Delks

I was disappointed to read that someone had found the spar slots to be 1/32" too wide in their laser cut ribs. I have a set of laser cut ribs which were produced from the same files as Sarik used and the spars are a comfortable fit in the slots. It would be interesting to know the exact size of the spar in question. Balsa sizes are rarely exact owing to the nature of the beast (shrinkage etc) and the thickness can vary slightly from side to side and also along the length of a sheet or strip. With this in mind I cut my own strip-wood for spars etc using a Proxxon KS 230 table saw (highly recommendable) which enables me to regulate the size accordingly. I have just measured 4 sheets each of 1/4" and 3/16" balsa and the results in mm were: 6.6-6.8-6.6-6.5 and 4.8-5.0-4.7-4.9. My stock of 1/16" sheet varies between 1.62 and 1.80mm. I don't regard this as a problem.

The wing on EP version has a slightly thinner section but will work well on the original CB - just needs a slight modification of the wing seat.

Sets of decals for the new Chilli Breeze EP are available from Tribal Signs which comprises 1 x wing + 2 fuselage Chilli Breeze EP. Take a look on their website for available colours etc and the set will cost £18.35 + £2.99 post. Should you need any lettering done for other models there is a very useful "lettering design function" available on the the website: TriblaSigns.co.uk tel: 01884 824084

Nice work Modelman - you've done a great job and good to hear that you are pleased with the results.

The publication is planned for the January and February issues of RCM&E - before the Yuletide celebrations begin!

The lettering is available from Tribal Signs.co.uk. On their website there is a lettering designer. Font: Brush Script MT - size: outerbox 300mm for the fuz and 400 for the wing - colour of your choice - high quality vinyl. They are helpful and friendly with a quick turn around.

The tailplane failures mentioned sound very much like victims of the dreaded elevator flutter. The Chilli Breeze has been popular over the years and people have sent me photos of their models fitted with ic engines ranging from a Magnum GP 25 up to an Irvine 40 (even a piped 40) and they have not reported this issue. It would appear that one of the main causes of elevator flutter is that the connection between the control surface and the servo isn't slop free. The the servo must be securely mounted in the fuz - metal gears are preferred to plastic - make sure there is no play at all in the connection between the servo output arm and the pushrod end and the other pushrod end to the control horn - the push rod should be a straight run with no bends at all along its length. Choose a firm medium grade sheet of balsa for the stab and forget about weight saving as you will most likely have to add weight to the tail if you choose a light grade balsa and you will also be building in a potential problem. I used a built-up tail for the prototype of the new EP version and that had surprisingly good torsional rigidity - you will see on the attached photo that I have avoided all end grain joints around the centre in an attempt to build in max strength and so far so good.....

There wasn't a set of ribs printed on the 1994 plan because, in those far off days, the sandwich method was commonly used. Things have moved forward since those days and programmes such as Dev Wing (highly recommended!!) are available. The new design features a slightly thinner wing section and a full set of ribs will be included on the plan. A full set of laser cut ribs should also be readily available from several sources but bear in mind that these ribs are designed to match the rib spacing shown on the new plan - an important consideration. The new version could be in the magazine as soon as the January issue. The new plan will feature a few added updates to the original so it might be worth waiting a couple of months. It will also be suitable for ic conversion just by changing the thickness of F1 and omitting the battery hatch. If you need a set of rib patterns + plus spacing details I could supply one.

In answer to the question re source of undercarriage: : I purchased the carbon fibre undercarriage from Hobby King. Unfortunately they have not had any in stock for a while which is a pity because it ideal for a small model like this and it was very good value.

The plan is going to be published in near future - possibly the December issue .

I am pleased to report that I finally got the Chilli Breeze EP project over the finish line and the results are very pleasing. The power train is: 4-Max 3541 kv1070 motor turning an 11"x5.5"APCe running on 3700 4s which gives 7minutes flying time comfortably. I visited the F3a Triple Crown event at the weekend and during a lull in the action Keith Jackson put the model through its paces and and it performed very well - as you would expect with Keith on the sticks! The 2m jobs are really something else and the size of the manoeuvres flown was breath taking. Here are a few pics of the new model rubbing shoulders with the big boys............

The Chilli Breeze EP plan is going to be published in the RCM&E. The prototype is now finished and the motor is a 4-Max PO-3541-1270 turning an 11"x7"prop on 3s/ 10"x6" on 4s. The model came out a bit lighter than expected - the ready-to-fly weight is 48oz which includes a 260g lipo. The photos show an alternative angular nose job but the original one could also be used. There will be a few tweeks still to do - more info soon.

