Reassembling a Belt Sander 6x48

JPG · Post by **JPG** » Thu Jun 16, 2011 7:10 pm

I am adding this link to a previous thread so the reference to 'Rob' will make sense http://www.shopsmith.net/forums/showthread.htm?t=8172&highlight=reassembly

As Rob has pointed out, it is not completely disassembled, but further than most will take it down. This thread is intended to illustrate one method of putting it back together. I have attempted to identify and illustrate where potential problems reside. It is possible to assemble it incorrectly and become quite frustrated when it does not go together smoothly(see Nick's Sawdust Session!;)).

The unit illustrated is an early Shopsmith Inc. gray version with the older Magna castings. The stickers are original and were carefully removed then reattached after painting. There are two other differences between this unit and newer vintage, and those will be pointed out below. The new paint colors are my personal preference - gold and coppertone from Rustoleum(hammered).

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Before reassembling. The table is not shown. I did not take pix of the table unassembled, but will take a couple showing the parts removed.

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A word about the bearing cavities in the side castings. There is a spring clip in the bottom that is installed with the fingers facing the bearing(flat side to the bottom). That white stuff is lithium grease(both sides of the clip). It has been pointed out that SS CS says the reverse when asked. So flat side s/b against the bearing, and the fingers towards the bottom of the hole. Mine were the other way when I disassembled it???

THE BEARINGS ARE 5/8" x 35mm x 11mm shielded 6202-10-ZZ << Added 6-8-14

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On the back side of both castings there are two clips on each that serve as sacrificial lambs when the belt tracks too close to either side. The hardened tinnerman clips will last longer than the softer aluminum casting.

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I pried the originals off and replaced them with new clips.

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The tracking adjustment knob and screw is inserted in the hole and pre-adjusted to about 1/2" thread sticking out the rear(that includes the knob thickness). More about that 1/2" later! See post #5. This is not critical since it can easily be adjusted even with a belt installed. Note the side of the tracking adjustment knob with the raised center faces towards the center.

Both this pix and the 'fixed' screw on the opposite side are shown with the roll pin sticking out towards the camera. This is not correct. The roll pins must be facing outward and ride in a groove in the casting. This will be shown later.

JPG · Post by **JPG** » Thu Jun 16, 2011 7:48 pm

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The other side has a fixed(but still adjustable with the belt off) tracking screw and it also should be installed with 1/2" exposed threads towards the rear. The tinnerman clip removed is 1/2" wide so it is a good gauge. More about that 1/2" later See post #5

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The 'knob' end of the idler drum has two or three parts to put back on. The large flat washer goes on first. Then on newer versions, a curved washer followed finally by the 'guide bushing'. The idler drum was cleaned out of old original grease and replaced with lithium grease. Not easy to do, but the ends will pull out(under spring tension) and provide access to the grease and each end of the shaft where the bearing bushings contact the shaft. Need extra hands or vise to do that.!

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A word about the 'guide bushing'. Notice it is not square, but rectangular. The long side runs front to rear. Only the shorter sides will fit into the slots they ride in.

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As promised a pix showing the fixed tracking screw roll pin properly inserted with the roll pin facing out into its groove.

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Finally the idler drum etc. installed in the casting. Notice the tracking screw is inside of the large flat washer so as to properly contact the tension cam. The guide bushing is riding in its slot and the tension pin is in its groove.

JPG · Post by **JPG** » Thu Jun 16, 2011 8:31 pm

Not shown, but the drive drum bearing was never removed from the non-adjustable side casting we have been working with.(see 1st pix post #1). With that casting positioned so that the both drums(the drive drum is also inserted into its bearing) face up, we will now address the 'other' end of the idler drum.

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Insert both spacers in their bores and position the guide bushing so that the long sides run front to rear(so it will fit into the slot in the second casting).

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After sliding the casting onto the drive drum shaft and the two spacers and the guide bushing, the idler shaft etc. should look like this.(Yes all that at once is a bit of a challenge, but perseverance will get it done) Notice the tracking screw roll pin, the tracking screw end and the guide bushing are all in the proper place.(Just like the other side).

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If the bolt is held vertical over the square hole in the casting and the assembly is positioned correctly, the bolt will drop straight down into the hole on the opposite casting.

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Pretty obvious, but the lock washer goes on first followed by the nut. At this time only finger tighten the two nuts.

JPG · Post by **JPG** » Thu Jun 16, 2011 8:51 pm

The tension release knob slips onto the idler drum shaft, but make sure the knob is oriented to the slot in the shaft.

