble...  It seems to be doing an extremely quick job of stage 1


First batch I did in this tumbler was Labradorite, I did a check after 3 days, and was shocked that the rocks were so rounded already, I thought it would be about a week to see this much progress!

Pre-tumble:


After 3 days in 60 grit coal slag: 












I then put in all my Agates & 46/70 SiC, and again checked on them after 3 days, and found them all nice & smooth, well, at least no sharp edges...  I put the agates, some dragons blood Jasper, and some ceramic media in there for a second run, & I'll check on it this Thursday to see how they're coming.  

I ran the tumbler at speed 1 for both batches of rock.  The Labradorite, I ran on the auto reversing mode since that stops for several seconds between direction changes.   The Agates, I ran in just regular mode for continuous tumbling action.   There was no discernable grit remaining in the Labradorite batch, but  I was still catching a small amount of SiC from the Agate batch in my 70 & 100 mesh screens.  

[pebblesky]

Very interesting experiment. My major concern is if the large rocks will attack the barrel too violently. Definitely keep us posted!

[chaosdsm]

May 14, 2024 19:06:27 GMT -5 pebblesky said:

Very interesting experiment. My major concern is if the large rocks will attack the barrel too violently. Definitely keep us posted!

My first trial with truck bed liner was a failure. I tried the Rust-Oleum truck bed liner, too soft & somewhat foam like, especially where it's thicker... It formed a super thin layer on the sides, and bunched up into the corners leaving a mess that I'm still working on cleaning out. Tumbling is actually doing most of that work for me, I'm just pealing away where the rocks have knocked it loose. I think I'll try the Herculiner product next time.

In "theory", the barrel should last a very long time if it's truly polycarbonate....   HOWEVER, I have my doubts, since the lid has already developed a crack in it.  I've already picked up 2 pieces of 6" solid core ABS plastic pipe to make my own barrels from, and have 3/8" abrasion resistant Lexan (from another project) to make end caps for the barrels.  ABS being stronger, denser, and more impact and fracture resistant than PVC and also only $17 for two 2ft sections!!!

[liveoak]

I think if you can come up with a replacement lid made of something durable, you'd really have something.
I certainly found the Vevor's speed & auto reversing did my coarse grinding, usually in ONE 2 week run.
The savings on the grit is worth enough incentive.

Please tag me when you come up with the solution

Patty

[chaosdsm]

May 16, 2024 6:43:26 GMT -5 liveoak said:

I think if you can come up with a replacement lid made of something durable, you'd really have something.
I certainly found the Vevor's speed & auto reversing did my coarse grinding, usually in ONE 2 week run.
The savings on the grit is worth enough incentive.

Please tag me when you come up with the solution

Patty

Since mine has already developed a crack, I could theoretically send it back, but where's the fun in that, especially for a DIY'er like myself 

So, this is what I came up with:  

This is a bit involved, and you'll need a few tools and other supplies....



Materials needed:

> A new cap can be made of anything very stiff. 3/4" plywood, 1/4" steel or aluminum plate, 3/8" polycarbonate or acrylic sheet, etc.... Plywood is cheap & easy to get pretty much anywhere. It's also easy to cut, drill, & work with.

> 5/16" Polycarbonate / Acrylic drill bit make sure you use a new bit, it needs to be very sharp - do not use a regular wood or metal drilling bits these can crack the polycarbonate rim of the barrel.

> 11/32" or 3/8" drill bit for drilling the new cap

> 5/16" - 18 Socket Screw x6 1 1/2" long for 3/4" plywood, shorter for other cap materials.

> 5/16" fender washers x6

> 5/16" - 18 wingnuts or locknuts x6

> "Rubber Gasket Sheet" at least 6" x 6" in 1/8" thickness to cover the opening

> hand held drill or for best results use a drill press if you already have one

> A way to cut the new cap to size



Remove the two studs that hold the door in place, then you'll want to mark out 4 more holes to be drilled as indicated below:





Keep the holes about the same distance as the two factory drilled holes and centered on the flats of the drum. Using the 5/16" drill bit, slowly drill the 4 new holes, don't push too hard, or go to fast, you want the drill bit to do the work so that you don't over stress or over heat the plastic or drill bit.



