Craftsman 10" bandsaw 113.244513 (5): Testing new lower blade guide (updated)

 I installed the new lower guide into the Craftsman saw, as shown in the photo below.  There were minor issues and one major issue as noted in the photo and the list below the photo.

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• There is interference between the left side of the thrust bearing axle and the case. This is easily fixed by cutting the ends of the axle down.
• There is possible interference between the right blade guide and the case.  Fix by cutting the guide length down. 
• Change all the set screws to Allen style headless screws.  This will help reduce places to snag when installing the sawblade.
• The thrust bearing is not centered on the blade.  For now I will install a shim under the lower blade guide support to move the guide over about 1 mm. 

The saw runs fairly well, with some noise. Once I get the above issues on the lower guide fixed, I'll replace the wheel bushings with ball bearings, and replace the worn tires. 

UPDATE: 

I bought a bottom style 10-24 tap on Amazon.com for $3.  It cleaned out the set screw holes very well.  Now the set screws don't jam and it's easy to feel when the screw contacts the blade guide.   I also shortened  the thrust washer bearing axle and the two blade guides.  Now there is no interference of those features with the case.  

I printed a set of shims to use under the lower guide support to center the thrust bearing  on the blade. The shims were nominally 1mm, 0.5mm, and 0.25mm thick.  Upon actual 3D printing, each shim was 0.13mm or so larger than nominal.   The 1mm and 0.5mm shims together seemed to center the blade on the bearing the best. 

The photo below shows the shims after 3D printing.

The photo below shows the guide installed with notes on latest changes.

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Craftsman 10" bandsaw 113.244513 (4): Lower blade guide redesign (results)

This lower guide replaces Craftsman Part 69174  in the 113.24413 model bandsaw. 

I did the lower blade guide redesign in Fusion 360.  See the diagram below with changes noted.  I increased the material volume around the blade guide set screws and added holes normal to the layer planes to accommodate 2mm reinforcing screws. The holes for the thrust bearing axle were enlarged to get a sliding fit on the axle, and 3mm set screws were added to hold the axle fixed.

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I 3D printed the guide out, using black PLA, 100% fill.  Because of the black plastic of the guide it is hard to photograph. The photos below show the guide with hardware installed from a front and rear view.  

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Some notes: 

• I have not used the Cura slicer software to calibrate hole sizes while printing. All holes in the guide were slightly small. I spent a lot of time drilling out holes, experimenting on test pieces to check for correct size. 
• I was not able to use a tap well for the 10-24 saw guide set screw holes.  The tap bottomed out against the bottom of the blade guide holes. Because of this the set screws tend to jam as they get near the blade guide. That makes it difficult to feel when the set screws are solidly against the guides.
• The 2 mm tread inserts I used from the bottom for the reinforcement screws were a little tricky to install. I put them on the tip of a soldering iron and melted them into the guide body.  I had to use a screw from the bottom side  to clean out the melted plastic from the from the holes, then install the reinforcement screws from the top side. 
• I didn't use a tap on the thrust bearing axle set screws, but rather let the screws cut their on threads in the plastic.  I don't think this will be a problem as the screws don't have to be torqued very much to prevent lateral movement of the axle.   Next time I'll use thread inserts to get  better seating on the screws. 

I will be installing the guide in the saw today and testing how well it works. 

Craftsman 10" bandsaw 113.244513 (3): Blade guide redesign plans

 I bought this Craftsman 10" 3-wheel saw in August of 2023 for $10.  At the time, it didn't have the switch key or a blade installed, so the owners just sold the unit for salvage.

I found a switch key for  Craftsman products on Thingiverse.com (link).  I  then  3D printed the key in PLA, The key has to be positioned with the "legs" up while printing, and then the support material under the "head" has to be whittled off, but the switch key functions very well, as shown below. 

The saw needs new tires, but I haven't ordered any yet. I bought a 56-7/8 inch 1/4" 14TPI bandsaw blade (link) for the saw and spent some time trying to tune up the saw.   In the process I discovered that the lower blade guide to the saw was broken.   The guide body, Craftsman part 69174, is cast from pot metal, and broke at an obvious weak spot as shown in the photo below.  I found a Thingiverse.com replacement (link).  The printed out replacement part is shown below.  It was printed in orange PLA with 100% fill.  The hardware for the thrust bearing has been moved to the new PLA bearing  The blade guides were missing in the original part. I used 1/4" bookshelf pins for the side guides. 

The photo below shows the lower guide after installation. The thrust bearing has a groove in its surface and needs to be replaced. 

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The problem with the 3D printed part is immediately apparent as shown in the photo below. The blade guide set screws produce stress that is normal to the 3D printed layers.  The part is weak in that direction and the stress causes fractures parallel to the layers as can be seen in the photo. 

Someone must have experienced this problem and revised the part to be more robust (link).  See screen capture below. 

Another problem to consider is the replacement of the thrust bearing.  See the photo below and the issues list below that. 

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Thrust bearings issues list: 

1. There is no provision for moving the thrust bearing laterally to center it on the saw blade. The lateral position of the blade is mostly determined by thickness of the bandsaw tires.  I don't know how much of an issue this lack of lateral adjustment will be. 
2. The current bearing is worn with a groove on its surface.  I found replacement bearings on Amazon.com (link). They are 3mm ID X 10mm OD X 4 mm wide.  I've also found 3mm stainless steel rod to make the axle (link).  I haven't yet found material to make the spacers.
3. The thrust bearing is difficult to install on the guide. The axle is currently pressed through the guide plastic body.  I don't like guessing the proper diameter to get a good interference fit for the axle.  Also without some sort of installation jig, pressing the axle stresses the plastic guide body and distorts the part. 

My plan for the plastic guide redesign are shown in the sketch below, which is a side view of the guide: 

1. Extend the material adjacent to the saw guide set screws and add reinforcing screws to prevents cracking of the plastic when the set screws are tightened
2. Eliminate the interference fit of the thrust bearing axle and make the holes a free fit. Then add set screws to prevent the thrust bearing axle in place. 
3. Produce the thrust bearing axle spacers using 3D printing, making their lengths asymmetric to keep thrust bearing centered on the saw blade. 

I will import the bearing guide stl file into Fusion 360 and modify it as needed to get a revised part. 

Craftsman 10" bandsaw 113.244513 (2): Workstand built

 I designed a stand for my Craftsman band saw in Fusion 360. The stand is made from 2 X 4 legs and 1 X 4 stringers. The top is 12 inches by 16 inches.  I picked up all the wood from KA5VZE's scrap pile.  

The photo below is the stand as built with the band saw mounted.  My garage floor is uneven, so I'm going to buy some leveling logs to put on the front legs.  Sooner or later I'll add wheels to it.   The way I built it was not really conducive to getting everything aligned well. 

Craftsman 10" bandsaw 113.244513 (1): Introduction

 I bought this bandsaw on August 31st, 2023, and puttered around cleaning and tuning it up.  I think I finally have it working reasonably well. 

The model number is 113.244513