Tag Archives: sink grinder

Sink grinder lives!

Still lots to improve here (like a splash guard and paint job) but the concept works. I love it when a plan comes together.

Each journey begins with a single step (pulley)

The old pulley would NOT come off the motor and yet another tool I lack is a gear puller. Note: despite its name a hack saw can actually be used for very fine work. This is not one of those times.

Alas, the shaft on the motor is too short for the supplied set screw to bite. So here’s the set up to drill a new hole to tap. I was very pleased to discover that I not only possessed the right tap, I also had the right drill. How odd.

It has taken me long enough but I’m in a time in my life where I consistently remember to keep the part clamped after drilling so that I can use the chuck to get the tap started straight. Small victories.

I normally work so small I was reminded this morning that I never got around to procuring a larger tap wrench. Oh, well this worked just as well.

Well that’s done at least.

Inside a Leland Faraday motor

To prevent any future fireworks I replaced the power cord on this old motor.

Whitney’s Slab Saw

Some years ago, I ended up in possession of my wife’s grandfather’s lapidary equipment. He died nearly four decades ago and I doubt these tools have been used since. In need of a motor for the Sink Grinder, I took a look at the Rock’s Slab-Trim saw. The motor seems to work just fine and I like the idea of putting old tools to work again.

Whitney Girouard’s slab saw and a bolo tie that he made.

Sink grinder

The “Sink Grinder” shown bolted to the wall above the sink. Rendered with Autodesk Inventor

Last December I realized that I need to up my game.

I have always been unsatisfied with the final finish of the etching process I use. I’ve spent hours and hours at the sink with various wet abrasives and despite how long I scrubbed I was never quite satisfied with the results. Furthermore, I have a long term goal to incorporate more champlev√© into my work. I’ve ground enough glass (very little) to know that power assist for that task would be the bees knees.

So I stared looking around for a powered grinder of some sort that was versatile and large enough for me needs and finally happened upon the Single Arbor Grinder (SAG-1) made by Denver Glass Machinery pictured below. It would be the perfect solution if I had a much larger workspace and a few grand of extra dollars.

The Single Arbor Grinder made by Denver Glass Machinery sells for $2300.

Then, I found this image showing the guts of the SAG-1 at the WarmGlass.com forum. A motor, two pillow blocks and a shaft? Is that all? I can build that.

I’m calling my design a Sink Grinder because there is where it will reside. The frame and motor will both be attached to the wall and easily removable. I’ve drawn three versions of this machine in Inventor so I think I’m ready to build the first prototype. Hopefully this one works so well that I don’t need to build a second.

Th last of the parts are on order, the shaft has been machined, and the frame is fabricated. All that’s left is assembly, and paint. Then the grinding can begin.

My experience with Austin Macfab

All’s well that ends well.

Austin Macfab, on Airport Boulevard in Austin, Texas is a family owned business and exactly the sort of place I was looking for to machine the arbor for my wet grinder. Kham Bourommavong, has worked at Austin Macfab for over 20 years and despite his admonition that he “doesn’t know business,” by all appearances his shop seems to be humming along. No doubt this is due in large part due to the efforts of his daughter with a business degree and a wife with years of experience in another private sector job both of whom he drafted when he purchased the business recently.

I have never jobbed out at part so was especially concerned with presenting a drawing that was very clear and used all the proper standards and nomenclature. This proved to be quite helpful to me, for when I picked up the part earlier this week I discovered that one critical dimension had been missed. After a short discussion and a review of the drawing Kham realized it was his oversight and though this meant that he had underbid the job the fix was easy enough and he had it finished in less than two hours. Despite this little hiccup, I would certainly recommend Austin Macfab for jobs like this to anyone.

It’s nice to know that some things can still be done by hand (granted, on a huge precision machine) instead of by CNC. I do a lot of CNC at my job at UT but high tech is not the best solution for everything. I got bids back from other machine shops in town who planned to CNC this part and they were well over $600. This is probably a perfectly reasonable price for all the various setups and programming required. But on Austin’s East side there are still plenty of places where guys go into work everyday, get dirty, and make stuff, and when you have decades of experience, you don’t always need a computer.

My experience with eMachineShop.com

In the last week I’ve been requesting quotes from local machine shops to manufacture the arbor for a wet grinder I’m constructing. I have been quite astonished by the variation in estimates. Then I remembered that a website called eMachineShop.com was featured in Wired Magazine some years ago and now seemed like the perfect time to give them a try.

The software download setup was free, super fast and I was hoping that I could import an .iges or .step file from Inventor but this feature seems to be still in beta and all I got was a handfull of error messages even though the part is relatively simple.

Fortunately the learning curve is virtually non-existent for a longtime user of VectorWorks, Adobe Illustrator, and Autodesk Inventor so after I skimmed one tutorial and I had gleaned enough to replicate my original part in about 20 minutes. In another 10 minutes I had a of list quote options to choose from. Sadly, for this “one-off” part the lowest quote was outrageously high compared to some I’ve gotten locally and worst of all, the lead time was listed at nearly two months!

Suffice to say, eMachineShop will not get my business this time but I think I’ll be going back to their software. I feel like I can learn a lot about manufacturing nomenclature and common practice by putting together a few more hypothetical estimates. Also, they offer many other processes besides traditional machining and I’ll surely give them a try in the future when I have need of something I can’t figure out how to make myself. But that seems to happen less and less frequently these days.