2x72 Belt Grinder

[Kim]

The next part is the platen itself.  This was very simple. Just a length of 2” x 3/8” flat bar with the ends chamfered a bit and two bolts welded to it.


This was inserted into the platen spine and attached with nuts.  I’ll be using lock nuts when I reassemble after painting.  But this will suffice for now.


With the platen arm in place, I can now put a belt on it!  Very exciting! The tracking works really well, so that’s a good sign.  I haven’t hooked power up to the motor yet, but I did go vroom-vroom and move the belt with my hand


The next subassembly is the table holder arm.  I’ve clamped the two angled pieces to the arm and am about to weld them into place.


After welding those I welded a short piece in across the front, like so (the top and bottom pieces with the clamps are just there to hold the little piece in alignment for welding.)


I had to bend the 1/8” steel parts to fit the front and back angles of this piece.  Bends are always a challenge to get in the right place.  Luckily, this doesn’t require too high of precision.  They just add a little strength and close the big holes in the tool arm.  They make it look much more professional too, I think.


And here they are welded into place - you can only see the top one here, which is the short one in the previous shot.


Next is the tube holder plate.  I made sure this and the spacer were square, then welded them in place.


And the last part of the table holder arm is the tube holder.  I welded this up like the previous two receiver tubes. It’s exactly the same only much shorter.  Then welded a 3/8” nut on one corner to lock the table post in place.


And now mount the table tube holder to the table arm using 4 3/8” bolts.  But before tightening the bolts down I put a square post in the receiver and pulled it up to the belt to make sure it would be perpendicular.  I used a piece of aluminum bar between the platen and the mock table post to help with this procedure.


And that brings us up to date on the belt grinder project. I’ve got the table to make still and I have to hook up the motor and VFD too.  Also have a tilting table, a small wheel attachment, and a large wheel attachment that I’ll be making before I’m done.  But the pile of parts left is getting small!

Thanks for checking in,
Kim

[Admiral_dk]

Looking good and you're moving rapidly forward with this build Kim 

Per

[Dave Otto]

Looking great Kim, nice work!

Dave

[Kim]

Thanks Per and Dave!

Yes, I’m really enjoying how quickly this project is coming together!  I’m chalking it up to not having so many little fidgety parts that all require high accuracy.  All of these parts are cut using a tape measure instead of a micrometer!  You can make up for a pretty big gap just using a wider weld bead    And I don’t want to discount the excellent plans and clear instructions that Jeremy provided. And his design is incredibly well thought out!  He’s got many ways to make up for inaccuracies that accumulate during the build and still make the finished unit come out very well.  I’d highly recommend his plans to anyone interested in a belt sander like this.  They are really well thought out and well done.


Yesterday the gland connectors arrived.  I was waiting for these before I wired up the VFD. Now that there here, I’m going for it.  I used a heavy-duty extension cord for this.  I cut a short length to go to the motor. Since it only has 3 conductors I ran a separate one for a ground.  I don’t know that I need this, but it seemed safe to me to have one. I should probably purchase a 4 wire cable for this, but for now, this will suffice.

I used the KB Electronics KBAC-27D VFD and it came with pretty decent instructions.  Not overly verbose, but I could follow them and tell how to set the jumpers!  What more do you need?

Then I did a quick test!  It worked, though the belt ran backward.  So I swapped two of the wires to the motor which fixed that problem.  And here’s a quick demo showing it running and showing how responsive the tracking mechanism is!
<a href="https://www.youtube.com/watch?v=UUAF8sXFcNs" target="_blank">http://www.youtube.com/watch?v=UUAF8sXFcNs</a>

The final part for the basic grinder is the Fixed Table.  This table, as its name implies, is fixed at 90^o to the belt.   That is what I frequently want anyway.  And this will mean I always have a good right-angle setting!

Here’s the fixed table welded up.


And with that, it’s time for a quick victory demo showing first sparks!
<a href="https://www.youtube.com/watch?v=ZJ6bqFgFVww" target="_blank">http://www.youtube.com/watch?v=ZJ6bqFgFVww</a>

I’ve got an 80 grit belt on there right now and it does a pretty good job of taking off metal.  I’m sure a more aggressive belt would do more, but this is quite good for most of what I want to do.

Now for the additional fixtures!  (and painting…)
Kim

[Dave Otto]

Nice! You sure are going to enjoy using that.

Dave

[RReid]

Great job so far on what looks like will be a super useful tool. Congratulations Sparky!

[propforward]

Wow - that is brilliant Kim, a top piece of kit. You can’t buy one of that quality. I could gave made good use of that today cleaning up some castings.

