2x48 horizontal grinder build along - 2022

[bjansen]

I made a couple 2x48 grinders and attached is a detailed build along. This is a fairly easy build that one can do with simple tools. It is largely just drilling and tapping holes.

A few key features of this grinder include:

-Nearly all parts are aluminum or painted steel to avoid rust

-The holes in the tables are blind (as I found that when I grinding on anything but a flat top, stuff gets in the way…for example when I am grinding slipjoint liners which have 3/32 pins holding them together, the pins will fall in a screw hole and hang the pieces up).

-It has a quick detach tool arm to make belt changes easier…also I often will rotate that tool arm 90 degrees to have a hand rest to perform free hand file work on liners.

-Because of the 1.5" toolbar, you are also able to utilize the tool arm slot (with a longer tool arm with different wheels attached) to accomodate 72" belts. For example, my surface grinder attachment is mounted on a longer tool arm and I can utilize this horizontal grinder to run it.

I came up with a parts list and the parts list along with this build along should get you there. If you ever are in doubt, just lay out the parts on your base and you will be able to figure it out. This is an easy build..just takes a bit of time.



This is a starting picture of all the components

To start, we will spot drill the motor shaft hole as well as the bolt holes.

We need to make clearance for the 56c motor. There are 2 ways to do this…if you have a mill, then you can simple mill out the area for the 56C motor face to inset into the bottom side of the base. If you do not have a mill, then simply drill right through the base with a 4.5” hole saw. In this build, I used a 4.5” hole saw to make the perimeter and then clear out the inside with a mill.

I then cleaned up all the rough edges of my pieces

 

[bjansen]

I then mocked everything up using a 2x48 belt and just layed everything out on the base.

Next we start fabricating the straight platen. Drill a couple 5/16” holes and widen them to allow for adjustment. I did this on the mill, but you can also widen will a round file.

Then mark the holes on the base and drill and tap 5/16” threads in the base. At the same time I marked the 5/16” tapped hole for the gas spring.

 

[bjansen]

I had to make a tad bit of clearance on the purchased tensioner.

 

[bjansen]

Tappin
Tapping the hole for the tensioner.

Now we are going to drill and tap the holes for the small wheel holder. The OBM model takes a 3/8” and a ½” bolt.

 

[bjansen]

Now back to the straight platen. We need to attach the angle iron to the flat platen. I drilled two ¼” holes in the angle iron, and then marked and tapped my platen.

I then clamped this up in the mill and made it exactly 90 degrees. If you don’t have a mill, then check it to see if it is close…if it is not close you could either try to touch it up on the grinder…or drill and tap the angle to allow for a couple more screws to push on the platen plate to true it up.

 

[bjansen]

 

[bjansen]

Now we are going to drill some holes for the work tables. There is going to be one for the drive wheel and then a longer one for the flat platen. Simple mark out the holes, drill them and then mock of your table and transfer the holes through to the piece. The best and most accurate way to do this is one hole at a time….or at least one at a time until you get 2 holes drilled and tapped, and then you can hit the rest when it is screwed down and cannot move.
Making these blind, tapped holes is key…as that will allow the top of your work rests to be perfectly flat and free of anything to hang up your work you are grinding.

 

[bjansen]

I then countersink the holes on the underside to allow for 82 degree screws to be flat with the bottom

After I got the drive wheel table mounted, I then mounted the motor, marked the table for proper belt clearance and then cut that out on the bandsaw.

 

[bjansen]

Next we are going to make the underside mount for the tool arm. Find a good spot for it (which is not that complicated), drill 2x 1/4” holes in each side piece, drill and tap a ½”-13 hole for the center piece and bolt it all up. Again use the transfer punches to mark where you need to drill and tap your base. I used blind, tapped holes for this as well to make it a cleaner look. I also put 3 pieces of masking tape on the tool arm to give it proper clearance for the mock up.

 

[bjansen]

Next, I drilled ¼” holes in the 3 open corners for a place to screw this unit down to a bench when mounting

Final assembly of the base/motor/platens

Because I have the mill, I flattened the tops of the tool rests….if you don’t have a mill then just skip this step.

I used 2 washers to provide clearance for the tool arm.

 

[bjansen]

Now we just have to fabricate the tool arm. Using a 1.5” square, I tapped and mounted the table, again using blind tapped holes to the top of the tool rest is clean. This is pretty straight forward, just mock it up and bolt it together. After it is bolted you can mark out and cut a spot for the small wheel to inset.
I used a 1.25” spacer block to raise up the tool rest to the correct height. In the hardware list, I am going to instead recommend using 3 1.25” aluminum spacers as that will be easier and likely better.

First I marked 3 random holes for the bolts and drilled those out with ¼” bit. I then enlarged the holes so the socket cap bolts could recess.

