Personal Articles Posts

Tube Mitering on a Lathe – Updated

Tube mitering is a fundamental part of custom frame building and I am sure there is always a need to be able to produce good results by hand and eye. Paper templates are a boon for speeding up the process and increasing accuracy but I decided to see how I would get on with some form of automation for the process. A milling machine, lathe or tube notcher can all be used but as I already have a lathe this seemed the way forward. I have described elsewhere making the tube blocks to enable this. My lathe is small with 500mm between centres.
I have obtained several Coba-Tech hole saws from Stakesy’s metalwork machinery suppliers (https://www.stakesys.co.uk/hole-punches-hole-saws/hole-saws-arbors/coba-tech-10-tpi-fine-tooth-holesaws). These are fine tooth saws as opposed to the more usual coarse tooth saws I have used in the past. For cutting good mitres in fine tubes I would say these are essential and Stakesy’s were the only supplier I could find. They also sell some tube notchers which are designed to be used with a conventional drill but I have no experience of using these.

Coarse and fine tooth saws (fine on the right)

Coarse and fine tooth saws (fine on the right)

Tube Bending and Panana Budget Tube Bender Review

Tube Bending and Panana Budget Tube Bender Review

Tube bending is something I avoid, however there are times when it is necessary. Some framebuilders do it as a feature of their work but I tend to only use bent tubes when it is necessary to solve a clearance problem as with the child’s first pedal bike. I purchased this bender for the princely sum of £90 from an Ebay retailer who I guess is based in China but had stocks in the UK. The brand may be a red herring as I suspect it is one of those tools turned out by a Chinese factory under different names. Indeed Stakesy’s have what looks to be an identical bender available on their site for £165, though they were out of stock when I ordered mine: https://www.stakesys.co.uk/tube-pipe-benders/manual-tube-benders/sta137-buzz-bench-top-manual-tube-bender.

Bespoke 2017

Bespoke 2017

An excellent display of custom building again this year with many highlights. I doubt if I spotted them all.
Lugs are back
Although they never went away it seemed to me that there were more lugged bikes than ever this year and in particular with stainless lugs, my own favourite. The standard of stainless steel polishing also seems to have gone up, though once again the bikes displayed by Darrell McCulloch (Llewellyn Custom Bicycles) were on another level.
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There was some brushed stainless in evidence, not something I have tried and I suspect difficult to do well.

Pro-Max 350w 6inch Bench Grinder –  Review

Pro-Max 350w 6inch Bench Grinder – Review

I purchased this machine from Metal Polishing Supplies after an online search. It is a “Budget” model in the world of Bench Grinders and bears a remarkable resemblance to a lot of other own brand models suggesting they are likely to be made in the same Chinese factory. Credit to Metal Polishing Supplies, however, in as much as the company has produced it’s own product leaflet which is written in clear english. They also offer a 3 year warranty.

Bespoke 2016

Bespoke 2016

Predictably I went to the Bristol Bespoke show again this April to keep up to date with current ideas and trends. The photo above is of the displayed Craddock track bike and I want one of his road bikes. Richard Craddock is not the only bespoke carbon fibre builder but has been doing it in the UK the longest. He uses Carbon fibre tubes and cuts and mitres in the usual way then overlays the joints. His bikes used to have a lugged appearance but now due to popular demand he has smoothed out the joints by feathering the layers. You can get a truly made to measure bike with his method.

Oxy-Propane Brazing – UPDATE 2

Oxy-Propane Brazing – UPDATE 2

I use oxygen and propane for my brazing. I did not want the expense and extra safety concerns of storing and using acetylene, and in particular did not want to get involved in contracts given the small number of frames I am likely to build as a hobbyist. Recently small contract free acetylene cylinders have become available. Personally I see no advantage in using acetylene for building lugged frames, but it does have advantages for fillet brazing. Propane is relatively cheap and long lasting and widely available for a small cylinder deposit. I use a 11kg cylinder. Smaller ones are OK but I have found the larger cylinder more stable, especially when using a gas fluxer, I don’t know why. Storing the smallest size cylinders of practical use of any flammable gas is common sense.
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Custom Frame Builders Association and Public Liability Insurance

Custom Frame Builders Association and Public Liability Insurance

Several informal meetings have taken place between Custom Frame Builders across the UK with a view to establishing an Association. At present there is no formal organisation established but an intention exists to make it such, primarily as a talking shop for exchange of information. Additionally it has been proposed to offer a EN/ISO test of frame integrity in conjunction with Reynolds. It has been mooted it may cost around £300 for 631 tube set and test and the frame can be lugged or fillet brazed or maybe Tig welded. Regarding entry to the Association, the only clear cut criteria which has been agreed by all the participants is Public Liability Insurance. The long term structure and function of such an organisation I am sure will evolve over the years but I would like to think there may be a place for Amateur and semi-Professional builders within it. The current forum is being co-ordinated by Phil Taylor, organiser of Bespoke Bristol but he is keen not to take responsibility for fully organising an association as he obviously has enough on his plate with the show. As a preliminary move I decided I would have to investigate Liability insurance as even though I have never sold a frame for profit it would be nice to have the cover and indeed even making frames for friends and family it is a sad fact of life that one would be wise to have some indemnity against frame failure leading to accidents etc.

Visit to Reynolds Technology

Visit to Reynolds Technology

I was fortunate enough to receive a tour of the Reynolds factory in Birmingham whilst attending an informal meeting regarding a proposed frame builders cooperative, which was held at the factory. The factory is a large warehouse building on a small industrial estate filled with a lot of vintage heavy duty and mainly British machines. As the factory is a very noisy place it was difficult to absorb all the intricacies of it’s workings but certainly gave me a better appreciation of where my tubes come from. Reynolds produce Steel tubes mainly but also Titanium. Most of the raw tubing is sourced in Taiwan where it is made to Reynolds specifications. Some Stainless tubes also come from the USA. The factory does most of the drawing and butting etc and final finishing to turn them into bicycle tubing, but also produces tubing for other uses, particularly motorsport. Most of their output is still steel tubing though use of titanium has been rising.

New Framebuilders Resource Website

New Framebuilders Resource Website

Eric Meinert of disc brake fixture fame ( incepi.net) has started a framebuilders resource website which has the largest number of frame building related links I have ever seen. Hopefully he will develop it further as framebuilders offer content. It also has a Facebook page. It covers the frame building community Worldwide so includes the UK. The web address is http://framebuilder.ca.

Servicing a Model W Gas Fluxer

Servicing a Model W Gas Fluxer

I have been running my Gas Fluxer now for 2 years before the gas pressure dropped right off and it looked like it would need servicing. The outflow valve was very stiff and showed evidence of white residue on the threads suggesting a leaking valve. The usual most likely cause of pressure drop off is a blocked flashback arrestor but in this case replacing it didn’t help. I resolved to empty the fluxer and replace any faulty seals.