well me having began work at 16 for a private company supplying and building bespoke chairs and did so for several years so my basic knowledge was enough to know i could do better,so £600 budget thats about a 5th of the cost of a nhs script chair.
it does 6mph has zero delays and 0-6 happens very very fast!it has big antitip system as its a bit lively and likes 2 wheels more than 4!
it can go nearly anywhere and has been custom programmed carefully by me with lots of help from some brill folk over on a wheelchair forum i frequent.
now it drives like anyones chair would in first gear use round the house,shops,park,woods etc and still has battery unlike the nhs one less than 5 miles it was dead! this has 2x 86ah lead bricks so can run for hours and tina looks so fecking happy running it with the hounds!
about 70 hours work single handed went from this
to this now useful thing thats fun and practical still fits through doors etc and drives perfect,
we now have 5 powerchair between the 2 of us and just built this one for me from a £50 ebay donor chair
still awaiting tubeless alloy wheels from hong kong to arrive,bloody slow boat 68 days and still not landed
last bit of the jigsaw see,pretty wheels though 
take care all,peace
i have a small electric tyre pump built into the battery box and a repair kit under seat,next trick is tubeless for the front end and a robotech controller at 48volt so double the power and speed doubles from 6 to 12mph and with a lithium conversion twice the range atleast,just have to save some dosh for another year or 2 and hope the current lead bricks last that long.
bespoke chairs can’t fault it very clever 
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