Cut the cover material to fit without going past the orange rubber, then clamp it to the top:



Using the drill bit you just drilled through the top with, mark the first two drill locations in the top by putting light downward pressure on the drill bit, and turning it a couple times with your fingers unless you're using steel for the cap, then you'll need a marker or center punch.



This will leave you with a shallow dimple at each drill location:





Drill the first 2 holes in your cover with a 11/32" or 3/8" drill bit. This will allow you a little room for error, then attach the top with 2 bolts & wing nuts, and finish marking the drill locations.  This is easier than moving the clamps each time, and more accurate.



You can get 6" x 6" natural rubber gasket at Lowe's or Home Depot in the plumbing department, or you can use silicon, nitrile, buna-n, or neoprene rubber from Amazon - for more convenience Amazon has some of these with adhesive backing.



This is the 6x6 sheet from Lowe's, it's about $3.






If you do use a 6x6 sheet like this, it's best to cut it into a hexagon about the size of the actual drum.




If it's non-adhesive, just center it as best you can on the top, and put your new cover over it. It's of course best to use a larger piece that will cover all the way past the bolt holes, as this will help fully support the polycarbonate .



Using the cap screws, inserted from the under side of the top, attach your new cap. You won't need to use a washer under the head of the screw if you use this style of cap screw:





BUT you do want to use a fender washer on top of the new cap this will help spread the clamping force over a wider area creating a better seal. I prefer the "extra thick" washers found in the specialty drawers at Lowe's. They are at least twice as thick as regular washers and will not bend.




Then just use the wingnuts to secure the new cap. Do NOT tighten one at a time.... Tighten in a star pattern like this:

only barely finger tight to start with, then a little tighter each additional time.

You can of course use lock nuts as well (nylon insert in the top of the nut that helps to deal with vibrations, keeping the nut in place), and doing so with a torque wrench, you can find a torque setting that should make for a water tight seal every time without any guess-work.


The rubber will eventually wear away, but should last a very long time and is pretty cheap to replace!

Be aware that if you don't use an adhesive backed sheet, and it's not cut to fit the new cap, the gasket will move on you a bit as you're tightening down the top.  


I had that thing just about as perfectly centered as could be, and it' still moved on me.  I'll have to wait for the correct drill bit, and also going to get an adhesive backed rubber sheet so it'll stay in place on the new cap.

Fortuantely, I already have almost everything including tooling.  The 3/4 plywood top is a cut-out from a speaker cabinet I'm building, though I also have plate steel & 3/8" Tuffak polycarbonate that I could use for a replacement cap as well.

[chaosdsm]

And as a proof of concept:  

I filled the drum about 2/3 with water,


put on the plywood cap, which currently only has 2 bolts holding it down, and will leave it in my bathroom sink overnight!




I actually suspect that it will leak because there are only 2 hold-down points securing the rubber, but time will tell!

[liveoak]

I have to give you credit for your ingenuity - I'll be curious to see how it holds up.
Personally, I might think to first coat the plywood with epoxy, as you don't want it to start swelling up.
And wouldn't it be better to use a larger piece of gasket that would have holes for the screws.
That way, the gasket would stay in place better AND you could replace it easy, since it wouldn't be glued down.

Keep us posted,
Thanks,
Patty

[chaosdsm]

24 hours later, and it leaked about 1mm of water.

Definitely better with full coverage gasket, was just saying that the 6" x 6" is the bare minimum you would need, and showing that it will work with the 6x6 cut down a bit.

Based on my little test: using 6 bolts and washers, instead of just the two I used (which were only finger tight), it should be 100% leak free without much stress applied!

Just a regular Polyurethane is all that would be needed to seal the plywood and protect it from spills.

