Horizontal Grinder Building - Thinking it through...

The idea isn't to grind full bevel length wise, but once the bevel and plunge are ground to close to final shape, then the length wise grind smooths out any imperfections in the bevel like hand sanding does. length wise grinding also allows each cleaning up of plunge lines, and getting them even. Since this is done at slow speed, it doesn't take much power. Nathan the Machinist has a really good video demonstrating length wise grinding, but I've not been able to find it in a long time. Maybe somebody can link to it.

Ken H>
 
A condition I often have at the grinder (horizontal or vertical) is low speed, low power, but high friction. The problem isn't the lack of torque or HP at the motor pulley, but in traction of the belt. Grinding the bevels like that on a platen is one of those situations. (there are more, such as scotchbrite on a platen, leather strop with low tension, felt or mylar belts are slippery, etc) A rubber or knurled drive wheel solves this for the most part.

I think you were already talking about a rubber drive wheel just wanted to point that out since the discussion about power requirements I think is sometimes confused with traction requirements and friction in the grinding setup.
 
Thanks Brock - that is one of them. It seems like there is another Nathan does that has better lighting. I'll bookmark that video for future reference. Thank You!
Ken H>
 
TBFsZSD.jpg
 
That looks like a pretty basic build Mike, but it also looks very useful!
What is the function of the two handles?
What are the specs on the base plate? Thickness? Type of aluminum? :)
 
Good job Mike - tell us more. What hp motor? VFD or single speed? What's the black on the drive wheel?

Looks like the two handles allow pivoting of base, I see a slot in the base at the middle handle. What is function of this slot?

Good job.

Ken H>
 
I must have pressed the wrong button! Previous post shows my horizontal grinder - not pretty but it does the job.

A few notes you might find useful:

It would be good to have the small wheel attachment on a sliding tool arm, I have to take up slack belt by re-positioning the tracking pulley and/or the small wheel attachment. This is why the tracking pulley spring is clamped. Some sort of sliding spring anchorage would be easier but a sliding tool arm would be even better. If possible you could angle the tool arm so whatever size small wheel you have fitted the belt runs onto the platen properly - (not angled as shown) This would save having to move the platen. There must be a way of calculating this angle.

I fitted the work table around the drive pulley but never use it as it chatters too much, with a rubber drive wheel it might be use-able.

The way my main work rest is fitted it always ends up rotating around the fixing post (inboard of the belt), this is worse if using a fence clamped to the work rest. Something to resist torque would be good. Obviously easy, quick, accurate and repeatable height and angle adjustment would be fantastic

In a previous post I talked about using 3 inch deep pulleys as you could move the belt instead of raising/lowering the work rest. You can still do this to a certain extent with 2 inch pulleys by running the belt off the edge but you need to allow space below and above your pulleys for the belt to overhang. You can see on my grinder where the belt has cut into the grinder base plate.

I would strongly recommend using a 2.5 to 3 inch pulley on your small wheel attachment so you do not have to fine tune your tracking for the belt not to wear your bearings or bearing supports. Alternatively make sure you have a small wheel of a diameter sufficient for the belt to clear your bearings/bearing supports and use this when working on other wheels/platens. Pic below shows the problem.



And just for your interest, my largest and smallest contact wheels :) The smaller one does just about work with flexible belts but you do have to run the machine slow and time your grinding to avoid the joints.



I will be following your progress with interest - I have the urge to build another one myself now :)
 
I've been very close to building my own dedicated horizontal grinder a couple times. Right now I have two GIB's and one is setup to flip horizontal; it pretty much stays that way. I have contact wheels of just about every size but, the two tools that I use in the horizontal position are a 10" contact wheel and a small wheel holder. I used to use the flat platen as well but found the splice running across the solid platen produced results that eventually became unacceptable to me. Still, if you're going to build a dedicated machine, you might as well have a flat platen section.

I have one of Nathan's radius end platens and it would be cool to be able to use it in the horizontal position but, it is only radiused at one end. I think it would be very difficult to get good results without being able to see what you are doing. One would need to flip the platen over and reverse the grinder. Also, in my opinion, it is best to have a file guide installed when using Nathans platen so if you are going to do that, there must be clearance.

I find that much of knifemaking is about problem solving. You want to have as many options as possible when trying to determine the best way to accomplish a task. With that said, adjustability and reliability in the work rests needs to be maxed out. If you just want to make one grinder for yourself, that's one thing but, if you want to build something other makers will want to use, it will have to fit their needs as well.

Bob
 
Good comments from both Brock and Bob. I had been giving some thought as to how to adjust for the difference in pulley diameters with the horizontal. Most of those don't have the tool arm to adjust for belt and pulley differences. Can the tracking wheel be made with enough swing to allow for this difference? OR - will it actually require at least one of the pulley's to slide to make up the difference?
 
Bob Ohlemann said:
I've been very close to building my own dedicated horizontal grinder a couple times. Right now I have two GIB's and one is setup to flip horizontal; it pretty much stays that way. I have contact wheels of just about every size but, the two tools that I use in the horizontal position are a 10" contact wheel and a small wheel holder. I used to use the flat platen as well but found the splice running across the solid platen produced results that eventually became unacceptable to me. Still, if you're going to build a dedicated machine, you might as well have a flat platen section.

I have one of Nathan's radius end platens and it would be cool to be able to use it in the horizontal position but, it is only radiused at one end. I think it would be very difficult to get good results without being able to see what you are doing. One would need to flip the platen over and reverse the grinder. Also, in my opinion, it is best to have a file guide installed when using Nathans platen so if you are going to do that, there must be clearance.