It is my intention to also update the Chilli Wind for an electric/ic version. There were in fact two versions of the Chilli Wind. The original published version was followed by a "stretched" version (+3" on the tail and +1 1/2" on the nose) which was not published. and this is the one I would use for the ep/ic conversion. As can be seen in the photos this was powered by a YS 45 rear exhaust two stroke and this required inverting the model for starting etc which I did not find a problem. I mention this because I have chosen to place the battery access hatch on the underside of the fuz on the epic Breeze as this frees up more space for the battery/esc/wires etc, simplifies hatch arrangement and avoids vandalising the top of the fuz.

The updated Chilli Breeze shares most of the details of its predecessor but now has a 13% modified NACA wing section and the fuz has been widened slightly to help with battery access, There are a few other minor changes but the moments etc remain as per the original. Although the new model is designed around an electric set-up I intend to show an ic mod on the plan.

The answer to your question is yes - it will be a pull out plan.

The Junior Rival will appear eventually but the electric version of the Chilli Breeze has kept me busy. I have also revised the JR design and used a parallel chord wing with simplified construction - It will also be about 10% larger. i did post some update details for the Chilli Breeze but they have appeared elsewhere in the plans section so I shall repeat them here: Work on the new ep Chilli Breeze has been progressing and the airframe is now finally ready to cover. I also aim to give details of an i.c. conversion on the plan. Construction follows the original design but the all sheet tail surfaces have been replaced with built up items and the u/c is now mounted on the fuselage. There are also a few other small changes but the good news is that laser cut ribs are now a possibility or, if you wish to cut your own a set of rib patterns will be on the plan. In the end I decided to opt for a bottom mounted battery hatch as this frees up space for battery and esc and avoids the the need to vandalise the fuselage top. The model was quickly assembled for the photos to give an idea of the general layout. I used SLEC medium grade balsa throughout and made no particular attempts to save weight and the bare wooden airframe weighed in at 17.8oz/505g. This is about what I expected with a built up wing but a foam wing will only add add a few extra ounces and save a lot of work!.

Work on the new ep Chilli Breeze has been progressing and the airframe is now finally ready to cover. I also aim to give details of an i.c. conversion on the plan. Construction follows the original design but the all sheet tail surfaces have been replaced with built up items and the u/c is now mounted on the fuselage. There are also a few other small changes but the good news is that laser cut ribs are now a possibility or, if you wish to cut your own a set of rib patterns will be on the plan. In the end I decided to opt for a bottom mounted battery hatch as this frees up space for battery and esc and avoids the the need to vandalise the fuselage top. The model was quickly assembled for the photos to give an idea of the general layout. I used slec medium grade balsa throughout and made no particular attempts to save weight and the bare wooden airframe weighed in at 17.8oz/505g. This is about what I expected with a built up wing but a foam wing will only add add a few extra ounces.

The Junior Rival is still on track to become an RCM&E plane but, for reasons that will become more apparent in forthcoming issues of the magazine, I have put the project on hold for a short while. I have also decided to simplify the wing construction a little in order to encourage less experienced builders to get involved.

There have been several people asking about sets of wing ribs for the Chilli Breeze. Work on the electric version is now underway and this will feature the same wing as the ic version and, with the help of Dev Wing, I have managed to create a wing section that is pretty much identical to the one included on the original free plan so those looking for a set of rib patterns need look no further. The electric version will have a servo for each aileron and will not utilise torque rods and the u/c will be mounted on the fuz but the original details for wing mounting are there on the original plan for those who want to use that method.

I have recently completed and covered the Junior Rival that I was building as a test bed for future electric projects. When I first started to read through this forum I was very surprised to read posts recommending weight saving tips regarding the Chilli Breeze airframe. By any standards a CB built as-per-plan with a built-up wing is a lightweight airframe. The Junior Rival airframe is a slightly larger than the CB but used a similar amount wood for the airframe and this weighed in at 602gm ready-to-cover. Medium grade balsa was used with a 36" x 4" X 1/16" sheet weighing 18-20gm and all other sizes multiples of this weight. 3mm light ply was used for doublers in place of .8mm ply. The finished model less battery came out 1246gm and the cg was achievable using as little as a 3s 2200 lipo. I found this very interesting as the original Chilli Breeze with a built-up wing weighed 1475gm - this was the dry weight so the flying weight would have to include an average of half a tankful of fuel so the total weight of a CB at take off was in fact approx 1600gm (about 3lb 9oz). It flew very well at this weight - the foam wing version came in about 100g more and the added weight was a bonus for windier days. At no time did I ever feel the the model was too heavy or that a reduction in the flying weight would improve the performance. It was always intended as an introduction to F3a style flying - not 3D flying From the above, bearing in mind that the Junior Rival is a little larger than the CB, we can safely assume that the take off weight for an electric CB using modern servos etc with a 4s lipo will be appreciably lighter than the original .36 ic powered version. In fact it is going to be at least 8oz lighter than the original design weight and this will not necessarily improve the flight performance - in fact quite the contrary. Fellow forum member KC alerted me to several posts regarding tailplane flutter and one of the forum members who had experienced flutter said he thought his problem was caused because he had used too light a grade of balsa for the tailplane and he cured the problem by substituting it for a firmer grade of balsa - a medium grade sheet of 1/4" is going to weigh between 70-80gm. If you want an ultra lightweight aerobat suitable for F3a style flying you are going to be limited to indoor flying or flat calm summer evenings but for average weather conditions in the UK (and a lot of other countries) I feel a Chilli Breeze needs to be somewhere near to its original design weight and it will be counter productive working out cunning ways to save weight.

