Cliff 1959 Posted July 28, 2019 Share Posted July 28, 2019 Does anybody know if a 2.5oz brass spinner would adversely wear the bearings on a 42mm dia. Thumper motor? Or would I be better off putting it in the cowl? Quote Link to comment Share on other sites More sharing options...
Don Fry Posted July 28, 2019 Share Posted July 28, 2019 Quite normal on IC motor, and a bearing is a bearing. Mind, make extra sure everything is balanced. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted July 28, 2019 Share Posted July 28, 2019 As Don says it will all come down to how well it is balanced. Any out of balance will put an additional load on the bearings of what is basically a balanced motor. Of course an IC motor can never be fully balanced so has bearings sized appropriately. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted July 28, 2019 Share Posted July 28, 2019 My 50cc powered 96" Hurricane has about 1kg of lead cast into the spinner would you believe. Very accurately set up with spirit levels whilst pouring in the molten metal. It has been flying for quite a number of years now, and so far there are no problems with the bearings. Great tickover! Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted July 28, 2019 Share Posted July 28, 2019 I've often contemplated the heavy spinner approach - do you notice any gyroscopic precession effects? I can imagine that it might promote quite a pronounced swing as the tail comes up... Quote Link to comment Share on other sites More sharing options...
Don Fry Posted July 28, 2019 Share Posted July 28, 2019 Yes. The laws of gyroscopes applies. It catches you out first time out if you don't watch it. Shove the rudder over, get the tail up, and try to not slam the motor to full chat. But it's an effect, it's not a problem. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted July 28, 2019 Share Posted July 28, 2019 No detrimental effect noticed with this set up. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.