Tube Benders

This is the CNC pipe bending machine where I worked doing similar work to Mr Hunt. This was the first go using some CA104 Al Bronze bend tooling I had made for 1/4" stainless tube.

The Hilmor bender linked to in an earlier post worked similarly to the one designed and built by Mr Hunt. A manual draw bender with bullet or plug mandrels in the bore.

We had similar issues to him regarding being pushed to outsource work because "sub-contract make it cheaper". I and a colleague went on trips looking at a few potential suppliers of bent pipes and tubes, one near Bury St Edmunds and one of them was South Lincs Fabrication (now SL engineering I think) who were quite a small outfit at the time. Turned out SL Engineering were making bent pipes and tubes for RR. One was a big no-no, it was like going back to the industrial revolution and would never have met our quality standards. SL Engineering were able to meet our quality requirements so were asked to quote for some bent pipes and tubes. Some of the parts being quoted were 3/4" stainless tube with one or two bends. We had a cycle time for cut off, deburr, degrease, bend, clean and blank off totalling about 12 minutes at a cost rate of £50/hour. Due to economy of scale (we batched all 3/4" tube parts so there was only one tooling setup cost spread over many parts), with material cost this came out to a cost per item of about £12. SL Engineering were asked to quote for one part consisting of 8 of these bent tubes (all slightly different) and the quote came back with a cost per piece of over £100 so a total cost of over £800 for something we were costing at less than £100. There was also an initial setup cost to buy suitably sized tooling that was about £1500. We kept the work. I think this reflects the difference in cost rates RR were working to compared to £50/hour and how much SL Engineering could charge and still look cheaper than in house production.

Martin C