Build Diary of a
Roadster (Kit Car)
Tube bender Projects
OK, so I built the go-kart and
found out that, because it was built for off road use and not as a
standard racing kart, there was no place to ride it without having
problems, so what to do as a project next?
I looked at was Autograss racing. I picked up information on
building a formula 600 car, did many an Ebay search for 600 cc
bike engines before it dawned on me that I was still trying to
build something that could only be driven at certain events, and
even then, only if I was prepared to race!
I looked at the possibility of taking a formula 600 through an SVA
test and putting it on the road, to do this would be a difficult
task, not just a matter of bolting on lights, but a full and
smooth body skin, a rear differential, wheel arches or mud guards,
collapsible steering column etc. No! a formula 600 is not
meant for the road.
I then found a strange forum on the Internet, with people building
their own cars! Some even making their own chassis, based on
the idea of the Caterham and many others, and helped by a book
published by Haynes. Build your own Sports car for as little
as £250. The book now seems to be out of print, but a
new one hit the shelves in February 2007 called: - Build your own
sports car on a budget.
So for just under £18, I bought the book. I marvelled at the
concept and have set myself an unrealistic task of completing my
own car in two years.
There is help out there, hundreds of others with the same idea,
many are building, many have built, either from scratch or with a
bought in chassis and parts.
There is a forum dedicated to the book I bought: - http://www.haynes.co.uk/forums/index.php
Chris Gibbs is the moderator. He posts amendments to the
book, helps with ideas and drawings for variations from the book
covering gearboxes, engines etc. Other builders supply ideas
and answers to many questions, pictures, drawings and support. All
in all, a community to the same end.
is a generic builder forum and can provide lots of information and
23rd June 2007
Bought the board to build
the chassis on 19 mm ply x 2440 mm x 1220 mm, also a load of scant
to strengthen and keep it flat. A small tub of white paint
to help with the marking out. Then a week working away from
home before I could get back in the garage.
5th to 7th July 2007
Back in the garage, another quick
coat of white paint on the board, worked out things like a cutting
chart, ordered the steel from K Steels, expecting delivery on
Friday. Started to mark out the chassis on the board and fit
blocks to keep the bars in place.
Steel arrived Friday morning as
expected. Raining, so continue with the board until finished.
I know that it is bad practice to
cut all the steel up but I could not store it without, so, out
came the band saw and over a hundred cuts and several hours later;
I had a pile of smaller lumps of steel.
The bandsaw is one of the best
things I could have in the garage for this build, it is certainly
a lot easier then sawing by hand. It can make cuts up to 45
degree angles, with the milling machine being used for all angles
above this using a large end mill.
With the board now on legs,
starting to lay out the bottom of the chassis, cutting angles as I
go, again with the bandsaw. Slot all the pieces in place,
weld up the front frame as it would not hold it self and this is
what you get: -
It needs tack welding together
before I go any further.
14th & 15th July 2007
A bit more over the past week when time allows, tacking the frame
together and then this weekend start to fit the uprights and top
frame, tack welding it as I progress.
25th & 26th July 2007
Did not get chance over the
weekend, so had a go during the evenings. What a
disaster! I added four diagonal braces, two in the sides in
the arm rest area and two in the top seat back area. When I
checked them I found the seat back diagonals did not match and
discovered the back was leaning over by a degree or two.
Enough to make one corner to corner measure 125 cm and the other
So the tack welds were ground out,
the back braced, pulled and hammered and then re-tacked. I
also managed to set some paper's on fire, so need to take a bit
more care with combustibles in the area.
28th July 2007
Cut and angled the pieces for the
rear suspension area, jigged it up but have not attached to the
chassis as I need some plates for suspension area.
I have ordered the plates from a
supplier on the forum and they are being laser cut, bent and
should be with me in about two weeks. Also on order are Maxi
ball joints and Transit drag link ends, basically to make sure I
can get the ball joints, I have been told by a motor factors they
are now obsolete!
Spent enough money on it this
month, £141.12 on Steel tube, £163.18 on the laser cut
parts and £69.92 on the ball joints and drag link ends.
£374.22. I think some of my "not used for a year or so
things" need to go on that Internet bid thing!
11th & 12th August 2007
Back from holidays this
weekend so another chance to work in the garage, attached more
diagonals, started on the transmission tunnel, attached the rear
sub-frame for the differential. The pile of tube bits slowly
getting smaller as I put them into place.
As I am building the chassis as
the book, I have starting to look for a Sierra as a donor, initial
thoughts are: -
There is a better chance with the
later model years of less corrosion to deal with, possibility of
ABS which means disks all round. I am not after a very
powerful engine just a simple installation at this stage.
Time will tell if I manage to meet the target price.
- Type 9 gear box
- Either 1600 Pinto or 1800 CVH
- Saloon not estate car (diff) (Only for the 1.6 Engines
1.8 & 5 speed seem to be all the same)
- Also later model year such as 1991 to 1993
- Sub £300
17th to 26th August 2007
Work on the Roadster has been a
bit slow this week, forgot to go and buy more 19 mm RHS must
get some when possible to complete the back section.
