Tools Posts

Tube Mitering on a Lathe – Update 2

Tube Mitering on a Lathe – Update 2

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 some time ago 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 had a lathe this seemed the way forward. Although I have since acquired a milling machine I feel the lathe is easier to set up for the process. I have described elsewhere making the tube blocks to enable this. My lathe is small with 500mm between centres.
I initially 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. Tube notchers are available, such as these: https://www.stakesys.co.uk/tube-notchers/tube-notchers. They are designed to be powered by a hand drill and are considerably cheaper than a lathe, though obviously are a one trick pony. The speed of the saws is set by the drill trigger speed and will be determined by feel rather than dials, but I am given to understand can be used quite successfully.

Coarse and fine tooth saws (fine on the right)

Coarse and fine tooth saws (fine on the right)

T47 and associated matters

T47 and associated matters

I was recently asked if I would be able to make a bike with an oversize bottom bracket and full internal cable routing, amongst other things. Although this project may come to nothing it has been on my mind for some time to use a T47 bottom bracket, my only personal reason for this would be that it gives the space to potentially run cables and cable guides right through. I have never been keen on partial internal gear cable routing which always looks untidy, and I have never been happy with the idea of drilling holes in chain stays.
I would choose T47 over press fit, do I need to say why, though I did make a press fit bottom bracket shell for a balance bike and it was OK as far as I am aware.
Ceeway do stock PF30 press fit bottom bracket shells, which appear to be the same dimensions as T47, so I presume it would be feasible to cut threads in a PF30 to make a T47. Paragon in the USA make both Stainless and Plain steel T47′s and Bear frame supplies do plain steel ones but both were out of stock at the time I looked. The upshot of this is I decided to make my own, how difficult could this be, well a lot more difficult than anticipated, but I got there.

Cubic Boron Nitride – Any Use to Framebuilders?

Cubic Boron Nitride – Any Use to Framebuilders?

I have had some problems in releasing my home made seat tube heat sink from the seat tube after brazing, in as much as the heat tends to seize up the threads and cone mating surfaces making it difficult to loosen. Otherwise my simple design works very well. More sophisticated heat sinks may not suffer with the same problems.
I therefore decided to try a Cubic Boron Nitride lubricant, which is available conveniently as a spray quite widely at prices of £20-£30 a tin. Whilst expensive, a little goes along way. It is normally used as a releasing agent for stainless steel moulds for firing glass in a kiln and apparently can be used on mig welding tips to prevent spatter sticking. It is often used as lubricant for bullets in a powder form (thankfully sold only in the USA), and is the “ceramic” in ceramic lubricants.
It is supposed to be stable up to about 600 degrees centigrade or thereabouts, and still remains active for repeated use. I sprayed the components of my heat sink before use and am pleased to say it worked really well, the whole item unscrewed and removed easily and the product itself was not consumed.
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It is true that I was silver soldering, so the temperature would probably be well within the specification, but I doubt the internal temperature of the sink would reach brass brazing temperatures so I am optimistic it will still work. I’ve also used it to lubricate the threads on my Jig where they are exposed to heat.