[chaosdsm]

I had written a nice long reply about the 2nd run of stage 1 on my agates, and mistakenly closed the webpage before posting 

So here's the short version.  Ran 2nd part with the auto-reverse feature, almost no change in the rocks other than a few pieces broke.  Grit was used up with only about 3 grams of SiC recovered between the 50, 70, and 100 mesh screens.  So it looks like the continuous action is better overall for stage 1.  

Here's a few of my favorites out of the mix:

[pebblesky]

Sounds promising and these tumbles look great!

[Son Of Beach]

Looking good

[chaosdsm]

This tumbler can spin so fast (speed 4 & 5) that rocks are plastered to the walls of the container by centrifugal force.   So, I decided to open this thing up and see if there's anything that could be done about reducing the speed!  




Dial controls, switch transformer, and TWO motors, but no belts, no gearing, so no direct way to change the default speed....   Anyway, got to looking, and that appears to be a DC transformer...  So I disconnected the two red wires off the larger direct-drive motor, and hooked it directly to a 3.2V LiFePO4 battery, and it spins at about 20%-25% the speed of the 1st speed when it's plugged in!  

I'm liking this development!  This means I can power this thing directly through solar charged battery power      I would basically remove the AC power cable and transformer, hooking the battery up to the transformer output lines.  I think 4 batteries setup for 6.4V / 100AH (four 50AH 3.2V batteries) will run this thing continuously year round at about 1/2 the speed, while still giving full control as though it were plugged into a wall outlet!!!    OR, I could go full 12.8V @ 100AH (four 100AH 3.2V batteries), bypass the speed control on the Vevor, and add an external 100% variable speed control for maximum control!  

Just need time to get everything done....

[Wooferhound]

I am an electronics technician and I can say that there is No Such thing as a DC Transformer. DC will make a transformer very hot so keep checking that, you could burn it up. I can't tell from the picture what is going on in there, but I would suggest that the Motor is DC and it could be directly run from solar batteries.

[chaosdsm]

Jun 20, 2024 16:32:54 GMT -5 Wooferhound said:

I am an electronics technician and I can say that there is No Such thing as a DC Transformer. DC will make a transformer very hot so keep checking that, you could burn it up. I can't tell from the picture what is going on in there, but I would suggest that the Motor is DC and it could be directly run from solar batteries.

Thanks for the reminder!  It's only been 34ish years since I took basic electronics.  The step-down transformer is only part of the circuit.  A rectifier is needed to complete the AC to DC conversion - which in this unit is a GBU610 bridge rectifier (top of pic just left of center) with the thin blue & black wires coming in from the transformer with the AC current, & going out as DC current through the two thicker red wires, which are the wires I would need to hook my battery pack to. 

SOURCE Tameson:
An AC to DC transformer is the transformer connected to an AC rectification circuit. A rectifying circuit converts AC voltage to DC voltage after a transformer has stepped down or stepped up AC voltage. These power or charge most electronic devices - including the chargers for your cell phones and laptops. 

[Wooferhound]

I have a small Solar power system that is enough to power some stuff in 1 room. I use it for lights, fans, chargers, weather station and a few more things. I probably save about $3 dollars a month using it, however it's priceless when the Mains Power goes out.

www.anotherpower.com/board/index.php?topic=1389.0

[chaosdsm]

Jun 26, 2024 13:08:22 GMT -5 Wooferhound said:

I have a small Solar power system that is enough to power some stuff in 1 room. I use it for lights, fans, chargers, weather station and a few more things. I probably save about $3 dollars a month using it, however it's priceless when the Mains Power goes out.

www.anotherpower.com/board/index.php?topic=1389.0

Definitely!   

I'm using LifePO4 prismatic cells for my solar power needs 

This is the battery box I'm building for this project:



Chinese 4x 50AH 3.2V LiFePO4 Prismatic cells (supposedly grade A) with 1.5mm carbon fiber thermal insulators between batteries, & 3MM carbon fiber shell.  

[liveoak]

I keep wondering if you could make the Vevor have adjustable speed.
Fast & auto reverse works great for grinding, but if you could slow it down then for pre-polish & polish.......

Patty