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The knob is retained onto the shaft by an external ring that fits into a shallow groove near the end of the shaft.

: snap ring installed.jpg (124.84 KiB) Viewed 19998 times

I think it a good idea to position the open end of the ring away from the open slot on the shaft.

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This pix is of a newer version and shows the platen mounting tabs are raised above the side of the casting. This eliminates the need for the 12 spacer washers(shown below) used in this older version. Yes the rust indicates it resides in the 'todo' pile.

: platen lip old.jpg (125.2 KiB) Viewed 19978 times

The older version has platen mounting tabs that are below the edge of the casting which requires the use of 2 thick spacing washers under each of the six platen mounting screws.

: platen spacers.jpg (66.44 KiB) Viewed 19974 times

I did not take a pix of fastening the 6 platen screws. I only snugged them up at this time.

JPG · Post by **JPG** » Thu Jun 16, 2011 9:40 pm

At this point I installed a belt and determined that the tracking screws needed to be closer to the rear(belt length will affect this) so I decided that 1/2" is NOT ENOUGH. So I changed it to slightly over 9/16". One of the 9/16" nuts will serve as a gauge this time. The tracking screw on the other side must be also changed.(accessible with the belt on)

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With that change, the belt barely slips onto the drums.

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The Medallion is a press fit onto the tension release knob. This is the original medallion after recreating the domed shape(it was pushed inward).

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Moving to the back, notice the double d shaped hole for the trunion stud. The stud has two opposing flats on the threaded portion that fit into that hole. The trunion lock nut(the round one with ss tool kit holes) screws onto the stud from the outside. The washer is between the locknut and the side casting.

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On the inside a flat washer, a 'cup' and a nylock nut hold the stud. Tighten the lock nut to at least the top of the nylon. Snug the trunion lock nut to keep things from moving.

JPG · Post by **JPG** » Thu Jun 16, 2011 9:58 pm

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Some consider this a mystery bolt. I think it serves a more positive locking action than the 'normal' one.

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It must be removed and moved as the trunion is moved back and forth between horizontal and vertical.

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After final tightening the two carriage bolts(resist the temptation to mimic a gorilla here. Just tight will do.

The hole plugs merely press into the holes in the casting.

Now would be a good time to securely tighten the platen screws. Really get on these, but do not let the screwdriver slip/cam out.

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The shaft cover also just pushes into the hole in the casting. It can be on either side.
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Finally the dust chute attaches with two screws, the hub goes on the shaft, and the mounting tubes go into holes in the base casting.

I messed up and did not get the last post 'posted'. I will recreate it below(post #9).

billmayo · Post by **billmayo** » Thu Jun 16, 2011 10:23 pm

The earlier belt sanders had a crown on the lower drive drum. I found that the later versions, the drive drum cross width is flat. The flat drive drum makes belt tracking less of a PITA. I have machined the earlier drive drums flat so that it helps set up the tracking quicker and keeps the sanding belt more centered without frequent adjustments. I find a new lower drum sleeve/cover helps as I have to remove the sleeve/cover before machining.

I would believe that everyone crowns the sanding belt when first installed otherwise the belt tracking is difficult to maintain.

JPG · Post by **JPG** » Thu Jun 16, 2011 10:32 pm

billmayo wrote:The earlier belt sanders had a crown on the lower drive drum. I found that the later versions, the drive drum cross width is flat. The flat drive drum makes belt tracking less of a PITA. I have machined the earlier drive drums flat so that it helps set up the tracking quicker and keeps the sanding belt more centered without frequent adjustments. I find a new lower drum sleeve/cover helps as I have to remove the sleeve/cover before machining.

I would believe that everyone crowns the sanding belt when first installed otherwise the belt tracking is difficult to maintain.

I was surprised that the drive drum was flat. I have to assume that SS Inc. started the flat drum since this was an early ss Inc. version.

It is possible however, that I 'flattened' it but I do not recall since I took this apart 2 yrs ago! How thick is the rubber? If too thin, then I did not!

JPG · Post by **JPG** » Thu Jun 16, 2011 11:00 pm

Time to stand tall!

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I will post table pix after I take them! See post # 15

Sneak Preview!:D

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jimsjinx · Post by **jimsjinx** » Thu Jun 16, 2011 11:25 pm

Man, that's one bad a$$ belt sander! Then I see the last pic, and blew coffee out my nose!!!! That's the longest Shopsmith I have ever seen! I can't wait to see what you're up to!!! Cool sander, and nice resto! jimsjinx