Cox Engines Forum
You are not logged in! Please login or register.

Logged in members see NO ADVERTISEMENTS!


Engine mount ? Hardwood Cox_ba12




Engine mount ? Hardwood Pixel

Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Latest topics
» my attempt at making an exhaust throttle for Cox .049
by roddie Today at 6:22 pm

» Anderson Baby Spitfire - looking for the aft tank and gasket
by dan vincent Today at 6:15 pm

» Another of C.T. engines cleaned ---- Cox Tee Dee .09 --- Just today (3/26/2024) more Cox parts
by sosam117 Today at 5:55 pm

» Cox powered boat litle shrimp hidroplane
by davidll1984 Today at 2:52 pm

» Introducing the new - "QZ" RR-1
by roddie Today at 1:08 pm

» STUKA bomb dimentions needed
by latole Today at 9:36 am

» Indexing COX cylinders
by davidll1984 Today at 7:56 am

» Introducing our Cox .049 TD Engines
by Yabby Today at 6:33 am

» 1/2a Skyray plans?
by 944_Jim Yesterday at 10:14 pm

» Postage stamp backplates
by JPvelo Yesterday at 8:52 pm

» Cosmic Winds, - Big Guy, Little Guys, Silver Guy and Wounded Guy.
by rsv1cox Yesterday at 5:18 pm

» My friend Ramón, his Cox .09 & Cox .010
by MauricioB Yesterday at 12:31 pm

Cox Engine of The Month
March-2024
balogh's

"COX Budapest" .049 engine



PAST WINNERS
CEF Traveling Engine

Win This Engine!
Gallery


Engine mount ? Hardwood Empty
Live on Patrol


Engine mount ? Hardwood

Go down

Engine mount ? Hardwood Empty Engine mount ? Hardwood

Post  oldguy Thu Jan 11, 2018 5:21 pm

I'm going to be scratch building my first S1 R/M. I have a piece of 1/4" red oak. This should work for making my mounts out of for the S1, right?
oldguy
oldguy
Gold Member
Gold Member

Posts : 368
Join date : 2015-12-10
Age : 70
Location : Idaho

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  Jason_WI Thu Jan 11, 2018 5:55 pm

Oak likes to split along the grain. I would use birch, beech, or maple. Something closed grain. Spruce would work too in a pinch.
Jason_WI
Jason_WI
Top Poster
Top Poster

2022 Supporter

Posts : 3123
Join date : 2011-10-09
Age : 48
Location : Neenah, WI

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  Ken Cook Thu Jan 11, 2018 6:42 pm

The Sterling S-1 A  ( Sheeted leading edge ) used poplar for the mounts. Engine mounts should be 3/8"x 1/2" for a .35 size engine.  The box didn't lie, it said hardwood mounts. Poplar is a hardwood due to it's species but the wood itself is far from being hard enough to use for it's designated purpose. A&J Free Flight kitted The YAK and F-51 Mustang in the 80's  based exactly on the Sterling Kits using the Sterling's instruction sheets. They used red oak for engine mounts. While it wouldn't be my choice if I was building one today, I wouldn't hesitate to use it. I've had my A&J planes flying since 1987 and they're still flying today.  Just let me mention though that a Sterling nose is very poorly designed. The engine bearers are 2" long and  only encapsulated between the 2 doublers which prevents the doublers from being squeezed together but doesn't do much for stiffening the nose from vibrations. Running the engine bearers back into the fuse offers a much stronger front end. The doublers on a stock Ring only extend to the back of the leading edge. Very very poor which sets up a stress riser allowing the  nose to break off directly in front of the wing. Reduce the stock 1/8" doublers to 3/32" 5 ply not 3 ply birch and extend the doublers to the high point of the wing and you won't regret it.
Ken Cook
Ken Cook
Top Poster
Top Poster

Posts : 5414
Join date : 2012-03-27
Location : pennsylvania

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  roddie Thu Jan 11, 2018 7:09 pm

I would personally use maple Jim... and 1/4" is NOT thick enough.

My S1 fuse is 1/2" balsa. If I were to re-make beams/bearers for it.. I would cut them to a 1/2" x 3/8" dimension. The 3/8" dimension is what would be drilled-through for the machine-screws to mount the engine. Note Ken Cook's advice on the "length" of the beams..

Actually... you might want to go with 1/2" x 1/2" if you opt for installing threaded-inserts.

