Why Didn't I Think Of That? - Top Tips Part 4


Top Tips, some you may know some you won't, but they all come in useful, especially if you're new to the hobby!

If you have any great tips that you want to share with other modellers, then send them to us at editor@flyingsites.co.uk or to the address listed on our 'Contacts' page.

Removing Broken Wing Bolts

A heavy landing can often result in one or both of those plastic wing bolts breaking, as they should. But more often than not they break flush with the fixing point.

To remove the broken bolt, heat a flat bladed screw driver, one that's just smaller than the diameter of the bolt, about blue heat (enough to melt the plastic) push the screw driver into the broken part of the bolt and leave it to cool, normally about 30 seconds. Then just unscrew the broken part of the bolt.
Courtesy Martin Chitty

Useful Tools - Surgical Forceps!

One of the most useful tools I carry in my flight box is a pair of surgical forceps, or arterial clamps. These are absolutely indispensable for taking the fuel tubing off the engine carb for draining the tank at the end of the day, particularly when the engine is partially cowled.

However, the best trick is to use them for putting a short length of fuel tubing onto a clevis to keep it from opening, without having to unscrew the clevis from the pushrod. Slide the tube over the end of the forceps, then pull them open. This stretches the tube open so that it can be placed over the clevis, down onto the shank which is threaded onto the pushrod. Reattach the clevis to the horn, and then it is a simple matter to slide the tube into position holding the clevis closed.
Courtesy Jonathan Mead
Vertical Fin Alignment

When fitting tailfins it is sometimes a pain to keep them vertical.

Try using a large rubber band (5 or 6") split into two equal portions and then re-connect them using twine. You will find by stretching the whole thing around tailfin & tailplane that slight tension is placed on the tailsection which will enable the fin to be held vertically until the adhesive cures.
Courtesy Martin Taylor

Fixing Canopies
The best way to cut out a canopy is VERY carefully!

I usually use a pair of scissors. First mark around the canopy with a water soluble marker pen. You can usually see a moulding line to guide you. Don't cut right up to the line, but work up to it a bit at a time. This avoids irreparable mistakes! And use different sizes of scissors if it helps.

As for fixing - I have had for years, a bottle of R/C Modellers Glue. Yes that’s the name of it! When wet its white colour similar to PVA, but it dries clear. Put the glue around the inside edge of the canopy - very sparingly, then hold in place with an elastic band or similar. It takes a good 12 -24 hours to set, but does it set - My Acrowot canopy has been in place for years and not come off.

Be carefully not to get any of the glue on any other part of the canopy because it will mark it and it doesn't wipe off, it just smears and looks even worse!
Peter Dennis - Flying Sites Editor

What's EPP

stands for expanded polypropylene. EPP foam is a semi-rigid foam that is highly flexible, and very resilient. Besides being used for gliders, it is also used for packaging, car parts, and car manufacturing processes, just to name a few.
Peter Dennis - Flying Sites Editor

Scale Panel Lines

One method I've used successfully is to mask the edge of each line or panel then build up a layer of light weight filler of even a build up of grey cellulose primer paint. Then, when dry carefully rub back with a light grade of 'wet & dry' paper (used wet if using paint primer) until the edge of the masking tape is revealed.

After this, just carefully peel back the masking tape to give a finely detailed panel, that blends into the rest of the aircraft. It take some time planning which panel goes where, but the results are worthwhile.
Peter Dennis - Flying Sites Editor

A Use For Profilm Backing Paper
I use Profilm to cover my models. But don't throw the backing paper away! I use the backing paper to protect my building board then things dont stick to it.
Don't Throw Away Broken Props
You have probably heard of this one already but will pass it on.
Broken props make excellent epoxy stirrers and also for paint.

When mixxing epoxy the residue on the prop blade can be simply scraped off
with a Stanley knife and the prop blade reused for further epoxy mixing.
Peter Smith

Protecting Your Plans
When building a structure that requires pining to the plan, (such as a flat bottom wing) use cling film to protect the plan. Simply use drawing pins to stretch and pin down the cling film smooth over the plan. When finished the film can be thrown away. Glues will not stick to cling film.
A roll of kitchen cling film is cheap and will last for many models.
Chris Madge.
Quiet Engine Mount On The Cheap
For a really cheap and effective way to quieten your engine try this:
Get yourself a metre of that brownish flat rubber strapping that is used in upholstery. It is attached and stretched in an interlaced pattern across the seat area of a chair to support the seat cushion. It is about 2 inches wide and one eight of an inch thick and is sold in D.I.Y. places by the meter.

