chemie

So I have been exchanging PM's with MESAFLYER regarding moving to a 10oz tank on the SSE.
The kit is designed for a Dubro 8oz tank but with a ST51 planned (Mesa is going with a OS55), I wanted more tank. I have a 10oz Dubro.

First option is to put in a hatch but the instructions are very specific "while the modeler may be tempted to install a hatch, for structural reason, this should not be done".

So I have been dry-fitting to see if there is another solution. The 8oz is designed to "pull out" through F-2 and over the wing tube and dry-fit testing shows this works. The 8oz tank is 2 1/4" wide while the 10oz if 2 1/2" wide. However, F-2 opening is 2 3/8" wide.

So I would like feedback on this option:

1. Cut out the portion of the fuse doubler where the floor mounts but glue in the "Popsicle" shaped cut outs. This will drop the floor 1/4" giving vertical clearance.
2. Cut 1/16" on each side of F-2 to give clearance. (Suggestions on how best to shave this amount? access is hard)

My worry is with Step 2. The F-2 is 1/8" ply and the vertical sections are only 3/16" wide so 1/16" is not insignificant. Am I making this too weak by going from 3/16" to 1/8" on this strip? I do not want a "new" structural issue....

First picture is the fuse doubler where the floor can be lower 1/4" by removing the marked section. As stated, I will glue back in the cut out to form a new surface for the floor to fit into.
Second pic shows where the 1/16" needs to be removed for the tank to squeeze through.

Thoughts? Other approaches?

MinnFlyer

My Feedback: (4)

Will the tank fit if you rotate it 90 degrees?

Allfat

My Feedback: (1)

I put a 10 oz tank in a 4* kit that I built, which is similar in construction to the SSE. I just shaved off some material off the sides of F-2. To do this, I simply took a hobby knife and started shavind off material on both sides until the tank could slide in and out. Then install the tank and enjoy! Hopefully this works out for you. Good luck!

chemie

MinnFlyer: I thought you were on to something for a while but no. It can not rotate the 90deg. when inside the tank area (it hits the fuse sides) so this won't allow you to pull the 10oz out.

Note: I assume I need to allow for removal. I am thinking about losing the plug or tubing hole etc. I can build the fuse around the tank but it would be impossible to access in the future. (like building the house around the piano).

chemie

Allfat: I have the 40*-40 ARF and it was not possible to change due to access. However, there is a LOT more wood on the F-2 on the 4*. (The ARF comes with a tank shaped like a cylinder with the sides cut off but it is almost 9oz since it is metric and I figure good enough).

bps

My Feedback: (3)

Here is a thought. Make two thin plywood rings and glue one to inside of the fuse on each side. Make a band clamp to hold the wing tube to the servo mounting board. That way you could remove the tube to get the longer tank in and out.
JEB

chemie

JEB: The wing tube is not in the way...the problem is with F-2

mclina

I recently rebuilt my Four Star 40, and I also installed a 10 ounce tank. I just had to shave down the former with my Dremel.

Weasel Keeper

My Feedback: (16)

If you would consider another tank, Hayes and Sullivan have narrower options in 10 and 11 oz tanks.

chemie

Weasel. Good point. Of course, I now have a 8oz and 10oz Dubro collecting dust but I guess I should have measured F-2 before buying the 10oz.

Is there an advantage to rectangle versus cylinder? The Sullivan [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&W=001603520&I=LXFU38&P=K]tank[/link] shaped like a cylinder looks like it will just fit.

It looks like the bung will be 1/4" to 1/2" lower with cylinder (it is centered versus at top of rectangle).

bgfireman

My Feedback: (13)

Chemie,
Can you shave a little off the side of F2, and then use a small piece of triangle shaped balsa to reinforce it on both sides? One side may even be enough. Either that or some fiberglass reinforcing tape. That is my two cents worth. I am not an engineer, but I did sleep at Holiday Inn last night.
Alan

Weasel Keeper

My Feedback: (16)

It seems to me that the cylindrical tank might be a better shape as it would take less fuel volume to keep the klunk submerged making the most of a given amount of fuel. Anyway, I've run into this problem before while building a 40 size Stinger and hate to take any structure from F2. So I checked around for narrower dimensions and found the Hayes and Sullivan tanks to work for me. Oh yeah, I have a few extra Dubros because of it too. I'm sure I'll find a use for them someday.

chemie

BG:

LOL. I am an engineer but not a mechie. Barely made it through drafting. Maybe Holiday Inn is what I need.

Weasel: I am with you. I do not want to shave F-2 unless I have too and I think the cylinder tank will just fit. I will dry build the rest of the fuse as I am still worried about the wing joiner getting in the way so I will measure three times before another $5 shipping order to TH.

yel914

My SSE had a Super Tigre .45 with an 8 oz. tank and I don't recall ever running out of fuel. Flights of 12 minutes were standard and most at 3/4+ throttle. How long did you want to fly the plane? Just thought I'd ask as you may not need to go to the 10 oz. tank. On the issue of a tank hatch-I had one on mine and probably would not do it again. It does weaken the structure. Man, I sure miss my SSE[]

chemie

I am surprised a small section of 1/16" sheeting makes that much differences but I figure they would not go out of their way to tell you not to do a mod in the instructions unless it matters.

