Gas engine stand off mounts??
 

What is the best way to mount an engine using "stand offs" and what type material is best for the "stand offs"?? Plan on putting either my 3w75,or 78 in a Lanier Staudacher, and either engine requires about 3" from spinner backplate to the engine backplate.
Also, anybody have experience with this plane needing nose/tail weight for either of these engines?? Thanks much for your help.
Terry

Gas engine stand off mounts??
 

Sorry, I meant an ADDITIONAL 3" needed to fill the stand off void.
Thanks again!!
Terry

Gas engine stand off mounts??
 

Check these out.
http://www.geocities.com/traviscouch/extra2.html
http://www.geocities.com/roger_forgues/engstandoff.html

Gas engine stand off mounts??
 

Use 1.5" dowel rod from the hardware store. Cut 4 pieces the length you need and then drill the appropriate size hole down the middle for the bolts. You can either glue tham to the firewall or not. Use a fender washer and a lock nut on the back side of the firewall. I stopped using blind "T" nuts on gassers. Too many have failed.

Bryan

Gas engine stand off mounts??
 

BTW,

I have some of Roger's (Aerografix) stand offs. He does exceptionally nice work!

Wiz

Gas engine stand off mounts??
 

I just mounted a 80cc ZDZ with some of Roger's (Aerografix) stand offs....and I also agree - he does nice work!

David Soniat - tampa, fl

T Nut Failure
 

Hi KleinBK,

When you say that T nuts failed, was this because the metal threads of the T nut stripped, or because the T nuts pulled thru the wood firewall with the bolts still attached? Or was it something else that caused the failure?

Thank you,

Bruce

Gas engine stand off mounts??
 

From high grade ply . cut witha hole cutter 12 1" pieces ( 3 for each spacer to get the 3" that you need ) and glue them together with epoxy.

You can glue it to the firewall or use it siply as a spacer.

epc.

Gas engine stand off mounts??
 

cu. in.

If you picture a "T" nut as the letter "T" so that the flat part of the nut is up. The vertical leg seperated from the horizontal leg. I have a baggie full of broken ones in all sizes that I have collected over the years just to show people not to use "T" nuts in a high vibration enviroment. The last ones I added to my collection are from a 3W-100 that departed the front of the plane in flight. The back side of all 4 "T" nuts were still in the firewall, but the threaded shank was still on the bolts.

Gas engine stand off mounts??
 

KleinBK,

Thank you very much. I had never heard of this sort of thing happening and will avoid T-nuts in the future.

Sorry to hear about the 3W100. :(

Bruce

Gas engine stand off mounts??
 

If you need standoffs that are more than 1" long, avoid any kind of straight posts. Torque will induce more vibration than you want.

What I do is to cut strips of 3/16 or 1/4 birch ply (Midwest). Stack the strips two vertical, two horizontal, two vertical, etc... Use CA to join them. This provides rigidity to prevent any twist from the engine but is much lighter than a solid wood standoff.

Difficult to explain, so I popped downstairs and took a picture :)

Gas engine stand off mounts??
 

Obviously, you have never tried them before. The standoffs on my plane are 3 3/8" long and I have no vibrations. And I have many very satisfied customers to prove it.
They have to be done right and installed right though.
http://www.geocities.com/roger_forgues/engstandoff.html

Gas engine stand off mounts??
 

Well, I have tried them. Not yours (which cost a small fortune), but 3/16 wall aluminum tube cut to length, 2.25 inches long. The BME 102 bolts down rigidly, but there is still some torque induced vibration. (The picture shows a BME 50 on a GP Pitts.)

Regards,
Craig.

Gas engine stand off mounts??
 

Well I don't know if you meant mine cost a small fortune, but I have no complaints.
Aluminum tubing as you describe them will not work properly, that's why I machine mine from barstock.
Expensive is quite subjective, you get what pay for.

mounts
 

Thanks so much to all for the emails/help-its great to have this kind of support from fellow modellers. Many absolutely great ideas as I build strong first-then worry about weight!! Thanks to all again and God Bless! Regards,
Terry

Gas engine stand off mounts??
 

When you figure the cost of your time and aggravation to try and manufacture a set of standoffs from dowels..etc, $35.00 is extremely reasonable! Besides if you've got $1500-2000 tied up in an engine, what an extra $35.00??
Roger,when I need a set of standoffs I'll be sure and get a set from you. The quality appears excellent.

Gas engine stand off mounts??
 

Thank you,
I appreciate it.

RE: Gas engine stand off mounts??
 

Question;  I am building NitroPlanes CMP P-40 War-Hawk 140 73" span, Basic kit 10.75 lbs. Recommended Engine(s) 2stroke. 1.08-1.20, 4stroke. 140. I have not bought the engine yet but its going to be gas. The pre-built plywood engine mount is part of the model's structure and designed for the standard glo fuel engine installation  (no Standoff). I want to build this bird  with retracts and flaps so it will be closer to 14 lbs. RTF. The CPRC-pro 26cc and the Evolution 26GS or maybe the Evolution 40GX[X(] are some of the engines I'm considering because they have glo style mounts. It makes me wonder,  Is the extra vibration of the gas engines the reason most  have standoff's?. Would it be better to modify the structure of the plane and use standoff's? Would the Evo. 40 be too much?[:o]

RE: Gas engine stand off mounts??
 

I use 3/4"X3/4" square Birch stock from Lowes. I know it's not the lightest way to do it but it's simple and easy for someone with limited woodworking skills such as myself. It also seems to reduce the twisting effect of large gassers.

RE: Gas engine stand off mounts??
 

What size bolts are you using to hold the engine to the fireall?