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.
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.