metal tank mount for the 049 td suggstion/ request

Good idea. A delrin fuel tank like this can also be made. Engine can be mounted using crankcase screw lugs or fuel tank screw lugs can be used.

Of course it can be made from red anodized aluminum backplate and fuel tank.

I agree that having the tank rotating from the starting forces is the biggest issue.
Would a o-ring gasket in a grove give enough friction to keep the tank in place?
The larger diameter does reduce the force this ring has to absorb.

Levent Suberk wrote:Good idea. A delrin fuel tank like this can also be made. Engine can be mounted using crankcase screw lugs or fuel tank screw lugs can be used.

The td does not have the screw holes like the red valve have but a backplate that screws in place.
So there is no need for the 4 screws / holes and the mount might be a bit cheaper to make.

Besides that detail your render is how it would look like yes,

The Norvel extended 1 ounce plastic tank mount is spaced for .049 Tee Dee, I believe. (Norvel .061 Big Mig has same bolt pattern. It requires cutting a hole in the bulkhead but uses Cox reed valve tank engine mount pattern. Short of rolling one's own, would this be a suitable solution?

cmulder wrote:...The tank part should screw on the back of the td  and have a centre post for the mounting screw.
The backplate should look like a 0409 reedy tank mount with the 4 mounting holes and a centre screw hole to mount the tankl and engine...

The fuel tank screws to where? Where is the center post for single mounting screw? On back plate? There must be four screws for mounting fuel tank to engine.

On the td 049 / 051 the backplate is screwed in. (the plate itself has screw threads and also the inside of the engine case)
To mount the tank; remove the engine backplate and put the tank in its place.
There is no need for aditional screws the tank IS the "screw" that mounts into the engine.

To mount the backplate on the tank part a single bolt is needed in the exact centre of the tank and backplate.
And inside the tank there will be a "stud" that this bolt screws into (again in the exact centre/middle)

GallopingGhostler wrote:The Norvel extended 1 ounce plastic tank mount is spaced for .049 Tee Dee, I believe. (Norvel .061 Big Mig has same bolt pattern. It requires cutting a hole in the bulkhead but uses Cox reed valve tank engine mount pattern. Short of rolling one's own, would this be a suitable solution?

Those are close ito the original cox design.
A full metal one is likely more durable.

cmulder wrote:On the td 049 / 051 the backplate is screwed  in. (the plate itself has screw threads and also the inside of the engine case)
To mount the tank; remove the engine backplate and put the tank in its place.
There is no need for aditional screws  the tank IS the "screw"  that mounts into the engine.

To mount the backplate on the tank part a single bolt is needed in the exact centre of the tank and backplate.
And inside the tank there will be a "stud" that this bolt screws into (again in the exact centre/middle)  

However those fine threads can not carry engine, in my opinion.

I think the thread carries the motor OK, but sometimes they unscrew.  Texas Timers used to sell one with quite a few holes drilled in the back because of the random position where the thread ends up.  It had no tank.  There is an old Tatone tank mount that was a bit small and heavy mostly because there were three? screws holding on a sheet metal back seal. Maybe something could be dreamed up like that with a bigger diameter and a bit longer for more fuel.  Or just a big bell that uses a standard GRP motor mount that bolts on.  Just thinking out loud. http://texastimers.com/
 https://i.ebayimg.com/thumbs/images/g/1bIAAOSwoCxg9wkk/s-l300.jpg Mine is 21 grams with the screws.

Kamtechnik has a radial mount for .049/.051 engines.  
COX Tee Dee Radial Mount

NORVEL mounts are here:
NORVEL Radial Mount

Never saw a complaint about these.

Can't remember where I read it. Maybe it was with a starter or something. Kamtechnik has some nice stuff.

Would you prefer the engine unscrewing and have no damage or a hydrolocked engine snapping its conrod?
Also if it unscrews a little the resulting airleak would stop the engine.
If you tighten the tank mount when the engine is hot then it should not come loose again.

This style of mounting a engine is proven.

andrew wrote:Kamtechnik has a radial mount for .049/.051 engines.
COX Tee Dee Radial Mount

I bought two of them from Kamtechnik, a .09 and .049, they are high quality items, very well made. I am glad they picked up the slack where Texas Timers left off.

