mr.snaproll

My Feedback: (38)

I have never used a RotoFlow tank for two reasons, you can't open them up for preventive maintenance, and you have to put your plane on its nose to get the fuel out. I've also heard that sometimes the sliding clunk gets stuck. Every tank has its down sides but I would rather replace a few lines than buy a new tank. Its always nice to see inside your tank. Most issues can be caught before they become a problem.

rexbirk

I have four of the Rotoflows. Three in 30cc planes and one in a 50cc. Have been running them all season and zero problems. So far I like them a lot. No leaks, no lines to harden and they are thicker plastic than Fuji Bottles which I worry are too easy to puncture. The few extra ounces are of no concern to me.

eddieC

My Feedback: (2)

LOL What are friends for?

MTK

Hi Rex,

Polyester bottles for water such as the FIJI, Dasani, etc and all of the clear juice bottles, are very tough and much more puncture resistant than one would think. When I build these gas tanks for guys, i am reminded every time exactly how tough these are to puncture. I have resorted to using a soldering iron to puncture holes in them to install fittings.

Yes wall thickness is very small but the material of construction, Polyethylene Terephlalate (PET) or polyester for short, is what makes them so tough, tougher in fact than most of the other typical tanks we have used over the years for gas or glow which are made from polyethylene. Soda pop bottles are made from the same materials and are under substantial pressure, typically 50 psi on hot days. If bottles blew up under that kind of pressure and lost product became an issue, soda pop makers would have found other materials to use for storing their sugar water.

I am not getting into the pissing match of which is better tho. The word "better" means different things to different people.

***For my application**** (top level aerobatcis competition), nothing I have used or seen is better than my water bottles and plastic fittings which I have sourced and sell along with a very inex*****ive gasoline fuel line. Also, filtered clunks such as Walbro (and others) eliminate bubbles in the lines regardless of how much foam an installation creates....One man's experience; as always, so YMMV!!

LarsL

Tazzz's question was straightforward... any issues with using in a glow fuel application as he heard there were issues with gas. He received his answer by the third post as Old Fart was doing just fine with a Saito 82. He did get a refutation from Jetmech05 who stated that after a few months in a 35% extra, a friend of his was not having any issues. That could have been the end of it unless there was a bone of contention over who was or was not having problems with their o-rings in a gas and/or glow environment.
Instead it has been the histrionics of people’s $5000 airplanes vs. $15,000 airplanes, people with the experience and diligence necessary for performing regular maintenance vs. those who are lacking or otherwise “don’t like” that task, and lastly, something about Peters up people’s jeans.
Tazzz at some point even said thanks, he got his answer. It has been fun to read and I have gotten a few good laughs.
Lars

raptureboy

Where can I get the fittings to build a tank for $5? All the one's I've seen available cost more than that. I like the idea of a clear tank.

chris923

My Feedback: (53)

Gentlemen,

I personally know the Owner of Roto Flow Tanks. He assembles and checks them personally..EACH ONE! I have them in 10 gas planes. 100's of flights never an issue in 4 years. Yes, they are heavy, yes they are expensive.
If you are building light, use a Fuji bottle and check you fuel lines every couple of months. If you are building a Warbird and weight is not an issue but accessibility is they are great.

3D guy should avoid them because of the weight.

sensei

This will get you pretty close, page down to the water bottle fuel cap items http://www.pspmfg.com/index.html and Dubro sells gas stopper for like $1.60, the bottle, buy something you like to drink. now for those that want to buy and fly there are other lightweight choices available ...

Bob

dingo9882

I was little worried about posting this because it seems the overall view of this tank are that its a bit of a waste of money. In my situation though it has really helped. I have a TF Giant P-47 Kit that I built and every year I have to change the lines. Now what everybody is saying is that no big deal. Usually they are right, except for me I have to remove the whole servo tray, linkages, cowl, and engine to replace 2 DAMN lines in the fuel tank. It is literally a 2 day project. So I went and bought this in order to not have to replace the damn lines any more. It is also not like I am doing 3D with it, so extreme aerobatics I am not worried about. But, in my situation I felt I needed it.

sensei

If you felt you needed it then you made great decision and I for one wish you the very best.

Bob

rexbirk

Good point. I guess maybe my main hangup with building my own is that I don't trust myself to build one that doesn't leak or fail. I have had a major brand tank stopper fail and dissolve the foam underbelly on a 50cc plane. It was a nightmare. Don't want that ever again. I am not a competition flyer and only a poor 3D flyer so I have never worried about saving every ounce but I see why you would want to.

smithcreek

My Feedback: (25)

I have a friend whose brother-in-law's cousin said he read a thread on the inter-webs once that didn't stick exactly on topic either. So, I guess it's happened before, at least that's what I've heard.

sensei

This is still a little of topic but lets put some life back into this thread,

You gotta just love it when some guys make this statement in some sorts or another: If you are flying a warbird or a civilian aircraft, weight is of little to no concern indicating obviously only IMAC and 3D type aircraft benefit from lighter wing loadings. This has already been insinuated two or three time in this thread alone. Come on boys, this has to be one of the grandest myths in RC, so just what do you think, because your airframe has one of those titles other than that of an aerobatic title tied to it the laws of basic aerodynamics changes and, or the Reynolds numbers are going to play a little nicer in your favor, come on, who are you trying to kid… Oh wait, I want my airplane to fly like an aerodynamic cinder block plagued with all those wonderful flying traits that go with it. I don’t think so, and neither does anyone else. Nobody just builds excessive weight into their airframes with the conception that this should make the overall flight performance envelope so much better. Just saying... Let the flaming begin.

