By continuing to use this site, you agree to our use of cookies. Find out more

Member postings for PeterF

Here is a list of all the postings PeterF has made in our forums. Click on a thread name to jump to the thread.

Thread: which glue for wing ribs
26/02/2016 17:16:26

Chris,

I have just bought a pack of 10 blunt 18g 1.5" hypodermic needles from ebay for < £3 posted that will do.

23/02/2016 23:16:37

I thought I would give the super phatic a try, ordered some and it has turned up but instead of the metal needle dispenser it has one of those plastic micro tubes often supplied with cyano. Gone and bought some needle dispensers as the micro tubes are just too floppy for trying to direct the glue into the confines of built up wings. Ho hum.

Thread: Peterf's 1/4 scale Falcon Models Tiger Moth
23/02/2016 22:58:09

Moving onto the wings, I want to progress the build even though there is lots of scale detail to be sorted out on the fuselage, that can all wait until the whole air frame from the Falcon kit is complete. I have started with the top wing, so I put all the ribs together, being a uniform wing along most of its length these should have all been the same. They are a little out, perhaps as a result of being cut by a router rather than laser cut, but no hassle as a little sanding bought them all to the same profile. The profile of the ribs is pretty much true to scale, slightly under cambered and relatively thin. This is a difference to the Flair kit which has a thicker wing section. The next stage was to cut the spars to length and remove all the CNC cut curved pieces for the ends of the wings from the sheets of ply and balsa. The spars were drilled to accept the fittings to connect to the fuselage and the ones for the landing wires. These were trial assembled then removed to get the ribs onto the spars. The wing was then dry assembled, the ribs needing a bit of a light file in the spar holes to make sure they slid onto the spars without splitting, but still having a good fit. Everything lined up nice, so it is now ready for final fettling before gluing. I know that it is abject laziness, but I could not resist buying the sheet steel fittings from Chris all nicely laser cut and ready to fit with minimal work on my part. The kit also comes with lots of drilling jigs in epoxy glass board so that you get the holes for these fittings in the right places, that is if you buy the CNC cut epoxy glass fittings.

Ribs being sanded to a uniform profiledsc04066.jpg

Metal end fittings on the sparsdsc04069.jpg

Dry assembled left hand upper wingdsc04072.jpg

Thread: converting over from nitro, advice plz
20/02/2016 20:52:32
Posted by Engine Doctor on 19/02/2016 10:24:05:

Going green ? Glow fuel is probably greener than electric power as methanol comes from vegetable based products.

Methanol MAY be made from vegetable based products, after all it is also known as wood alcohol, but it is very rarely made that way.

The vast majority of the world's methanol is made in huge petrochemical plants, I know I design them and have worked on many methanol plants around the world. The last plants I worked on were huge, one made 3,500 tonnes per day of methanol and the other 5,500.

The first stage in making methanol is to take natural gas, mix it with steam, heat it to 900 centigrade and 300 psi in a large furnace like a power station boiler to crack the natural gas to carbon oxides and hydrogen.

CH4 + H2O = CO + 3 H2

Then you compress the carbon oxides and hydrogen to 1200 psi and react them to form methanol.

CO + 2 H2 = CH3OH

Some of you will have noted that between the two reactions there is a spare hydrogen molecule which is burnt as fuel in the furnace. Attached are a couple of photos of the furnace (steam reformer) in a large methanol plant, and that only shows 2 out of the 14 rows of tubes along with a photo of a methanol plant.

methanol-plant-at-night.jpg

dsc08134.jpg

dsc08150.jpg

Thread: Peterf's 1/4 scale Falcon Models Tiger Moth
20/02/2016 17:26:13

In the end I had to go and do it, I could sleep at night and kept coming out in cold sweats. SO here it is, the first one in it's rightful place, although Chris's prototype may have had one of these. I can see the logic, the large lifting forces generated by the tail plane could try and pull the fuselage apart at this location. I was not short of moutning brackets because I did not use the suggested method for the tail plane struts which had a dowel with metal inserts, I used an aluminium tube with a dowel stiffener inside.