The laser cut parts arrived and
happy with them, saved my a lot of time and effort trying to make
the pieces the hard way by hand. Managed to bend the rear
tubes RP1 & RP2 on an old pipe bender I have in the garage,
new it was worth keeping!
I attached the rear top suspension
points and then realised I had then at the wrong end so out came
the grinder to take them back off and then another go, think I got
it correct this time.
Hoping that, in a few weeks, all
the sections will be fitted and then the chassis can be fully
welded. I have to make up the jigs to attach the front and
rear wishbone points and tack these in place, 4 tubes for the
transmission tunnel and finish off the rear of the car, perhaps
three to four weeks then!
1st to 3rd September 2007
Done a bit more, progress
is slow, as I am not getting a lot of time in the garage. Have
attached the round tube, finished off the transmission tunnel and
done the steering supports. Wishbone brackets to tack on
next, jigs first!
15th September 2007
Just an update on recent progress,
the chassis has not changed much from above. I have made the
front wishbone mounting jigs and have tried fit the wishbone
brackets. I seem to be 8 mm ( 4mm per side) out on the lower
front frame mountings and this seems to be a mixture of mounting
the uprights inward slightly from book and the brackets having at
most a mm out on height. Nothing to major and will be sorted
either with a packing piece to fasten the brackets onto, or
I might just rebuild the front frame before the chassis is welded.
Pre-fabricated wishbones have been
ordered from a supplier on the forum, and the parts should arrive
in 3 weeks time. I also received a few missing pieces from
the laser cut parts, this was down to the book not always listing
the correct number wanted, so until you build it you never
Lastly for whenever I get the
donor car I am having a straight cut reamer reground to a 1 in 8
taper required to modify the Sierra uprights to take the Maxi ball
This should also allow me to make
my own mushroom inserts for the tops of the Sierra to take the
Transit drop link ends. Nothing like a bit of forward
So although not much is going to
show over the next few weeks. Once the wishbones arrive
these will be fitted to the jigs to make sure all is a good fit
and the brackets will then be welded in place, then I also hope to
have the chassis fully welded.
Simple cutting jig to help with cutting compound angles
On some of the steel tube
sections you have to cut two angles at the same time, such as the
14° and 26° angles on FF2 and FF3. Well with a
normal band saw or cut off saw, you can set one angle and have to
find a way to set the other.
So perhaps this little idea will
help. It requires a bit of maths and a few bits square tube,
I used 19 mm. The maths bit is all about a right angled
Tan (ø) =
o/a or opposite over adjacent
sides. The opposite in this case is the 19 mm from the tube
and Tan 14° = 0.2493, so the adjacent length works out to be
76.2 mm or close. a = o/Tan (ø)
So I made a jig with these two
lengths as in this picture: -
The opposite length is the top
piece of 19 mm tube and the adjacent length is 76.2 mm or closest
I could make it.
So you rest a square tube on the
edges and it will sit at an angle of 14 degrees. Put this in
the bottom of the vice, rest the tube across the corners then
clamp up. Set the cut off or bandsaw over at 26 degrees and
the compound angle can be cut in one go. The jig shown has
two angles on it, 14 on the left and 17 on the right. Hope
22nd September 2007
I have remade the front frame and
aligned the two verticals U1 and U2 to meet against the brackets
when using the front wishbone jigs. Therefore I should have
less of a problem when they are attached. The old frame has
been re-cycled, as in cut up so I may reuse the straight bits if
needed. Time has also been spent rearranging the contents of
the garage to allow me to walk around the chassis without having
to climb over everything.
6th October 2007
Bit of a gap again before work
continued on the chassis. I have reworked a Cosmo Welder,
putting on a Euro torch and a separate power supply for the wire
feed. Results with it are now quite good. It is a 130
amp device with bottle carrier and top lid containing the
wire. Anyway have been doing some welding with it on the
chassis, actually started last weekend but only a small
amount. Managed to get a few hours in today before my
welding mask started to fail! Tried replacement batteries
but with no change so think before I dazzle myself altogether I
need a new mask. One comment, there are lots of joints to
weld up and lots of grinding to do as well in my case!
Views here with the chassis upside
down and one on it's side. I am trying to do all the "from
top" welds, then turn it over and do all the welds that are once
again "from top", then turn on side etc. Hopefully
this will make it easier for me to do. Must get them walls
As I mentioned above, I had cut
all the steel tube in one go, well as the chassis progress
continued I found the odd error in my cutting chart, things like
missing the odd metre from a piece of bar. Small
discrepancies in the book where the appendix is not listing
quantities of tube, so I found these errors when trying to put it
all together. Such as not cutting 4 off SB1 and 2 off SB2,
2 off is this and that. Cutting FF2 and FF3 too short at 320
mm instead of 359.5 mm. So all in all a few mistakes, so to
help any others I am including a link to my cutting charts at the
bottom of the page. As I find mistakes I will update this
link. Saved as a normal text file it could be opened by any
basic text package. Do not forget this is for an as book
If you wish to contact me, please
E-mail by clicking on the following link and then remove the
Updated 25/08/07 Cutting length
chart is here
25 x 25 mm tube
Updated 25/08/07 Cutting length
chart is here
19 x 19 mm tube
© A Hodgson