Guillow's rubber
-
cdwheatley
- Posts: 92
- Joined: Sun Dec 03, 2006 1:03 pm
- Location: Waterlooville, Hampshire, England
Guillow's rubber
I know from what I've read elsewhere that the big blue rubber bands that Guillow's supply with their series 500 kits are the first thing to be ditched when attempting to fly any of them, but as a potential first time flyer can someone please explain why? And if they really are no good then a) why are they in their kits in the first place, and b) what do I use instead?! Thanks
-
kittyfritters
- Posts: 732
- Joined: Tue Jan 03, 2006 6:58 pm
- Location: California
Chris,
If you have a green or blue rubber band in the kit, ditch it. You can probably get a flight of about 100 feet out of it and that's it. You can't really stretch it to pack the winds in and with the square crossection, even with lubrication it just won't do the trick.
What you need is 1/8 inch, flat, F.A.I tan sport rubber, or the equivalent. It's usually sold by the pound in hobby shops. Some of the current production Guillows kits have a piece of this rubber in them. If your model weighs less than 27 grams, or so, you can use one loop, about one and one-half times the length from the prop hook to the motor peg. If the model is between 27 grams and 36 grams you need a double loop. If a 500 series model weighs more than 40 grams you probably don't want to try to fly it.
Tie the loop in the rubber with a square knot then pull an overhand knot down on top of it. Trim the loose ends off to about 1/8 inch. I use a long stick with a notch at the back to push the rubber to the back of the model so I can hook it on the motor peg.
You need to lubricate the rubber to get power out of it and keep it form breaking. Pre-mixed rubber lube is available. The classic lube is a mixture of glycrine and green soap, it works but is a little messy and gets all over the inside of the model.
I use automotive silicone lubricant that comes in a spray can. It does not harm the rubber and lubes when dry. In the US I use STP brand, I don't know what brands are available in the UK, but check your auto parts store. I put the rubber loop in a plastic sandwich bag and spray the lube in to get it wet. Then I close the bag and rub it around to make sure that the lube gets all over the rubber. When you take the rubber out the lube drys. Armor-All rubber protectant (sometimes called tire dressing) is a similar silicone compound that works well also.
See if you can get a rubber winder at a hobby shop. They usually have a 5 to 1 or 10 to 1 gear ratio so that you only have to wind it 100 turns to get 500 or 1000 winds on the rubber. A satisfactory one can be made of a hand powered twist drill. Do not simply chuck a prop hook in the drill, it will pull out with disasterous results. If you make one the winding hook has to loop behind the chuck as well to prevent pull out.
You have to have a winding "stooge" to hold the model by the motor peg while winding. This is usually a device (Google it to see what they look like.) or a person. (If using a person be be aware that if the rubber band breaks and comes through the back of the model, it's going to hurt. It's also probably better if they are wearing glasses.)
You pull the rubber out the front of the model and stretch it to about twice it's length with the winder. Wind in about half the number of winds you intend then slowly walk toward the model ending up at the nose when you get the count you want. Takes a little practice. Hook the prop shaft to the rubber (Don't loose it here.) and you are ready to launch.
Start your trimming flights with 50 to 100 turns, just enough so that you have some power and are not just gliding, and work up. Make your adjustments to the rudder and elevator to get the flight path you want. Depending on the model, with 500 Series models you will usually be using 500 to 1200 turns for your flights after you get it trimmed out. Rubber bands don't last forever so be sure to examine them for tearing and other wear. If you see wear, don't chance it, just make a new motor.
I could go on a lot longer about the fine points of rubber motor control, and I don't consider myself a real expert at it, but this should get you started.
Howard
If you have a green or blue rubber band in the kit, ditch it. You can probably get a flight of about 100 feet out of it and that's it. You can't really stretch it to pack the winds in and with the square crossection, even with lubrication it just won't do the trick.
