Early Greenie Question - Gilmer Drives
Posted: Sat Feb 22, 2020 1:06 pm
Trying to historically discover the point in production of the early Greenies when MAGNA added the clutch to the Gilmer Drive System.
First machines with A series headstock were sand cast. Beginning with B series headstock they were injections into steel molds and had the narrow casting sprue line across the top and edges.
The original drive was solid shaft. When seizures of quill would occur, the gilmer solid drive would keep cranking away and bend parts.
They added the drive clutch to slip and prevent that damage if a saize occurred.
Later they moved away from the gilmer toothed belt to a Poly-V similar to an automotive serpentine belt which was much better. It’s what they’ve used from the 1960’s coming forward.
I have had discussions with Russ Chapman who has been a great resource for me in obtaining and identifying the early Mark 5 manuals.
Early versions of those had integrated parts manuals and latter versions split them into separate manuals as various design changes occurred that did not require changes in the operation side of the manual.
For those of you who have A series headstocks knowledge I would greatly appreciate any information regarding when the clutch was added and try to pin down the serial number where it changed. I have yet to find a copy of an early manual or parts list to restore that reflects the change.
Even my late friend Bill Mayo didn’t know when it occurred just that clutches were present in A series headstocks he had seen.
Whether they were made that way OEM or retrofitted by an upgrade made available to users i don’t know yet.
We discover new things all the time due to the diligence of the members who help me preserve and restore manuals and documents.
I have hopes that someone out there in our family may have a bulletin or announcement they can share.
It such a significant change it would have been announced to the dealer network.
Of the two dealer manuals I have received copies of, nothing was mentioned.
Your help in answering and documenting this question would be helpful.
Kindest Regards,
Everett L. Davis
aka Shopsmith Historian
First machines with A series headstock were sand cast. Beginning with B series headstock they were injections into steel molds and had the narrow casting sprue line across the top and edges.
The original drive was solid shaft. When seizures of quill would occur, the gilmer solid drive would keep cranking away and bend parts.
They added the drive clutch to slip and prevent that damage if a saize occurred.
Later they moved away from the gilmer toothed belt to a Poly-V similar to an automotive serpentine belt which was much better. It’s what they’ve used from the 1960’s coming forward.
I have had discussions with Russ Chapman who has been a great resource for me in obtaining and identifying the early Mark 5 manuals.
Early versions of those had integrated parts manuals and latter versions split them into separate manuals as various design changes occurred that did not require changes in the operation side of the manual.
For those of you who have A series headstocks knowledge I would greatly appreciate any information regarding when the clutch was added and try to pin down the serial number where it changed. I have yet to find a copy of an early manual or parts list to restore that reflects the change.
Even my late friend Bill Mayo didn’t know when it occurred just that clutches were present in A series headstocks he had seen.
Whether they were made that way OEM or retrofitted by an upgrade made available to users i don’t know yet.
We discover new things all the time due to the diligence of the members who help me preserve and restore manuals and documents.
I have hopes that someone out there in our family may have a bulletin or announcement they can share.
It such a significant change it would have been announced to the dealer network.
Of the two dealer manuals I have received copies of, nothing was mentioned.
Your help in answering and documenting this question would be helpful.
Kindest Regards,
Everett L. Davis
aka Shopsmith Historian