Mike Sosna's 1.8X Gingery Mill
My friend Mike Sosna from Stoughton, Saskatchewan in Canada, displayed this Gingery milling machine at the Estevan Model Engineering Show in October 1999. Here are some photos and notes he sent to me recently. Mike is not on the internet.
Here I am boring a large faceplate 15.75" in diameter. It has 8 slots 3/8" wide. The compound feed from my lathe is on a riser box to reach the center. I have a couple of sizes of riser blocks. When I cut the band saw bearing hole on the bottom wheel, I had the head set to maximum height and two riser boxes under the compound rest. It just fit.
The small faceplate is 8.75" in diameter. It has no slots, but I drill and sometimes tap holes in it.
I have a 3/8" wide cutter here. It's on a #3 Morse taper arbor I made. Also shown is my vise. It opens to 5", is 4" wide, and swivels 360ƒ. It's made in the same manner as the mill, 1/4" plate by 3". I'm squaring out the slots on a table that tilts for Dave's (Gingery) dividing head to cut bevel gears. I also built a vertical vise that swivels 360ƒ. It's built like the horizontal vise. I have a set of Morse taper collets for the mill, but I bought them.
Take a look at those hold downs at work. They're a lot faster setting up with than using scraps of metal. A bearing shell cutter is mounted in the head. It's pressed on an arbor, and cuts faster than a fly cutter. I made the cutter by random cutting slots and part of the relief in the bearing with the big grinder, and finish off and sharpen with a Dremel.
Dave's (Gingery) dividing head. I made the tail stock a little different. It works OK. Here I am cutting a 40 tooth 16 DP gear. I made the cutter. It works real good on white metal but gets dull on steel after cutting one gear.
It took a while, but this is what I came up with for the feed transmission. How do you connect the head, something that goes up and down, to the gear box that doesn't move? The red handle by the belt is on an eccentric. Move forwards and the gear train is engaged. I have to figure out a better way to lock it. It jumps out of gear sometimes.
The gear box is a copy of my lathe but the opposite way round. I mostly use the low end for feeds on the cross slide. Six inches can take half an hour. Thank God for automatic feeds. I don't use the faster feeds. It takes too much power (the belt slips.) I haven't figured out anything to use threading for on the mill. I do that in the lathe.
The forward and reverse is the same as the lathe. The feed rod to the back is engaged. The forward one is not. Can you figure out how they work? The red washers are spring loaded and have pins welded on them. The gears spin freely.
Between the head and the tail stand there is 16" of cutter space. I'm flycutting the base for the tilt table. There's a 5" radius on it. I rarely use this feature, but it's nice to have.
Here is the belt drive. Four steps on the step pulley, and two steps on the motor. I didn't like the look of Dave's (Gingery) angle iron system, so I came up with this. It's all on ball bearings.
This view under the bed shows how I formed it. The bed is the only piece I didn't machine. The local machine shop machined the top and the pads on the bottom ends. They said it just made it on their mill. I believe one could scrape it.
Here's a look at it mounted on its stand. On the left, the small drawers contain shims, bits, cutters, and collets. The center drawers are for vises, face plates, and the tail stand. The right hand drawers contain tools, the dividing head and some spare room. The white strips on the bed and the head are pieces of measuring tape for reference. On all the feed rods I used 20 tpi threaded rod. It takes a little time to move from A to B but you have good control when cutting. The dials are easy to read. If the gibs are loose, the table walks a little, but if you make your last cuts in one direction, you're good to a thousandth. The only bad part of the mill is the square ways. All the ways are 5/16" X 5-3/8". Overall, I'm surprised at how well the mill performs. It's a little slow, but once again, thank God for automatic feed.
All the castings are less than 100 cubic inches. (A 4" pipe about 9" long.)
Inside #3 Morse Taper
Outside 1.85" x 8tpi
Nose 1º" X 1º"
Head center above table
Head Center above Feed Rods
Back and Forth 21"
Between Head & Tail Stand 16"
Low (on motor belt) 48, 69, 122, 187 rpm
High (on motor belt) 95, 139, 244, 375 rpm
Low (on head belt) 92, 134, 236, 363 rpm
High (on head belt) 184, 268, 473, 726 rpm
Table Size 18" X 5"
# of T-Slots & Size of Slot 3 (3/8")
Feed Dial Graduations 0.001"
Face Plate, Size & Slots
Small 8æ", custom
Large 15æ", 8 x 3/8"
Vises, Horizontal and Vertical
Jaw Opening 5"
Jaw Width 4"
Mill Dimensions 36" L X 40" W X 36" H
With Stand 36" L X 42" W X 63" H
Table to Floor Height 39"
Head Bearings Timken LM 67000LA
Cone FAG KLM67010
Email: Robert Grauman
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