What you need is 1/8 inch, flat, F.A.I tan sport rubber, or the equivalent. It's usually sold by the pound in hobby shops. Some of the current production Guillows kits have a piece of this rubber in them. If your model weighs less than 27 grams, or so, you can use one loop, about one and one-half times the length from the prop hook to the motor peg. If the model is between 27 grams and 36 grams you need a double loop. If a 500 series model weighs more than 40 grams you probably don't want to try to fly it.
Tie the loop in the rubber with a square knot then pull an overhand knot down on top of it. Trim the loose ends off to about 1/8 inch. I use a long stick with a notch at the back to push the rubber to the back of the model so I can hook it on the motor peg.
You need to lubricate the rubber to get power out of it and keep it form breaking. Pre-mixed rubber lube is available. The classic lube is a mixture of glycrine and green soap, it works but is a little messy and gets all over the inside of the model.
I use automotive silicone lubricant that comes in a spray can. It does not harm the rubber and lubes when dry. In the US I use STP brand, I don't know what brands are available in the UK, but check your auto parts store. I put the rubber loop in a plastic sandwich bag and spray the lube in to get it wet. Then I close the bag and rub it around to make sure that the lube gets all over the rubber. When you take the rubber out the lube drys. Armor-All rubber protectant (sometimes called tire dressing) is a similar silicone compound that works well also.
See if you can get a rubber winder at a hobby shop. They usually have a 5 to 1 or 10 to 1 gear ratio so that you only have to wind it 100 turns to get 500 or 1000 winds on the rubber. A satisfactory one can be made of a hand powered twist drill. Do not simply chuck a prop hook in the drill, it will pull out with disasterous results. If you make one the winding hook has to loop behind the chuck as well to prevent pull out.
You have to have a winding "stooge" to hold the model by the motor peg while winding. This is usually a device (Google it to see what they look like.) or a person. (If using a person be be aware that if the rubber band breaks and comes through the back of the model, it's going to hurt. It's also probably better if they are wearing glasses.)
You pull the rubber out the front of the model and stretch it to about twice it's length with the winder. Wind in about half the number of winds you intend then slowly walk toward the model ending up at the nose when you get the count you want. Takes a little practice. Hook the prop shaft to the rubber (Don't loose it here.) and you are ready to launch.
Start your trimming flights with 50 to 100 turns, just enough so that you have some power and are not just gliding, and work up. Make your adjustments to the rudder and elevator to get the flight path you want. Depending on the model, with 500 Series models you will usually be using 500 to 1200 turns for your flights after you get it trimmed out. Rubber bands don't last forever so be sure to examine them for tearing and other wear. If you see wear, don't chance it, just make a new motor.
I could go on a lot longer about the fine points of rubber motor control, and I don't consider myself a real expert at it, but this should get you started.
Howard
-
cdwheatley
- Posts: 92
- Joined: Sun Dec 03, 2006 1:03 pm
- Location: Waterlooville, Hampshire, England
Wow that was VERY useful, thanks Howard! 
.
By "1/8 inch" I presume you mean 1/8 inch wide? I have some 'proper' looking rubber going spare in my series 200 Fokker Triplane and SE5a kits, do you think that would be ok to use? By the way, my series 500 kit's all up weight is around 20g, that's not too bad is it?
.By "1/8 inch" I presume you mean 1/8 inch wide? I have some 'proper' looking rubber going spare in my series 200 Fokker Triplane and SE5a kits, do you think that would be ok to use? By the way, my series 500 kit's all up weight is around 20g, that's not too bad is it?
-
supercruiser
- Posts: 405
- Joined: Wed Jun 15, 2005 8:47 am
-
kittyfritters
- Posts: 732
- Joined: Tue Jan 03, 2006 6:58 pm
- Location: California
Chris,
20 grams, without rubber, is an excellent weight for a 500 series model. If that weight is with the green rubber band in it you have a real winner.
First, check that your wings and tail surfaces are on square and are warp free. This is your starting point for trimming. Now, make sure that the model is balanced.