Tail plane Strut mounting bardsc04063.jpg

19/02/2016 21:16:41

Manish,

You beat me to answering, I had tried it in various locations and it seemed to fit there. Not sure that I will do anything about it.

Cheers,

Peter.

17/02/2016 20:30:59

Ron, Manish,

I have started sorting out everything for the wings, checking all the parts before I start. I have come across this piece from the laser cut steel, there is only one and I have checked my plans but can not find it on them. Do either of you recognise it or is it spare. As their is only one I wondered about it being from the fuselage. I have looked at the photos of the laser cut steel sheet before snipping the parts out and it only has one, at the upper center of the sheet.

dsc04042.jpg

steel.jpg

Edited By PeterF on 17/02/2016 20:31:32

16/02/2016 23:25:57

Moving forward with some final bits on the fuselage. The rudder turnbuckles are now properly bolted to the control arm and tensioned right. I have also changed the rear undercarriage arms to some 4mm tube which looks better than the original set up per plan using 2mm threaded rod and clevises. 4mm may be a little larger than scale but it is not noticable.

Manish, I think I will be OK with the wire for the elevators as there will be a leather patch over the hole in the covering which can have a slit in it if need be, the hidden threaded wire ends for the elevators do not have turnbuckle in, so the hole only needs to be 2mm dia. Otherwise, it will need the crimped tubes removing and new ones adding per your discovery, like minds fall into the same trap.

Rudder turnbucklesdsc04037.jpg

Rear undercarriage rods per plandsc03281.jpg

Rear undercarriage bars using 4mm tubedsc04035.jpg

Edited By PeterF on 16/02/2016 23:29:01

Thread: Do you think some sort of registration system would protect the hobby from rogue flyers?
10/02/2016 22:26:06
Posted by Beth Ashby Moderator on 10/02/2016 21:39:18:

Concerns have been raised in recent threads and action has already been taken in USA and Eire. We know the EASA process is under way here and a result is due in spring.

The forum would like to get a feeling for what the average modeller here would find acceptable, if changes to the status quo have to be made.

Discuss your opinions here...

Edited By Beth Ashby Moderator on 10/02/2016 21:41:3

The poll and your post are different. You state in the post you would like to find what people would find acceptable but the poll is for something else. Someone may agree to some simple registration even though their belief is it will not make any difference.

Personally, I do not believe registration will stop the rogue fliers, does legislation and jail stop knife crime.

Thread: Hitec Aurora 9
10/02/2016 22:16:53

I have not checked this but I would do something like set it up as a motor glider with 2 aileron servos and 1 flap servo with the outer aileron servos. This will give you channels something like

1 aileron 1, 2 elevator, 3 motor, 4 rudder, 5 aileron 2 & 6 flaps.

I would then connect the inner ailerons to channels 7 & 8. You then need to add some programmable mixes from flap to channels 6 and 8 and ailerons to channels 6 and 8. You will need to set the mix rates to give the required lower throws. Obviously end up with an optima 9 receiver.

Thread: Peterf's 1/4 scale Falcon Models Tiger Moth
31/01/2016 18:01:58

Completed the control wires for the elevator. I have made the guide rod for the upper control wire from scratch, including a shackle from plate to closer match the full size plane I am modelling. The whole system works very well. This now takes me to the end of the fuselage build in the instructions. All that is left is to add a lot of scale detail and cover it. Before that happens I need some wings.

Elevator control wires and guide rods.dsc04028.jpg

Elevator up.dsc04030.jpg

Elevator down.dsc04033.jpg

Thread: Flair Taube information needed
31/01/2016 08:43:36

Chris,

The control throws are 50mm in each direction for the rudder and 15mm in each direction for the elevator. These are the throws I have had on mine since I built it 10 years or so back and have been fine.

I have added a bit of the plan below to show how the CoG is defined, 152mm back from the front of F5, which is the front former built into the wing section, i.e. the front fuselage / wing joint. I have recently measured my CoG as I have swapped to electric and I am flying with it 140mm back from F5 so my CoG is a little bit forward. When I originally built the model it balanced a little forward as my engine was a 40 4 stroke and a little heavier than the recommended one. At first I put some lead on the back of the fuselage for test flights at the 152mm CoG and it flew OK. I gradually took the lead off over a few flights and it flies fine balanced a little forward. I have kept the same 140mm position with the new electric motor and battery installation.

