By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Forum House Ad Zone

Rob Roy advice needed

Reverse eccentric rod offset.

All Topics | Latest Posts

Search for:  in Thread Title in  
Anthony Taunton22/09/2020 20:28:40
8 forum posts

What is the received wisdom on the making of the reverse eccentric rod on Rob Roy, namely the 1/4" offset required? Carve from solid? silver soldered fabrication? I have also seen adjustable versions involving a threaded rod. Is adjustment necessary to achieve perfect valve timing?

Thanks in advance

Tony

Baz22/09/2020 20:40:35
1033 forum posts
2 photos

Having access to a CNC mill I carved them out of the solid, first op was the straight and offset view then a simple fixture to tip them sideways to profile them, held by 5BA bolt in the eye and a small clamp at the eccentric end.

Phil H123/09/2020 13:38:06
467 forum posts
60 photos

Anthony,

I was going to machine mine from solid but I thought I would give the laser cut versions a try. They arrived and consist of 4 flat profiles with 2 additional rounded ends for each rod (a rounded end is silver soldered either side of the flat profile of each rod). A photo will probably help I suspect.

I plan to silver solder all the additional ends to the flat profiles, bend the reverse rods as carefully as possible then set all 4 onto the same fixture to machine the expansion link slot with a slitting saw.

Phil H

Anthony Taunton23/09/2020 15:56:46
8 forum posts

I originally built mine in February 1986 (long project; lots of things got in the way, a familiar story!) Anyway now I'm retired, and have a chassis that runs on air, I intend to re-do the eccentrics, as I was never too happy with them. I think I heated them and then bent them to shape back in the day when I had hair, but bending them correctly and getting the offset alignment exact etc is a bit unpredictable I found. I would be interested to hear from anyone who used this method and what problems they had, if any.

Tony T

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Sign up to our Newsletter

Sign up to our newsletter and get a free digital issue.

You can unsubscribe at anytime. View our privacy policy at www.mortons.co.uk/privacy

Latest Forum Posts
Support Our Partners
cowells
Sarik
MERIDIENNE EXHIBITIONS LTD
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

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.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest

 

Donate

donate