Eerf grinder build-a-long

S

Sandeggo

Joined
Nov 17, 2014
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So I figured why not post a work in progress of an eerf grinder I started today. This is more of my element rather than knife making as I'm a welder, fabricator, welding inspector and a welding instructor for a community college. After I finished my knife yesterday and I'm out of blade material so I decided an upgrade of the ole harbor freight is in order. Today at work I saw a guy doing nothing, and it just so happens he runs the cnc plasma cutter so I decided he needed something to do. The plasma struggled to cut the thick plate but a bad kerf I can live with. The plasma also has a wide kerf so I decided I'd just drill or mill my bolt holes. I wanted to set this grinder apart from the crowd so I had my student put my initials in my grinder. I use the same symbol on all my stuff and will eventually be my makers mark on my blades. I have read just about all the threads out there about pulleys and VFD. For this grinder I'm going to go straight to vfd. It will have to wait until after Christmas to get up and going but I promise there will be some good stuff along the way.
On the cnc

After dross removal and a quick pass on the wire wheel


Starting the drilling madness

As far as I got tonight.(yes I'm aware my garage is a pig sty but Christmas break is Thursday.)
 
Sweet. This will be lot of fun to watch considering your background. We love lots of photos.:)
 
Great start!!!! Can't wait to follow your WIP on this as I'm getting mine started after Christmas.

Jay
 
Good job - That grinder is going to turn out GREAT. BTW, did you have a CNC to drill the holes? OR have to do the old fashion way with a drill press? 2hp 3 ph motor planned? Have you made a decision on VFD yet? I went with an IronHorse motor due to cost - $127 shipped for a 3ph 2hp motor. I cheaped out with a NEMA1 Chinese VFD for $116 shipped, and put good filters over the air inlets to prevent dust from getting inside. We'll see how long it lasts.

I'll be following this thread.

Ken H>
 
Antlerhog said:
Great start!!!! Can't wait to follow your WIP on this as I'm getting mine started after Christmas.

Jay
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You'll see it on instagram first lol

Ken H> said:
Good job - That grinder is going to turn out GREAT. BTW, did you have a CNC to drill the holes? OR have to do the old fashion way with a drill press? 2hp 3 ph motor planned? Have you made a decision on VFD yet? I went with an IronHorse motor due to cost - $127 shipped for a 3ph 2hp motor. I cheaped out with a NEMA1 Chinese VFD for $116 shipped, and put good filters over the air inlets to prevent dust from getting inside. We'll see how long it lasts.

I'll be following this thread.

Ken H>
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No cnc for the holes. I used my digital calipers and my ryobi drill press. I need to get a Jacobs chuck for my mill and I'll never use the drill press again. I've heard good things about the Chinese motors and vfd's. I will be hunting locally to see what I can come up with. I met a guy in my local tooling shop that does vfd and motors so I'm gonna see what he has. I'll be building all but the contact wheel to keep the cost down as much as possible. So far my build total is $0.00
 
I've been searching high and low since yesterday trying to find dimensions for a 2 wheel flat platen. I realize that the dimensions of the grinder and attachments aren't really critical but I need a good starting point as I have never seen a 2x72 for knife grinding in person. I've only ever used burr kings and industrial machines.
 
I guessed that about 10" of platen will work earlier today, I'm not 100% thrilled on how it came out with the plasma but it'll do. I drew the design on word. Copy and paste to paint to save it as a bitmap. The bitmap is easily converted to a vectorized drawing to communicate with the torch. I'll probably end up scrapping it cause it's pretty rough.

Cut the platen arm out of 1/4" and brought it home and layed out the holes and drilled them.

Then I layed out and drilled the holes for the base plate.
Then it was time to do a little mockup.

Can anyone give me a reason why I should bolt all of this together?
I think I'm going to weld the long pieces that the tooling arm rides on to the vertical arm. Then weld that whole assembly to the main upright, then weld that whole thing to the base plate. For the top of the tooling receiver I plan to get rid of the 3 spacers and make that one solid piece. Then that assembly will bolt on so I can remove or clean it or whatever. I wish I would have studied the prints more before going drill happy but I had to get this all done by tomorrow so I can weld it up at work. I don't have a tig at home.
Anyone have this dimension?
I measured the drawing with my calipers and figured it's about 2.25" to it but I'm not sure if my drawing is messed up.
 
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I opened the DXF to check myself, and it had it as 2.5 inches from the edge. The EERF grinder plans aren't very well dimensioned, but to be fair it'd be a mess with all the holes everywhere. By the way, I'm eagerly watching this WIP, as I hope to build the EERF someday.
 