Framebuilder Tooling – Using a Milling Machine

Framebuilder Tooling – Using a Milling Machine

A Milling Machine is usually the second major machine tool any aspiring metalworker will obtain, after a lathe. More correctly known as a vertical mill as horizontal mills do exist. Whereas a lathe mainly turns objects in a circle, the milling machine will make objects square and cut slots as well as performing tasks that can also be done on a lathe such as drilling and tapping (being more flexible for this), boring holes and sawing (using a ‘slitting saw’) and mitering tubes.
 Basically it consists of a drill mounted on a column which can be moved up and down, pretty much the same as a pillar drill. The head is wound down slowly and has an accurate depth scale on the operating handle. There is also a plunge section as you would find on a pillar drill with a large handle which can be used for rapid drilling but is locked out for more subtle milling operations. The column can often be tilted from side to side to enable cutting at an angle but in practice this is not very useful and it is usually better to mount the work at an angle. The mill can be used as a drill press. Some mills are sold as mill/drills but I am not sure of the difference. Drills can be mounted in a drill chuck but other tools are best mounted in a collet chuck system which is more accurate and secure. The drill head itself can only move up and down, so the shaping of the metal is achieved by moving the table in two axes, against the milling cutters of which there are several types. Collet chucks and the like are usually attached to the mill head using a morse taper. These have a tapped hole in the top which is to further secure them in the drilling head with a threaded bar. Unfortunately a lot of potentially interchangeable lathe tools have a tang (a projecting bit of metal) which is to facilitate their ejection from the lathe tailstock. This means they will not fit into the mill head. I am mystified as to why tooling manufacturers do not make interchangeable tools.
*(Belatedly I have discovered my mill can accept tools with a tang by fully extracting the drawbar, I do not know if all mills are capable of this. I have not seen any reference to it anywhere so it may well be worth asking if you are considering a specific purchase)
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Femi 782XL Metal Cutting Bandsaw – Review

Femi 782XL Metal Cutting Bandsaw – Review

I have wanted a bandsaw for some time but have been deterred by their size and weight in as much as one would have needed a permanent space allocating in the workshop, which I do not have! I then discovered the Femi portable saws, the 782XL being the smallest and only weighing 16kg. It will cut solid metal up to 41/2 inch diameter at a reasonable speed and the blade requires no lubrication during cutting. It stores away under my bench. 
I also obtained one of the matching tables which folds flat so also takes up no space. Although the table is sold as matching the bandsaw I could only match up one hole to slip a bolt through to make sure it is stable in use when being used as a table saw. It seems perfectly stable when used otherwise resting on a bench or the floor.
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Extras available are a small cutting table which attaches easily by clamping in the material clamp and a quadrant kit which in retrospect I probably will not use as it appears to be designed to help feed a large sheet at an angle, the size of which I cannot envisage using. Oddly Femi do not supply a fence guide which I think you really do need when cutting small pieces on the table. It is possible to purchase generic fences from places such as Axminster but I do not know for sure if they will fit.

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.

Disc Brake Fixtures on Kickstarter – UPDATE 2

Disc Brake Fixtures on Kickstarter – UPDATE 2

Eric Meinert, from Canada, has just launched a Kickstarter project to fund his POST MOUNT disc brake fixture. Suitable for both frame and fork as with previous fixtures, and suitable for both 140mm and 160mm rotors. The fixture can be ordered by pledge on Kickstarter: https://www.kickstarter.com/projects/4608648/bicycle-post-mount-disc-brake-jig. It will subsequently available from his Incepi website.

This fixture now complements his other available fixtures which are available from his INCEPI website at:  http://incepi.myshopify.com
There is an ISO disc brake tab fixture, below, which I purchased through a previous Kickstarter launch.
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Additionally there is now a FLAT MOUNT fixture which I understand is likely to become the accepted standard for road bikes. I think the price for the fixtures is very reasonable despite having to import them from Canada: effects of Brexit not withstanding!
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I have no experience of flat mount fitting on steel frames but The only commercial supplier I could find of the flat mounts themselves was Paragon Machineworks in the USA. However when I was at Bespoke 2016, Bear Bikes in Leighton Buzzard did have some on display and although they are not advertised as such I am sure they can supply them.

Some Small Lathe Projects

Some Small Lathe Projects

Since Jon Thompson’s post on introduction to a lathe I thought it worthwhile to share a few of the small bits I have produced since obtaining my lathe, to give a further idea of some of the possibilities. The first thing you discover is that a lathe straight out of the box is only the start, and most of the jobs I think up usually require additional lathe tools from commercial suppliers; or require the making of bits yourself specifically for individual jobs.
The first thing I wanted to make was a heat sink for brazing the top end of seat tubes; something I now feel is essential for fillet brazing stainless steel in this situation. These are commercially available but on reflection those I have seen would be unlikely to fit in my frame jig should I wish to braze in situ, so I can make my own more fit for purpose. One further point is that despite the Chinese allegedly dumping cheap steel on the open market, none of it has come my way and metal is an expensive commodity to buy, especially in the small quantities usually required.

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.

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.