8" lap on grs powerhone?

Chujybear

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Hi.
I have the power hone for sharpening my tools.
My collection of Laps is a mush mash from over the years.
Among my laps I have a few eight inch laps.
I'm going to by some backing plates (resin, I believe) for my laps.
My question is- is there any reason not to use the eight inch laps on my powerhone?
Thank you.
 

Chujybear

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Hello Brian.
There is room for the fixture.
Only thing I could see Bering an issue, is some kind of torque on the driving shaft when the tool is out towards the edges of the lap...
It'll also be faster, but I don't see that as a bad thing either.
 

Ron Spokovich

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There may be a couple of things to consider, assuming you have enough working to maneuver a fixture to sharpen your tools. First, is weight of the entire disk. You'd want to keep the weight the same as a 5" disk. Second, do not bear down hard on the periphery of the disk when sharpening, as the load on the bearing will be multiplied and too much will promote wear. Let the abrasive to the work. You may need to drill small holes underneath disk assemblies to lighten them. Sounds like this may be something insignificant, but it isn't. Manufacturers, like Mercedes, warn against installing too big of a wheel on their vehicles, for this reason. If you have enough room and disks, this sounds like a good idea. . .make use of what you have.
 

Brian Marshall

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Power hones are generally not as precision a machine as a lapidary unit - so any out of round, wobble or up and down movement on an 8" lap may be magnified a bit.

If you have a lathe or a friend with a lathe you can make the lap any diameter you want...


Brian
 

Chujybear

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Yes Ron,
Can attest to that by the number of times we twisted the drive shaft off my friends Subaru outback monster truck.


Thanks Brian.
It's a bit of a wobble I was hoping the plates would alieviate.
 

rod

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Like Layne says,

I have been using 5, 6, 8 inch dia laps, no problem, some have backing plates, others don't, no problem with my GRS power hone, and always had plenty of room for my tool holder.

Rod
 

LVVP

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I have been using 6, 8 inch dia laps,too no problem. Works great.
 

Brian Marshall

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The other consideration with using 8" laps...

The various fixtures were not designed to use a surface that large.

Not enough "reach". Much goes to waste.


Unless, of course - you are able to wear out the "rim" - and then chuck it up in lathe and trim off the worn section?

I can do that, but I'm normally much too lazy.

I simply buy the 6"s and once a year I may have enough energy to trim a few of them - if there's enough unused diamond left toward the center to warrant that...


They are cheap enough nowadays that I can throw them away or give them to students to work at extracting the last little bit of use left out of 'em.


Brian


Oh yeah, I do prefer the SOLID machined aluminum master laps. Not the cast & machined, hollow backed things the suppliers are flogging now.
 
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rod

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A further thought ... diamond lap disks are so inexpensive today, in comparison with a short time ago, between $9 to $11 on ebay and Amazon now, as compared with over $100 back a few years, so not a big outlay if you do decide to go smaller. By the way, having laps both and without backing plates, I would no longer spend money on backing plates, the 1/16 inch thick laps work well as is.

Rod
 
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