Then just like everything else, use your transfer punch to ID the holes on the tool rest, drill and tap blind holes.

Use a bandsaw, other grinder/files, etc. to clean up a spot for the small wheel

 

[bjansen]

That is it. It is a fairly easy build, and I think it is worth it given the upgrades you can make on the tool rests and quick change tool arm. Here are some finished pics.

And a parts list

B Jansen 2” x 48” Horizontal Belt Grinder Materials List

Tools needed: Drill press, drill press vise & drill bits, Taps, transfer punches, general hand tools and finishing equipment (sand paper, files, etc).

Materials List- Metal:

Part Name	Qty	Description
Base Plate	1	10” x 20.5” .750 Aluminum Plate (6061 or 7075) (Note: Check Ebay, as there is typically a fair selection of fairly prices pieces in this size). This is the base to which you will bolt everything to. The thickness and material type of this plate is not super critical…you could probably use ½” aluminum, or even thinner steel.
Drive wheel work rest	1	4” x 6” .750 Aluminum flat bar
Platen work rest	1	3” x 12” .750 Aluminum flat bar
Small wheel work rest	1	2.5” x 6” 1” Aluminum flat bar
Flat platen angle iron support	1	Hot Role A36 Angle – 1.5” x 2.5” x 10” long .250 thick wall
Platen	1	3/8” thick, 2” x 11” A36 or 1018 (or any kind of steel really) You could also harden a piece of tool steel which would make a longer wearing platen.
Tool arm holder pieces	3	1.5”x3” .750 Aluminum flat bar
Tool arm	1	Square Aluminum 1.5” 9” long
5/16-18 threaded insert	1	Threaded insert for a 5/16-18 bolt…this is tapped into the aluminum tool arm box on the underside of the grinder. Mcmaster Carr # 96137A140.

Materials List -Hardware:

Part Name	Qty	Description
Drive Wheel	1	4” Drive/Contact Wheel - Oregon Blade maker (ebay) or Beaumont metal works
Tracking mechanism assembly	1	Beaumont metal works sells their complete tracking mechanism package, with a gas spring. Overall, this is not the ideal design, but it will work. To make this build easier, I just purchased one of theirs. You could also design and make your own...or design a better tracking device that would allow the tracking wheel to pivot closer to it's own axis. If you are going to buy Beaumont's it is called "EF-48 Tension and Tracking Assembly" - $207
Small wheel holder	1	Small wheel holder for the Beumont EF-48 grinder or Oregon Blade maker (Ebay)
Small wheel	1	Oregon Blade Maker (Ebay) or sevral other places like USA knifemaker, Beumont metal works, etc. Note: I use a ¾” small wheel 99% of the time I use this grinder.
3/8” bolts (for motor mount)	4	3/8”-16” Thread, 1.5” length.
Platen bolts/washers	2 ea	Socket Cap Screw, 5/16” threads - .750 length - washers to match
Platen assembly bolts	2	¼” x 20 1” socket cap screw
Washers	2	2 Stainless washers to provide spacing for the tool arm. I just used standard washers for ¼” bolts.
Assembly bolts for tool arm holder	2	Flat Head Socket Cap Screw ¼”x 20 Thread, 1” length
Assembly bolts for work tables and tool arm holder	14	Flat Head Socket Cap Screw ¼”x 20 Thread, 1.75” length
Quick release bolt clamp for small wheel work rest tool arm	1	McMaster Carr 6271K22 This is a cast aluminum handle with a 5/16-18 threaded stud.
Work table spacers	10	McMaster Carr #92510A767 Aluminum Unthreaded Spacer, 1/2” OD, ¾” length, ¼” Screw Size
Small wheel tool rest spacer	3	McMaster Carr #92510A770 Aluminum Unthreaded Spacer, 1/2” OD, 1.25”” length, ¼” Screw Size
Assembly bolts for tool arm	3	Socket Cap Screw, ¼-20” threads – 2.5” length
Motor and drive/wiring		This is for a variable speed set up: I used a 1HP Baldor VEM3546 (56C, 3 phase 208V, 60 hz, 1760 RPM motor). 3 phase, 1 hp motors can often be found on Ebay for cheap. You will also need an AC motor drive. I used a KBAC -24D. There are cheaper alternatives, but the KBAC series drives are very nice and easy to use. These are not cheap, unfortunately but are very good drives. For this horizontal grinder, I would also purchase the on/off line switch for the KBAC 24D. For a single speed set up: I used a 1725rpm single phase, 1 hp (56C - TEFC) motor – for example a Baldor VL3510 or a Leeson 110494.00. An even slower motor, such as the 1140 RPM Baldor VL3508 is also a good option. You will really not need this grinder to spin super fast. You will then wire this up to a simple on/off motor switch.

 

[Drew Riley]

Nice work!

 

[DanF]

Very nice