Building a vibratory tumbler... (nope, probably buying one instead)

aarongough said:
The main issue is that I never found any sprockets that were large/small enough. I remember seeing that first design on eBay a while back, the sprockets he was using were plasma cut in his shop.
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In 520 chain (a standard motorcycle chain) there are "stunter sprockets" available up to 70 teeth. A front sprocket can be had with as few as 13 teeth. In addition to the chain reduction, a simple 6:1 belt jackshaft, you could get a 1725 rpm motor down to about 53 RPM at the drum. If you want a slower tumble, get a bigger pulley on the jackshaft. Because the belts are on the fast side, you won't have slippage problems.

And, having a ~200 tooth sprocket waterjet cut out of 1/4" plate at my local vendor would probably cost right around $150. If you're custom making sprockets, you could do fun stuff like elliptical sprockets to oscillate the speed up and down.
 
Might be a dumb idea but what about a cement/concrete mixer. You can find those fairly cheap.
 
bladsmth said:
What I have surmised so far is that the tank shape is very important.
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The tank shape is important, and the location of the tank relative to the vibration is also important. The goal is to create circulation where the media is swarming around in loops. It's not just vibrating, the contents are tumbling.
 
stupid forum software won't let me post my entire reply in one post. good lord...


"This circulation is what prevents hot spots where two things just sit stationary relative to each other and rub dents into each other." ^ goes up there.
 
swh_4401.jpgI've read about DIY vibratory tumblers and they don't sound like success stories. I've heard many people say that the manufactured machines are "tuned" properly. Because of this, I chose to make a DIY rotary 5-gallon bucket tumbler. Its a bit undersized for my needs so I'm eager to see how your project turns out.

I am using a 2HP motor with VFD in addition to a pulley speed reduction (2" pulley on motor, 6" pulley on drive shaft). I started with the VFD only, but I was running at such low speeds that I would occasionally stall the motor. On one side of the bucket is a 1" drive shaft with two rubber wheels. On the other side is two casters. I'm running 100 to 150 knives per month, 20 at a time. Annealed knives take 4 hours per batch to get a nice even finish. Hardened knives take 6 hours or more to go from scale to bare metal. The pic here shows my tumbled finish with 10 seconds of touch-up with a handheld scotch-brite pad.

A few notes about bucket tumblers:
1. The forces are pretty immense. A standard 5-gallon bucket only lasts about 2 to 4 hours before it starts cracking and leaking. Adding a liner made from a second bucket (with top and bottom cut off) extends the life to 10 to 20 hours.
2. That being said, I would avoid a design that requires mounting anything (such as a drive gear) to the bucket. When the bucket fails, you want to switch them out without a hassle.
 
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So I've been thinking about everyone's input so far, as well as doing a bunch more research. One thing I realized is that I've seen a lot of photos of stonewashed finishes, but I'm not at all sure how they were all applied. I know I've seen a bunch done in vibratory tumblers, but I haven't seen too many where people said they'd used a rotary.

If anyone has pics of blades done in a rotary tumbler it would be great to see them!

Here's one great article I found about tumbling: http://www.raytechmetalfinishing.com/science-mass-finishing.php

I've also found out about some suppliers here in Canada that I wasn't aware of before, who sell both machines and media. I will be getting some prices from them today.

So far the best media prices I've seen are from C&M Topline, they sell most of their media for around $1 per pound.
 
P.Brewster said:
View attachment 475573I've read about DIY vibratory tumblers and they don't sound like success stories. I've heard many people say that the manufactured machines are "tuned" properly. Because of this, I chose to make a DIY rotary 5-gallon bucket tumbler. Its a bit undersized for my needs so I'm eager to see how your project turns out.

I am using a 2HP motor with VFD in addition to a pulley speed reduction (2" pulley on motor, 6" pulley on drive shaft). I started with the VFD only, but I was running at such low speeds that I would occasionally stall the motor. On one side of the bucket is a 1" drive shaft with two rubber wheels. On the other side is two casters. I'm running 100 to 150 knives per month, 20 at a time. Annealed knives take 4 hours per batch to get a nice even finish. Hardened knives take 6 hours or more to go from scale to bare metal. The pic here shows my tumbled finish with 10 seconds of touch-up with a handheld scotch-brite pad.