I find that much of knifemaking is about problem solving. You want to have as many options as possible when trying to determine the best way to accomplish a task. With that said, adjustability and reliability in the work rests needs to be maxed out. If you just want to make one grinder for yourself, that's one thing but, if you want to build something other makers will want to use, it will have to fit their needs as well.

Bob
Click to expand...
I got the idea from Nathan, tried it, and now it's a vital part of my knifemaking process. It's great for cleaning up plunge lines and getting the scratches lengthwise before handsanding. This is how I solved the problem you mentioned:

PxOTgFk.jpg

5Qn0N4V.jpg

oE52wfC.jpg


My grinders also tracks just fine in reverse.
 
In answer to questions a few posts back:

The two handles are to adjust the work rests which are mounted in slots. They are nothing to do with the base which is fixed and sits on a shelf below worktop level, it is not fixed down so can be swiveled.

I dont know the grade of aluminium, it is 1/2 inch thick

Motor is 2hp vfd driven. I only used 2 hp as I had the motor available after upgrading my vertical to 3hp.

The black on the drive wheel is electrical tape which I added for extra traction when I was running the 3mm contact wheel.
 
I have my 6061 5/8th plates here. Getting ready to order motor and various wheels.
Can anyone recommend an appropriate motor for this build? I am thinking 1 to 1.5 HP 56c mount. The Leeson motor on my Esteem grinder has served very well.

Also, I can't seem to find a keyed rubber drive wheel for the life of me. Any ideas? Other options than keyed mount? I found this wheel on ebay,
 
Brock, the wheel you linked to on ebay, are you SURE it's got a keyway? The seller states: "Please Note: This wheel does not have a keyway. It is for a threaded arbor similar to the Grizzy 1015 setup."

It seems most folks recommend putting the crown on the tracking wheel, and running the drive wheel flat. The idea a crown on both tracking and drive wheel will tend to fight each other. I'm planning to run a 3" aluminum drive wheel with a 1-1/2 hp 3600 RPM motor. I really think 1hp would be plenty, but wasn't much difference in price so I went with 1-1/2 hp for $142 shipped.
 
Ken H> said:
It seems most folks recommend putting the crown on the tracking wheel, and running the drive wheel flat. The idea a crown on both tracking and drive wheel will tend to fight each other. I'm planning to run a 3" aluminum drive wheel with a 1-1/2 hp 3600 RPM motor. I really think 1hp would be plenty, but wasn't much difference in price so I went with 1-1/2 hp for $142 shipped.
Click to expand...

Without ratchet tension , belt will slip on aluminium drive wheel .On every grinder without ratchet system belt slip on heavy pressure........ no mater how strong is used spring .It is easy to check ! Rubber coated drive wheel is smart decision when used gas or steel spring for tension on belt .Crown on AL drive wheel will only make that worse .If grinder is built right very slightly crown on tracking wheel is more then enough .
 
I'm making progress on my horizontal grinder also - got VFD drive, got 1-1/2 hp motor, got tracking assembly built (mostly copied KMG tracking setup. Got aluminum metal on order for the baseplate. Here's the idea I've got for layout at this time. I'm not sure about the slack belt portion, I do a good bit on vertical grinder, both when sharpening and shaping handles.

I'm hoping the small wheel section will allow me to put the 1/2" small wheel in place, and have enough turn over ends of the two platens for the lengthwise grinding of blade flats we've talked about before. Right now, I've got a 2.5" aluminum tracking wheel in the tension setup, but plan to replace with a 4" UHWM plastic wheel. I'm using a 4" UHWM wheel for tracking on my vertical grinder and it's working pretty good. I'm not sure how well it would work for a production grinder that's in use 40 to 50 hrs/wk, but for my hobby use, I think it's going to work ok. I've got the small wheel system made along with wheels. Got 3 more 4" UHMW wheels turned, just need to machine for bearings.

I've not got details worked out on how to make the adjustable work rests, but do plan for them to be adjustable rather than fixed.

Horizontal_Grinder.jpg
 
Natlek said:
Without ratchet tension , belt will slip on aluminium drive wheel .On every grinder without ratchet system belt slip on heavy pressure........ no mater how strong is used spring .It is easy to check ! Rubber coated drive wheel is smart decision when used gas or steel spring for tension on belt .Crown on AL drive wheel will only make that worse .If grinder is built right very slightly crown on tracking wheel is more then enough .
Click to expand...

I've been running a 3.8" aluminum drive wheel for the last few years with no belt slippage problems. A lot depends on how much belt is wrapped around drive wheel. I've really laid pressure on belt when grinding heavy stuff and can't tell any slippage problems. On the horizontal there won't be anywhere near the pressure applied to the grinding. No hogging of blades or other heavy grinding, that's what the vertical is for. I don't think slippage will be an issue for the grinding this horizontal will be used for. Heavy spring pressure isn't planned so the belts will be easy to change. At 71 yrs I don't have the strength of years past.
 
HSC /// said:
why not get the one from KMG?
note, they suggested I build up the middle with tape to create a crown to help the tracking,
Click to expand...

I most likely will get my tracking and drive wheels from Beaumont. I wanted a rubberized drive, but I just can't find a good one. Saw one guy on youtube case a resin/rubber compound of some sort on a drive wheel (or was it a contact wheel?). Anyway, it didn't look very convincing as a solution.
 
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