[cnr6400]

I was worried when you mentioned "fixed table" - I wondered why it needed to get fixed. Then I continued reading... 

That Very Funky Device install looks great too. The machine will certainly remove some stock fast! Might make for some warm fingers. Better keep some cold  handy to cool them off. 

[Kim]

Thanks Dave, Ron, Stuart, and CNR!

Yeah, it can get things hot pretty quick! 

Interesting anecdote:  The last few days I've been having trouble unlocking my laptop with my finger scanner.  It usually works quite well on the first or second try.  But it's been telling me it can't recognize my fingerprint.  I think I've figured out that working with this welding and grinding and such, I must have burned my fingertips enough that the reader doesn't recognize my fingerprints! 

Nothing big, it doesn't even really hurt... but I have been handling some metal that is pretty hot and I quickly remember I need to put the gloves back on to touch it!

Kim

[Baltic]

Fantastic job there Kim,
Well ! you do not muck around, seems like only a couple of weeks ago you where cutting all the bits now hit is nearly finished, '
your welds are getting better also, you should be very happy with yourself 

Gary

[Kim]

Thanks Gary!
I'm quite pleased with how it's turning out!

Kim

[gary.a.ayres]

You have every right to be!

Solid, powerful machine you have built in a short space of time.

  from another Gary

[Kim]

Thank you, Gary!

Yesterday and today I worked on the accessories.

First was the tilting table (as opposed to the fixed table already made).  I started by welding up the pieces to make the table support and hinge.  The 4” length of DOM tube isn’t welded in.  It will be welded to the post in the next step.


Right here – this is where we weld the DOM onto the post.  I worked hard to get the tube straight and square.


Then I welded the locking tab to the DOM, and here’s the assembly just before I tack it to the top which will complete the tilting table.


Here you can see the tilting table installed on the tool arm and set to 45^o.


And here’s the 90^o shot.


Next, I welded together the parts for the large wheel attachment (Contact Wheel as I believe it is called).  This will be the fork that holds the large wheel. 


Just another one of those really helpful hints in Jeremy’s directions – he gives an excellent example of how to position the wheel axle at the correct place AND maintain perpendicularity at the same time!


And here’s a demo of the tilting belt in action.  You can see that the belt stays centered at the same spot in either the horizontal or vertical positions!   I just love that kind of attention to detail in a design, you know?
<a href="https://www.youtube.com/watch?v=0_sPvxd0U10" target="_blank">http://www.youtube.com/watch?v=0_sPvxd0U10</a>

And finally, I welded up the Small Wheel attachment.  I was very pleased with my welds on this one.  And as I was admiring it, I suddenly had that sinking realization that I’d ever-so-beautifully welded one of the parts on backward! 


That tab (lower wheel mounting plate) was supposed to be pointing in the OTHER direction!  Shoot!  Of course, I couldn’t have double-checked the part when it was only tack-welded in place. I had to wait to notice till after I’d done the full weld.

So after kicking myself for a while, I finally decided to think like a welder and I took it to the bandsaw and cut through the welds on both sides.  Then cleaned up the split weld beads on the belt sander.   And here’s the two pieces separated.  Not bad for a newb, eh?


And here we are, finally re-welded pointing in the correct direction!  (yes, I checked BEFORE tacking it in place, AFTER tacking welding it, and after the full welds.  It’s in the right place this time!  )


And that, my friends, was all I could stand out in the shop.  We’re having a heat wave here in the NW and it’s getting TOO hot for me to handle out there.  Especially because I have to put on long sleeves to weld!  (I hear you can get sunburned from arc welding if you don’t cover up, not to mention burned by any weld splatter that might happen!)

Thanks for looking in on me.  I’m getting close to finishing this fun little side project!
Kim

[crueby]

Is there a particular type of belt that you use on a machine like this for metal work? There are a lot of different formulations of grit out there, how do you pick?

[Kim]

Well, it's not like I know a lot about sanding belts, but from what I've read, ceramic belts are the best and longest-lasting abrasive for metal work, but also more expensive, of course.  Zirconia belts are the next best followed by aluminum oxide.  Though I think they will all work.  What I've read says the ceramic will last 3x longer than Zirconia, and 10x longer than aluminum oxide.  But I don't have any long-term experience to back this up.  It's just what I've read online (so it must be true, right? )

I got a set of six ceramic belts - two 36 grit, two 80 grit, and two 120 grit.  Figured it was a good way to start and I could experiment some.   On my old belt sander (the Ryobi 6" disk, 4" belt combo that this  2x72 is replacing) I always used 80 grit.  It just seemed to be a good compromise. I used that for wood and metal both!  I'll probably do the same with this one

You thinking about making one, Chris?   It's a fun project!

Kim