The real key to getting it to fly is balance. The balance point is shown on the plans. Some people stick pins in the wing tips at the balance point and support the model from them. I just stick my finger tips under the wing tips at the balance point and pick it up. Less possibility of damage to the wing tips. The model should sit level when picked up at the balance point.
I'll stand you a pint that your Hurricane is tail heavy. You will probably be stuffing modeling clay into the nose to get it balanced. I sometimes glue BB shot inside the nose. If you fly the model tail heavy it will stall and spin in and you will be picking up pieces. If it is too nose heavy it will dive into the ground.
Balance the model with the motor in it. Wind in a few hundred turns and let the motor unwind while holding it in a slightly nose high attitude. This will let the unwound rubber motor lay approximately where it will in flight. Now, balance the model. I actually make mine very slightly nose heavy and adjust for it with a little up elevator. This prevents a stall/spin when the motor unwinds and the model transitions from powered flight to glide.
You can adjust the elevator and rudder by breathing on them, in your open mouth, while gently (Don't break anything!) bending them in the direction that you want. The heat and moisture in your breath will soften the covering slightly. When you take the tail or elevator out of your mouth and hold the bend while the covering hardens up again (a few seconds) you will find that the part will have taken a set in the direction you wanted. Another way is to glue small tabs of thin (.005 inch), clear acetate sheet to the trailing edges of the tail and elevator. You adjust by bending the tabs.
You want a glide in a level attitude with a slight tendency to turn to the right. You don't want it to dive into the ground, but don't try to make the glide too floaty. Whatever you do, you do not want the model to pitch up and stall. That breaks models.
When you have gotten the glide dialed in adjust for power. Powered flight adjustments are made by angling the thrust line. You wedge the nose block or thrust button right or left or up and down. Rubber powered models start out with a burst of power so they usually need some down and right thrust. The down thrust keeps the model from stalling, (or with a lot of power looping) under power and the right thrust will keep it from spiraling in to the left under power. Low winged models tend to fly left under power and glide right. (High winged models fly right under power and may actually need left thrust). A good starting point is the prop shaft 2 degrees down and 2 degrees right.
Begin with 50 to 100 turns and see what the model does under power. If the thrust adjustments get the model to fly straight ahead under low power, up the winds and test. If the model flys straight ahead from the launch point and will not climb it may need a little less down thrust or, in extreme cases, some up thrust. The objective is to get the model to climb as steeply as possible, without stalling, while turning to the left under power and make a smooth transition to a gentle right glide when the motor unwinds. This flight pattern will, generally, give you the best performance and keep the model from flying too far away from you.
When you get it all trimmed and go for maximum winds I would launch the model aimed slightly to the right of any oncoming breeze and slightly right wing down. This will use the wind to help control the initial burst of power and keep the model from spiraling in to the left, immediately after launch, when the torque is highest and the airspeed is lowest, dispite correct adjustmets for the rest of the power range.
Hope this helps.
Howard
20 grams, without rubber, is an excellent weight for a 500 series model. If that weight is with the green rubber band in it you have a real winner.
First, check that your wings and tail surfaces are on square and are warp free. This is your starting point for trimming. Now, make sure that the model is balanced.
The real key to getting it to fly is balance. The balance point is shown on the plans. Some people stick pins in the wing tips at the balance point and support the model from them. I just stick my finger tips under the wing tips at the balance point and pick it up. Less possibility of damage to the wing tips. The model should sit level when picked up at the balance point.
I'll stand you a pint that your Hurricane is tail heavy. You will probably be stuffing modeling clay into the nose to get it balanced. I sometimes glue BB shot inside the nose. If you fly the model tail heavy it will stall and spin in and you will be picking up pieces. If it is too nose heavy it will dive into the ground.
Balance the model with the motor in it. Wind in a few hundred turns and let the motor unwind while holding it in a slightly nose high attitude. This will let the unwound rubber motor lay approximately where it will in flight. Now, balance the model. I actually make mine very slightly nose heavy and adjust for it with a little up elevator. This prevents a stall/spin when the motor unwinds and the model transitions from powered flight to glide.
