Hollowing Rig - Initial assembly

[Dan Mosley]

Today was day 2 of getting to play around with making a hollowing rig. The first day was nothing to talk about because all I did was go buy some steel for the project ($65-$75.00). But not all of it was meant for the hollowing rig. I made a 1" tool rest and fixed a broken welding cart with a couple small pc's and replaced the 5/8" axle (Pictures below). I picked up the welding cart and tanks for $50 (garage sale). Ok, so I started by laying out how I was going to make it on paper (using some of Stuart's pictures for reference) with measurements and cut up alot of the steel with my chop saw.

Today - Day 2 - I used a 110v, flux cored mig welder to tack the pc's in place so I could assemble most of it. The welder is weak honestly but it worked for now to tack it up - later when i get a torch set ill finish up the welding in a better way. The frame is 1 1/4 tube steel and I made a coupler out of 1" solid core that has a 3/4" hole drilled in it that I can slip in and out of the 1 1/4 tube steel - other end will hold a 3/4 solid goose neck tool.
I had a friend at a shop put a couple nuts on it and tap it and figure out how I want to do the tip for cutters.

Everything else i drilled and tapped myself. I used 1/4" small bolts for the holds and ground flat areas on the rounds to help keep it from slipping. Later ill add 1/4 nuts tack welded in place and drilled and tapped.

The goose neck is 3/4" solid cold rolled also and was heated and bent into the same configuration as the one I bought from Monster Tools. A flat area ground for the tip "almost" to the half way of the bar. I still need to drill and tap it. I still have more work to do on the laser and other parts so ill post more as i complete it.

Picture 1 - Rest 1" solid round
Picture 2-4 - Beginning of the hollowing rig assembly
Picture 5 - old and new welding cart with new axle and wheels from Harbor Freight

Is it a fun project ? Yep, but I have had alot of small headaches along the way and trips to the hardware store etc....
Will it work well ? Stay tuned....................LOL

Comments or suggestions ?

Thanks Dan

 

[Matt Hutchinson]

I am very new to turning hollow forms, but what I have noticed so far is that you can never have too many hollowing bars. What I mean by that is make sure you also make a hollowing bar out of 1" stock if possible.

You might be wondering why the heck you would need that, but I have been playing around with some cherry that has knots and crotch grain in it. The 3/4" bar in my D-handle was getting bounced all over the place. I moved up to the next size, 1.25" stock with no D-handle, and I could hog down to the bottom of the 12" tall form with no issues. Obviously if the form has a small mouth you would have to just stick it out with a smaller bar, but for more open mouthed forms heavy is great!

That said, your setup looks good! I think you'll be making vases in no time!

Hutch

 

[Fred Wissen]

Nice setup! I have been looking to make one of these for some time now. You might have just motivated me enough to do it.

Thanks!

 

[john lucas]

I highly recommend it. For those who think you have to have a welder and lots of fancy metal working gear, NOT. I made my first one from 3/4" steel bar, some square tubing, some Allthread rod, and a 3/4" sleeve. I wish I had a photo of it.
You will need a hacksaw,file, drill bits, and a 1/4" tap and handle but that's it.

I cut the 3/4" bar to length. ONe of them longer than the other. I attached these together with short lengths of square tubing. Since I didn't have a welder at the time I simply drilled the 3/4" bar and bolted it together with All-thread rod and nuts. I suppose you could leave out the square tubing and just use nuts on both sides of the 3/4" bar but the square tubing did make it look a lot better and I think it was more rigid. I did file the square tubing to fit the 3/4" round bar.
Then buy a 3/4" sleeve from Lowes. These are about 2" in length. I slid about 3/4" over the 3/4" bar and then drilled 2 holes 1/8" in diameter all the way through. I used 1/8" spring roll pins that you can get at the hardware. Drive these through the holes. That holds the sleeve in place.
Now drill and tap 2 more holes in the sleeve for the set screws. These will hold your tools.
You can drill the end of a 3/4" bar with a 1/4" hole. Then you can glue in short pieces of 3/16 HSS metal cutting bits. I just use medium CA glue. You can drill the holes at an angle if you want a cutter that cuts more on the side or you can leave it straight out the end for initial hollowing and cleaning up the bottom.
I made the secondary tool rest out of wood. My first one was for a mini lathe so I made the secondary tool rest so it would sit on the floor. At first I clamped it to the bed but later on I decided this wasn't necessary. Just some weights on the bottom to keep it steady. I still use this same rest but it's cut down and clamps to the bed of my powermatic.

 

[john lucas]

Photos of home built hollowing rig

I forgot that the hollowing rig I am using is simply the old screwed together one that has been welded. The screwed together rig worked fine but when I finally got my welder I had to weld everything in the shop that I thought might benefit from it.
You can see the wooden secondary rest. The close up shows the 3/4" sleeve with the roll pins and set screws. You can see the holes in the 3/4" bar where the bolts used to go through. The vertical post is for my laser.
The cutter is something new that I'm experimenting with. It is a metal cutting parting tool that I've mounted in a a custom bar. One end was turned down so it will fit the captured bar or any of my handles that accept 3/4" tools. I'm going to try to use it to cut the bowl from board.

 

[Harry Robinette]

hollowing rig slicer

hey Guys
When you make your d-handle tool rest put UHMW 😕 (I think that's the initials)inside the slot top and bottom it makes a huge differents. We made these about 7years ago,the super slip really helps your control going to 1/8" thickness on the vase walls.
Hope this helps.

 

[Dan Mosley]

Harry............sorry but im not following what your suggesting......can you explain

 

[Harry Robinette]

hollowing rig slip

Don
If you put uhmw plastic on the top and bottom of the capture portion of the
back tool holder it lets you slide the D handle very easy.This let's you get a very fine and smooth movement of the cutter.
The steel to steel gets grabby and sticky after you've been using the tool awhile.We put 1/4"uhmw that was cut to fit and then sanded off any little
ragginess from the cutting.Just screw it on and counter sink your screws.
Hope this helps.

 

[Joe Greiner]

UHMW and HDPE

UHMW (Full name Ultra-High Molecular Weight polyethylene) is the poor man's Teflon. Both hard to find in retail quantities. And HDPE (High Density PolyEthylene) is the poor man's UHMW. It's slippery too.

If thick HDPE sheets are hard to find, make your own from the flat sides of milk and juice bottles. Laminate in the oven when SWMBO is away from home. Allow about 10% extra stack thickness for cooling shrinkage. I use two 1/4" sheets of aluminum above and below, with a stack of washers or coins in the corners for thickness control; add about 20 lbs of lead for compression; heat to ~350 F, and let cool overnight. YMMV.

 

[ray hampton]

Joe, in your post you said to set the stove at 350 degree ,do you know the temperature that this plastic melts at ? I like your idea

 

[Harry Robinette]

Uhmw

Dan
You can buy UHMW from Woodcraft they have it in blocks and 3"x36" sheets
1/8,1/4 ,3/8,1/2, and 3/4 and not very expensive.

 

[Joe Greiner]

Joe, in your post you said to set the stove at 350 degree ,do you know the temperature that this plastic melts at ? I like your idea

Found by experimentation (aka brute force and ignorance), when a sheet of 1/8" x 4' x 8' HDPE, if available, cost about $100. Also, oven thermostats seem to be "calibrated" with a yardstick and a piece of chalk. In any event, making my own is still faster than mail or internet order.

Another source of slippery sheet goods is food cutting boards from garage sales. Really inexpensive, and uniform thickness. For purists, buy new in the housewares section of department stores.

IMHO, UHMW is more appropriate for high-speed applications, e.g. wheel bushings.