Will L wrote:Le Corbusier wrote:.. I can't help feeling that there must be a way to mount the bogie itself so that it is sprung off the main CSB? ....Hopefully in such a way that it can be calculated as a simple 0-6-0 with the percentage of weight allocated to the Bogie truck via the spread sheet in line with the loading requirement? Presumably the bogie itself could then be simply compensated as the loco would be isolated from the compensation by the CSB? Couldn't what I think you are calling the rubbing plate (still not fully up to speed on the nomenclature to make deciphering the more abstruse threads fruitful ) ride on a version of hornblocks attached to the CSB in a similar manner to the drivers?
This sort of idea makes logical sense, I may even have suggested something similar myself see here However I have yet to see it done. By the by, that post also covers a CSB version of the fake front bogie used by the Bachmann Baldwin
I have a concern by the fact that that the effective height from the rail head to the CSB fulcrum needs to be the same for the bogie to rubbing plate assembly as for the driving wheel axle bearing block assembly. Basic CSB are amenable to kitchen table modelling techniques and accuracies but do rely on all the wheels and axle blocks being the same size, as a difference of only one or two tenths of a millimetre in rail head to fulcrum height would be significant in terms of the CSB calculations. Achieving this degree of accuracy for the bogie assembly seems to be to be altogether more tricky. For this reason I have tended not to suggest supporting bogies on the main CSB but went in steed for methods that rely on something you can measure accurately enough, i.e that the running plate is parallel with the track. See the very next post to the one referred to above or here which extends the whole idea to locos with more than 2 driving axles.
Will L wrote:"Le Corbusier" PMed me querying me exactly what I meant byand asked for a diagram. I hope this one will elucidateWill L wrote:... I have a concern by the fact that that the effective height from the rail head to the CSB fulcrum needs to be the same for the bogie to rubbing plate assembly as for the driving wheel axle bearing block assembly. ...
The diagram as drawn seems to suggest that all the attachment points of the wheels to the CSB should be at an identical height above the rail height? ... Maybe I am getting confused about this?
Anyway here goes ...If there is no weight acting on the CSB then surely this height will relate directly to the heights of the anchor points in the frames ...and the deflection which you have drawn relates to the spread sheet calculations ...... dependent upon the C of G and the relative positions of the anchor points?
If this is the case, then surely so long as the height from the wheel tread at the contact point with the rail to csb attachment point is the same for both the drivers and bogie truck, then what you have drawn will have been achieved? ...and the spread sheet will do the rest as far as deflections and relative weight distribution is concerned? If this is the case and I haven't misunderstood, then it seems to me that so long as there is a built in method of adjustment on the the bogie (which can be locked off permanently once set) you can initially set up the chassis 'rigidly'* and unloaded allowing it to be adjusted to horizontal relative to the track?
By rigid I mean with a stiff wire substituted for the csb so that there is no deflection when just the chassis is involved. This should allow the bogie to be adjusted so that everything lies level to the track. Then the correct CSB and body weight can be added and the loco will function as an 0-6-0 ?