Continually Vexed by This Contraption

I managed to locate a suitable DC motor and controller for the vibratory deburrer, and then set about designing a proper lower ‘chassis’ for the system. I’ve been trying to make all equipment wheeled as much as possible for easy movement around the garage or basement, but I also needed leveling pads on the unit (I want it to shake and rattle, but not roll). The bottom chassis looks rather small, and I hope that it won’t have a tendency to fall over as a result.

3/4HP DC motor mounted and ready for action.

I welded pipe nipples to the chassis and stuck what I hope will be appropriately sized springs onto them.  The legs of the bucket frame now have pipe nipples and washers welded to their bottoms – they should slip into the springs from the top.  The motor location is adjustable back and forth by a little bit so that it can be aligned with the weight shaft (which will be bolted to the previous motor mounting plate on the bucket frame).  The weight shaft mounting has been a bit of an annoyance – I started with a hunk of aluminum bar stock and bored a pocket on each side to hold a 5/8″ ID bearing.  A short shaft then passes through the bearings and will have a weight plate on either end of the shaft:

Not the prettiest welding , but as long as it holds together I'll be happy.

I’ll be able to adjust the vibration amplitude by simply aligning the plates – 180 degrees apart for ‘purr like a kitten’ all the way up to 0 degrees apart for ‘funny, I don’t recall there being any fault lines around here’.

Although the bearings are 5/8″ ID, I’ve had a heck of a time trying to coax any 5/8″ rod through them.  I finally decided to see if thermal expansion could assist, so I threw the rod in the freezer and stuck the bearing bar in the oven on low.  Half an hour later, I pulled out both parts, tried to slide the rod through and…

"Oh, bother," said Pooh.

The rod managed to get perhaps 1/16″ into the bearing before thermal conductivity stepped in and ruined the fun.  It turns out that perhaps I should have been a little more careful when selecting bearings – these are +0″/-0.0003″ on the inside diameter.  Either I’ll need to find some undersized rod (generally $$$) or I’ll have to make a stab at turning down this existing rod by just a couple thou.

2 thoughts on “Continually Vexed by This Contraption”

  1. I considered application of excessive force, but I think I’d bash the bearing innards up or have the bearings pop out of the aluminum bar (it’s just green Loctite retaining compound keeping them in). We do have a nice hydraulic press at work that I’ve used for really stubborn stuff, but I found something at Menard’s that fits the bill beautifully for a shaft – stay tuned for the next exciting installment, in which I reveal further incompetence in my welding abilities.

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