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-   -   Cheap and Simple ideas that work (https://www.rcuniverse.com/forum/rc-jets-120/8482841-cheap-simple-ideas-work.html)

bigplumbs 02-16-2009 12:52 PM

Cheap and Simple ideas that work
 
In these difficult economic times I thought it might be a good idea for us to share our ideas in respect of cheap and simple things that we all could use so that we can save a few pennies. (To spend on other model products of course).

I will kick off with the following which was the subject of a thread that gave me the idea for this thread:

1) Make non return fill valves for retracts and brakes from car tyre or motor bike valves using the valve and a nipple soldered into the end. Saving per valve approx £19.00

Please feel free to post your ideas

Regards

Dennis

NUNU 02-16-2009 02:38 PM

RE: Cheap and Simple ideas that work
 
a little physics here....torque=force x lever arm...so most of us will use a 220 oz torque servo and the thing only moves a few degrees in either direction....suggestion: use a smaller arm on say 110 oz digital servo (and maybe a longer control arm) you can calculate your actual power using the formula......and before anyone loses there minds about the safety issue..remember the weakest link...if your servo for instance put out 50 pounds of torque but your hinges will break out of thier BALSA blocks at only 20 pounds???..using this you could save hundreds in servo money [8D]

highhorse 02-16-2009 03:06 PM

RE: Cheap and Simple ideas that work
 
Coincidentally, there was another thread recently regarding inexpensive air system components. That one was for making AIR TANKS.

[link=http://www.rcuniverse.com/forum/fb.asp?m=8303418]walmart ait tanks[/link]

Is it OK to talk sourcing and not just ideas? I don't want to dork up your thread....Send a PM to Sean and see if he will weigh in. The guy is a genius at saving $$ by finding "RC" stuff in other marketplaces before they recieve the 500% "RC" markup and packaging and that adds up to HUGE savings on the small items, just like your bike tire valve thing.

This thread [link=http://www.rcuniverse.com/forum/m_8386712/anchors_8390337/mpage_1/key_heat%252Cshield/anchor/tm.htm#8390337]heat shield blanket sources[/link] sourced, for example, ceramic heat sheild blankets at about an 80% discount to the major RC suppliers.

highhorse 02-16-2009 03:12 PM

RE: Cheap and Simple ideas that work
 


ORIGINAL: NUNU

a little physics here....torque=force x lever arm...so most of us will use a 220 oz torque servo and the thing only moves a few degrees in either direction....suggestion: use a smaller arm on say 110 oz digital servo (and maybe a longer control arm) you can calculate your actual power using the formula......and before anyone loses there minds about the safety issue..remember the weakest link...if your servo for instance put out 50 pounds of torque but your hinges will break out of thier BALSA blocks at only 20 pounds???..using this you could save hundreds in servo money [8D]
Great idea...I found this program to help [link=http://members.cox.net/evdesign/pages/linkage_design.html]servo requirement calc[/link]

highhorse 02-16-2009 03:21 PM

RE: Cheap and Simple ideas that work
 
Dave Rigotti posted this bit of brilliance a while back for a cheap and simple BRAKE which is effective and meets AMA regs. It could save a LOT of $$ for the guys flying lighter jets and jets off of grass where hard-core brakes are just expensive overkill.......



http://www.rcuniverse.com/forum/fb.asp?m=4350040

Boomerang1 02-16-2009 04:06 PM

RE: Cheap and Simple ideas that work
 
Old method: I plugged the ECU battery in via a deans plug to a charging jack & through a double pole switch to the ECU.

New method: Fitted the plug straight to the ECU & just plug the pack in to turn it on.

Not a great money saving but I eliminated the switch, charge jack & a heap of wiring. I changed plugs to the Sermos type as they are easier to plug/unplug. - John.

SinCityJets 02-16-2009 04:16 PM

RE: Cheap and Simple ideas that work
 
Here's the source for the best airline.

http://www.freelin-wade.com/fre-than...157-p-260.html

icepilot 02-16-2009 05:47 PM

RE: Cheap and Simple ideas that work
 
Instead of spending $65 on a UAT, simply use a small $4 Dubro (or any other brand) tank with a centered pickup -
I have used this in all my jets including the 1/6 F-16 with 100 flights, and I have never had a single flameout!
KISS...

Tor

SinCityJets 02-16-2009 06:32 PM

RE: Cheap and Simple ideas that work
 
Tor,

I use a 2oz. Sullivan tank (stood vertical) with the clunk centered in the tank on my Kolibri nano-turbine. Works great.