Bob

OldScaleGuy

My Feedback: (2)

Wow......., this almost gets comical at times. Most of the scale planes that i build (like it or not) need additional nose weight. It is better (in my opinion) to have usable nose weight than a larger portion of dead weight such as lead or steel.

radfordc

My Feedback: (14)

When he says that weight is not an issue in a warbird he means that in an "intelligent" sort of way. The difference in weight between a Roto tank and a Dubro or water bottle tank is insignificant as long as the weight is in front of the CG. You can remove some of the lead from the nose if required. Warbirds should fly at a higher wing loading than a 3D plane in order to fly in a scale manner. For example, my 21 pound 81" span P-40 with a DLE 55 flys like a fighter...my 21 lb 96" span Yak 54 with a DLE 55 flys like a high performance acro plane. Different horses for different courses.

MTK

I'd like to know that too, since I know what it costs me to source fittings, gas lines, clunks and clear PET bottles equipped with teflon liners. It's a heck of alot more than 5 bucks per tank assembly, I can assure you....

Take the plastic fittings only: there's the bulkhead threaded fitting, the plastic flat washer, the rubber seal and the plastic nut that secures each to the tank. I chose to offer that set-up not because it's cheap but because it allows the buyer flexibility if he ever needed to revise his configuration...these are all removable and reusable. No glue necessary

MTK

I think the guy should be commended for his innovative, out of the box thinking that has created a good solution to some of the modeling public. Not every one agrees and that's fine....

I build gas tanks too from the fittings, gas line, PET bottles and Walbro clunks I have sourced. I will guarante this: neither the guy that builds Rotos, nor me make much money from that endeavor. Why do it to begin with? Certainly not for the aggravation; or threads like this one....

I can't speak for him (but I suspect he feels the same way) but for me, I got sick and tired of the other commercial stuff available....yellow tygon that got stiff way too soon, plastic tanks that cracked, rubber stoppers that were undersized and never really sealed properly. There had to be a better way. I think our solutions are helping our fellow modelers. That's my bottom line.

chris923

My Feedback: (53)

I fly Gasser warbirds, and hang the biggest engine on them as I can. Tank weight is NOT my issue. IF it is YOUR ISSUE, Don't USE THEM!

RichardGee

My Feedback: (156)

w/o packaging certainly the weights would be close... but my point is NOT to applaud a miniscule weight savings in a 40 pound plane; it was to point out that the repeated claims of "heavy" when compared to a conventional tank, are incorrect. I used DuBro, Kraft and Sullivan tanks for 40 years before RotoFlow tanks were ever dreamed up. Not all engine failures are caused by a faulty tank, but EVERY tank failure I have seen was caused by the use of gas line and stopper that succumb to the harsh environment of gasoline. Regular maintanance is a must - just hope you catch the failure before it catches you... I really don't care if this discussion sways a single opinion, but it is helpful to separate the fact from the fiction...

sensei

I for one made my heavy weight comparison claim to a soda pop tank if you read all the posts, not a conventional tank as you put it. In that weight comparison there is certainly no fiction, is there. Fact is one can build 2 or even maybe 3 soda pop/water bottle tanks for the weight of one conventional tank in a 40% airplane or larger but as you stated in your last post; this is really a minuscule weight to be bothered with in a 40 pound plane indicating a few ounces here or there just doesn’t really matter in stuff this big, not to mention the great risk of a tank failure associated with building your own tanks compared to the $$$ (Roto). So to each their own and happy flying…


Bob

Mustang51

My Feedback: (25)

Does AMA or IMAA even allow converted soda bottles to be used? Just Sayn'

sensei

LOL, and yes for many years.

Gray Beard

My Feedback: (-1)

I was a safety inspector for IMAA for a lot of years and there was never any rules that you couldn't use them. There were a lot of them being used. The funny thing to see was guys using them for pressure bottles for retracts that came in from other states not thinking about the hot Claif. sun. Air filled bottles in the center of the fuse plus hot sun equals some small explosions and broken planes. We did give warnings to pilots using plastic bottles for air once we found out what was happening.

jetmech05

If I would have had a roto flow tank in my extra I would have been able to have finished my only IMAC competition I've had a chance to enter this year.... Want some fun be at the bottom of a vertical up line and go dead stick due to a stuck clunk because of a hard landing

MTK

Geez, the soda pop or water bottle bottles are designed to handle as much as 100 psi without bursting. Try pressurizing the typical polyethylene DuBro or Sullivan and if you get 15 psi, I'll buy you a pop.

Lessee, they are safer to use, lighter, seal better and will not rupture in a crash. Whaddyathink??