Scroll Saw Repair Using TinkerCad, Flatbed Scanner, and 3d Printer

The Excalibur II

This was a top of the line scroll saw back in 1982 when it was purchased. It did an incredible amount of work in it's day. Sadly it broke in the early 2000's and parts could not be found. It sat in a corner of the shop for years. Then was moved to the upstairs of a barn where it sat for the past 17 years. I've decided its time to fix it.

Things needed to complete this repair are as follows;

Socket set

Screw drivers

Hex keys

Rubber mallet and pry bar may come in handy

A printer with scanning abilities or a flat bed scanner

Computer

Internet connection

3d Printer with carbon fibre reinforced filament and supporting software

I cleaned the saw, then brought it into my shop. It looked fine but when the motor turned, the blade didn't move.

My assessment "Saw is broken" duh!

I removed the drive belt so I could spin the pulley easier. I didn't feel or hear anything odd. So I began looking around and found a small hole. So I looked in it of course. While turning the pulley the problem was found. As you can see in the third picture a piece is broken.

Unfortunately this broken piece was one of the first pieces to be installed when building this machine. I took lots of pictures while taking this apart. I will use them as reference when putting it back together. If I put it back together.

This is the broken part. When the drive shaft spins, this piece moves back and forth. It pulls and pushes an actuator arm that in turn connects to the upper and lower actuator arms that drive the blade mechanisms. Clear as mud, right? Simply put, this makes it work. Its broken, so it doesn't work.

I searched the net and came up empty. A 40 year old saw part is impossible to come by. I thought about having a piece machined or, maybe I could use aluminum welding rods and fix it myself. But if I destroyed the piece, how would a machinist make me a new one. I decided I had better do some measurements.

To start the design process I scanned the part with my Brother printer . I used a sharpie first to assure a nice dark image.

I used free online tools to prepare my scan for use in Tinker Cad. In these pics you can see how I removed the background, darkened, and created a .svg file I could import into Tinker Cad. The pictures show the addresses of each of the free websites I used but they are a bit to small for some eyes. My own included. The sites are as follows:

https://tech-lagoon.com/imagechef/en/background-remove.html

https://tech-lagoon.com/imagechef/en/image-to-monochrome.html

https://www.pngtosvg.com/

Tinkercad is an amazing tool. Once I imported and sized my .svg image, I was able to build around it with solids and holes until I had recreated the part. No need to figure out the angles, just follow the scanned image. Once all my creations were in place, I just removed my scan, selected everything else and clicked combine and voila! One additional cut out and two small additions and I was done. I then exported my creation as an .stl file.

My next thought was 3d printing. If I had a part printed and it fit, then I could attempt aluminum welding without worry. If I messed up I'd give the printed part to a machinist to copy. Problem is I don't have a 3d printer.

I uploaded my .stl to a website and for $8, shipping included, I got myself a perfect copy of my creation. BLEW MY MIND!

I had chosen the cheapest option they had in case it didn't work well. After receiving my perfect part, I decided to order one made with carbon fibre reinforcement and just use it. I was now finding that my price had risen astronomically. Even reordering the one I had just purchased would have been over three times the price. Garrr@#! What to do now.

This was my first experience with Tinker Cad and 3d printing. If I had my own machine surely I would be able to do more than just fix this scroll saw. So yes, I decided to dive down the rabbit hole. I bought a Creality ender6 3d printer. I have lots of pics of assembling it. This Instructable isn't about building a 3d printer though. Maybe I'll do another Instructable on how to assemble it another time.

Of the many programs out there to prepare .stl files for printing, I have chosen PrusaSlicer. I'm new to this and I find it pretty easy to follow. I bought carbon fibre reinforced pla filament and printed my own part.

It was so exciting to have my own printed part, after 5 months of having the machine in pieces in my shop. I put it in and reassembled the saw. It works great so far. If it breaks again, I'll just print another part with a stronger filament and see how that goes. In the mean time, I'll enjoy my new hobby by printing other items.

This is just a simple test with thin material to show it running.

I'm quite pleased with how this project turned out. I also look forward to incorporating 3d printed items into future Instructables.

Tinkercad was also super fun to work with, so thanks to Autodesk for offering such a marvellous tool for free. I look forward to trying out their Fusion 360 program next.