Chad

mongo 02-16-2009 09:26 PM

RE: Cheap and Simple ideas that work
 
Cheap and Simple ideas that work,
always show up right after i have spent lots of money on 2-3 complex schemes that don't work.

can i get an "amen"

hooker53 02-16-2009 10:05 PM

RE: Cheap and Simple ideas that work
 
Aman Brother!!!! Ha.

icepilot 02-17-2009 03:39 AM

RE: Cheap and Simple ideas that work
 
1 Attachment(s)
My hopper tanks are 4 oz Sullivan tanks standing horizontally on the narrow side, without clunk as it can move
during high G maneuvers. It simply has the pick-up tube centered inside the tank, this way it will always be in
the middle of the fuel and far away from any air - works great!

747drvr 02-17-2009 09:44 AM

RE: Cheap and Simple ideas that work
 
Totally agree with the above . Hundreds of flights with no problems . IMO , UATs are a waste of money.....

Marc

AndyAndrews 02-17-2009 10:11 AM

RE: Cheap and Simple ideas that work
 
BVM and SM? hahahah I couldnt resist!

Ron101 02-17-2009 10:18 AM

RE: Cheap and Simple ideas that work
 
Quit RC and take up hiking.... :D


bigbri 02-17-2009 11:06 AM

RE: Cheap and Simple ideas that work
 
1 Attachment(s)
After my expensive electronic brake valve failed I was looking for a more reasonable alternative. I have switched to these valves and lube the wheel brakes lightly with silicone grease. Works awesome! re-lube brakes about every 30 flights or so Works just like ABS braking....14.95 vs about 100 dollars....85 dollars saved on each jet!!!


Robart 186 One-Way Air Control Valve

mugenkidd 02-17-2009 11:11 AM

RE: Cheap and Simple ideas that work
 
skywritter smoke pump $89.99 and a single $15 smoke nozzle from Todd, puts out just as much smoke if not more than my buddies $200 jet smoke system. I do run a 11.7 volt lipo to the pump and he uses a 7.4v .


http://www2.gpmd.com/image/s/sulg0753.jpg

highhorse 02-17-2009 11:45 AM

RE: Cheap and Simple ideas that work
 


ORIGINAL: icepilot

My hopper tanks are 4 oz Sullivan tanks standing horizontally on the narrow side, without clunk as it can move
during high G maneuvers. It simply has the pick-up tube centered inside the tank, this way it will always be in
the middle of the fuel and far away from any air - works great!
Sorry, I don't understand how a clunk hurts in this app? And it seems to me that while an air trap drains nearly all of it's fuel before it sends a bubble down the line, this setup will drain less than half before causing a flameout. What am I missing here?

SinCityJets 02-17-2009 12:02 PM

RE: Cheap and Simple ideas that work
 
HH,

A regular UAT is also only good for about half the tank size (dpending how far down the air trap goes.) It can't go to far down or it will flame out inverted. I don't understand the missing clunk either, but the main difference is of course, the price.

causeitflies 02-17-2009 01:26 PM

RE: Cheap and Simple ideas that work
 
I use the same setup with a pleated paper filter in the center of the 4oz tank. Gets all but about 1oz. Even with half a tank you are only looking at 2oz.

747drvr 02-17-2009 01:41 PM

RE: Cheap and Simple ideas that work
 
Guys,

The reason it works is that the pick up is ALWAYS in the centre . A clunk compromises this and effectively just turns it into another tank ( just smaller) . Any air that is introduced into the tank will hug the outside of the tank and stay away from a centralized pickup . A clunk pickup flailing around could possibly move into the air zone . If you never burn into the air trap you can be sure that you'll never get air in the system from an unported main fuel tank clunk . People who see the sack in a UAT as a feature that will filter out air bubbles and suck to the end are missing the point that the airtrap fuel should be considered unusable . At the end of a flight I very rarely have more than a fifth of the airtrap filled with air .

As far as the filtering benefit of the UAT , I figure all the filtering that occurs before the fuel goes in the tank and before the engine is enough.

Marc

F106A 02-17-2009 03:05 PM

RE: Cheap and Simple ideas that work
 
Marc,
I think what they are confused about is years ago the same setup was used but there was either a sintered bronze filter or a pleated filter on the end of the brass tube, supposedly to break up any air bubbles.
As stated above, a lot of people think that the fuel in a UAT tank is usable, when in fact, the UAT fuel should never be used.
If, after a flight, you find you had to use the UAT fuel, either get a bigger main tank or shorten your flight times.
BRG,
Jon

747drvr 02-17-2009 03:18 PM

RE: Cheap and Simple ideas that work
 
I used to make mine with the pleated filter but decided that it was overkill . The plain central pickup in a 2 or 4 oz tank ( depending on the size of the plane) has served me well for the last 5 yrs .

Marc

sidgates 02-17-2009 04:23 PM

RE: Cheap and Simple ideas that work
 
Marc,
I assume the second tube in your tank goes to your main tank(tanks). Why even bend the tube?

causeitflies 02-17-2009 04:30 PM

RE: Cheap and Simple ideas that work
 


ORIGINAL: sidgates

Marc,
I assume the second tube in your tank goes to your main tank(tanks). Why even bend the tube?
...to fill it up all the way.


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