This will have a ST51 or OS55 so thought a little more fuel would help.

mesaflyer

Hi chemie,
I have been away from my build for a few weeks. Glad to see your making progress.
I would have to disagree with your assessment that an 8oz tank will pull out, that is without making some kind of mod. Mine will not pull out, no way without modifying something. I was able to use the 8oz on my sons profile plane, got lucky, a perfect fit.
I will get started again soon on my SSE. I think I have the hatch figured out, and I am not worried about any structural weakness. There have been several people that have made the hatch without any problem.
I did look into other tanks, but as I recall, there wasn't any advantage to them, so I bought the Dubro 10oz. I like the "bottom lip" in front of the Dubro. Helps with the plumbing.
I'll post a pic as soon as I can find my wife's camera.
Oh, and thanks for the PM letting me know about this thread.

mesaflyer

chemie,
Here are a couple pics of the 10oz tank. It's hard to tell in the pic, but the outlet for the tank is about 1/4 taller than the slot in the fire wall for the hoses to pass thru. No big deal, going to put a little foam between the tank and firewall anyway, that will set the tank back from the firewall, so give more room for hose bend. Also, you can see some hardwood pieces that I have glued to the firewall and to F-2, and then shaped them. When I get the hatch all done, I'll post some more detail pics and info on what I did. Until then................

Gray Beard

My Feedback: (-1)

As mentioned, there are a bunch of different makes and models of tanks out there, you should be able to find something that will fit without any trouble. I have even used tanks designed for jets just to get get a tank to fit inside a Corasir fuse, that gull wing can really get in the way.

mesaflyer

Well, let me re-phrase. IF, you don't make any mods to the plane, even the 8oz tank can't be removed. The problem is the length between F-2 and the wing tube, and the angle the tank needs to make in order to "lift out" up and over the tube. Now, if there was a shorter 8oz tank, it might work. Shorter being from front to back in this case. So, back to any tank bigger than 8 oz, still needs to be shorter than the Dubro 8oz, which would make it almost a "cube" shape. Very tall, and very wide (probably wider than the fuse), and very short (from front to back). I'm not saying it can't be done, it's just that in my research, it just wont fit without some extensive mods. I am at work, so can't supply any dimentions of the tank and the compartment it has to fit in. Hope this helps. And this is why I am building a hatch.

chemie

Mesa:

I have fully assembly (dry) fuse and I can in fact pull the 8oz Dubro out through F-2 and over the wing tube. There is a small section cut out of the tank floor where you can have the front of the tank drop down and get over the top of the wing joiner. Unless I am missing something from the top assembly, I think it fits fine.

The 10oz does not fit through F-2.

I have ordered a Sullivan which is 10oz but the same dimensions as the 8oz Dubro except it is 1/4" taller in height. I will drop the floor 1/4" and it should fit (unless the height then becomes an issue with the wing tube). However, I will let you once the tank arrives. Even if length is an issue, I can cut out some of the "tail end" of the tank floor as there is space underneath to lower the tank front down and get clearance.

However, I would love more details Mesa because, as I said, in my dry assembly I CAN get the 8oz out so I am worried I am missing something and need to ensure the new 10oz will work.

Thanks for the pics. I thought through the hatch and how to build but chickened out when I re-read the instructions saying not to. Hopefully Tank #3 wins.

h@h racing

My Feedback: (1)

I used the 10 oz soft tank in mine and left the tank shelf out. Glued foam to the top and bottom of the tank compartment and the tank slides between the foam. I used fiberglass reinforced tape and made two pull tabs attached to the tank. I did remove some material from the F2 to get the tank in but have seen no problems yet. You can pull the tank out over top of the joiner tube with the soft tank. I also run the ST G51 in this plane.

mesaflyer

chemie,
I wish I had an answer for you. Maybe with dry fitting there is enough "play" to get the 8oz tank out. I dunno, but I tried mine every which way I could, and it would not come out.
h@h,
That is a great idea! I did use one of those flex tanks once on my Mustang. It was sitting against a former, and after about 20 flights, it had a groove worn almost all the way through the tank. That problem should be eliminated by gluing foam to the tank. Also, lowering the floor is what I would have done, if I ever build another SSE. But I like the "no floor" idea even better, as long as the tank is not sitting on the lower cross brace, or protected by foam. I would also mount the engine sideways and build a cowl. I think the extra work is worth it, looks wise.
chemie,
You might want to check this out. Sounds like it worked pertty good for h@h. If you use a flex tank, just be carefull and make sure that it is not rubbing against any "edge" surface, like dummy me did.

carrellh

For strength, you could "double" the former using something like 1/16 aircraft ply. Then shave it as necessary for the width or diameter of the tank.

chemie

I have a Sullivan 10oz ordered: [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFU38&P=0]tank[/link] and will advise if third attempt fits. I was not sure about the flexible ones so went with this one instead but agree it is an option.

h@gh: Any CG issues with the ST51? I added a bit to the rudder so I am hoping it balances off with the larger engine (ST muffler is a pig for weight).

h@h racing

My Feedback: (1)

Reciever just behind the wing tube and the battery between the tube and the tank. I added some to the tail also.
The tank will come out pretty easy as the foam lets the front of the tank drop down while trying to clear the wing tube. Now getting the hoses out the holes is another story with the built up cowl and engine in place.