EERF file

R

RiverOaks

Joined
Sep 27, 2013
Messages
16
Hi, just thinking about building the eerf grinder and I was wondering if anyone has the modified file with the 2 tool arms. I know it was posted a while back but the links are no longer active.
I have the current single arm file and don't have the expertice to make changes to it.

If someone would give me a copy of that other free file it would be greatly appreciated.

Thanks
 
If and when you build your eerf grinder, you can improve the tracking by moving the pivot location of the tension arm and replacing the tension spring with either a compression spring or a gas spring. If you go with the gas spring, the 60lb works best. If you need further detail let me know and I'll post photos or a sketch.
 
Thank you both very much! How long should the gas shock be?

ZAPH1 The pdf you provided is exactly the same as the cad file I already have... Are you telling me this cut diagram already has provision for 2 tooling arms??
 
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Two arms as built. Unless you mean two tool arms and a platen, for 3 arms total. On the new version I'm building I only have one arm, and simply attach the toolrest directly to the platen arm.

SANY0001.jpg
 
What I meant is as your picture is with 2 slots for 2 arms...

I have one more question before I order my motor and controller... I've read some people us a 3600 RPM motor and others an 1800 RPM...

I plan on using a Leeson 116106 2 HP 1740 56HC 208-230/460V 3 Phase Induction Electric Motor with a
KBAC-27D 2HP NEMA 4X ANALOG VFD 115/230VAC 9520 controller. I want to use 120 Volts but also have the flexibility of 220 in the future.

Is an 1800 RPM motor the way to go vs 3600RPM?? Is my controller the correct model for what I want to do? I've done a ton of reading but just want confirmation as I've seen conflicting information.

Thanks you all very much!!
 
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If I was purchasing new I would opt for the 3600 rpm motor. Im putting a grinder together myself right now (GIB) and from my research for "efficient" operation you need the high speed (or high "surface speed" I should say) The AO belts are happy at 4000-5000sfpm and The Ceramic 6000 and up but running slower is fine

Many commercial belt grinders operate in the 4000 to 8000 sfpm range. To get close to 4000sfpm with an 1800 rpm motor you would need an 8" drive wheel (if my math is correct) and you can get close to 4000 sfpm with a 4" drive wheel on a 3600 rpm motor, 4710 sfpm with a 5" drive wheel.

Plus with the VFD slowing down if needed isnt a problem.

Hopefully all that makes sense...
 
If you look closely at the two arm grinders. Its just a few extra parts cut and bolted on. No new files needed.
CW
 
I had read somewhere that 1800 RPM motors could be run in X2 mode (double speed) with the VFD to achieve higher desired speeds and even had more torque at lower speeds... Something about 2 pole vs pole motors.
Still need some clarification on this.

Thanks
 
I believe that 1700 RPM motors will deliver more torque at the lower speeds but they won't have the higher SFM of the 3400 RPM motors, presuming that you use the same gear ratios. 1HP is 1HP, you just have to decide if you want speed or power. Having mostly used a single speed grinder which only has the "holy s***" speed, I grind mostly at lower speeds when I get to use nicer grinders.
 
Yes indeed. I think I'm just going to diy the whole thing.

Just wanted to say you have great prices on your grinder in a box!! I'm in Canada though so shipping, duties and taxes really make it less attractive. I got some waterjet quotes and it was double what you sell your kit for not including the metal!!
 
Thanks! I know the shipping adds a lot. I wish I had better international options, but I still send quite a few out there.

Jamie
 
RiverOaks said:
Yes indeed. I think I'm just going to diy the whole thing.

Just wanted to say you have great prices on your grinder in a box!! I'm in Canada though so shipping, duties and taxes really make it less attractive. I got some waterjet quotes and it was double what you sell your kit for not including the metal!!
Click to expand...

I've heard quotes of 35+ hours assembly for the gib. There is a video series on the tube. I wouldn't have guessed but for a home shop assembly I can believe it. Now in a production shop with various drill presses with dedicated setups, the time would be much less.

Somehow you need to put a price on your time. Some would say its free but you forego the ability to do anything else when you do something else.

Good luck and keep us posted.
 
polarbearforge said:
Thanks! I know the shipping adds a lot. I wish I had better international options, but I still send quite a few out there.

Jamie
Click to expand...
The fact that you even ship to Canada is great! And for what it's worth from someone who shops online way too much you're already using the best method... From a buyers perspective anyway.

Like I said I'm just going to DIY the whole thing. I'll post pictures when it's done.

Thanks to everyone who replied!
 
PT Doc said:
I've heard quotes of 35+ hours assembly for the gib. There is a video series on the tube. I wouldn't have guessed but for a home shop assembly I can believe it. Now in a production shop with various drill presses with dedicated setups, the time would be much less.

Somehow you need to put a price on your time. Some would say its free but you forego the ability to do anything else when you do something else.

Good luck and keep us posted.
Click to expand...

I'm not very mechanically inclined and had only a home shop with limited tools when I started and finished mine in a Saturday. Of course, I didn't paint, weld or mount it on some crazy horizontal/ vertical contraption like some others. :)
 
PT Doc said:
I've heard quotes of 35+ hours assembly for the gib. There is a video series on the tube. I wouldn't have guessed but for a home shop assembly I can believe it. Now in a production shop with various drill presses with dedicated setups, the time would be much less.

Somehow you need to put a price on your time. Some would say its free but you forego the ability to do anything else when you do something else.

Good luck and keep us posted.
Click to expand...

35 hours? Even in a home shop that is the longest I have ever heard. I built one in an afternoon with a hand drill (mainly to prove it could be done). I don't think I would hit 35 hours if I totaled the laser run time with the time to turn all the needed wheels on a lathe.

I'm curious how many have said it took that long?

Jamie
 
polarbearforge said:
35 hours? Even in a home shop that is the longest I have ever heard. I built one in an afternoon with a hand drill (mainly to prove it could be done). I don't think I would hit 35 hours if I totaled the laser run time with the time to turn all the needed wheels on a lathe.

I'm curious how many have said it took that long?

Jamie
Click to expand...

I saw a video series, I think 6 in total and I thought that seemed excessive. Maybe he totaled up the video time as part of it.

Guys name is Tyler Johnson on YouTube. It was a very good build for someone wh doesn't yet have the skills.
 
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I watched a little bit of his videos. Very nicely done. If he did prep and paint everything that would take a large chunk of time.

All of mine are "painted" a natural color, sometimes a light rust color... ;)

Jamie
 
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