2x72 belt grinder build

just saying. the delta is also a direct drive. I hear you on the belt being captive. I probably would rather have a dedicated machine for both.
I posted a thread debating whether to even includ the disc and am not sure how useful it’ll be. A big issue is there isn’t a shield around this disc. If I find the disc to be at all useful I’ll probably buy a separate one. This is more of a “because I can” feature.
 
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I posted a thread debating whether to even includ the disc and am not sure how useful it’ll be. The big issue is there isn’t a shield around this disc. If I find the disc to be at all useful I’ll probably buy a separate one. This is more of a “because I can” feature.
I have a 6x48, with a disc 9". no shield I had to make the disc it was missing. I cut through my fingers nicely, I hit the edge of the disc and sliced deeply onto the tops of 2 fingers.. deeply since there's not a lot of meat there to begin with. I removed the disc and only put it on when I need it. I've never had a problem with any of my belt sanders... Think of the disc as a tablesaw blade with finer teeth (sandpaper and metal)
 
I posted a thread debating whether to even includ the disc and am not sure how useful it’ll be. A big issue is there isn’t a shield around this disc. If I find the disc to be at all useful I’ll probably buy a separate one. This is more of a “because I can” feature.
Years ago, Sears used to sell a metal disc that you mount on a table saw which was to hold a 10" sanding disc. I put it on an arbor and the end of a small motor, 1/4 or 1/2 hp, and then built a box around it. That thing is very handy, gets used lots and nice to have set up all of the time. Pretty simple project. Back then, I only worked with wood. Granted, for what it is, that is probably what I would do again. I will try to get a photo later.

So I guess I am suggesting build or buy a separate one. Seeing as my 2x72 tilts, that disc would be going horizontal too....looks dangerous.
 
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Years ago, Sears used to sell a metal disc that you mount on a table saw which was to hold a 10" sanding disc. I put it on an arbor and the end of a small motor, 1/4 or 1/2 hp, and then built a box around it. That thing is very handy, gets used lots and nice to have set up all of the time. Pretty simple project. Back then, I only worked with wood. Granted, for what it is, that is probably what I would do again. I will try to get a photo later.

So I guess I am suggesting build or buy a separate one. Seeing as my 2x72 tilts, that disc would be going horizontal too....looks dangerous.
those are still sold by the wood working retailers, and online retailers.
 
This is the sander. I know not of the standards these machining forums usually show, but it does work well. Just a simple option for you.

;)
 

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    Sander.jpg
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Keeping with the lots of pictures and progress updates theme, here is the millwork on the arm that holds the front two rollers and platten.
I opted to change the specs. The slot was designed as 3" long, I cut 4". Slightly longer adjustment range, although at full extension that is only going to be 2" of overlap in the arm guides shown in the previous piece, so not really well supported.

I made this out of 2" x 2" solid CRS bar, in part because I had bought 20' of it back when steel was affordable.

Milling the 1/4" by 4" long by 2" deep slot was time consuming. I used a 1/4" drill and drilled a series of holes first. I managed to break off a 1/4" drill in the process. Then set up a nice new 1/4" carbide rougher in my mill to cut slot, using about .300 depth at a pass. Unfortunately on the second pass there was a piece of the 1/4" drill left in there and that snapped the rougher. Sigh. I didn't want to unclamp the piece and get it out where I could see it and invert it, and paid the price.

Between compressed air, and a scribe, I dug the drill fragment out and went to work with a 1/4" carbide extended length finishing mill to cut the rest of the slot, cutting at about .25" depth of cut and a slower feed.

I also shortened the arm by .5" after reviewing the perimeter belt length measurements. It matters whether the platten is set to straight vertical or tilted, decided a I needed just a little shorter in the total range. It's really a cosmetic feature, but I still need to set this up on the rotary table and round off the end. I'll use the bandsaw first to get it in the ballpark.
IMG_4329.JPGplattenarm.jpeg
 
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that's going to be heavy. How much does that one piece weigh about? I guess mass is good for what it's doing. But moving that machine will require a fork lift..
 
that's going to be heavy. How much does that one piece weigh about? I guess mass is good for what it's doing. But moving that machine will require a fork lift..
Ayup. But, as you know, I have forks for the loader on my tractor ;)
Steel is just a tad over 1/4 pound per cubic inch. 13.5" long, so about 14 pounds for this piece.
I'm hoping the mass of this arm helps keep vibration out of the front platten and rollers. I'm making the second arm, for the table, out of square tube so that part won't be of the same mass.

I figure when it's done it'll get mounted on my preferred stand, a piece of 3" tube going into a hexagon frame filled with concrete. I may even use two 60lb bags for this one to make a stable base.
 
The belt grinder build continues. I'm finding this project to be a good match/challenge to my machining skills, I certainly have a lot to learn.

I had recently met another HM'er who lives about an hour away. Visited yesterday with a project in mind. I wanted to build the drive wheel for my belt grinder. Design calls for a 6" wheel, and I figured aluminum would be a good material to keep the rotating mass somewhat limited. I'm making the drive wheel a bit wider than the belt, 2.5", just to give a little extra width for belt tracking. Just turn that out on the lathe, right? So a chunk of 6" round by 3" long 6061 is how much? Onlinemetals wants $350+ for a 1' piece of 6" round. Hmm. McMaster wanted about $20 for a 3" long piece of 1/2" wall 6" aluminum tube, and about another $20 for a 5" diameter 1" thick aluminum disc. Well, I just need to join those together and I'll have a wheel.
drive-pulley.jpeg

The aluminum part is the light gray component above, the brownish center hub will be broached to match the motor key, and threaded to allow the backplate for the 9" disk sander to screw into it. I had initially thought about TIG brazing those two aluminum components, my TIG goes to about 200A with air cooled torches so I was skeptical that I'd be able to actually weld it. But @Dan Krager offerred to let me try his MIG spool gun, which he had brand new still in the case. We messed around with some aluminum coupons until we got something that at least showed some strength under a vice and hammer test, basically cranking that MIG welder to its max output, and getting the technique down for the spray transfer weld. I wouldn't want to actually post a picture of what the welds looked like :(

But with a little cleanup in the lathe, I got something that doesn't look bad. I had chamfered the edge of the aluminum disc about 1/4" deep on each side before welding it to give some penetration. I am certain the weld doesn't go all the way through the 1" thick disc, but it filled the chamfer nicely. Pictured here is turning the first side as well as facing the center, then flipping it to work on the other side after drilling and boring the 1.75" center hole.
IMG_4332.JPGIMG_4334.JPG

I'll need to drill and tap the 4 bolt holes on the mill. Then I'll make the center hub (brown part). When the hub is made up, I'm thinking I'll chuck the whole assembly back in the lathe and take a couple of finishing passes to true to whole assembly up as concentric as possible.

Here's a few extra pictures ('cuz we all love pictures). The aluminum wheel next to the heavy steel platten arm, and the whole thing so far.
IMG_4335.JPGIMG_4336.JPG
 
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