You can adjust the elevator and rudder by breathing on them, in your open mouth, while gently (Don't break anything!) bending them in the direction that you want. The heat and moisture in your breath will soften the covering slightly. When you take the tail or elevator out of your mouth and hold the bend while the covering hardens up again (a few seconds) you will find that the part will have taken a set in the direction you wanted. Another way is to glue small tabs of thin (.005 inch), clear acetate sheet to the trailing edges of the tail and elevator. You adjust by bending the tabs.
You want a glide in a level attitude with a slight tendency to turn to the right. You don't want it to dive into the ground, but don't try to make the glide too floaty. Whatever you do, you do not want the model to pitch up and stall. That breaks models.
When you have gotten the glide dialed in adjust for power. Powered flight adjustments are made by angling the thrust line. You wedge the nose block or thrust button right or left or up and down. Rubber powered models start out with a burst of power so they usually need some down and right thrust. The down thrust keeps the model from stalling, (or with a lot of power looping) under power and the right thrust will keep it from spiraling in to the left under power. Low winged models tend to fly left under power and glide right. (High winged models fly right under power and may actually need left thrust). A good starting point is the prop shaft 2 degrees down and 2 degrees right.
Begin with 50 to 100 turns and see what the model does under power. If the thrust adjustments get the model to fly straight ahead under low power, up the winds and test. If the model flys straight ahead from the launch point and will not climb it may need a little less down thrust or, in extreme cases, some up thrust. The objective is to get the model to climb as steeply as possible, without stalling, while turning to the left under power and make a smooth transition to a gentle right glide when the motor unwinds. This flight pattern will, generally, give you the best performance and keep the model from flying too far away from you.
When you get it all trimmed and go for maximum winds I would launch the model aimed slightly to the right of any oncoming breeze and slightly right wing down. This will use the wind to help control the initial burst of power and keep the model from spiraling in to the left, immediately after launch, when the torque is highest and the airspeed is lowest, dispite correct adjustmets for the rest of the power range.
Hope this helps.
Howard
-
cdwheatley
- Posts: 92
- Joined: Sun Dec 03, 2006 1:03 pm
- Location: Waterlooville, Hampshire, England
Howard - very, very useful information, many thanks. In fact I'm going to print it out and keep it for reference.
supercruiser - yes it's the Hurricane! Thanks for your help too.
Gentlemen, I have a rather embarrassing confession to make - when I weighed my model I misread my wife's kitchen scales (well, the markings are quite close together) and the model is nearer 30g than the 20 I had first reported
. I must admit I was a bit surprised myself that it should turn out so light as I'd not done any lightening of the framework or anything like that, other than to use Japanese tissue in place of the Guillow supplied stuff. At least it's DEFINITELY much less than the 40g you mentioned though Howard so it should still fly ok!
supercruiser - yes it's the Hurricane! Thanks for your help too
.Gentlemen, I have a rather embarrassing confession to make - when I weighed my model I misread my wife's kitchen scales (well, the markings are quite close together) and the model is nearer 30g than the 20 I had first reported
. I must admit I was a bit surprised myself that it should turn out so light as I'd not done any lightening of the framework or anything like that, other than to use Japanese tissue in place of the Guillow supplied stuff. At least it's DEFINITELY much less than the 40g you mentioned though Howard so it should still fly ok!-
cdwheatley
- Posts: 92
- Joined: Sun Dec 03, 2006 1:03 pm
- Location: Waterlooville, Hampshire, England
Well folks, I've now had my first attempt at flying one of my models......it wasn't very successful.