In any case; the plywood nose-doublers are used to cap-off the beams. Note Ken Cook's advice on the grade of plywood.. and extending them back further than noted on the plan.

See if you can find an old maple bureau that's being thrown out. Seriously.. one solid-maple drawer-panel would have enough square-inches of stock to make beams for dozens of models. Ripping strips on a table-saw is not difficult.
roddie
roddie
Top Poster
Top Poster

Posts : 8159
Join date : 2013-07-17
Age : 64
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  oldguy Thu Jan 11, 2018 7:46 pm

Ken, Robbie.
 I meant to say I would double the 1/4" redwood.  And looking at the plans I see what you are talking about, running the engine bearers and doublers back further over the wing. I will take your advice on that, and use the thinner 3/32 doublers. And Yes the fuse is 1/2".
oldguy
oldguy
Gold Member
Gold Member

Posts : 368
Join date : 2015-12-10
Age : 70
Location : Idaho

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  pkrankow Thu Jan 11, 2018 8:12 pm

Hard maple, not any of the soft maple varieties. Order through Brodak, or find a plank, old chair, locker room bench and go to town with a table saw.

Yes i said chair, maple kitchen and dining sets are almost exclusively hard maple and a broken chair has a lifetime of wood in it.

Since this is a contest plane that may not fly much oak might be fine. White oak would be better.

Phil
pkrankow
pkrankow
Top Poster
Top Poster

Posts : 3025
Join date : 2012-10-02
Location : Ohio

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  oldguy Sat Jan 13, 2018 4:01 pm

Well I went ahead and ordered up some maple 1/2 x 1/2 from Brodak.  I will be mounting a McCoy .35 on the nose of this R/M. I'm also debating with myself, whether to order a set of ribs or make myself. I have always made them myself but nut for a .35 size plane.
oldguy
oldguy
Gold Member
Gold Member

Posts : 368
Join date : 2015-12-10
Age : 70
Location : Idaho

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  pkrankow Sat Jan 13, 2018 8:20 pm

Bigger ribs are easier than small ones. Dont sweat it.
Phil
pkrankow
pkrankow
Top Poster
Top Poster

Posts : 3025
Join date : 2012-10-02
Location : Ohio

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  oldguy Sat Jan 13, 2018 9:19 pm

pkrankow wrote:Bigger ribs are easier than small ones.  Dont sweat it.
Phil

Hey thanks for that.
oldguy
oldguy
Gold Member
Gold Member

Posts : 368
Join date : 2015-12-10
Age : 70
Location : Idaho

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  RknRusty Sat Jan 13, 2018 10:48 pm

I'm glad you went ahead and got the Maple.
You know oak has tiny xylem tubes through its length. Pick up an oak dowel and suck or blow into the end grain. It will pass air like a soda straw. I expect that betrays some undesireable weakness.
Rusty

_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!


My Hot Rock & Blues Playlist
RknRusty
RknRusty
Rest In Peace
Rest In Peace

Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  Jason_WI Sat Jan 13, 2018 10:51 pm

RknRusty wrote:I'm glad you went ahead and got the Maple.
You know oak has tiny xylem tubes through its length. Pick up an oak dowel and suck or blow into the end grain. It will pass air like a soda straw. I expect that betrays some undesireable weakness.
Rusty

Only red oak does that. They make whiskey barrels out of white oak. White oak has tyloses which seals the ends of the pores. red oak does not.
Jason_WI
Jason_WI
Top Poster
Top Poster

2022 Supporter

Posts : 3123
Join date : 2011-10-09
Age : 48
Location : Neenah, WI

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  Ken Cook Sun Jan 14, 2018 10:45 am

I can tell you from experience, red oak works just fine . It wouldn't be my first choice but it does the job. I've used it on several combat foamies and have stuffed them into the ground without failure. In addition, it's far stronger than the rice wood used in the ARF models that use larger engines than the Ringmaster. Your only trying to keep the doublers from squeezing. The nose of a Ringmaster in it's entirety is far weaker than the wood bearers themselves. In other words, the nose is going to break at the wing's leading edge before the mounts can be broken.
Ken Cook
Ken Cook
Top Poster
Top Poster

Posts : 5414
Join date : 2012-03-27
Location : pennsylvania

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  Cribbs74 Mon Jan 15, 2018 1:04 am

Hickory is the hardest wood we have in the US as far as I know. I have a bunch of it at my disposal. Luckily hard rock Maple is stockpiled at my home.
Cribbs74
Cribbs74
Moderator

2022 Supporter

2023 Supporter

2024 Supporter

Posts : 11892
Join date : 2011-10-24
Age : 50
Location : Tuttle, OK

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  Jason_WI Mon Jan 15, 2018 1:39 am

Cribbs74 wrote:Hickory is the hardest wood we have in the US as far as I know. I have a bunch of it at my disposal. Luckily hard rock Maple is stockpiled at my home.