I have recently completed and covered the Junior Rival that I was building as a test bed for future electric projects. When I first started to read through this forum I was very surprised to read posts recommending weight saving tips regarding the Chilli Breeze airframe. By any standards a CB built as-pe-rplan with a built-up wing is a lightweight airframe. The Junior Rival airframe is a slightly larger than the CB but used a similar amount wood for the airframe and this weighed in at 602gm ready-to-cover. Medium grade balsa was used with a 36" x 4" X 1/16" sheet weighing 18-20gm and all other sizes multiples of this weight. 3mm light ply was used for doublers in place of .8mm ply. The finished model less battery came out 1246gm and the cg was achievable using as little as a 3s 2200 lipo. I found this very interesting as the original Chilli Breeze with a built-up wing weighed 1475gm - this was the dry weight so the flying weight would have to include an average of half a tankful of fuel so the total weight of a CB at take off was in fact approx 1600gm (about 3lb 9oz). It flew very well at this weight - the foam wing version came in about 100g more and the added weight was a bonus for windier days. At no time did I ever feel the the model was too heavy or that a reduction in the flying weight would improve the performance. It was always intended as an introduction to F3a style flying - not 3D flying From the above, bearing in mind that the Junior Rival is a little larger than the CB, we can safely assume that the take off weight for an electric CB using modern servos etc with a 4s lipo will be appreciably lighter than the original .36 ic powered version. In fact it is going to be at least 8oz lighter than the original design weight and this will not necessarily improve the flight performance - in fact quite the contrary. Fellow forum member KC alerted me to several posts regarding tailplane flutter and one of the forum members who had experienced flutter said he thought his problem was caused because he had used too light a grade of balsa for the tailplane and he cured the problem by substituting it for a firmer grade of balsa - a medium grade sheet of 1/4" is going to weigh between 70-80gm. If you want an ultra lightweight aerobat suitable for F3a style flying you are going to be limited to indoor flying or flat calm summer evenings but for average weather conditions in the UK (and a lot of other countries) I feel a Chilli Breeze needs to be somewhere near to its original design weight and it will be counter productive working out cunning ways to save weight.

Hi - the answer is yes the ribs will all be capped - it could even be fully sheeted for very little extra work/cost. "The Rival E" wing in the photos features NACA 0013 root section and NACA 0014 tip section and has slightly larger than 2 1/4" aileron chord - this results in the thickness of the leading edge of the aileron exceeding 1/2" so in this case it is probably cheaper to go the built up route but but cost was not a defining factor in the choice of aileron construction - it just didn't seem a good plan to throw away all that valuable balsa in the form of wood shavings and I liked the idea of a built up aileron. The wing section for the updated Breeze has not yet been finalised but will be 12% thick.

Hi Kc Thanks for the interest. The holes in the ribs are in fact for a paper tube for the servo leads - I will install the tubes just before joining the wings (and cutting a hole in the root rib which I somehow forgot!). Both designs will be around 50" span and if things go according to plan the designs will be published in RCM&E. I also have in mind larger versions of both designs for 5s or 6s.

I am currently working on updates for the Chilli Breeze/Wind and Rival designs and thought you maybe interested in the progress. The wing section chosen is NACA 0012 - several sections were trialled on the original Chilli Wind and this found to have the best flight characteristics but because the u/c was mounted in the wing I opted for a slightly thicker section with the u/c mounting in mind. I have posted a few pics here to show the new built-up wing structure that will be used on the updated designs and it is proving to be light and strong - no more wing-mounted u/c's!! Although this is the Rival E wing the construction with be common to all models. The up-dated designs are completely new versions of the originals but I think it would be a good idea also to update the originals to bring the into the 21st century way of thinking as they were good flying machines which were quick to put together.

The updated Chilli Breeze and Rival designs are finally under way and, although a bit later than expected, we have visible progress! These will both be for 3/4s and the motors are the Hacker A30-10 XL 900kv and the Airtek hobbies 3548 900kv for props in the 12x6 - 14x7 range. The first of the models is the Rival E but the wing construction is shared by both models. Building for lightness whilst retaining structural integrity is a bit of a balancing act but I don't anticipate any problems in that regard but the wing construction, although very enjoyable, is time consuming and care needs to be taken. The new Rival E will have a more extrovert character than its big brother and have a broader appeal. I have been using the "new" balsa supplies from SLEC and although it appears to be expensive it is good quality and I have enjoyed working with it.