The one thing I did do that was not on the plan was to add bracing wires from the top and bottom of the fin post to the back of the tail plane. I found that the tailplane as flexible and when you pulled full elevator it actually bent the tailplane down, which was more effective at diving the plane than the elevator was at climbing it. It cost me a nose area rebuild to find that out. The bracing wires are shown in a couple of the photos. The photo was taken before the bracing wires were added in original IC configuration. I am not the only person to find that these wires are a great help, there are others I have discussed this with who have independently found the need for them. It is not always needed, I guess depending on the stiffness of the balsa in the tail plane. I would recommend that you think about this.

Peter.

a5416418-72-p5050011.jpg

dsc04015 (custom).jpg

dsc04018 (custom).jpg

dsc04023 (custom).jpg

31/01/2016 07:26:23

Chris,

I missed your original post as I was away before Christmas. I have the Flair Taube, I will dig out my plans and reply with the info later.

a5416419-84-pic-003.jpg

Thread: Peterf's 1/4 scale Falcon Models Tiger Moth
30/01/2016 07:29:33

That was a neat idea - not sure how the post got orphaned though.

Posted by ron thornhill on 29/01/2016 13:18:41:

Hi Peter just thought you may be interested with what I did with the turn buckles. I bought two lots, one with eyes and one lot open ended then swaped one end of each making easier to fit on with just a split pin. Your thimbles look brilliant, didn't think of that, too late now.img_3759.jpg

 
29/01/2016 07:26:13

Manish,

I had looked at those from the ship modelling site but the one type did not look the part even though they had then at 0.8mm ID, and the better looking ones may have been to large. My issue was the turnbuckles only had a 1.5mm ID hole so I could not accept anything larger, so making my own guaranteed a fit. I chose brass tube because you can usually get it in thinner wall than copper. I also looked on the ship modelling site for the shackles as I need them for the upper elevator guide rod, but looking at the full scale of the plane I am modelling showed that it had a shackle made from plate not bar, so I will make my own for that.

Peter.

28/01/2016 06:59:29

This is the photo of the completed thimbles after the long side had been trimmed, I accidentally used the same one twice in the post above.dsc03991.jpg

27/01/2016 22:20:13

The full size model has thimbles in the loops on the control cables to stop the cables wearing as they rub within the fittings on the control horns. The kit does not include anything and is set up for you to just bend the wire through the fittings. In an attempt to add some scale details I have made up my own thimbles, a few hours work to make the 16 required for the model. The cabling supplied in the kit is about 0.7mm diameter. The holes in the fittings and turnbuckles are 1.6mm. I sourced some 0.8mm ID x 1.5mm OD brass tube, 3 pieces 300mm long being plenty.

I filed a small slot in some hard balsa to rest the brass tube in. I put some soft steel wire around 0.6mm diameter through the brass tube, placed the brass tube in slot in the balsa and filed the top half of the brass tube away using an ordinary metal working file. I lifted the soft steel wire from the tube and then ran a small triangular file down the slot left in the brass tube to clean it up. The steel wire is put in the middle to give the file something to work the brass tube against and to file it completely away. The first attempt did not sue the wire and as the top oif the brass tube thinned down it deformed inwards making life difficult.

The next stage was to bend the end of the brass tube around a 3mm steel bar in the vice. I found that I did not need to anneal the brass tube. However, I did hold some steel cable in the slot to try and help keep it formed. I found that I needed to hold around 1cm of straight length on the one side to keep the bend formed well.

However, I only needed about 5mm straight length for the thimbles, so I made a jig up from some scrap ply to cut off the bent section at the right place. This left me with thimbles with uneven legs, so I then had to cut the longer leg down to suit the required 5mm length, again using the ply jig. In the end I used one complete 300mm length and about 50mm from the second tube.