Hickory is pretty hard stuff and available most anywhere. We have trees that grow around here called ironwood. Some kind of hornbeam. We use it for wood bearings. I cut some on my bandmill into boards to be used in the bottom of an auger bunk feeder that the auger rides on. It threw sparks off my saw blade when cutting it. It wears better than uhmw plastic.
Jason_WI
Jason_WI
Top Poster
Top Poster

2022 Supporter

Posts : 3123
Join date : 2011-10-09
Age : 48
Location : Neenah, WI

Back to top Go down

Engine mount ? Hardwood Empty engine mounts

Post  Eddy Wed Jun 27, 2018 11:20 am

I know there might be laughs over this, but I have since the 70's, used new popsicle sticks for beam engine mounts. They are made from White Popular, I epoxy between the layers and clamp together. For the .35 size engine, I use six sticks which will give a 1/2 inch width for the mount. For a .15 engine, I will use five sticks, it will give a 3/8 mount. And for 1/2 A, only 3 sticks are needed for a 1/4 mount. In years past when I flew some combat, a scratch built from plans, I still used this method for engine mounts. Simple and easy, an in all honesty no problems at all. If you have a Hobby Lobby near, a box of 1,000 popsicle sticks goes for under $5.00.
Eddy
Eddy
Silver Member
Silver Member

Posts : 90
Join date : 2018-04-29
Age : 79
Location : Portage, Michigan

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  GallopingGhostler Wed Jun 27, 2018 12:58 pm

Eddy wrote:I know there might be laughs over this, but I have since the 70's, used new popsicle sticks for beam engine mounts. They are made from White Popular, I epoxy between the layers and clamp together. For the .35 size engine, I use six sticks which will give a 1/2 inch width for the mount.

Eddy, I'd say instead perhaps you had the last laugh. Basically you were making plywood. Even though the grain was going more or less in the same direction, the Epoxy was imparting strength to the layers, and also strengthening the wood by soaking into the pores.

Plus, you've given me thoughts on how I can manufacture engine mount beams and other aircraft uses. One of the oldest hobby shops in Amarillo Texas closed a couple years ago. Another in Lubbock did too. All that's left is the one hobby store in Amarillo that sells mostly R/C car fuel and related, not much aircraft stuff.
GallopingGhostler
GallopingGhostler
Top Poster
Top Poster

2023 Supporter

Posts : 5214
Join date : 2013-07-13
Age : 70

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  oldguy Wed Jun 27, 2018 1:06 pm

Eddy wrote:I know there might be laughs over this, but I have since the 70's, used new popsicle sticks for beam engine mounts. They are made from White Popular, I epoxy between the layers and clamp together. For the .35 size engine, I use six sticks which will give a 1/2 inch width for the mount. For a .15 engine, I will use five sticks, it will give a 3/8 mount. And for 1/2 A, only 3 sticks are needed for a 1/4 mount. In years past when I flew some combat, a scratch built from plans, I still used this method for engine mounts. Simple and easy, an in all honesty no problems at all. If you have a Hobby Lobby near, a box of 1,000 popsicle sticks goes for under $5.00.


Hey Eddie, no laughs from me as a guy who just mostly scratch builds and fly's for fun i'm always looking for ways to do things out of the norm.I'm going to try your idea on my next build what ever that turns out to be.
Thanks eddie
oldguy
oldguy
Gold Member
Gold Member

Posts : 368
Join date : 2015-12-10
Age : 70
Location : Idaho

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  TD ABUSER Thu Dec 15, 2022 12:02 am

Forget about using poplar or birch, or popsickle sticks for a model that is powered by a Cox TD [or more].

