|Roger Holebrook||04/06/2015 18:06:51|
|8 forum posts|
The bare frame has been assembled for a trial fit together with the six suspension springs. The springs are as specified on the plan and supplied by one of the ME suppliers. These springs are 1" long by 5/16" 18swg and 8 turns. They also appear to be "music wire" as opposed to stainless steel.
However, when only partially loaded(two small lead acid batteries) the springs are fully compressed. Now there have been many 08's built to this design, so has anyone else experienced this problem and how was it overcome?
|Neil Wyatt||04/06/2015 18:56:31|
16449 forum posts
Can you give more detail, Roger? Which design, all-up weight, gauge and what size batteries?
Four similar springs except they are only 1/4" diameter reduced to about 3/34" long suit my shunter - it is 3 1/2" gauge and 1 7Ah lead acid battery, but with lead ballast so it weighs 28 lbs.
If your is the same gauge with two similar batteries but no ballast I would guess that six such springs could be more or less Ok, although 5/16" springs will compress more easily than 1/4" diameter.
|Bob Brown 1||04/06/2015 21:14:10|
981 forum posts
I think a spring of the size you indicate should give a working load of around 10 to 12 lbs. The working load is just part of the specification as a spring of this size should have a rate of about 26lbf/in, so with 6 springs and an evenly distributed load that equates to 60 to 72 lbs. This all assumes 1/2" of travel but that is not the travel you are going to have, on my shunter the axles have about 1/8" of travel and have a pre load applied that is take by the horn stays, e.g I have to screw the horn stays down against the axle box/spring. With out the batteries the axle boxes are still against the horn stays but once installed it all settles down to a nice running position.
If I get a chance I'll take some pics.
Edited By Bob Brown 1 on 04/06/2015 21:15:10
Please login to post a reply.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.