I got the model balanced ok and, when it wasn't caught by the slight breeze, it seemed to glide quite well. I couldn't get any sort of controlled powered flight though, bar one of a few seconds when the air was completely still - does this have to be done when there's no wind whatsoever?! Anyway, apart from that all that happened was that as soon as the model left my hands it seemed to go all over the place, entirely randomly, before usually nose diving into the long grass in the field I went to very shortly afterwards. There just seemed to be no knowing where it would go. In the end I decided to go for broke, making several hopeful attempted flights, increasing the turns each time (I even did a bit of stretch winding on my own). I managed to get up to 600 or so before the rubber unexpectedly broke. I managed to get some of it out of the fuselage but a large 'lump' of twisted rubber remained at the rear by the motor peg, impossible to remove. I couldn't even fit the spare rubber I'd brought with me because the remains of the old one were in the way. Fortunately though, the model itself survived almost entirely in one piece. There was some very minor paintwork damage to the spinner, the antenna came loose so I decided to take it off completely myself so it didn't rip the tissue if it was pulled off in any future crashes, and also a very small dent to the leading edge of one wing. I've now patched it up (didn't take long!) and it looks as good as new again.
I don't really know what do to now. Have I chosen a particularly awkward subject to get flying (series 500 Hurricane) or am I just not cut out for this?! It would be so nice to see one of my creations take to the skies successfully, even just once, but I'm not sure I want to try again after this. I'm feeling thoroughly disheartened at the moment, and a little envious of everyone else that's been able to get their models flying
.
I got the model balanced ok and, when it wasn't caught by the slight breeze, it seemed to glide quite well. I couldn't get any sort of controlled powered flight though, bar one of a few seconds when the air was completely still - does this have to be done when there's no wind whatsoever?! Anyway, apart from that all that happened was that as soon as the model left my hands it seemed to go all over the place, entirely randomly, before usually nose diving into the long grass in the field I went to very shortly afterwards. There just seemed to be no knowing where it would go. In the end I decided to go for broke, making several hopeful attempted flights, increasing the turns each time (I even did a bit of stretch winding on my own). I managed to get up to 600 or so before the rubber unexpectedly broke. I managed to get some of it out of the fuselage but a large 'lump' of twisted rubber remained at the rear by the motor peg, impossible to remove. I couldn't even fit the spare rubber I'd brought with me because the remains of the old one were in the way. Fortunately though, the model itself survived almost entirely in one piece. There was some very minor paintwork damage to the spinner, the antenna came loose so I decided to take it off completely myself so it didn't rip the tissue if it was pulled off in any future crashes, and also a very small dent to the leading edge of one wing. I've now patched it up (didn't take long!) and it looks as good as new again.
I don't really know what do to now. Have I chosen a particularly awkward subject to get flying (series 500 Hurricane) or am I just not cut out for this?! It would be so nice to see one of my creations take to the skies successfully, even just once, but I'm not sure I want to try again after this. I'm feeling thoroughly disheartened at the moment, and a little envious of everyone else that's been able to get their models flying
.-
plasticbuddha
- Posts: 12
- Joined: Thu Aug 02, 2007 8:14 pm
- Location: Peoria, Illinois
-
kittyfritters
- Posts: 732
- Joined: Tue Jan 03, 2006 6:58 pm
- Location: California
Chris,
Sorry about the bad flight experience. Let's see what we can do to improve it.
First, about the broken rubber. What did you have for a motor, how long was it, and did you lubricate it? Unlubricated rubber motors break, period. I don't know if you have wire coathangers in the UK, but if you do, cut the straight bottom out of a wire coathanger and bend a hook, about 1/8 inch in diameter in one end. This makes an ideal tool for retrieving bunched rubber from the back of a model this size.
If you get the Don Ross book, Rubber Powered Model Airplanes, you will find a chart, on page 91, that gives you the maximum number of turns per inch for various sizes of rubber. For example, if your motor is 4 strands (double loop) of 1/8 inch, flat, tan rubber you can wind a maximum of about 69 turns per inch. For the kind of sport flying that we are doing you would wind 80% of the maximum. So, if your motor loop was 10 inches from hook to peg you could wind in 690 turns, maximum, or about 550 turns for sport flying. I would probably use a motor loop about 16 inches long with that model which would be 1100 turns for contest flying and 850 turns for normal flying. This is another good reason for keeping models light, if the model were light enough to fly on a single loop of 1/8 inch flat rubber you could wind 97 turns per inch.