New Hampshire "ROCK MAPLE" was what my LHS sold for mount material and there was a good reason why.
Some years later the maple became lighter, softer and not as good because the selection of the best OLD GROWTH WOOD was getting more scarce.
Maple is still your best bet..but you might need to order from a hardwood specialist to find you some of the good stuff..
TD ABUSER
TD ABUSER
Gold Member
Gold Member

Posts : 179
Join date : 2020-11-01
Age : 68
Location : Washington

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  roddie Thu Dec 15, 2022 6:40 pm

There's been some good advice on how to use any of the hardwood choices for engine bearers posted in this thread. What I've taken from those is; to build the profile-style nose of your model airplane with engine bearers that are beefy-enough for the recommended engine screws.. and long-enough to transfer some vibration rearward, to be absorbed closer to the central structure of the model. Hacking-up a kit-fuse is not for the faint of heart.. Laughing  and many modelers won't do it.. but you can make new extended plywood doublers to hide the hacking!

Avoid having a "diving-board" nose on that profile model-airplane! Vibrations can come from a poorly or non-balanced propeller.. as well as harmonic-vibrations that may come from the engine... when it's running in its sweet-spot. Fuel can get foamy.. a less-than quality needle-valve could drift.. wheel-collars can loosen.. as well as other fasteners..

There's been an old desk on the side of the road on my work commute. It's a big-oL wooden desk with 6 drawers.. looks like it came out of a courthouse. I've ogled it.. and imagined what type of wood it was made of. It would be a sin to remove a drawer for it's hardwood (no doubt it would have dovetail joinery) I imagined it as "my desk".. in "my workshop".. Laughing  but it would take four strong young adults to move it into a home and down a set of stairs. It's been there more than a week and i really hope that someone rescues it.
roddie
roddie
Top Poster
Top Poster

Posts : 8159
Join date : 2013-07-17
Age : 64
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  HalfaDave Thu Dec 15, 2022 7:13 pm

Hi All,

The fuelproof/wing/fuselage joint is the most important.
A nice Cox engine will erode any wood, over time...
Good Rock Maple is very nice.
Same density as aluminum, but easier to glue...
Transferring the power of a Cox to wood,
Is the challenge.
Someone will do it...
One day,

Dave
HalfaDave
HalfaDave
Platinum Member
Platinum Member

Posts : 557
Join date : 2022-12-06
Location : Oakville, Ontario

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  aspeed Sat Dec 17, 2022 1:39 pm

I used maple for some engine bearers on the F2D combat planes for a while. It was much lighter than the aluminum that is commonly used. I revealed this knowledge breakthrough to the local combat guys and they like aluminum better because it bends and doesn't break. That would lose a match. For me, that is not an issue, but it is more trouble to fuel proof it so I use aluminum now anyway. I still will use the maple on other stuff though. I found a nice knot free straight grained piece of flooring at a Lowes store that made a lifetime supply. Some stores would not sell single pieces, but that one was by the sq. ft. so I got a long piece and used the table saw and the milling machine to get it to size because the table saw has a lot of slop, being a $5 garage sale item. Had my eye on some bamboo stock. It is very hard and strong but kind of heavy.
aspeed
aspeed
Platinum Member
Platinum Member

Posts : 787
Join date : 2013-01-18
Location : Leamington Ont. Can.

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  TD ABUSER Wed Feb 01, 2023 5:51 pm

Eddy wrote:I know there might be laughs over this, but I have since the 70's, used new popsicle sticks for beam engine mounts. They are made from White Popular, I epoxy between the layers and clamp together. For the .35 size engine, I use six sticks which will give a 1/2 inch width for the mount. For a .15 engine, I will use five sticks, it will give a 3/8 mount. And for 1/2 A, only 3 sticks are needed for a 1/4 mount. In years past when I flew some combat, a scratch built from plans, I still used this method for engine mounts. Simple and easy, an in all honesty no problems at all. If you have a Hobby Lobby near, a box of 1,000 popsicle sticks goes for under $5.00.
Why can't I ever get away with doing stuff like this...?
Are you wood screwing / sheetmetal screwing a Cox TD .049 to 3 plys of popsickle sticks...?

Back in the day some TD .049 Combat Planes used 5 ply 1/4" thick aircraft plywood..and that didn't work real good.
The screws would loosen before the plane ran out of fuel.
TD ABUSER
TD ABUSER
Gold Member
Gold Member

Posts : 179
Join date : 2020-11-01
Age : 68
Location : Washington

Back to top Go down

Engine mount ? Hardwood Empty Re: Engine mount ? Hardwood

Post  Sponsored content


Sponsored content


Back to top Go down

Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum