Jacobs gear hobber
![Bomber girl crush zipper](https://kumkoniak.com/54.jpg)
During construction Tom, Gary, another friend and myself agreed to some changes. My role in the project was to build the first article off production castings and make the drawings. It is not a Jacobs hobber it is a Hammond hobber -))
![jacobs gear hobber jacobs gear hobber](https://metal.duncanamps.com/images/hobber/hobber204_slide.jpg)
![jacobs gear hobber jacobs gear hobber](http://metal.duncanamps.com/images/hobber/hobberb.gif)
The picture you show is the prototype machine. (Gary Martin produces and sells the castings) Tom Hammond re-designed the Jacobs machine and made it a bit smaller, but also improved the rigidity. There was a recent article in MEW by Chris Robinson explaining this very well.Īs was stated earlier the castings and drawings are available from Gary Martin of Martin Model and Pattern in Portland Oregon (Gary is a HSM advertiser) Most taps only have relief on the first few threads, so that when using them as a hob you should cut from the end rather than cut across. The other issue is the way cutting edge relief is ground on a tap. The one I recieved was very nice quality and the service was exceptionally good.Ĭamdigger- As John Stevenson says, acme taps can be used, but you end up with odd gear pitches. i didn't want to blow the budget on one from Ashe Gear for trial. Jtiers- The hob I am using is from an ebay seller located in Hong Kong.
![jacobs gear hobber jacobs gear hobber](https://i.pinimg.com/474x/ce/27/2e/ce272e7ab2ad131eccfc145e273c96e5--gears.jpg)
If someone was cutting a helical gear they would have to add the helix angle to the angle of the gear cut.ġ200RPM- Gary does ship the kit in USPS flatrate boxes. Uncle Pete- There is a complete set of drawings that I think are pretty good ( I did them -)) They could be fixed up a bit by a real cad guy, but that's beyond my current ability.įorrest- The helix angle for the hob is adjusted by angling the work head.
![Bomber girl crush zipper](https://kumkoniak.com/54.jpg)