Robin 2160 Build Thread

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[alan c]

Hi DB,

Yes it is the same as I have, except the arm has only one side to it, I was going to use a steel wire rod direct to an extra servo for it. I was thinking of using a longer piece of steel to go through the mount so I could put a collar on the top, may help it from working loose and falling off. Niel's idea of putting larger grub screws in might also be the go. These have been great photos.

Happy New Year    Apache

IMPERATIVE that you put a servo saving bend in your wire,    to have a direct link is to coart a bust servo,    i used to use a buggy servo saver,  never lost a servo

[kinverflyer]

I would not recommend putting a bend in the rod, any sort of movement other than that from the servo will cause the nose wheel  to twist. I use solid wire on a push pull system, this has worked very sucessfuly on the both the SR22 and the 337. The most important thing is use a high torque metal gear servo at least 11kg.

[alan c]

each to his own martin,  but the final drive gear in any servo in this instalation will be the smallest, this is the one that will go,   with a solid pushrod, there is no give, and, eventually, it will go,        just my opinion of coarse,            your field is a nice strip, there are those out there that are not, and the servo will need a little help              ask me how i know

[shogun]

Hi Guys

My Robin had its maiden flight today.  Lovely.  No problems other than I'm suspect of the nose leg set up.  Requires further investigation.

[kinverflyer]

Both the SR22 and 337 have been flown at many different sites up and down the country some good and some not so good. I have used not so positive control linkages on nose legs before and suffered the consequnces. A nose leg twisting on landing is not fun especially when you end up with a crushed canopy, ask me how I know!

The servos I use are the Tower Pro 11kg metal geared and cost about £14, I have yet to strip one or damage it, even if I did it would still work out cheaper than a crushed canopy.

Just remembered I used the same set up on the Cessna 152 which I sold some time ago, I have sinced watched it being landed by different pilots and seen it bounced on to the nose leg from several feet with no other damage than that of the pilots pride.

[DB P7966]

Hi Shogun,

Nice to hear and well done.  Can you give some details of your aircraft
Weight
Engine used
Nose weight on front leg
Servo used on nose leg
Was a closed loop used or a straight push rod.

Also what are your concerns on the nose leg

All the above will help.

Lets have some pics as well.

Looking forward to your reply.

Regards

DB

[shogun]

Hi DB

The engine is a Laser 1.80.  More than sufficient power.  Cruised around at 1/2-throttle which was scale like.  Weight is 21-lbs which includes about 8-oz lead up front to get the C of G as recommended.  (Bear in mind that I have 2 x 4200mAh batts. 6-volt, for the Rx (now changed to a Spektrum AR9100) and a single cell for the glow driver, all positioned against the firewall.)

Don't know the weight on the nosewheel but the plane rotates quickly; not a lot of runway required and that is without takeoff flaps!  Used 1/2-flaps for landing.  12-15 knot wind.

There was no trim change either at 1/2-flaps or 1/1-flaps.  After takeoff she only required 2-clicks of aileron trim in this case.  Everything else was spot on.

The steering is by way of a direct piano wire from a HS645MG.  I've fitted a shock absorber to the servo arm/wire coupling.  Seems to work.  I did try a Towerpro high torque, metal gear servo for the nosewheel steering but it dosen't like being on a "Y"-lead with another servo.  A lot of glitching.  Too much current draw I was informed.

There are two main problems with the nosewheel assy. as I see things.  First, the 6mm rod which attaches to the oleo is a very soft metal and will bend easily.  It's surface has a roughened finish which is bad bearing in mind that it fits into the alloy nose block and then grinds away at it.

I've replaced it with a 6mm carbon steel rod, 75mm long which facilitates a collet on the top end for added security.

The second problem with the original assy. is that the rod is secured in the oleo with 2 x 4mm grub screws positioned opposite each other.  Bad!  The rod then has only two points of contact, namely at the grub screws and because the rod is of smaller diameter than the hole in the oleo, it will pivot at the grub screws and work loose (wear) and did in fact do just that.

What I was recommended to do was to drill and tap another 4mm thread in the oleo at 90-degs to one of the grub screws and have 2-only screws at right angles to each other holding the rod in the oleo.  This will prevent the rod pivoting as there is much more contact area with the rod to the oleo.  It seem a much firmer arrangement. I dispensed with grub screws and used 4mm cap head screws.

She flew yesterday for the first. There was a low cloud base, fog, wind and rain so the flight was only 7-mins and no aeros were attempted.  The plane was examined when I got home and the only problem was the nose leg assy.  So I'm very pleased!

I've got pics. but I haven't figured out how to upload them here.  I can e-mail if you like?

