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Member postings for Alan Jackson

Here is a list of all the postings Alan Jackson has made in our forums. Click on a thread name to jump to the thread.

Thread: Folding Bike design & build
11/04/2019 16:46:01


I started out with a patent agent but had to dump him because he complicated things too much and would not change some claims because he said the controller would not like it. I contacted the controller and he said it was not a problem. So that saved me money and I eventually got the best out of a bad job.


11/04/2019 12:45:33

Hi ega


11/04/2019 10:52:48

Hi ega, Rod, John, not done yet, perko7, and all

I had to go through the patent process just to be able to show it to others. It is a necessary requirement, otherwise nobody is interested and/or will copy if they want: that really only suits big industry, so unlike the copyright process which costs nothing can be drawn on a fag packet and now lasts 70 years the world over. The whole bike has been reduced where possible. The wheelbase is minimalised. The rider is positioned midway between the wheels and there is little tendency to tip backwards over the rear wheel without intentionally trying to. The pedal crank length has been reduced allowing the whole bike to be lower while still keeping the necessary clearance for the pedals etc. This means an average person can put both feet on the ground when stationary. I have included in the design provision for a gas strut to be incorporated into the seatpost support. The frame locking arrangement enables the seatpost to pivot a without affecting the locking mechanism. The wheels are disc because that is what I could make to keep them slim. Spokes or ribbed discs can be used and also be stiffer and lighter. As to mudguards luggage racks lights etc. they can all be added, but It depends on what you want. I was trying to design a minimum mode for a distance of about 2 or three miles or so. As to ride quality which is subjective I have ridden a Brompton which was ok but not wonderful. A humming bird was a hard unforgiving ride and a clumsy fold.


10/04/2019 11:36:04

Thank you for your kind comments and as to the Dahon reference, I too have shown this to some manufacturers who have shown a similar response. They liked it, but also said it would cost a lot to develop etc. They were generally too risk averse and conventional. Most folding bikes are just a reassembly of many standard parts on a hinged frame. On this bike I disregarded convention (Threw caution to the wind, as they say) but convention and caution rule. The gear ratio is about 50 gear inches, which suits a midrange ratio for general purposes. The hard part of any design is to set the design requirements. The phrase you can only have any two of the following, springs to mind: Time, Quality, Cost.

On this bike I wanted about a three to one gear ration for the small wheels. Using a conventional chain of 0.500” pitch will give a large minimum 48 tooth chainwheel. I chose an 8mm pitch chain which reduces the chainwheel size massively. I calculated that with a slightly reduced pedal crank length (Which even expert cyclists failed to notice) driving a smaller wheel diameter it would take a 400lb person, standing on one pedal, (mustn’t just say man) to break the chain. And if that was not enough safety factor, then a duplex 8mm chain could be used with minimal width increase, which, would have the same strength as a 0.500” chain. However, this seemed too big a risk for very conventional, cautious minds. The Chain runs in angle section frame members, thus using the frame as a chain guard. As to handlebar adjustment the bike is designed around an average sized adult.

The handlebars are fixed in position, but the saddle can be easily adjusted. There has to be compromises or it will only fold up badly. Look at a Brompton, the horizontal distance between the saddle and handlebars is controlled by having to accommodate the rear wheel in the folded position. My biased view is that the handlebars seem to be too far forward. Hub gears could be used but this will add up more weight. Dureillier style gears are light but mean an exposed chain which is not good when folded in crowded places. My problem is that I am now too old, but when I was younger, I was much more interested in other wasteful pursuits.

Edited By Alan Jackson on 10/04/2019 11:59:03

09/04/2019 17:21:43

I know this is not Model Engineering but it certainly kept me occupied in my workshop so I hope it is not too off topic a subject here. For years I have been trying to design and build a folding bike that can be folded easily into a slim and manageable folded package and have now patented the idea. The idea was to try to get to a small slim suitcase arrangement that can be carried close to the body or wheeled on the front wheel when folded, using the seatpost extended, in a similar way as a suitcase is wheeled at airports etc. Most folding bikes fold in the centre of the frame on a vertical hinge that brings the wheels side by side. Then the handlebars are folded alongside the folded assembly. This results in a smaller side view envelope but a much wider end view envelope due to the wheel widths, pedals and handlebars. Making generally a wide package of about 350 to 400mm.This is difficult to carry because it must be held away from the body, giving the upper arm muscle a severe work out. In the folded position they are usually wheeled on additional small castor wheels, which are only suitable for smooth surfaces. So over any uneven terrain they must be carried. The width also limits loading more than one bike in many vehicles.

