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Ted Reischl
03-29-2018, 4:36 PM
I do not do a lot of deeper hollowing, but every now and then. . . Always wanted one, but my usage is so low it does not justify the cost. I think they are priced fairly after building this one, took me about 8 hours total. But! The price of materials was really low. All told, I have $30 in this thing. We have a great scrap yard here. All sorts of bits, chunks, cutoffs that they let you sort thru and then they charge by the pound. In my case, all the material was $13. The hardware was more expensive, $17. But that was because I purchased at Fastenal which is also close by. Some items have minimum quantities so I have a few extra nuts, bolts, etc. Anyhow, here it is:

382630

382631

382632


There was nothing tricky about building this thing. If anyone wants to build one I would make a few recommendations. First, the parallel links are best drilled taped together. That way the holes are aligned. Make sure your drill press is tuned up for a perpendicular cut. On this one I used aluminum tubing for the base post and the "upper arm" (that is the first arm connected to the base post) Both of them are infilled with hard maple with a very tight press fit. The base plate is 1/2 aluminum. The "secret" to making one of these are shoulder screws (bolts). On this one, they are .5 diameter X 2.5 long. Then I used a lock nut on the 3/8-16 threads so I could adjust the amount of movement.

Now, the good part! It works and it works really, really well. I use a Sorby Sovereign tool bar with interchangeable heads. I purposely caused a catch by really putting the pressure on. It moved the part a bit in the chuck but that was it, no flying tool handle, no big deal. What a person needs to understand about these things is that they have maybe two purposes. Absorb the shock of a catch and keep the tool horizontal. That is it. For a low use one like this there is no need for bearings or precision machining.

JohnC Lucas
03-29-2018, 6:47 PM
Very nice. I wish out metal yards would do that. You used to be able to go in and get what you wanted by the pound but now they won't even let you in the gate. Insurance they claim.

Ted Reischl
03-29-2018, 7:27 PM
I hear ya. Oh, btw, in case anyone is interested, the materials would cost about $55 from an online source, cut to size and delivered. Would definitely speed up the build process. I spent a good part of my time prepping material to the right size. But hey, a bargain is a BARGAIN! LOL.

daryl moses
03-29-2018, 7:42 PM
Ted, I think it looks great!! And evidently it works so that's a good thing.
I'm a do it yourselfer as well and love making "stuff".

Tony Pisano
03-29-2018, 8:49 PM
Very nice. Our scrap yard is the same. After practically begging if we could poke around, the guy behind the desk said " You know what my boss said would happen if I let one effin piece of metal leave this yard" we finally got the point.

Mark Greenbaum
03-30-2018, 8:53 AM
That looks pretty nice, solid, and robust. I made a system from stuff being scrapped at work, and I have about $70 in shoulder bolts, and bronze bearings. The end effectors (i.e., cutting tools) came to a bit more ($150 for Sorby straight and swan necks - used) but I am almost complete. I still want to get a Hunter carbide cutter for the insides of deep hollow forms.