The previous post shows them being installed. They can not be completely bent together until they have been installed.

Brass tube with steel wire inside in slot in balsa ready for filing downdsc03979.jpg

Brass tube filed down, steel wire visibledsc03982.jpg

Brass half tube cleaned up ready for bendingdsc03985.jpg

End of half tube bent to form the thimbledsc03986.jpg

Collection of uneven thimblesdsc03989.jpg

Collection of completed thimblesdsc03989.jpg

Close up of a completed thimble before installationdsc03998.jpg

27/01/2016 22:02:14

I have finally got back to the build and have decided to tackle the control cables for the rudder and elevator, rudder first. I made up some thimbles to go through the loops in the wires. I’ll cover making the thimbles in the following post. Pictures show the fittings made up from sheet brass, these were in the kit of parts from Falcon, just needing to be folded around the bolt. I have also soldered the two halves together to stop them opening up. For the adjustment of the rudder cables I have a set of 4 very nice turnbuckles from Mick Reeves, not perfect scale but will look OK on the model. I am still waiting to get the right bolts to attach them to the brass fittings, slight oversight on my part. Once everything was attached, a quick check with the Rx connected to the rudder servo showed the correct 2.5” displacement on the rudder. I had already worked out the geometry and chosen the hole on the servo arm and the APE settings on the Tx to get the right movement and for once, I got it right.

Rear control arm, brass fitting and thimblesdsc03999.jpg

Rudder bar, brass fitting, turnbuckles and thimblesdsc04001.jpg

Cables connected to the rudderdsc04007.jpg

Cables connected to the rudder bardsc04004.jpg

Rudder works, turn rightdsc04011.jpg

And turn leftdsc04012.jpg

Thread: Forum members' new models: Let's see them.
18/01/2016 20:22:19

Here is my Christmas present all assembled and now waiting for that elusive first thermal. This is the 3.0m span Gracia from Topmodel in the Czech Republic. Straightforward assembly, the wings are very nicely put together. The motor is one of the GliderDrive models from HobbyKing, an outrunner inside an outer can with rear exit bullet connectors so no wire to rub inside a narrow nose. I am glad I did not go for the 3.5m span version, room is tight in the workshop with the one I do have.

dsc03971.jpg

Thread: EDF exhaust tubes - why?
13/01/2016 08:41:50

Simon,

A proper link to my test page **LINK**

One thing I realised is that I did some extra tests with a parallel duct the same diameter as the fan, hence the exit area was essentially 127% of FSA, velocity reduced, there was some pressure recovery and the load on the fan reduced. The overall thrust was lower so was the power draw and the efficiency was also down. I also looked at an obround (obround = oblong with rounded ends) exit to the duct with 100% FSA as the model I was building needed that shape of duct (B2 Stealth). See photo showing obround duct.

In terms of the blunt end created by a motor, the air behind this will form a recirculation pattern and the jet of air from the annulus will gradually close in. There will be in effect a cone shaped back flow area and in an ideal world the cone will close in at an angle of around 10 degree. This means that ideally, the duct you add should close in at a similar angle so that you maintain a more uniform flow if you have a 100% FSA outlet, see sketch.

A cone with a small angle will create a lower pressure loss than a more abrupt angle. In fluid flow we normally aim for 30 degree or less for very low pressure loss. Also, if we have a non uniform flow and wish to have enough pipe to end up back at a more uniform flow profile over the tube, we could use 10 pipe diameters, sometimes for a high accuracy flow meter we may use 50 pipe diameters or put flow straighteners in.

_exhaust test.jpg

dsc01500.jpg

edf duct.jpg

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E! 

Latest Forum Posts
Support Our Partners
Sussex Model Centre
Wings & Wheels 2019
Slec
electricwingman 2017
Cambridge Gliding Club
CADMA
CML
Sarik
Advertise With Us
Latest "For Sale" Ads
Has home isolation prompted you to start trad' building?
Q: The effects of Coronavirus

 Yes - for the first time
 Yes - but Ive bashed balsa before
 No - Ive existing projects on the bench
 No - Im strictly an ARTF person

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us