This bike uses the frame components to actuate the folding mechanics, avoiding, tough to operate, overcentre clamps etc. There are only two hand operated clamps, one at the rear stay and one for front wheel. The seatpost actuates a strong locking method and the seat tube is unlocked when the rear stay is folded. The handlebars are automatically unlocked when they are set in the folded position. When folded, the seat post can be withdrawn freely up to a limiting stop, and used as an extended handle, as with a suitcase. The brake cables are hidden inside the handlebars to give a clean uncluttered look. The folded handlebars lock under the rear wheel rim enabling the package to be carried, using the steering tube as a lifting handle. The pedals can be folded inside the package, the lower pedal acts as a stand for the folded bike. The low frame enables easy mounting avoiding the rider having to cock their leg over the saddle. The folded dimensions are 720mm long, 520mm high, and 160mm wide, with 16inch wheels. The bike weighs 10kg (22lbs) but this could be reduced with better materials. The frame components are only mild steel rectangular box section, so there is much scope here.

There are some more pics in my album




top view folded.jpg

Edited By Alan Jackson on 09/04/2019 17:22:29

Thread: Low rate automatic house plant watering system
03/03/2019 12:44:59

watering system.jpgHi Colin,

Here an evaporation controlled irrigation system. Wen the water in the top dish evaporates the water flows out then replenishes the tank for the next go.


distribution pipe.jpg

03/03/2019 10:28:04

Hi Colin

I spent many hours trying to make a plant watering system. I eventually made a system that used evaporation to instigate watering, which I patented, now long expired. I will try to upload some photos into an album, but will have to do it later when the slow internet I have is less busy.


Thread: Trends in Radio Ads
07/02/2019 10:24:33

I watch some programmes on Quest etc like "How its made" but just do not understand why they have to play loud irritating rock music while the commentator tries to talk over it. Do the programme makers think what they are showing is so boring that the music!!! will make things better?


Thread: Mini Mill Belt drive conversion
04/11/2018 18:38:51

Thank you all for your replies. I have forwarded them on to my friend and hope he carries out the conversion you have gone to the trouble to explain. Thanks again


04/11/2018 11:20:15

I have a friend who has a mini mill which has stripped its plastic gears. He is looking for a replacement 37 tooth helical gear. I have seen in the past magazines a belt drive conversion, but cannot remember where the article came from in the MEW. Can anybody point me to the article or better still are there conversion kits available?



Thread: A question for Thomas the Tank Engine fans
25/09/2018 12:00:51

Lots of engines on the scrap heap crying 2

... and that's before Annie and Clarabel start selling their stories to the paparazzi...

I do hope your are not referring to the alleged steamy incident when Gordon shunted Clarabel up the sidings one dark night. That was years ago and I thought long forgotten.

24/09/2018 12:19:40

Politically corrected, the Fat Controller has been renamed Mr Topman

Thread: Colchester chipmaster rebuild
10/09/2018 15:48:16

Well done Adam, I am quite sure you will be very happy with this lathe


Thread: A Rant to our suppliers of drills
20/08/2018 17:58:40

I always drill first with a small pilot drill then a drill just smaller than the finished size, finally open the hole up with the required size, this avoids any drill point grinding coming into play and avoids oversize holes. I think it is an accepted fact that drills usually cut oversize if the drill point is dictating the cut.


Thread: Hand files for aluminium
06/08/2018 09:31:40

I have found that painting the file surface with white spirit helps to reduce the file clogging. I use a wire brush to clear most of the file grooves but I still have to pick out the stubborn bits with a pointed object.


Thread: Rear toolpost for parting tool
20/07/2018 17:45:31

I did the same as Chris and added slots to my cross slide that can fit a rear toolpost etc.rear toolpost1.jpg

Thread: reel mower sharpening?
16/07/2018 18:09:53

Years ago I tried to sharpen my Dad's cylinder lawnmower. Well it took me all day to dismantle it then place it on my old lathe to skim the cylinder and reassemble it. Eventually I devised a thin sheet of metal the width of the cylinder clamped to one of the cross bars that space out the bearing end plates. On the other end of the metal sheet I clamped a parallel, oval shaped sharpening stone that was used for sharpening scythes etc. The plate assembly was pushed up to the cylinder so that the sheet metal acted as a spring. Then by dragging the lawnmower backwards it sharpened the cylinder. This worked very well and I sharpened quite a few lawnmowers. I even thought about making and selling them but rotary blade mowers were becoming the thing. This way saved dismantling and reassembling the whole mower.


Edited By Alan Jackson on 16/07/2018 18:11:29

Thread: Surface Grinder, luxury or essential?
06/07/2018 10:06:55

End of full travel

Here is my home made surface grinder made from the bottom half of a Dore Westbury mill and a large lathe toolpost grinder. It is very useful for many small uses and finishing after machining.


Start of full travel

Edited By Alan Jackson on 06/07/2018 10:08:10

Thread: L. H. Sparey Running Centre
22/06/2018 11:23:16

Hi James,

If you look at my photos you will see a simple design I made years ago and its still working very well.p1040869.jpg


Thread: M-Machine
20/06/2018 10:21:49

Hi All,

I would just like to convey my appreciation of M-Machine. I ordered some metals on Friday evening and it was delivered on Tuesday morning. How's that for fast efficient service.


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