Friday 8 September 2017

All four wheels


All four wheels are now attached, with hub covers in place.  The drive wheels had keys and keyways which had to be made to fit.  Some needed little more than de-burring, others needed a substantial amount of fettling.  I am not sure that I have the right touch for a fitter, I seem to take forever trying to get a good fit without removing too much material. 
The rear disk brakes fit with no problem - Wa-Hay!  They dragged a little, but the pads can be persuaded to sit at their outer limit to relieve the binding.   I have added some more grease to the rear wheel bearings, while they were still readily accessible.  Any surfaces which cannot be reached by paintbrush have been treated with a rust proofing layer of WaxOyl.  To make life easier for myself, I filed the space between the castellations on the castellated nuts, so that I could insert the split pin without too much difficulty.
Now, back to the leaf springs.  they will be prepared and painted, including the front springs which I attached for the look, and will now dismantle.  Before doing a lot more, I shall re-check the assembly and bolt tightness so far, apply grease and WaxOyl missed the first time around.  Next, any poor paintwork will be improved, a bit at a time on this occasion.
I think that there are some parts which could collect moisture and dirt.  The only one I have noted so far is the hole in the securing plate for the front spring assembly.  If that fills with dirt or water, corrosion seems bound to follow.  I thought that a little silicone sealant might prevent dirt and moisture getting in, and not be difficult to remove if necessary.
I am wondering if a sympathetic local garage man should be asked for an independent check for roadworthiness at some future time - it is a principle that a workman is the least able to check his own work in an unbiased manner.
My handcart has arrived, together with fittings for being pulled (intended for a pedal bike).  I intend to use it for extra water and fuel, and for miscellaneous bits and pieces, e.g. shopping bags.
I note from the main drive sprocket dimensions that a 60 pitch chain will be used.  This (according to international standards) has a tensile strength of about 7000lbf, well capable of transmitting the 800lbf load generated by a 2.25 inch diameter piston at 200 psi. Let's hope that the rate of wear will be low.

4 comments:

  1. Gregory, I rather thought that this would be the case. I am doing a bit at a time starting at the back, so the front wheels should be re-assembled by the time I need to paint that area.

    ReplyDelete
  2. Thank you for your good advice. I was in two minds about what to file, and was thinking that the greater strength would be kept if minimal filing was done. But in future, if a different slot is to be used, then more filing will be needed.

    ReplyDelete
  3. Greg, my calculations are:
    Force = Pressure X Area
    assume that the crank has the same length as the radius of the chain wheel, so that the force on the chain will be about the same as the force on the piston through the connecting rod and the crank.
    The piston area - Area = pi X D^2 / 4 .
    D = 2.5 in
    pi =3.415926
    so, Area = 3.1415926 * D^2 / 4 = 3.976 sq in
    (maximum boiler) Pressure = 200 psi
    Force = Pressure X Area
    = 200 X 3.976 lbf
    = 795 lbf (~ 800)
    I have used imperial units (as I was taught) throughout to ensure consistency,
    As the rotational speeds are much lower than for internal combustion engines, then the power will be lower, as power = force X speed

    The road wheels are about twice the diameter of the final chain wheel, which gives a driving force of almost 400lbf. This will be reduced by rolling resistance, disk brakes binding, etc. The Lykamobile should be able to tackle a hill of 1 in 3, even with a full load (all up weight of 1200 lb?).

    ReplyDelete
  4. Greg, thank you for your critique on my back of envelope calculations. I shall look forward to comparing notes on the actual performance of the completed cars. Though I am not sure I have any really steep hills in the immediate neighbourhood!

    ReplyDelete