Why did I make this?

GB SISSON

Well-known member
I cobbled this together after work. I have made a few of them in the past and they work well.
 

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I think it's called a gizmachi.

That's the Italian name for this device. ;) It is based on something called a 'blind trunnel', and I'm not making this up. I use it for a certain function on our engines. The used-up cup brush is just a spacer.
 
Don't know what it's used for but by driving the bolt head with wedge into a blind hole will expand it and allow some grip in order to lift/pull whatever from where it's at. Or provide a threaded stud where there ain't none.:confused:
 
In the summer of '71 I helped a man plank a 52' wooden schooner he built in his backyard. The planking was fastened with 'trunnels', this word being derived from tree-nail. This was traditional for fishing schooners as the cod was filleted and pack in rock salt in the hold and this was not a good environment for metal. The 1" locust trunnel was driven into a hole through the planking and clear through the frame behind it. Then the trunnel was sawn short at each end and split with a chisel. The split was vertical on the outside of the hull and horizontal inside at the frame, thus not splitting the plank. If there was something in the way inside the hull such as a bulkhead and there was no access to split and wedge the trunnel, a blind trunnel was used. The hole went only partially into the frame, say 3/4 of the way. A saw kerf was cut into the leading end of the trunnel and a wedge was started into the kerf. As 51 merc stated, the wedge would bottom out on the blind hole and expand. The outer process at the plank side would remain the same. My pilot bearing/bushing puller works on the same principal as the wedge bottoms out on the blind hole in the crank. A lot less messy than grease, although I think that hydraulic method is clever.
 
Hey thanks for sharing! I've never used this technique before - but it will stick in my brain and I'm sure I'll use it sometime in the future. In a way, it is sort of like the concrete anchor bolts that I use at times - an 'expansion' joint at the end of them is what holds them in place.

Have a great day!
B&S
 
This thing took all of 5 minutes to make and I just removed my pilot bushing in less than 30 seconds. I tested my old transmission input shaft in 8 flywheels and found one with a bushing that felt brand new. Most of then allowed about 1/8"- 1/4" up and down movement. I'll pull that one and use it. Call me cheap, I'm used to it!
 

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The KRW pilot puller I use has a bit of trunnel in its ancestry...
It has a cup identical in function to yours and a hollow center pulleroutener that is the diameter of the hole through the pilot except at its end, where it has a ridge to catch on the outside of the hole in the bearing. That end is split and the sides collapsed into the split enough to allow the ridge to pass through the hole.
Once the puller has been inserted into the bearing, a steel rod is inserted though the hollow ram to expand the tip and allow it to hook on. A simple nut on the outside of the ram then smoothly yanks out the bearing.
 
No! that's only half of the coverage of Gizmatchi, the tools that take things OUT. Gizmatchi that put things IN are classified under "Bangers and Mash."
 
GB, where did you get the word Gizmatch? My dad used to use it but he's old enough he doesn't really recall. I askedd a few Italian friends and no-one knows it. Is it slang for "thingamajig" or gizmo?
 
I got it from a guy named Bolts who lives in Prescott AZ. And actually, gizmachi is Italian for thingamajig.
 
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