6 x 72 belt & centerless grinder project

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Sep 2, 2019, 11:55 PM
Frank S

3 Attachment(s)

6 x 72 belt & centerless grinder project

OK since we don't have the old tools in progress sub forum I wasn't sure where I should post this one as this is not a tool yet.
it will be my next major project build.
A 6in. by 72in belt grinder with a powered counter wheel for centerless grinding / polishing function. additionally it will be able to be used either vertical or horizontal. when in the horizontal position I will have a feature by which I can use the tip roller as a notcher for tubing.
I am developing a double acting 2 or possibly 3 stage hydraulic cylinder and will need this machine to grind and polish the OD of some of the tubes as the correct sizes I need can only be bought in large quantities on special order. I can't justify spending several $1000.00 for a prototype cylinder the tubing I already purchased honed to size was already near a $1000.00
Since I have a 8 hp motor the bearings the steel and will make the time I figure I will come out ahead of the game
here are some Jpegs of the drawings I have so far. there are a lot more details I need to work out but have some of the items already machined and cut for the project.
Attachment 30988

Attachment 30989

Attachment 30990
Sep 3, 2019, 05:32 PM
metric_taper

Quote:

Originally Posted by Frank S

OK since we don't have the old tools in progress sub forum I wasn't sure where I should post this one as this is not a tool yet.
it will be my next major project build.
A 6in. by 72in belt grinder with a powered counter wheel for centerless grinding / polishing function. additionally it will be able to be used either vertical or horizontal. when in the horizontal position I will have a feature by which I can use the tip roller as a notcher for tubing.
I am developing a double acting 2 or possibly 3 stage hydraulic cylinder and will need this machine to grind and polish the OD of some of the tubes as the correct sizes I need can only be bought in large quantities on special order. I can't justify spending several $1000.00 for a prototype cylinder the tubing I already purchased honed to size was already near a $1000.00
Since I have a 8 hp motor the bearings the steel and will make the time I figure I will come out ahead of the game
here are some Jpegs of the drawings I have so far. there are a lot more details I need to work out but have some of the items already machined and cut for the project.
<snip 2 photos>

Attachment 30990

Does the wheel "powered counter wheel" spin the shaft when it's in contact between the belt and this wheel? Then the hydraulic cylinder, does this drive some support that holds the work in such a way it spins freely and without centers in each end as a power feed? From your description, I think your making a piston shaft from tube material for a hydraulic or air cylinder.
I've never heard of a centerless belt sander type grinder.
Sep 3, 2019, 08:02 PM
Frank S

3 Attachment(s)

Quote:

Originally Posted by metric_taper

Does the wheel "powered counter wheel" spin the shaft when it's in contact between the belt and this wheel? Then the hydraulic cylinder, does this drive some support that holds the work in such a way it spins freely and without centers in each end as a power feed? From your description, I think your making a piston shaft from tube material for a hydraulic or air cylinder.
I've never heard of a centerless belt sander type grinder.

belt powered counter wheel you see pictured spins at a different RPM than the belt the wheel will be to cause the cylinder or shaft tube what ever is loaded in the machine to rotate opposite of the direction of the belt due in part to the wheel being made of a substance that will allow friction contact rotation in order for this to be guaranteed the supports under the cylinder are slightly off center which makes the cylinder lean hevy towards the friction wheel. There is also a calculation table that depicts optimum positioning of the work piece which in the case of my grinder design will require the work piece center line to be slightly below the centerline of the belt roller. By skewing the friction wheel axis a few degrees left or right of the belt roller axis this will cause the work piece to travel in the direction of the skew.
Optimally I would drive the friction wheel with a separate drive motor connected to a VFD for rotational speed control.
As the build progresses I may find myself heading in that direction or that may be changed out and added at a later time.
I still have to design the feed on feed off rolling support for this machine as well but that is a simple matter of using a series of inline skate wheels.
Here are some pictures of machines that show some of what I will be doing
This is a cheap beld grinder with a centerless attachment the complete unit sells for around 3 to 7 grand
Attachment 31002
this picture shows the feed on feed off conveyor on a disk wheel centerless grinder quite a bit more elaborate than I will require
Attachment 31003
This is a picture of a high end belt type centerless grinder probably 40 years old
Attachment 31004
So as you see they have been around for a while and I am not doing anything that far out of the box excepting for I am hoping to have minimal cash outlay for a machine which will be far more versatile once I complete it