General Category > Toy Makers
Gear Toy
RickKr:
Then came cutting the gear teeth. For this, I used a 1/8" wide, 14tpi blade, again in the Carter Stabilizer guide. The curves on the gears did not require use of the 1/8" blade, but making the turns inside to bottom did.
After the tooth profiles were cut, I cleaned up the gullets using the bandsaw blade. I held the tooth bottom in close to the blade and moved it laterally using the front surface of the blade sort of like extremely fine sandpaper to clean out the roughness left by the turns at the bottom. Worked surprisingly well and allowed me to get nice square corners. Before is the gullet on the left, after on the right.
Bandsaw cut gear teeth.
Rick
RickKr:
I made a jig for my 4x36" belt sander table for sanding the gear and gear bases to finish size. To minimize the amount of sanding, I did the OD sanding after cutting out the teeth. No point in sanding wood that won't remain.
The jig consisted of a base which had the key on the bottom for the table slot. This key was pivoted on the left side and slotted on the right to allow adjusting its distance from the belt, the use of which will be discussed below.
The jig had a top slider piece that had pivot holes for each size of gear and the base. It also pivoted on the left side, on the same point as the base. It had a pivoting slot on the right, but it was never locked down. This pivot allowed the slider to move inward and outward so the roughed gears could be sanded progressively smaller, with the slider pivoting in until it reached the end of the slot, which acted as a stop on the sanding action. The point of that "stop" was set by locking the base distance from the belt and remained the same for all diameters of blanks.
Pivot holes were placed such that each gear would "stop" sanding at the correct finish diameter (visible in the second photo). The gear base is 2" OD. The gears started at 3.375" OD and increased by two inches for the medium (5.375") and large (7.375") gears. This jig made for very fast and accurate sanding of the ODs.
Gear tooth profiles were sanded on a 1x30" belt sander. The smaller size sander was required due to the narrow width of the platten, for getting in there to the bottoms of the tooth side profiles. The bottoms had alread been cleaned up adequately using the bandsaw as described in an earlier post, but I did go in with sanding blades on the scroll saw to sand down the few spots missed by the bandsaw.
Rick
RickKr:
Here are the finished gear teeth cut and sanded in the blanks.
Next came drilling the holes for the cuttouts, prior to scroll sawing. I used 1/2" and 3/4" Forstner bits for the drilling, but the sanding sleeve for the 1/2" spindle sander spindle is oversized, so the smaller radiuses ended up closer to 5/8".
And the finished scroll cut and spindle sanded cutouts.
And with this, I am out of material for today. Still to come for the gears is drilling out the respective peg and center pivot holes, but that may have to wait a bit. Granddaughter arrives tomorrow morning.
Rick
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