Fixing A Broken Bandsaw With A Custom Steel Part

When a large bandsaw broke down due to a cast iron part snapping in two, [Amr] took the opportunity to record the entire process of designing and creating a solid steel replacement for the broken part using a (non-CNC) mill and lathe.

For those of us unfamiliar with the process a machinist would go through to accomplish such a thing, the video is extremely educational; it can be sobering both to see how much design work happens before anything gets powered up, and just how much time and work goes into cutting and shaping some steel into what at first glance looks like a relatively uncomplicated part.

It’s always interesting to get insight into the end-to-end workflow for different tools and methods. We’ve previously highlighted a series about the day-to-day work in a metal shop, and of course there is [Dan Gebart]’s series on mechanical prototyping that shares not just building, but some 40 years of experience worth of tips and tricks.

16 thoughts on “Fixing A Broken Bandsaw With A Custom Steel Part

      1. You can feel a ridge or groove of as little as a thousandth of an inch – without gloves. But I think there is another reason. They are not real hands. They have a bit of a Zoidberg look to them. Any whoop whoop whoop whoop whoop in the video?

        1. While I understand it doesn’t appear to be relevant in this shop, but under extreme temperature conditions glove are worn around moving machinery, when metal is blistering hot or well below zero. Safety cuffs mitigate hazard somewhat, but the hazard remains

        2. I an a electrician in Ontario. And if are not wearing glove at any time on the job we get three warnings fined and fired. That as been on any of the jobs I’ve been on for that last 10 years. and thows don’t count as gloves.

      2. I seem to cut my hands every day in the vocational school for metalworking I started attending half a year ago. Usually it’s because I touched something with razor-sharp, oily, sticky metal chips on it either by accident or out of thoughtlessness.
        At other times it’s because I was loosening a bolt which some half-wit gorilla tried to strip of its threads, and my force turns into momentum very quickly, making me punch something with a sharp corner.

        Last week while taking some sandpaper to a workpiece still in the chuck of a lathe, spinning the chuck with my left hand since I’m not an idiot, I wrapped my grip around the part for better contact and the actual skin of my right hand folded and pinched so that my grip involuntarily tightened and stopped all the momentum I had in the chuck. The 6.7kW lathe motor could have ripped my arm off easily.

        Cuts and bruises and having to wash your hands often is an inconvenience, but maintaining functional limbs is well worth the trouble. The gloves I use have a thick elastic fabric and corrugated rubber on the palms. They’re great for nuts and bolts and cleaning chips off machines. As soon as I run a machine they come off.

  1. The original part was cast iron, not steel. Cast iron was a poor choice by the manufacturer for this part. Cast iron is great under compression, but terrible under tension which this part was subjected to in adjusting the blade tension.

  2. NIce video.. On thing that I see quite often is people using drill chucks to holding milling cutters. Drill chucks are designed for thrust loads not side side loads that occur in milling. If you have a choice you’re better off holding a milling cutter in a collet.

      1. Using the right tool for the job is important. If you are not alone in the workshop it is essential since a tool worn by misused can be lethal.

        ER collets are cheap and versatile, and so are Morse taper holders for them.

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