Easy Sherline Tool Post Grinder

Discussion in 'Horological Tools' started by Joseph Bautsch, Mar 13, 2019.

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  1. Joseph Bautsch

    Joseph Bautsch Registered User

    Dec 9, 2006
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    The attached photo shows an easy to make, less than half a day, tool post grinder for the Sherline. A two and a half inch length piece of 3/8" square cold rolled steel, faced off and with a 45 degree edge is strapped to the body of an pneumatic pencil grinder. The straps are worm screw 5/16" clamps on each end of the bar. The grinder is a Astro Pneumatic Tool Co. device. It turns 58,000 rpm. Thats way more rpm than needed for any project. The max psi is 90, but runs best at 60 psi. The silver band on the back of the grinder is an off/on speed control. The grinder is for light weight grinding, shaping and polishing and takes the 1/8" diameter shaft attachments. . The grinder is set up in a Sherline adjustable tool block, for 3/8" cutting tools. With a protractor any angle can be set up on either side of the work or head on.

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  2. Uhralt

    Uhralt Registered User
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    Sep 4, 2008
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    Looks good. How do you prevent the abrasive dust from grinding damaging the lathe? I managed to kill the front ball bearing of the headstock of my Sherline. Since then I avoid grinding on the lathe.

    Uhralt
     
  3. karlmansson

    karlmansson Registered User

    Apr 20, 2013
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    Plastic bag that the work pokes through tends to do the trick. Probably easier with a collet than with a chuck though.
     
  4. Joseph Bautsch

    Joseph Bautsch Registered User

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    My understanding of the Sherline head bearings is that they are sealed. Grinding is a common work procedure in using any lathe and with sealed bearings, grinding dust should not have any affect on them. To find out Sherlines recomend procedure, the effect of grinding, I have sent a question to the engineering and technical people there for a response. I'll let you know what they say.
     
  5. MartinM

    MartinM Registered User
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    I use an thin sheet aluminum shield on my mini lathe that surrounds the chuck and keeps the abrasive elements out of the intersection of the output shaft and the machine body. It is held in place by setting it on top of the machine and using the magnetic mount for a dial indicator.
     
  6. Joseph Bautsch

    Joseph Bautsch Registered User

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    Here is the response from Sherline. Evidently there are more components of the machine that are subject to damage from fine grinding dust. Occasional grinding will have a minimal effect. But should not be an ongoing work process. Sherline also recommends using the toggle switch cover.

    "Joseph,
    Grinding dust is the absolute worst thing for any machine. We do not recommend grinding on our machines.
    The headstock bearings are lifetime sealed bearings. However, grinding dust will find its way into everything (including the speed control.
    If this is going to be something that you do once in a while, then the impact on the machine will be minimal.
    If you are turning your machine into a fulltime grinder, there will be premature wear on the bearings.
    I highly recommend buying the toggle switch dust cover p/n 3015 (https://www.sherline.com/product/3015-toggle-switch-dust-cover/ ) for the power switch on the speed control. If grinding dust gets into the switch, it will short it out."
    Have a great day,
    Karl"

    A good cleaning after each use will go a long way to extending the life of the lathe, but that is true after any use not just grinding.
     
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  7. Joseph Bautsch

    Joseph Bautsch Registered User

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    Attached is a couple of photos showing how I made Jerry Kieffer's lantern pinion knurling tool. The knurls sold by Sherline are hardened HSS tool steel for cutting. The only way to get the shape needed for the lantern pinion knurling tool is to grind the shape. There is, and rightfully so, concern for the grinding dust getting into the machine head and controller. The solution is to use an upholstery vacuum tool held next to the work being done. That will pull most all the grinding dust into the vacuum. A small green stone is used for the 45 degree inside facing and a larger green stone was used to cut down the outside diameter to the size needed. Both the lathe and the stone should be turned at a slow rate of speed, with the stone cutting on the backside of the work. Even so grinding on the Sherline lathe is not recommended on a regiular basis.
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  8. Uhralt

    Uhralt Registered User
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    Joseph, thank you for following up with Sherline! My bearing was killed after only a few minutes of grinding. Maybe the dust cover wasn't working or they may have changed it after I got my lathe. Anyway, I will remain cautious and cover what I can if I need to grind on the lathe.

    Uhralt
     

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