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

aarongough

aarongough

Joined
Mar 12, 2013
Messages
1,167
I've been thinking about switching over to 'stonewashed' finishes for a long time, I think it makes a lot of sense for me given that I'm making working knives. I've finally decided to pull the trigger after seeing photos of Daniel Fairly's stonewashed blades the other day, which look absolutely gorgeous!

I've been researching this for a while as well, and unfortunately there don't seem to be any commercially made tumblers that are really the size I'm after. The tumblers from C&M Topline seem very well made (and Dan Lord is a really nice guy!), but their largest 'doughnut' tumbler (the TLV75) is too small to fit a kitchen knife or larger fixed blade, and their next step up is positively huge, weighing in at 400lbs!

My plan is to design and build a tumbler sized in between those two, at around 1 cubic foot capacity. The design overall will mimic the 'Mr Deburr' units that C&M Topline sell:

300dbc.jpg

The tub and base will both be welded assemblies, this is a perfect project for me to learn to weld which I've been meaning to do for a while! The tub will likely be made from 16GA or 14GA cold-rolled steel sheet, with a polyurethane liner of some sort cast in place inside. The tub will be reinforced with angle steel along the edges and a plate along the bottom for mounting the oscillating mechanism.

Underneath the tub there is a pair of pillow blocks supporting a jack-shaft that holds the offset weight that provides the oscillation in the tub. The jack-shaft is connected to the motor by means of a v-belt and pulley. The motor is attached to a hinged plate and it's weight is what keep the belt tight.

The springs that isolate the tub from the base are my main question mark right now, I'm sure I can use something like die springs, but I'm not yet sure how I'll attach them to the tub and base.

The motor will be a 1725RPM 3/4HP 115V single phase TEFC motor, with a simple magnetic starter for safety.

I'll be posting a full BOM and drawings so that others can build one too if they so desire, hopefully it turns out well. I'm putting a bit of a rush on this project as I'd like to use it for my next batch of knives!

If anyone has photos of the jack-shaft assembly from a Mr Deburr unit I'd love to see them, I need some inspiration on how to make the weight assembly that attaches to the jack-shaft!

-Aaron
 
Last edited:
...reserved for useful future input...
 
Reserved for future comment.

Man, just build big Ball Mill, and use this as thumbler >.>
 
Kosa_PL said:
Reserved for future comment.

Man, just build big Ball Mill, and use this as thumbler >.>
Click to expand...

I have considered making a rotary tumbler, seems like it would actually be more expensive though because in order to get the slow rotations you need (~36RPM) you really need either a speed control for the motor, or a gearmotor. The vibratory tumblers are a proven design so I'm going to try that instead. I'm pretty sure that either way would work just fine.
 
Nathan the Machinist said:
...reserved for useful future input...
Click to expand...

Haha, I was asking for that one!

Nathan, if I remember right I believe you have one of the Mr Deburr units? Any chance you could snap a photo of the jack-shaft assembly for me? A focus on the weight assembly would be ideal!
 
I've been pondering this issue for some time, too. Decent vibratory tumblers are kind of pricy, and let's be honest, I'm cheap.

aarongough said:
I have considered making a rotary tumbler, seems like it would actually be more expensive though because in order to get the slow rotations you need (~36RPM) you really need either a speed control for the motor, or a gearmotor.
Click to expand...

I'm not so sure about that...

[video=youtube;oh2kdAhk60I]https://www.youtube.com/watch?feature=player_embedded&v=oh2kdAhk60I[/video]

This one's pretty dang fast, but even simpler/cheaper to build, depending on what you can scrounge up for a motor/drive sprockets etc...

[video=youtube;opXT3CUaox4]https://www.youtube.com/watch?feature=player_embedded&v=opXT3CUaox4[/video]

Either one's got to be better than a tube full of media in the clothes dryer; which actually works very well but it's not good for the dryer.

How fast is too fast?
 
Hey James!
In the first video I count 3 revolutions in 9 seconds, which puts it right around 20RPM. The second one is doing around 1 revolution per second, so around 60RPM.

I have a gear-motor that I scrounged that does 360RPM, so gearing that down is a possibility, I believe it's a fan duty motor though (shaded pole design) so I'm not sure how it would hold up in this application. 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...

The second design uses rollers under the barrel. I have done this in the past and I found that once you loaded a certain amount of media in the barrel the whole thing would start to slip on the rollers. I might have just gotten unlucky though, perhaps a better design would work more reliably.

It's definitely worth thought for sure. I know that vibratory machines are meant to be much faster, but they're also way louder than a wet rotary tumbler.
 
One additional point to consider is that the two types of machines create noticeably different finishes, the rotary tumbler creates long tool marks, whereas the vibratory machine creates lots of small dot marks...

Haven't seen too many examples of the rotary finish, so I can't say definitively which finish I like better. I think the vibratory finish probably looks a bit more intentional.
 
I'm really interested in this one too.


I was wondering if the weighted shaft if horizontal or vertical


Also, the size of the weight and it's rough dimensions / how off center it is.

I think that boxhas a U shaped bottom.

I was thinking if you started buying one of their commercially made liners, you would have box dimensions and a simple supply of liners.
 
A while back I snagged two 3/4HP vibrator motors. They are 3Ph, so I can vary the vibration rate. My plans are to di the same project you are starting.

What I have surmised so far is that the tank shape is very important.
 
Looking forward to see how this shapes up also!

I recently built myself a rotary tumbler

c6jyCsP.jpg


I had tried to do a smaller vibratory tumbler in the past but found the mounting of the springs and manufacture of the tank to be particularly perplexing.
Cost wise I dont think it was too bad at all.
the worst parts being the motor and gearbox, i think they were around $120 and $150 respectively.

Figured you couldnt do speed control with a VFD because I wouldnt want to run a motor for that long at low RPM without auxiliary cooling.

My surface grinder has a 18" chuck and my oven is the same depth, so I built the tank to be able to fit 18" blades.
Not gonna build a bowl that size! Mr deburr type tank of that size seems doable though
 
One thing to consider is that rotary tumblers work much faster than vibratory but vibrator gives a more polished finish.
 
Bill Burke said:
One thing to consider is that rotary tumblers work much faster than vibratory but vibrator gives a more polished finish.
Click to expand...

That's good to know. As it happens, I don't want a polished finished when I consider tumbling... in fact just the opposite - to produce a low-maintenance, lower-glare finish.
 
You must log in or register to reply here.
Back
Top