Author Topic: Wooden Bandsaw  (Read 9289 times)

Offline dwc

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Wooden Bandsaw
« on: April 16, 2021, 11:45:35 AM »
About a month ago I asked you guys for some advice about building a wooden bandsaw. Many thanks for the replies, they really pointed me in the correct direction I think. There seemed to be some interest in seeing the project so here we go...

One of the suggestions was to use a half shaft from a car but I wasn't sure how I could incorporate that. It did get me to look at kart parts again though and now I'm the proud owner of a 30mm kart axle and break disc hub. I've spent most of my time so far building the frame and buying parts. I think the frame is stronger than needed for a saw of this size but I'd rather too strong than too weak. In the attached photo the frame is just dry fit together. I've literally just finished gluing it together and lets just say it was a stressful experience. The glue caused the wood to swell ever so slightly which meant putting the parts together was a challenge. I had to resort to the larger precision adjusting tool, one part of one joint will need some repair work.

The saw will be 750W with a target of 150mm depth of cut on a 350mm wheel diameter.

The design is all done in FreeCAD making extensive use of the Assembly3 plugin. I have mixed feelings about this software. I've played with SolidWorks and Fusion360 enough to know that I could have banged out this design reasonably quickly, with FreeCAD it was an uphill battle the whole way. It's frustrating because it's close to being good enough but it's lacking the polish of a commercial offering.

Offline dwc

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Re: Wooden Bandsaw
« Reply #1 on: May 13, 2021, 07:47:14 AM »
Time flies when you're having fun, the wooden bandsaw now sort of works! Turns out I'm terrible at remembering to take pictures of my work in progress, sorry :-(

The frame is finished, the bearings are mounted, the wheels are trued up, the tensioning and tracking mechanism is installed, and a blade has been put on the machine. I've run it up and, with great care and not a small amount of fear, cut some wood. The crown on the wheels is enough to hold the blade in place for small cuts which feels like a good thing. I've yet to make the covers or the blade guides so I'm staying well out of the way when it's running!

And now for the bad news... The first time I fired the bandsaw up everything went fine but after a few test runs the RCD tripped in the consumer unit. Obviously that made me suspicious but I reset the switch and tried again, it was fine. A few more trials later and now the motor is tripping the RCD every time. It seems to be happening as the centrifugal clutch disengages. When the motor is on the bandsaw it takes longer for it to spin up to speed and the trip happens just as I hear the clutch disengage, with no load it spins up almost instantly (and trips). I'm hoping the motor isn't toast, any advice would be most welcome. The motor is just a bog standard single phase 750W job that you pick up for cheap from eBay.

Offline Sea.dog

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Re: Wooden Bandsaw
« Reply #2 on: May 13, 2021, 09:38:25 AM »
Replace the start capacitor.

Offline awemawson

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Re: Wooden Bandsaw
« Reply #3 on: May 13, 2021, 10:01:35 AM »
Looking good and I expect Mr Spink's advice will sort the motor - good luck :thumbup:
Andrew Mawson
East Sussex

Offline krv3000

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Re: Wooden Bandsaw
« Reply #4 on: May 13, 2021, 04:04:04 PM »
 :thumbup: brill