Cox Engine Test Stand

Marleysky wrote:Here's a 5 second recap of the last 30 minutes of my typing and loosing all of it cause I touched the wrong button.  

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXD966&P=7

Well, at least I am not the only one with this problem.... But after a few times, I do as stated above. Copy teh text every so often if it is a lengthy message.

Testify Brother.....
..........................Lost to the Ether Kim

There's a couple of different ways to approach this. It's best to have dedicated mounts for each engine size and type. Some engines mount "radially" to a firewall.. and some mount on "beams".

Let's say that you have Cox "reed-valve" engines with integral fuel-tanks. The "Bee"/.049's mounting-pattern is slightly larger than the "Pee Wee" .020's. I would personally make separate mounts. You can choose to mount the engines with machine-screws with captive "blind-nuts" installed behind the firewall to accept them. This would be a good method.. and would handle "repeated" mountings and dis-mountings.

Using small wood-screws is also an option.. but as you mentioned; they will strip-out with repeated mountings/dis-mountings. You can extend the service-life of the mount by sticking wooden toothpicks (cut-short) in the mounting-holes with a drop of super-glue. This will give the wood-screws "new-wood" to bite-into. I've done this with small (1/2A size) airplanes having a radial firewall.. and it holds the engine tight.

Not sure how thick the main board is, but you can get 2-56 blind nuts and long 2-56 machine screws from Micro Fasteners.

https://www.microfasteners.com/

You might also a square of hardwood on each side of the vertical support to take some long #2 socket head wood screws, also sold by Micro Fasteners. I use blocks of hardwood---got them for free from a local cabinet shop---with the test stands that Matt and Bernie offer, and have yet to wear out any.

Maybe you could mount a "sacrificial" strip of wood on the front surface, and replace it when it wears out and/or gets soaked? It would be the most flexible solution, you could install engine mounts with different patterns and would not need to worry about extra holes.

Something like this:



If you are going to run only 2-3 different engines on the mount, then it might be easiest to use blind nuts as Marleysky suggests.