Why Cast Iron?

[Rustrp]

If I get to it I will post pics of the build.

I know you opened with; "I'm thinking of...." Now it's one more piece I have an excuse not to scrap out.

PS. I think in this particular application I would steer clear of bronze bushings. Dry isn't a good match and oil just makes things worse.

 

[coffmajt]

Thank you both for the very generous offers but I think I need to find a local source, since I doubt this will be a one off kind of thing. I will also look at getting some bronze bushings for this project. If I get to it I will post pics of the build. Not sure I will for a while though as cabin fever has hit the wife & I and we need to go camping as soon as the weather improves a little. We bought a new travel trailer in October 2016 and have not been able to use it yet.

I have been happy with Speedy Metals for small chunks of cast iron, that way you can specify pretty close to the final dimensions you need and not pay wasted freight charges on something you will not use -- Jack

 

[Rustrp]

I have sourced cast iron from small barbells at Wally World and Canadian Tire. Sometimes I find them and the cast disc types at the local thrift store. I have heard horror stories about sand inclusion etc but have never found them myself. I have used several of the barbells but have not yet found a use for the discs. I did see a You Tube video of a guy who made a precision drill press using a disc as the base.

I think the misc cast iron pieces are okay for any non-critical piece as far as strength or ease o accessibility but most items like gym equipment and exercise weights do not rate high on QC.

 

[HomeMetalMan]

I see Hbilly that you are asking why I have used cast iron for the bearings on my end mill sharpening fixture, lets first consider the requirements.

The essential requirement is for the spindle to move very freely, and without any clearance which would permit it to shake. The latter being achieved by the use of split bearings which enable the clearance to be adjusted.

The need for the spindle to move freely is then achieved by the combination of mild steel moving on cast iron.

At this point we go beyond my understanding of the situation. However, it is known that dissimilar metals move more freely over each other than two similar metals and for mild steel with cast iron this is particularly noticeable, especially at slow speeds.

As has been said earlier in the thread, cast iron is also self lubricating, in any case, the use of a lubricant is taboo as this would capture minute fragments from the sharpening task being undertaken and would be self defeating.

Harold

 

[HBilly1022]

Although there was no need for you to use your valuable time to respond to this thread, I certainly appreciate it. More importantly, I appreciate and respect all the time and effort you have put in to creating and maintaining your website with all the information and knowledge you offer so freely. It is the perfect site for people like myself who are learning this hobby and like to make things.

Thank you so much. Sending you a PM.
John