NeilJBorja said:
I opened the DXF to check myself, and it had it as 2.5 inches from the edge. The EERF grinder plans aren't very well dimensioned, but to be fair it'd be a mess with all the holes everywhere. By the way, I'm eagerly watching this WIP, as I hope to build the EERF someday.
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Thank you very much, I was hoping the scale was correct. For those watching this that haven't worked with prints or with drawings that are to scale that are not sure exactly what I did. On the far right of the base plate on the drawing is a 1" dimension. I took my digital calipers and measured on the drawing. It came out to .327", then I took my calipers and measured the missing dimension which came out to .739". I divide .739" by .327" which equals 2.259". That's awful close to 2.25" so I figured my calipers were off a little bit from the lines on the drawing. Now that I have confirmed it, it is safe to say that the drawings are scaled correctly.
 
No problem. Just to clarify, we're talking the centerline/center of the holes right? I've been working on getting the EERF drawings properly constrained and dimensioned in SolidWorks, but it's such a chore that I haven't taken the afternoon to sit down and get through it.
 
NeilJBorja said:
No problem. Just to clarify, we're talking the centerline/center of the holes right? I've been working on getting the EERF drawings properly constrained and dimensioned in SolidWorks, but it's such a chore that I haven't taken the afternoon to sit down and get through it.
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Yeah. I know my centerline drawing sucks lol. You're right, a lot of the dimensions are missing, and a lot of them aren't crucial. I figured with this dimension I better get it right in case I can't get a direct drive motor right off the bat. If you're going to do all that work in solid works, I'd focus on the assembly dimensions. That's really what I am asking for with this missing dimension since I am not drilling the holes and since I don't have the rectangular slot for the upright to go into. It's all unnecessary as I am welding the upright plate.
 
I'm really liking this build so far. Looking forward to the finished grinder.
 
Got a little done on the grinder today. Got the upright welded to the base plate and welded the long spacer pieces to the upright. Still got a lot of finishing left to do on it. The new school that I started teaching for in August doesn't currently offer tig so I'm pretty damn rusty. Don't laugh at my weld.

 
Sandeggo said:
Got a little done on the grinder today. Got the upright welded to the base plate and welded the long spacer pieces to the upright. Still got a lot of finishing left to do on it. The new school that I started teaching for in August doesn't currently offer tig so I'm pretty damn rusty. Don't laugh at my weld.

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That's a pretty nice lookin weld to my untrained eye. Cool seeing this come together.
 
Cool grinder build, im staying tuned and those tig welds look awesome to me! I am a welder too but haven't had a chance to do much tig welding yet but I plan on staying after hours soon here and practicing. Thanks for sharing.
 
BallewBlade said:
Cool grinder build, im staying tuned and those tig welds look awesome to me! I am a welder too but haven't had a chance to do much tig welding yet but I plan on staying after hours soon here and practicing. Thanks for sharing.
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Thanks man, being a teacher I don't get to weld as much as I did when I was under the hood for 12 hours a day so it's kind of a hard pill to swallow when your skills diminish.

people that have a tilting grinder
How often do you actually use it in horizontal mode? I have an idea for a pivot but don't know if it would be worth fabricating.
 
I would say I use mine in horizontal about 40% of my grinding. The small wheels are far easier to use in horizontal and getting long straights ground square on the flat platen is easier in horizontal as well. If you haven't checked out my GIB build, it is here. You might find some helpful stuff there.

I wouldn't get too wrapped up in how pretty your grinder is. If you use it for its' intended purpose, it is going to be filthy all the time anyway. I think that platen support looks fine. I would just mention that it is really useful to be able to wrap your fingers around the actual platen from either side for good control on delicate grinding operations.

Bob
 
RangerBobTX said:
I would say I use mine in horizontal about 40% of my grinding. The small wheels are far easier to use in horizontal and getting long straights ground square on the flat platen is easier in horizontal as well. If you haven't checked out my GIB build, it is here. You might find some helpful stuff there.

I wouldn't get too wrapped up in how pretty your grinder is. If you use it for its' intended purpose, it is going to be filthy all the time anyway. I think that platen support looks fine. I would just mention that it is really useful to be able to wrap your fingers around the actual platen from either side for good control on delicate grinding operations.

Bob
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Thanks, I have seen your build thread. You are a much better machinist than I am that's for sure. I only use my mill to true stuff up right now. I've only had it for a couple months and have very little tooling. I built the platen so it will use angle to space the platen off the side plate that is shown so I should have access to both sides.
I may end up just using this one in vertical fashion as I have planned. I can alway build a horizontal machine or tilt mechanism if I feel the need. I am anxious to get this one up and running and don't want to hold off progress for design changes.
 
Now that the holidays are over, I got $150 grizzly gift card from my brother in law, I finally got my order. I needed a hold down for my mill to do a few operations on the grinder. Well I got those done and threw a little paint on it today. Still gotta make a tensioner, tracking, and cut the grizzly wheel for bearings. Then I'll order wheels, a motor, and a vfd. I have 220 but it's far away from where I'll be doing my grinding. Is there really any reason why I should just wore this for 115? Eventually I'll order a 3ph motor for my mill and run both off the same vfd.
1A32B1A7-0D46-48B4-B93D-5409B463763B_zps3d3fwarh.jpg
 
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