Second, the erratic flight. How did you do the nose? Is it stock according to the plans? If it is, there is your problem. The stock Guillow's nose will not hold the thrust button tightly. Powered trim is achieved by small angular adjustments of the thrush line. When you have a loose thrust button the model will go all over the place. This is the one place were you absolutely have to do a little engineering with the Guillow's kits. Check my hangar at www.virtualaerodrome.com to see how I handled this on my Stuka and Rufe. This is not the only solution but it works. I have seen people simply epoxy a wooden former into the front of the plastic cowl (See my Spitfire nose on shot.) to give a solid base for thrust line adjustments. Whatever you do to solve this you will not be able to get good powered flights without being able to get the thrust button to stay put.
Another possibility, did you use the stock Guillow's thrust button? What does it look like, is the front of it rounded or does it have a short, tubular extention on the front of it. A Guillow's thrust button has a hollow back and if it does not have the extension on the front for extra bearing surface it is unusable. It needs to be replaced with either a current Guillow's thrust button or an aftermarket thrust button (Dare or Peck or whatever you have over there.) that has a solid back for more bearing surface. Another reason that the front end has to stay tight is that the motor, being longer than the hook to peg length, flops around inside the fuselage as it unwinds. If the thrust button, and any adjustable nose plug, are not tight the motor will change the thrustline adjustments as it unwinds.
Third, are you using the kit prop? Unfortunately, the prop supplied is not very efficient. Having the right prop makes a very noticable difference in the performance of a model. See if any of your local hobby shops carry the Ikara, or Igra props from the Czech Republic. For some reason the Czechs know how to make great rubber power props. The six inch diameter, round tipped Ikara or square tipped Igra (both red plastic) work very well with the 500 series Guillow's kits and should do well with the Hurricane also.
We'll make you a flier yet!
Howard
Sorry about the bad flight experience. Let's see what we can do to improve it.
First, about the broken rubber. What did you have for a motor, how long was it, and did you lubricate it? Unlubricated rubber motors break, period. I don't know if you have wire coathangers in the UK, but if you do, cut the straight bottom out of a wire coathanger and bend a hook, about 1/8 inch in diameter in one end. This makes an ideal tool for retrieving bunched rubber from the back of a model this size.
If you get the Don Ross book, Rubber Powered Model Airplanes, you will find a chart, on page 91, that gives you the maximum number of turns per inch for various sizes of rubber. For example, if your motor is 4 strands (double loop) of 1/8 inch, flat, tan rubber you can wind a maximum of about 69 turns per inch. For the kind of sport flying that we are doing you would wind 80% of the maximum. So, if your motor loop was 10 inches from hook to peg you could wind in 690 turns, maximum, or about 550 turns for sport flying. I would probably use a motor loop about 16 inches long with that model which would be 1100 turns for contest flying and 850 turns for normal flying. This is another good reason for keeping models light, if the model were light enough to fly on a single loop of 1/8 inch flat rubber you could wind 97 turns per inch.
Second, the erratic flight. How did you do the nose? Is it stock according to the plans? If it is, there is your problem. The stock Guillow's nose will not hold the thrust button tightly. Powered trim is achieved by small angular adjustments of the thrush line. When you have a loose thrust button the model will go all over the place. This is the one place were you absolutely have to do a little engineering with the Guillow's kits. Check my hangar at www.virtualaerodrome.com to see how I handled this on my Stuka and Rufe. This is not the only solution but it works. I have seen people simply epoxy a wooden former into the front of the plastic cowl (See my Spitfire nose on shot.) to give a solid base for thrust line adjustments. Whatever you do to solve this you will not be able to get good powered flights without being able to get the thrust button to stay put.