Stewart

[alan c]

ok martin  i give in,  what do i know?

[Andyc]

Just remembered I used the same set up on the Cessna 152 which I sold some time ago, I have sinced watched it being landed by different pilots and seen it bounced on to the nose leg from several feet with no other damage than that of the pilots pride.

Just what are you trying to say here?..........

Andy...........

[DB P7966]

Hi Shogun,
Many thanks for that.  Some good feed back which can be used.
Regarding placing pics on here do the following

1. ensure your pic size is about 50 to 60 kbs.
2. Click on reply after putting any words place courser on next line down.
3. Click on the Additional Options button
4. Click in the space by Attach click browse and navigate to where your pics are. This will upload one at a time.

If you wish to attach more pics click more attachments and you will have another opportunity to browse to your pics.  Have a go see how you get on.

Regards

DB

[apache]

Hi Shogun

I like your ideas on the front wheel assembly, I was intending to use a longer steel rod myself, I guess if we all put our 2 bob's worth in, we'll get this front wheel right. I'm with DB, would like to see some pic's when you get sorted out. By the way, what servos did you use throughout, I intend using Hitec 475's with a 6volt battery, have a torque of 5.5 kg's.

Cheers Apache

[shogun]

G'day Apache

Servos have been changed to:-

Hitec 5645MG on Elevators.  645MG Ailerons/Rudder.  645MG on Flaps.  591 on Throttle, 645MG for Steering.  6.0-volts.

Some pics. here show the 'old' setup.  Using AR9100 Rx and done away with the Opto Isolaror.


Shogun

[DB P7966]

Hi Apache

Sure you only get 5.5 kg on 6v   I thought it would be about 10 at least.

Cheers  DB

[DB P7966]

Hi Shogun,

Very nice

I like tidy installations it gives you a feel good feeling ::cc

Well done.

Regards

DB

[apache]

g'day DB

Hitec say 5.5 kg's on the box, so I guess that what it is, I have a large Zero with a 26cc Zenoah in it using futaba 3001's with no trouble, so I hope the 475's will be good enough on the Robin, keep me informed, you have done a good job here, this is a great forum.

Cheers Apache

[apache]

G'day Shogun

Very classy installation, hope I can get close, one of our club members users only laser engines and they appear very good, I'm putting a  DL50 with 22x8 prop, probably will cruise at about 1/3 throttle, but on the plus side should not have to include lead, I thing DB's ZDZ50 was a neat fit. All the best I won't be fitting mine out for about another 3 months, just to busy, please keep us up to date how your goes

See ya  Apache

[Mpx]

The full size has a very unusual handling characteristic and I wonder if the model also works with the same thing.  The proper spin recovery for the Robin 200 series is to keep the elevator at full up while applying opposite rudder, instead of letting the stick forward.  Models usually recover with just centralised controls and this model probably will as well.  But if someone would be willing to try out the full size recovery and report back, I would be most curious to know the result.  Do it with lots of spare height just in case.........  !

The 2160's engine tended to stop after 3 turns in a spin, due to prop blade drag.  (The other R200 i.e. 2112 and 2120 are not affected.)  I suggest you don't bother with this scale effect though!

Harry

[kinverflyer]

Some not very scale flying!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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YouTube - Robin 2160

[paulplane]

Hi All, Have just picked up the Robin.  Opened the box, I thought it was Xmas come early. ::cc
Wife not too impressed, took over her kitchen to open the box and stole the table.   I told her it was for Wison

Took some pics just to start with.  Must admit my first thoughts are. very nice  Should have it ready to display for the NATs

Motor ready for it is a ZDZ 50

Today, I got a YT Robin!!!!!!!!!!!!!
Its the blue one, all finished, just that Saito 300 to put in, now.
Will post pics...

[alan c]

where you bored stuey?      ANIMAL

[Andyc]

Stuey is always bored!.........

Andy.........

[paulplane]

Right! Robin finished, engine installed, just needing some final clearing up round the cowl cut outs, on-board ignition fitting (Twin Mag), as each cylinder has two plugs. Exhaust fitted well, round the u/c leg and clears its travel...

Love the twin cylinder picture - Drooool!

Robin 2160 Build Thread

Robin 2160 Build Thread

Robin 2160 Build Thread

Robin 2160 Build Thread

Robin 2160 Build Thread

[kinverflyer]

Very nice, whats the engine? and if you need Stuart to test fly it he treats them with respect : LOL

[paulplane]

The engine is a Saito 300 TD-P. A 50cc twin plug, twin carb. The actual engine is on a test stand on an earlier post on this thread...
Twin receivers and twin batteries control opposite controls so if one Rx goes down, some control would remain.