Well, Barrie, whatever method you decide upon, to secure the tires to the wheels, best wishes and good luck! Al Messer --- Barrie Purslow <bpduo@xxxxxxxxxxxxx> wrote: > Rich, > > The wheels are already on the axles - and have done > many miles, such that > the tread is "hollow". > > Please see my reply to Charles regarding alignment, > > Regards, > > > Barrie > > > > > As far as the 1thou per in interference is > concerned, is this the norm > > that is allowed for shrinking cast iron onto steel > (as if you go for any > > more you cause the cast iron to crack as it is in > tension)? But going the > > other way round, shrinking steel onto cast iron, I > suspect that you can > > subject the cast iron to larger loads before it > goes BANG, but if you are > > shrinking onto a spoked iron casting, you ought to > be careful you don't > > cause the centre boss to collapse. In this case, > maybe the centres should > > be machined and fitted to the axles before > shrinking on the tyres. > > > > An alternative viewpoint is to work out how much > expansion of the steel > > you can get by heating it, which will ulitmately > give you the inteference > > fit. > > > > One other thought - best to make sure you have a > shoulder somewhere on the > > arrangment, to make sure that the tyre is dead > square on the wheel when > > the whole thing goes tight. If it goes tight on > the 'huh' I suspect it > > might work itself loose in service, no matter how > tight an inteference fit > > you think you've got. > > > > Yours, > > > > > > Rich. > > > > > > On Thu, 17 Nov 2005, cbrumbelow@xxxxxxxxxxx wrote: > > > >> Be sure your assembly arrangement allows time to > get the tyres/tires on > >> and lined up before the temperature difference is > gone. It might be well > >> to leave the exteriors of the tires enough > oversize to allow truing cuts > >> once everything has been assembled. Some might > even suggest that the > >> final truing take place between centers with the > tires on the wheels and > >> the wheels on the axles. And, you might want to > match each tire to a > >> specific wheel center as you turn the sets. Am I > reading correctly that > >> you will have wheel centers of a nominal 8" > diameter and an interfereance > >> fit of 0.008 inches? Charles > >> -------------- Original message -------------- > >> > >>> I have just acquired, at great expense, a piece > of steel tube 8" I.D. > >>> and > >>> 3/4ins. wall thickness. I am about to start > machining it to produce six > >>> steel > >>> tyres which I intend to shrink onto three pairs > of existing, cast iron > >>> wheel > >>> sets (after machining off the current treads). > The plan is to make the > >>> tyres > >>> with one thou per inch of interference, expand > them with heat then > >>> shrink them > >>> onto the wheels. > >>> Before I pluck up courage to do this job does > anyone have any advice to > >>> offer? > >>> > >>> Barrie > >> > >> MODEL ENGINEERING DISCUSSION LIST. > >> > >> To UNSUBSCRIBE from this list, send a blank email > to, > >> modeleng-request@xxxxxxxxxxxxx with the word > "unsubscribe" in the subject > >> line. > >> > > MODEL ENGINEERING DISCUSSION LIST. > > > > To UNSUBSCRIBE from this list, send a blank email > to, > > modeleng-request@xxxxxxxxxxxxx with the word > "unsubscribe" in the subject > > line. > > > > > > > > -- > > No virus found in this incoming message. > > Checked by AVG Free Edition. > > Version: 7.1.362 / Virus Database: 267.13.3/173 - > Release Date: 16/11/2005 > > > > > > MODEL ENGINEERING DISCUSSION LIST. > > To UNSUBSCRIBE from this list, send a blank email > to, > modeleng-request@xxxxxxxxxxxxx with the word > "unsubscribe" in the subject line. > __________________________________ Yahoo! FareChase: Search multiple travel sites in one click. http://farechase.yahoo.com MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.