Another possibility, did you use the stock Guillow's thrust button? What does it look like, is the front of it rounded or does it have a short, tubular extention on the front of it. A Guillow's thrust button has a hollow back and if it does not have the extension on the front for extra bearing surface it is unusable. It needs to be replaced with either a current Guillow's thrust button or an aftermarket thrust button (Dare or Peck or whatever you have over there.) that has a solid back for more bearing surface. Another reason that the front end has to stay tight is that the motor, being longer than the hook to peg length, flops around inside the fuselage as it unwinds. If the thrust button, and any adjustable nose plug, are not tight the motor will change the thrustline adjustments as it unwinds.
Third, are you using the kit prop? Unfortunately, the prop supplied is not very efficient. Having the right prop makes a very noticable difference in the performance of a model. See if any of your local hobby shops carry the Ikara, or Igra props from the Czech Republic. For some reason the Czechs know how to make great rubber power props. The six inch diameter, round tipped Ikara or square tipped Igra (both red plastic) work very well with the 500 series Guillow's kits and should do well with the Hurricane also.
We'll make you a flier yet!
Howard
-
cdwheatley
- Posts: 92
- Joined: Sun Dec 03, 2006 1:03 pm
- Location: Waterlooville, Hampshire, England
Thanks for your reply Howard.
The rubber I used was some of the 3/16" stuff that came with my series 200 Fokker Triplane and SE5a kits. It was 1 1/2 times the distance from the prop hook to the motor peg, as you suggested, and well lubricated with a silicone spray I bought from my local Halfords - a well known chain of automotive/cycle parts stockists here in the UK. I used a single loop, as when I weighed the model again on my wife's (possibly not ever so accurate) kitchen scales it came out at 20g or a bit over without any motor installed.
So far so good (I think) but from your comments about the nose, thrust button, and prop it seems I got it all completely wrong. I made no modifications to the nose at all, and the thrust button is the stock one that came with the kit - as is the prop - but is the one with the extension on the front. It's probably too late now to make any modifications, especially to the nose, but I will bear in mind all that you have said when it comes to building my next flying model and hopefully that will be much more successful.
While I would like to think that I have gotten the hang of actually building these models to a reasonable standard, it would seem that there is much for me to learn about actually flying them. I think I have been trying to run before I could walk! Oh well, better luck next time.
Thanks again,
Chris
P.S. You were right PB!
.
The rubber I used was some of the 3/16" stuff that came with my series 200 Fokker Triplane and SE5a kits. It was 1 1/2 times the distance from the prop hook to the motor peg, as you suggested, and well lubricated with a silicone spray I bought from my local Halfords - a well known chain of automotive/cycle parts stockists here in the UK. I used a single loop, as when I weighed the model again on my wife's (possibly not ever so accurate) kitchen scales it came out at 20g or a bit over without any motor installed.
So far so good (I think) but from your comments about the nose, thrust button, and prop it seems I got it all completely wrong. I made no modifications to the nose at all, and the thrust button is the stock one that came with the kit - as is the prop - but is the one with the extension on the front. It's probably too late now to make any modifications, especially to the nose, but I will bear in mind all that you have said when it comes to building my next flying model and hopefully that will be much more successful.
While I would like to think that I have gotten the hang of actually building these models to a reasonable standard, it would seem that there is much for me to learn about actually flying them. I think I have been trying to run before I could walk! Oh well, better luck next time.
Thanks again,
Chris
P.S. You were right PB!
.-
Geoffrito
- Posts: 14
- Joined: Fri Aug 10, 2007 6:43 pm
Does the model glide OK? The motor in my model broke, and I ended up cutting a panel of tissue by the rear-most former out to remove it. Ah well. Are any of the surfaces warped though? I dont know much about 'serious' flying, just the little things that helped me get my models airborne (for a little bit, at least)
-
cdwheatley
- Posts: 92
- Joined: Sun Dec 03, 2006 1:03 pm
- Location: Waterlooville, Hampshire, England
Geoffrito, yes the model glides ok and none of the surfaces are warped - everything is straight and true. I will try the metal hook idea of Howard's for retrieving the remains of the motor and if that doesn't work I will just leave it there!
