Making a spring washer

[tomfisherParticipant @tomfisher]

Hello,

I have recently acquired an Emco rotary table, which is missing the spring washer that fits between the crank and the quadrants. I have sourced some from Accu, but they are not the right diameter, and don’t bear on the edge of the quadrant circumference as does the original. For this reason (I think) the quadrants turn very easily with the crank.

How difficult is it to make a spring washer of the bellville type? The original is 1mm thick, has a 12mm hole and is about 30mm o/d.  What material should I use? What heat treatment is suitable?

All help gratefully received.

Tom

[duncan webster 1Participant @duncanwebster1]

<p style=”text-align: left;”>Have you tried https://www.springxpert.com/products/disc-springs-din-2093-belleville-washers-din-16983?variant=53599655985532&currency=GBP&https://www.springxpert.com/collections&gad_source=1&gad_campaignid=21046431281&gbraid=0AAAAAqNaUPk-i9PkJUzKGtpNaS9PtUNh3&gclid=Cj0KCQiAgvPKBhCxARIsAOlK_Er4yjzFSHQxGyeB0h0th_yV4sCmZZpboJGsftb8WDt5EJEYerLOw-gaAsZVEALw_wcB</p>

[FulmenParticipant @fulmen]

The basic spring steel is heat treatable carbon steel, same as you would choose for a knife. In fact countless knives are forged from old leaf springs every year. The heat treatment is simple: Heat until red, quench in oil and temper to blue.

My table used a open, C-style spring for some reason, so when I lost mine I quickly fashioned a new from a brake line clip: https://adventuretaco.com/product/brake-line-clip/

[old martParticipant @oldmart]

If you are not in a hurry and have an ebay account, then these Chinese sellers may have the exact size that you want.

ebay 388087953128   I couldn’t get the link to paste.

 

[Charles LamontParticipant @charleslamont71117]

I have made rather smaller ones by turning the top-slide to allow me to part them off at a small angle. I found the tempering fairly critical. Too much and they permanently squashed flat, too little and they snapped.

[Graham MeekParticipant @grahammeek88282]

The Bellville washer used on the Emco Rotary table has a slot in it to provide access to the screw locking the sector arms. Some years back after a breakage of the original on my Rotary Table. I had to get a standard Bellville modified at a local engineering company who wire cut the slot.

The only down side to the Emco arrangement is that it weakens the spring washer and a suitably placed hole would be better. This however would probably need Spark Eroding or maybe Laser cutting.

Regards

Gray,

[Grizzly bearParticipant @grizzlybear]

Hi,

PCP air rifles contain bellville washers, those that I have seen are approx 12mm diameter.

Obviously not suitable for your job.

Good luck…………

[FulmenParticipant @fulmen]

<p style=”text-align: left;”>It shouldn’t be necessary to machine the angle, I would try to press it. And solid carbide should cut spring steel without too much issue, I have machined HSS successfully that way in the past.</p>

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