gphil

I got a new mount for a Satio 72 anyway was suggested and should fit. The eng does go into the mount Dave Brown no problem but the question is just how close to the ends of the mount should the bolt holes be. Seems to get close to the end of the parallel mounts. I think it is ok and was wondering. Not too close to the firewall but about 1/8 of an inch away. Don't want to touch. The mount is made of plastic compound. Let me know and thanks guys. gphil

tailskid

My Feedback: (34)

What plane are you putting the engine on? Usually the thrust washer determines how close to the cowl opening should be....if you do not have a cowl on your plane, I like to put the engine right about in the middle of the mount (assuming that is OK with the CG).

gphil

The plane is a 60 size Stick (Drastick) from Texas RC. Going to be a sideways mount. The mount I have seems too short. gphil

scale only 4 me

My Feedback: (158)

If when you drill the front holes you you have as much meat in front of the hole as you do on either side, you're fine, if it looks like you're going to blow out the front, you may want to look into a four stroke mount, they are usually a bit longer

a picture would help


good luck

gphil

Great advise Scale Only For me There will be a little meat on each side in front but close.

JohnBuckner

My Feedback: (1)

The front of the engine mount lugs need only to be flush with the front of the plastic mount beams in fact on some installations I even cut the beam so to be flush or near flush with the engine mount lug. The material of the mount that is forward of the engines mount lugs serve no purpose and add nothing to strength.

The DB's are my favorite and work quite well.

John

gphil

thanks John,   I was thinking that with the bolts so close to the end they might twist out but then the other three would be strong.   Just dotting my "I's" and crossing my "T".   Thanks   gphil

jester_s1

There isn't any sideways force on those bolts aside from a little bit of shear force from the engine thrust (we're talking an ounce or two here). All of the force on the bolt holes is straight up and down from the clamping pressure that the bolts provide. No sideways force means no bolts twisting out.

Steve Steinbring

Gary, good advice given! You might also use some nylock nuts when bolting down your engine avoids things getting loose.

scale only 4 me

My Feedback: (158)

I typically "Tap" threads directly into the nylon mounts,, no need for a bolt on the bottom in most cases.

good luck

gphil

Yup Steve these guys are always On Spot with advice.  Thanks for the input.   Like my club says,,,,,,Hey guy its a ARF       To me it stands for   "Almost Really Finished".      Sure I am slow but I earned it.    gphil

Propworn

My Feedback: (3)

The Dave Brown motor mounts are great. All of the mounts have a little extra length that allows some adjustment for the C of G. I only use the 4 stroke mounts even for 2 stroke installation I cut off what isn’t being used at the front. You do not have to cut the mount flush with the front of the engine lug I would leave it a bit longer for extra support. Bring your motor to the hobby shop to make sure of proper fit. Usually placement of the 2 stroke motor is further back in the 4 stroke mount but the thickness of the beam is greater as well. The bottom of the beam is at an angle so using a nyloc nut is not recommended unless you spot face the angle so the nut does not put any side force on the motor mount beam. Instead when you drill and tap the hole only run the tap through the mount far enough you see a bit of the tip of the tap extend through the bottom of the mount. If done correctly this will give a bit of an undersized tapped hole at the bottom of the beam which will do the same as the nyloc nut in keeping the screw from backing out.

Dennis

gphil

All masters of the art.  Thanks.    I tried the " Epogrip" and  recommend it,,,,works great.   gphil

Gray Beard

My Feedback: (-1)

I do like John and Scale. I cut off the extended part of the mounts and I tap in the threads. I have a lot of used mounts and when I have one with over sized holes I use the fiber lock nuts. No set rules. I tend to buy more of the Great Planes adjustable mounts when I need a new one. They are usually in stock at my LHS but I really have no favorite brand. I also have a small stock of aluminum mounts that I like.