Howard, I've been looking at the nose blocks on your Rufe and Stuka at the Virtual Aerodrome. I can see that they're a much more solid base for the thrust button, but how exactly is it made adjustable? I found this at Sam's Models here in the UK (right at the bottom of the page) http://www.samsmodels.com/acatalog/Section_C.html, what do you think?
Howard, I've been looking at the nose blocks on your Rufe and Stuka at the Virtual Aerodrome. I can see that they're a much more solid base for the thrust button, but how exactly is it made adjustable? I found this at Sam's Models here in the UK (right at the bottom of the page) http://www.samsmodels.com/acatalog/Section_C.html, what do you think?
-
kittyfritters
- Posts: 732
- Joined: Tue Jan 03, 2006 6:58 pm
- Location: California
Chris,
That's quite a site. For some of this stuff, even in the States, we have to order it from Sam's. I would have to see how big that adjustable nose block was but it might be a good idea. In any event, those 1/32" shaft, for smaller models, and 3/64" shaft plastic nose buttons are what you need to replace the Guillow's nose buttons.
What is not apparent from the photos of my nose block assemblies is that the front plate fits into the end of the torque box with a little clearance. Putting thin balsa wedges between the front former and the nose button plate allows tilting of the nose button up an down and right and left. We're only talking about a few degrees here. With wedges in place, the nose button plate does not move in flight, but is removeable to wind. The nose button itself is in a tight hole in the front plate and has a drop of C/A applied around the edge to make sure it stays there. The balsa wedges are applied with a Uhu glue stick to keep them in place but make them removeable when necessary.
I sometimes use a Gizmo Geezer (from Canada) prop assembly.
http://www.gizmogeezer.com/free.htm
This has an adjustable nose button with three small screws for adjustment. You can get the nose button separately, but it has an odd sized shaft diameter.
I'm leaving on holiday, this evening, for a week so I probably will not reply to anything else until the 21st.
More later,
Howard
That's quite a site. For some of this stuff, even in the States, we have to order it from Sam's. I would have to see how big that adjustable nose block was but it might be a good idea. In any event, those 1/32" shaft, for smaller models, and 3/64" shaft plastic nose buttons are what you need to replace the Guillow's nose buttons.
What is not apparent from the photos of my nose block assemblies is that the front plate fits into the end of the torque box with a little clearance. Putting thin balsa wedges between the front former and the nose button plate allows tilting of the nose button up an down and right and left. We're only talking about a few degrees here. With wedges in place, the nose button plate does not move in flight, but is removeable to wind. The nose button itself is in a tight hole in the front plate and has a drop of C/A applied around the edge to make sure it stays there. The balsa wedges are applied with a Uhu glue stick to keep them in place but make them removeable when necessary.
I sometimes use a Gizmo Geezer (from Canada) prop assembly.
http://www.gizmogeezer.com/free.htm
This has an adjustable nose button with three small screws for adjustment. You can get the nose button separately, but it has an odd sized shaft diameter.
I'm leaving on holiday, this evening, for a week so I probably will not reply to anything else until the 21st.
More later,
Howard
-
kittyfritters
- Posts: 732
- Joined: Tue Jan 03, 2006 6:58 pm
- Location: California
Chris,
I think I see the source of your confusion about the adjustable nose block. None of the pictures that I posted at Virtual Aerodrome clearly show that there is a former at the front of the torque box that matches the size of the adjustable nose button plate. The wedges go between this former and the plate.
Maybe this photo of my 300 series Aeronca will help.
http://s121.photobucket.com/albums/o207 ... t=612d.jpg
Got to go catch a train.
Back next week,
Howard
I think I see the source of your confusion about the adjustable nose block. None of the pictures that I posted at Virtual Aerodrome clearly show that there is a former at the front of the torque box that matches the size of the adjustable nose button plate. The wedges go between this former and the plate.
Maybe this photo of my 300 series Aeronca will help.
http://s121.photobucket.com/albums/o207 ... t=612d.jpg
Got to go catch a train.
Back next week,
Howard