A few notes about bucket tumblers:
1. The forces are pretty immense. A standard 5-gallon bucket only lasts about 2 to 4 hours before it starts cracking and leaking. Adding a liner made from a second bucket (with top and bottom cut off) extends the life to 10 to 20 hours.
2. That being said, I would avoid a design that requires mounting anything (such as a drive gear) to the bucket. When the bucket fails, you want to switch them out without a hassle.
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That's great input! What kind of media are you using? I'm surprised the buckets die so quickly!

I've been thinking about the idea of making a 5 gallon tumbler again since last night when it came up in this thread... If it required that much maintenance though then it might not really be practical.
 
Roadracer_Al said:
In 520 chain (a standard motorcycle chain) there are "stunter sprockets" available up to 70 teeth. A front sprocket can be had with as few as 13 teeth. In addition to the chain reduction, a simple 6:1 belt jackshaft, you could get a 1725 rpm motor down to about 53 RPM at the drum. If you want a slower tumble, get a bigger pulley on the jackshaft. Because the belts are on the fast side, you won't have slippage problems.

And, having a ~200 tooth sprocket waterjet cut out of 1/4" plate at my local vendor would probably cost right around $150. If you're custom making sprockets, you could do fun stuff like elliptical sprockets to oscillate the speed up and down.
Click to expand...

That's good info mate! Hadn't though about using motorbike sprockets! I previously had a look at bicycle sprockets, but mounting them was a bit of an issue.
 
P.Brewster said:
I'm running 100 to 150 knives per month, 20 at a time. Annealed knives take 4 hours per batch to get a nice even finish. Hardened knives take 6 hours or more to go from scale to bare metal. The pic here shows my tumbled finish with 10 seconds of touch-up with a handheld scotch-brite pad.... A standard 5-gallon bucket only lasts about 2 to 4 hours before it starts cracking and leaking. Adding a liner made from a second bucket (with top and bottom cut off) extends the life to 10 to 20 hours.
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That's very interesting... how fast is the bucket turning and what kind of weight and volume are we talking about, in steel and media? Do you fill the bucket half-full, nearly full, etc?

ETA there is a good deal of info on these type questions in the link Aaron posted above...
 
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So I'd previously looked for tumblers in Canada, and really didn't have any luck. One company 'vibra-finish' basically never called me back after they realized how small my order was going to be, they usually deal with 3200lb orders for media...

However I just found a company called 'KTS Tooling Supply'. They're selling the Raytech 0.75 cu ft vibratory tumbler for $1,118. That's less expensive than C&M Topline's machine and because it's local I can go pick it up to avoid crazy freight prices for the large package. It's still expensive, but that may well be an option.

The only downside of that machine is that I don't think I'd ever be able to use it for chef knives.
 
Just had a chat with KTS regarding their tumblers. The main issue is that the machine is cheaper, but the media is much more expensive! They only have 1 type of ceramic media as well which isn't super helpful.

Seems like C&M Topline is still the best overall choice for the tumbler and media. I just went back and found the quote the sent me for a tumbler, fluid system and 3 types of media and it's very reasonable when compared with the crazy media prices I've seen from a few other places.

I'm going to have a quick phone call with Dan Lord now to see just how big of a blade you can fit in their TLV75 tumbler. Will report back.
 
aarongough said:
That's good info mate! Hadn't though about using motorbike sprockets! I previously had a look at bicycle sprockets, but mounting them was a bit of an issue.
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You can make a sprocket of any size you wish.

Start with a plate and drill some holes in a circle with hole spacing matched to chain spacing.
 
aarongough said:
That's great input! What kind of media are you using? I'm surprised the buckets die so quickly!

