Carl Goldberg mounts for red postage stamp backplate reedies

Balogh,
I have no interest in these, but if you pull off a neat trick, I'll make sure to get a Dubro clip to "the stateside distribution point." Feel free to hit me up if you gain traction in your quest. Until then, I will try to find a way to get the clip to you.

Ron, Jim,


Thanks for your generous offers.


I got a few 3D courtesy pieces from Jason Wi and also bought from Bernie some 3D printed mounts that Jason Wi produced, but I saw that the last pieces were sold out by Bernie some time ago, so I thought Jason's production run has been over.

My 3D units have been partly utilized but some also snapped...I boiled others in hot water in hopes they will soften up like the black COX props..

International shipments are unreliable during Covid times (it has been almost a month I have been waiting for Dick Russ' 1/2A Streaker to arrive here from Oklahoma, with no sign of its whereabouts whatsoever..in pre-Covid times it took 9days for Bernie to ship here from Canada or Matt to ship from US)  and I thought if someone on CEF volunteers to stock the 16 from ebay then later when Covid shipping miseries are over I could buy some from that stock...

I can try printing out of glass fiber and carbon fiber zytel. Standard zytel is brittle just off the printer. I do boil them to anneal them but that may not be enough as they will dry out again in arid environments.

Not sure I can add much more thickness anywhere without it fitting like the CG molded one. Where do these tend to break?

Thanks Jason, they mostly break where the thin plate intersects the thicker bracket. Some break already under the torque when the spring starter is wound clockwise, some later due to engine vibration. Some were cured well with boiling.

Maybe with a bit wider slot for the spraybar up and down you could afford a bit thicker plate with glass fiber?

im good for 2, but not all of em...

I could volunteer to buy the pack of 16 but a 27% Value Added Tax plus import duty is added in Hungary...plus I am not sure how long it takes to ship here...so someone in the US should better buy the package and resell it to whoever are interested on CEF in smaller lots. I am in for 3 or 4. The auction ends in a few hours though. The Goldberg mounts are rarities nowadays and I would regret to see this opportunity go...

Same problem here. By the time they're shipped out here and are taxed they'd end up too expensive for most at what I'd need to sell/ship them for.

Jason_WI wrote:I can try printing out of glass fiber and carbon fiber zytel. Standard zytel is brittle just off the printer. I do boil them to anneal them but that may not be enough as they will dry out again in arid environments.

Not sure I can add much more thickness anywhere without it fitting like the CG molded one. Where do these tend to break?

Jason, do you think you could form a ”chamfer” into the inside corners between the thin part that faces the engine backplate and the thicker part that works as a spacer? Maybe between the triangular part and spacer part too?

Sometimes sudden changes in thickness of a structure cause stress concentrations, that combined with the vibration... A chamfer (not sure if it’s a correct term for the round ”fillet” shape that I mean) would spread the stress over a larger area.

Not sure if I could explain this in a way anyone understands, but imagine it being steel, about 20x the size and with a nice thick continuous weld seam done by a pro into all the inside corners of the part

Kari,  yes this is what is called "stress relief by smooth transition " in stress analysis. I was also trying to add that chamfer or fillet from CA glue to relieve the stress, but CA does not adhere well to the material of the mount.

I'm seeking STL files for postage stamp engine mounts. Any links to follow?
Thanks
Dave Rigotti

Jason_WI wrote:I can try printing out of glass fiber and carbon fiber zytel. Standard zytel is brittle just off the printer. I do boil them to anneal them but that may not be enough as they will dry out again in arid environments.

Not sure I can add much more thickness anywhere without it fitting like the CG molded one. Where do these tend to break?

Dave , Jason hasn't been on in a while but Chancy (New222) Has printed some of these in this thread , you may contact him through PM and see if he will share >> https://www.coxengineforum.com/t14812-cox-postage-stamp-engine-mount He was just on not long ago 2-3 days

OK I'll give him a PM. Thanks

getback wrote:Dave , Jason hasn't been on in a while but Chancy (New222) Has printed some of these in this thread , you may contact him through PM and see if he will share >> https://www.coxengineforum.com/t14812-cox-postage-stamp-engine-mount   He was just on not long ago 2-3 days

I'm still looking for the STL file to 3D print for my own use the mounting backplate. Any takers please?

Dave Rigotti wrote:I'm still looking for the STL file to 3D print for my own use the mounting backplate.  Any takers please?

I believe Jason @Admin and Ron @Cribbs74 still maintain contact with him. Perhaps they could contact @Jason_WI or PM you his contact info?

By the way, noticed that last time you logged on was 4-1/2 months ago, and your participation is kind of low. Not saying there is a problem with that, but unless you are known by a few in this small engine community forum here, could be a reason why a some are shy to provide you a reply.

I've logged in a few times in the last 2 months alone looking for a reply. Not overly motivated when all I hear are crickets....

Dave Rigotti wrote:I've logged in a few times in the last 2 months alone looking for a reply. Not overly motivated when all I hear are crickets....

@Dave Rigotti , out of curiosity I looked at your previous posts, we are a friendly community here. One thing our @Admin encourages here is a new poster introduce themselves in the Introductions section in the main menu.

Have you introduced yourself, yet? This is a chance to let others know your background, experiences, why you came to Cox Engine Forums.

Only a very few of us have parts printing machines. I certainly don't have one.

And, people like to have an idea of who is inquiring. This helps them to steer folk in a direction to help, but also adds a human side to the person they can associate with.

So, I don't think any of a non-response was out of meanness.