Regarding concerns about the sturdiness of the Norvel plastic tank mounts, they are decently sturdy. I Figure-9'd my Q-Tee into the terra firma from about 60 feet up, and it survived without cracking.

2nd time I crashed Q-Tee (2015), very thorough indeed.


Norvel .061 Big Mig with Norvel tank mount, before crash.

I don't know what plastic Norvel used, but appears to be as sturdy or perhaps sturdier than Delrin. Delrin is strong. I did similarly to my Sterling Minnie Mambo with Cox .049 R/C Bee back in 1982 from 100 feet into the ground, buried engine about 4 inches deep in the grassed soil. It survived without even stretch marks.

Regarding making a mount tank out of metal, perhaps a solution would be provision for a Kamtechic mount Tee Dee or Medallion to the metal tank, to allow freedom of engine orientation?

I don't make a habit of crashing, but just seems that old Murphy is out there, and obviously before this flight (decided to fly on a windy day, then the Norvel power sagged for some odd reason, could not keep flying into wind, no throttle control, spun it into the ground to keep it from getting too far away (about 150 - 200 yards away from me).

Galloping Ghostler, you have to stop testing those mounts. You're killing those poor Q Tees. I had problems with vibration on the Norvel mounts with a TD running a pretty small prop. It was making air bubbles. No problem with the Norvel motors though. I guess the Norvels have a lighter piston. I broke a couple red Cox mounts with some "somewhat light" crashes. I do like the fact that the Norvel mount has the same bolt pattern as the Bees.

GallopingGhostler wrote:...............
Regarding concerns about the sturdiness of the Norvel plastic tank mounts, they are decently sturdy. I Figure-9'd my Q-Tee into the terra firma from about 60 feet up, and it survived without cracking.
.............

That's the tank on my Honker (my avatar). I swapped a NORVEL .061 and integral tank for the Black Widow that was originally on the plane, but I found that the tank did not give quite as long an engine run that I wanted -- I left it on to add to the nose moment and plumbed in a Fuji Film can tank behind the firewall.

Before the Fuji can went in, I had noticed what appeared to be a curved blade of grass inside the NORVEL tank and couldn't, for the life of me, figure out how it possibly got in there -- it turned out to be a glue fillet that had broken loose from inside the tank. This mount was apparently blown from a single mold with an open backside. This opening was then filled with a circular plug that was glued in. Over time, I suppose fuel and vibration caused the adhesive to deteriorate and come loose, adding a second reason to use an external tank rather than the integral mount tank.

GallopingGhostler wrote:Regarding making a mount tank out of metal, perhaps a solution would be provision for a Kamtechic mount Tee Dee or Medallion to the metal tank, to allow freedom of engine orientation?

To mount the tank you would remove the engine backplate and screw the (round) tank in its place (just like with the kamtechnic mount)
Once tight the backplate would be mounted on the tank.
Since the single mount screw is in the center you can rotate the tank/engine to any angle you like.
Then tightning that screw and mount the backplate/tank/engine as one unit to onto the firewall.

The whole tankmount would be made up from only 3 parts; the tank, the backplate and the screw.
Unless testing shows there is a need for a gasket ring between the tank and the backplate then it would be 4 parts.

The whole tankmount would be made up from only 3 parts; the tank, the backplate and the screw.
Unless testing shows there is a need for a gasket ring between the tank and the backplate then it would be 4 parts.[/quote] Sounds like a good plan. Lighter than the old Tatone tank mount that I linked before. Just need a price and see how many orders you may get.... The Tatone mount had the bolts go right through the tank from the front and the sheet metal backplate sealed with a rubber gasket I think. It would have been squeezed on to the firewall. Somewhat crude, but the mount was just a casting so it would have been quick to machine. Now of course there is CNC.

aspeed wrote:Galloping Ghostler, you have to stop testing those mounts.  You're killing those poor Q Tees.

Remember that breakfast cereal commercial 40 years ago, "Why don't you give it to Mikey, he hates everything!" Look to the positive, I am your crash durability specialist. If the newly designed metal tank can survive my use, then it can survive anything.