I've been thinking about the idea of making a 5 gallon tumbler again since last night when it came up in this thread... If it required that much maintenance though then it might not really be practical.
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I'm using McMaster Carr PN 4918A2 (5/8" V-cylindrical smooth). No real "maintenance" other than swapping out buckets when the current bucket leaks.


james terrio said:
That's very interesting... how fast is the bucket turning and what kind of weight and volume are we talking about, in steel and media? Do you fill the bucket half-full, nearly full, etc?

ETA there is a good deal of info on these type questions in the link Aaron posted above...
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In accordance with the advice in that link and others like it, I am filling the bucket just over half full. That works out to about 40 pounds of media, I'm estimating. Then I'm adding another 10 pounds of knives. I find that my ear is the best gauge for adjusting the speed, amount of media, amount of water and amount of detergent - a good, loud grinding sound is what I'm looking for.

Video here http://youtu.be/60-6E9lGrcQ By my count I'm spinning at 40 RPM. This video shows a few things that are different than my current setup (a) bucket is 6 or 7 gallon, (b) pulleys are the same diameter, and (c) rollers are different (now I have one roller running on the flange of the bucket, near the mouth).

In a bucket, I add about 1/3 gallon water, 1 fl. oz. purple power degreaser, and some borax. If I add too much water or too much detergent, I lose the grinding action.
 
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P.Brewster said:
I'm using McMaster Carr PN 4918A2 (5/8" V-cylindrical smooth). No real "maintenance" other than swapping out buckets when the current bucket leaks.

In accordance with the advice in that link and others like it, I am filling the bucket just over half full. That works out to about 40 pounds of media, I'm estimating. Then I'm adding another 10 pounds of knives. I find that my ear is the best gauge for adjusting the speed, amount of media, amount of water and amount of detergent - a good, loud grinding sound is what I'm looking for.

Video here http://youtu.be/60-6E9lGrcQ By my count I'm spinning at 40 RPM. This video shows a few things that are different than my current setup (a) bucket is 6 or 7 gallon, (b) pulleys are the same diameter, and (c) rollers are different (now I have one roller running on the flange of the bucket, near the mouth).

In a bucket, I add about 1/3 gallon water, 1 fl. oz. purple power degreaser, and some borax. If I add too much water or too much detergent, I lose the grinding action.
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I'll be honest, I'm starting to lean toward simply buying a TLV75 vibratory tumbler... I realized I could sink a bunch of time into building a tumbler, or I could sink a bunch of time into making knives. Given that my goal is to fill all the orders on my backorder list by the end of the year, I may have to just bite the bullet and let my credit card hurt for a while...

Yours overall looks like one of the better ones I've seen so far. I'm guessing the reason your buckets die is because they're flexing so much in between the rollers from 60lbs of media and knives. If you were to add more rollers underneath that cradle the shape of the bucket I bet you could eliminate the bucket failure.

On automationdirect.com I'd be able to buy a 1/4HP DC motor and a controller for about $250, not sure that such a huge motor is needed for this. With that said this is why I'm leaning toward just buying something. I could spend time trying to source all these component and then build something that simply doesn't work. I'm not sure Im prepared to deal with that loss of time right now. Disappointing as I was somewhat looking forward to building a machine and learning to weld in the process!
 
aarongough said:
Yours overall looks like one of the better ones I've seen so far. I'm guessing the reason your buckets die is because they're flexing so much in between the rollers from 60lbs of media and knives. If you were to add more rollers underneath that cradle the shape of the bucket I bet you could eliminate the bucket failure.

On automationdirect.com I'd be able to buy a 1/4HP DC motor and a controller for about $250, not sure that such a huge motor is needed for this. With that said this is why I'm leaning toward just buying something. I could spend time trying to source all these component and then build something that simply doesn't work. I'm not sure Im prepared to deal with that loss of time right now. Disappointing as I was somewhat looking forward to building a machine and learning to weld in the process!
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Thanks - and yes, I totally agree - more support would lengthen the lifespan of the buckets. However, the bucket is abrading and therefore getting thinner and thinner over time - so it will eventually fail, regardless of support.

To explain my setup a bit: One of the videos in this thread shows a bucket tumbler riding on rollerblade wheels. One wheel is friction-driven by a motor shaft. This was the design that I initially attempted to copy with a treadmill motor - it was a miserable failure - the friction-drive slipped and the motor control was wonky. I had the 2 HP motor and VFD set aside for a grinder build, so I used that on my tumbler. Then I added the drive shaft, and finally the pulley. What was supposed to be a $100 project turned into a $900 project. What I have now is basically a temporary solution - it's getting me from point A to point B but I want something bigger and/or better. I also don't want $700 in motor and controller tied-up in the tumbler.

Other DIY projects:
http://www.practicalmachinist.com/vb/general/homemade-vibratory-tumbler-parts-material-ideas-231440/
http://www.cnczone.com/forums/mass-...ies/14464-home-brewed-vibratory-finisher.html
http://www.cnczone.com/forums/mass-...a-stratigies/40365-diy-vibratory-tumbler.html
 
About 2:40 Chris starts talking about their finish and shows the machine. Probably not very useful, but it's interesting nonetheless.

http://youtu.be/Nj6p8p6vfZQ

I enjoyed both parts of the tour if for no other reason than to watch the surface grinders and other processes.
 
P.Brewster said:
Thanks - and yes, I totally agree - more support would lengthen the lifespan of the buckets. However, the bucket is abrading and therefore getting thinner and thinner over time - so it will eventually fail, regardless of support.

To explain my setup a bit: One of the videos in this thread shows a bucket tumbler riding on rollerblade wheels. One wheel is friction-driven by a motor shaft. This was the design that I initially attempted to copy with a treadmill motor - it was a miserable failure - the friction-drive slipped and the motor control was wonky. I had the 2 HP motor and VFD set aside for a grinder build, so I used that on my tumbler. Then I added the drive shaft, and finally the pulley. What was supposed to be a $100 project turned into a $900 project. What I have now is basically a temporary solution - it's getting me from point A to point B but I want something bigger and/or better. I also don't want $700 in motor and controller tied-up in the tumbler.

Other DIY projects:
http://www.practicalmachinist.com/vb/general/homemade-vibratory-tumbler-parts-material-ideas-231440/
http://www.cnczone.com/forums/mass-...ies/14464-home-brewed-vibratory-finisher.html
http://www.cnczone.com/forums/mass-...a-stratigies/40365-diy-vibratory-tumbler.html
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Fair enough mate, makes sense about the bucket thinning. Funny how that nice drive and VFD ended up in that role! If it's getting the job done then it's money well spent in any case!

Omega Leather Works said:
About 2:40 Chris starts talking about their finish and shows the machine. Probably not very useful, but it's interesting nonetheless.

http://youtu.be/Nj6p8p6vfZQ

I enjoyed both parts of the tour if for no other reason than to watch the surface grinders and other processes.
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Thanks! Good link!

The machine they're using is called a high energy centrifugal finisher, those things are seriously expensive. Much faster than the other methods though as I understand it.
 
So I just had another chat to Dan Lord at C&M Topline, he was very helpful as always.

He said I should be fine finishing blade up to about 10" length in the TLV75. Basically as the part length goes up you need to run less parts in order to make sure they're all getting finished ok. I'm only going to be doing batches of 8-10 which should be totally fine.

He said that trying to finish a chefs knife probably won't be reliable in that machine. It will physically fit but it likely won't rotate properly in the media so it would end up with one area over-finished and the other areas barely touched. To finish knives of that size you'd need to go the next step up to one of the Mr Deburr tanks.

I'm getting a quote on a used Mr Deburr tank as well as for the TLV75. The Mr Deburr is going to be a fair bit more expensive even just for the media (takes 4x the media!) so we'll see, not sure I'll be able to afford the larger machine... That would be the most 'future proof' way to proceed though.
 
The Mr. Deburr machines do a really nice finish. Don't worry about the media cost or quantity. For knife making purposes you will probably never replace them. Buying them by the bucket is also a lot cheaper. Shop around, you are not restricted to just the ones from the machine manufacturer.
 
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