All you need do is cut 2 strips to fit under the engine lugs. Punch 2 holes for the engine bolts. Use a proper multi sized hole punch. The type used to punch holes in leather belts with the rotary punches that click into position is good.

Cut these strips larger than the engine lugs so that, when tightened down, the engine no longer contacts the engine bearers. Ideally, the rubber rectangles should fold down between the bearers and the bottom curved part of the crankcase. So wooden bearers work best.

If using a specially made aluminium engine mount, use another rectangle between the mount and 'F1' the firewall or bulkhead too.

Tighten everything down and you will be amazed at the difference.
Tim Costello
'Pringles' Tube

"Once you pop you can't stop" the advert says but what do you do with the
empty Pringles tubes?. If you cut 3 or 4 or so empty tubes to different heights and tape them together you end up with a bench tidy to keep your offcuts or knives or brushes in, or whatever you can think of.

Also The lids are great to mix epoxy on. When it sets just peel the hard residue off and use it again.
Andy Happs

Wing Joining Advice

Hi, I'm just learning to fly r/c aircraft after flying free flight since being a child so this tip is for people new to r/c flight.

I had put together my first trainer (Hobbico Superstar) and being used to flying gentle free flight models didn't use enough epoxy on the wing joint, result of this was that the wings parted on the third flight and me experiencing my first trip to collect the remains armed with a black bin bag!!! Not wanting to give up I went out and brought another trainer (the excellent Boomerang), this time using old 35mm film cannisters to mix the 30min epoxy in and pouring it into the cutout for the wing brace, after first coating only half the the wing brace with epoxy.

Then inserting it into the cutout by pushing and pulling so that halve of the brace is totally covered and glue is squelching out(there is no need to rush this as the epoxy takes a while to set ).Remove any excess with a thin plastic scrapper and wipe the area with meths, leave the glue to dry. When it has set repeat the proccess with the other side, this time mix a bit more than last time so you can give each root rib a good coating as well, bring both wing panels together so the epoxy is being pushed out from between the root ribs. Clean up the excess as desribed before and bind together with sticky tape. When the epoxy has set remove the tape and you will have a nice strong smooth joint. Thank you for taking the time to read this.
Tim Coppin
(bulk epoxy buyer).

Vinyl Stickers

Much ado is made about printing on vinyl or on to the backing papers of certain types of covering, as I am employed in the sign industry I can cut my own decals but I also have this suggestion which works excellently for basic letters and numbers etc and with a little thought complex decals, Print the image mirrored (all PC artwork packages allow this) and then with a pritt stick apply the paper page to the backing paper of your covering then cut out with scissors or scalpel.

Also your local sign shop is a good place for materials, ask them to keep the cuttings of vinyl for you (the ones that end up in the bin) although sometimes it maybe heavier and slightly thicker this is negligble.
Happy Landings
Terry Jones @ Ballymoney Model Flying Club

Drying Out

Occasionally a mishap will occur and a model disappear into the sunset. Even more occasionally, it will reappear when someone finds it in a back garden, often after some time. It is often possible to salvage the electronics etc, but they could have been exposed to wetness. The trick is to dry them out completely. To do this, go to Woolworth's and buy a packet of dehumidifier crystals for 1.49.

Get an airtight box, and some sort of mesh. Support the mesh so that dissolved crystals and water can drip through, place the components and crystals on top and seal the box. Leave it a couple of days and you can safely re-use the Rx, servo etc In my case it was a Zagi that disappeared for ten days, the Rx was dried by keeping it in a warm place as I searched high and low for Silica Gel. It works okay, but I would have felt safer using Chemistry rather than luck!
Terry Sullivan

Super Fast Setting Epoxy

Save old egg boxes as mixing epoxy in the individual sections makes an excellent mixing container. For the super fast setting epoxy, pour in the correct amounts, and use a cigarette lighter to heat the bottom of the egg cup (try not to set the cardboard on fire of course) then mix the epoxy, its very runny after being heated and mixes very easily and set in half the time it says on the bottle.
Alan Gardner.

Avoiding Screwdriver Damage
A little tip for you guys regarding using a screwdriver on your models, especially near thin covering. A small piece of rubber tube that fits just over the screw head will keep your screwdriver from slipping off and going through your wing!
Terry Sullivan
Removing Broken Wing Bolts
For removing the remnants of a plastic wing bolt after it has sheared, heat the tip of a screwdriver and push it in. Wait for the plastic to re-set, and unscrew the bolt. A small Allen key will do it too!
Terry Sullivan
Fuel Tank Leak Test
The best way to test a tank is to seal it up, then immerse it in hot water. As it heats up the air inside expands and any leaks will be seen. It also has the advantage over cold water that you know that no water has got inside the tank.