# Looking for input on how to construct a tool post grinder.



## dbq49 (Jun 10, 2014)

I have looked on utube but find it lacking on how to construct a tool post grinder.  I don't think I want to strap a die grinder in a wooden block to get the job done.  Looking for the right sized motor and set up for maybe a pillow block and shaft.  Any and all input for ideas would be great.  I know that we all don't go out and plunk down up to 2k for a grinder. Thanks dbq49er.


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## kd4gij (Jun 10, 2014)

What are you looking to do with it? Are you looking to grind your chuck jaws. or todood grinding? Pillow blocks arn't realy a good choice for a TP grinder, thay arn't made for the speed required to get a good finish. What size lathe do you have.


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## dbq49 (Jun 10, 2014)

I was going to start with dead centers.  The ones that came with the lathe are worn badly.  My lathe is an Atlas 10X48.:thinking:


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## Andre (Jun 10, 2014)

If your looking to turn hardened carbon steel dead centers, some carbide insert tools will do the job.


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## kd4gij (Jun 10, 2014)

You would need a good tight spindle to get a good finish. Do you have a QCTP on your lathe. I have used a fordom style flex shaft tool in a 1" boring bar holder with good results. I have seen where people have used this for a TP grinder http://www.harborfreight.com/120-volt-circular-saw-blade-sharpener-96687.html If you look at the way it mounts it would be easy to adapt . I plan on getting one for that purpus soon.


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## David Kirtley (Jun 10, 2014)

I use my Proxxon rotary tool.  A little pricey but a whole different league than the Dremel. 
http://littlemachineshop.com/products/product_view.php?ProductID=2891&category=





I have two holders, one that fits on the compound:



http://littlemachineshop.com/products/product_view.php?ProductID=2935&category=

and one that fits in a tool holder:



It makes a pretty light weight tool post grinder but it also is good for slitting with the dremel cutoff discs.


A little cheaper would be the one that they make for the little SEIG lathes:
http://littlemachineshop.com/products/product_view.php?ProductID=4671&category=1




A little small but could easily be adapted to another lathe. And it is only $160


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## ddmunroe (Jun 11, 2014)

David Kirtley said:


> I use my Proxxon rotary tool.  A little pricey but a whole different league than the Dremel.
> http://littlemachineshop.com/products/product_view.php?ProductID=2891&category=
> 
> A little cheaper would be the one that they make for the little SEIG lathes:
> ...


_"What type of bearing do you guys think this grinder will have " Roller, needle, tapered roller" ?
Could you use bronze bushings made on a lathe with oil drip feed or oilite bronze ?
Cheers
dd_


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## xalky (Jun 11, 2014)

Tapered roller bearings are the way to go. I began planning work on a TPG a while back, but its on the back burner right now. Ray C on this forum made one about a year ago with an excellent write up. Do a search. It might be in the members projects section.

Sent from my SPH-L710 using Tapatalk


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## dbq49 (Jun 11, 2014)

kd4gij:  I do not have qctp.  ddmunroe:  Your question is inline with my thinking, has anyone used one of these?  What kind of quality is in this tpg.  It does not mention speed of the tpg or the hp of the motor.  As I understand light cuts are the norm and I have seen were some posts across the web have talked about 1/2hp motors.  Seems over kill to me.  Are the grinder wheels priority to this machine??  On other posts I see 60 and 80 grits being used.  What sized arbors are used?    I have a long shaft HF die grinder but size limits of stones and vibrations are still a concern of mine.  But keep bringing up ideas.  On MyMachineShop.net  has a simular unit for $300.  It looks like the switch is mounted on the top not the side but looks the same after that.  I love getting all the info and help.  Thanks!!!)


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## kd4gij (Jun 11, 2014)

dbq49 said:


> kd4gij:  I do not have qctp.  ddmunroe:  Your question is inline with my thinking, has anyone used one of these?  What kind of quality is in this tpg.  It does not mention speed of the tpg or the hp of the motor.  As I understand light cuts are the norm and I have seen were some posts across the web have talked about 1/2hp motors.  Seems over kill to me.  Are the grinder wheels priority to this machine??  On other posts I see 60 and 80 grits being used.  What sized arbors are used?    I have a long shaft HF die grinder but size limits of stones and vibrations are still a concern of mine.  But keep bringing up ideas.  On MyMachineShop.net  has a simular unit for $300.  It looks like the switch is mounted on the top not the side but looks the same after that.  I love getting all the info and help.  Thanks!!!)




 Do you have the electric HF grinder or the air. Eather one should work fine. Just make an aluminum mount for your cross slide. Thay should take 1/4" shank stones. You caould make an arbor for a larger wheel


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## JimDawson (Jun 11, 2014)

kd4gij said:


> Do you have the electric HF grinder or the air. Eather one should work fine. Just make an aluminum mount for your cross slide. Thay should take 1/4" shank stones. You caould make an arbor for a larger wheel http://www.lowes.com/pd_87494-1069-6117_0__?productId=1103105



*Just be sure to use wheels rated at the driver max RPM.  Grinding wheels are ugly when they blow up.  A lot of die grinders will turn 20,000 plus.*


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## Ray C (Jun 11, 2014)

Take a look here:  http://www.hobby-machinist.com/showthread.php?t=19687&page=3&highlight=tool+post+grinder

Ray


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## dbq49 (Jun 11, 2014)

Ray:
I saw this thread and copied some pics and some directions before I posted my request for input.  I like what you have done!
This would be great to have.  As ddmunroe asked what kind of bearing are in the 4671 tpg.  No one responded to his question of bearings.  Cheap junk is still junk and not worth the money.  The info on the web site does not supply much info. and no one else has stated that they bought one or are using one of the 4671 tpg.  Thanks for your reply, keep in touch.  DBQ49er


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## Ray C (Jun 11, 2014)

dbq49 said:


> Ray:
> I saw this thread and copied some pics and some directions before I posted my request for input.  I like what you have done!
> This would be great to have.  As ddmunroe asked what kind of bearing are in the 4671 tpg.  No one responded to his question of bearings.  Cheap junk is still junk and not worth the money.  The info on the web site does not supply much info. and no one else has stated that they bought one or are using one of the 4671 tpg.  Thanks for your reply, keep in touch.  DBQ49er




I managed to get a Nachi P5 taper bearing at a very low price on eBay. I no longer have the model number but I once tried to look it up and couldn't find it.  It was something similar to this but with a smaller bore diameter.  http://www.vxb.com/page/bearings/PROD/Kit13628

Anyhow, a P5 or ABEC 5 quality bearing that suits your chosen shaft diameter will do the trick.  You can probably find a 20mm one for 50 or 75 bucks.  I wasn't worried about ultra quality on the driving (radial) side bearing because the force of the wave washers keeps the taper bearing crammed into position.

Ray


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## Big Bore Builder (Feb 8, 2015)

Made these several years ago.  Posted a lot of photos of both here on Hobby Machnist.







Both have 0-90 volt DC motors and variable speed drive.


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