By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

2019 Mass Build

General mass build discussion thread.

All Topics | Latest Posts

Search for:  in Thread Title in  

Articles

RCM&E FLY-IN 2019

RCM&E FLY-IN 2019

Pop 13th 15th Sept in your diary!

Low pass Pete05/03/2019 04:23:13
avatar
206 forum posts
118 photos

Chris you may have a point. A very quick look at this early hour suggests that the dotted line on the plan for the wing centre line may be incorrectly drawn at the least. We need to correctly establish what the problem is before we assemble the wing.  My gut feeling is that the main brace may also be long.  It would not be the first time to have anomalies on the plans and also the cut parts as well.

Would be best to check via the designer Lyndsey Todd if possible. I will do some more detailed measurements later if possible today.

Best regards

Peter

PS  if you take a look at the build instructions you can see that when Lyndsey built the original the main brace did not meet the No 2 rib.  That picture also confirms that 11 ribs per wing half is correct.  Also I would expect that if the dimensions of the 2 dowel locating parts for the front of the wing align with holes in F2 then this would be a good guide to the final correct dimensions of wing centre section between the first rib on each wing half,  Hope that makes sense.

Edited By Low pass Pete on 05/03/2019 04:30:42

Edited By Low pass Pete on 05/03/2019 04:38:05

Edited By Low pass Pete on 05/03/2019 04:39:11

Low pass Pete05/03/2019 05:06:23
avatar
206 forum posts
118 photos

Ref anomalies on wing build. This why in my opinion the Mass Builds are so useful and good interaction. The feedback via this Forum is great and we all hopefully end up with a great model which may not be exactly the same but as a result of some hard work and thought regarding plans etc. look and fly well.

I have never designed my own model to date but this is now my third Mass build and I had similar small queries much as Chris has found on the other ones. Free plans sometime do not seem to be transcribed as per the original designer intended as the plans are drawn up by others for print. I'm sure Peter Miller would agree with me on this as the Ballerina plans (MB 2016) had some small issues. Ballerina was however a very successful Mass Build.  I converted Skywriter (MB 2017) to IC power and have a super sport biplane.

Happy building everyone.

Peter

Edited By Low pass Pete on 05/03/2019 05:09:09

Low pass Pete05/03/2019 09:15:32
avatar
206 forum posts
118 photos

I am certain that the dotted line is now NOT the centreline of the wing centre section. I think it is actually not shown as such but can be plotted at the end of the spars.

Laying my parts out supports this theory

img_6373.jpg

Chris Walby05/03/2019 13:10:57
avatar
926 forum posts
222 photos

Hi LPP,

I thought II had measured from wingtip to dotted line and the wingspan was about right!

I'll redraw it tonight with the correct wing dihedral and see if it comes out where you indicate on your photo, no doubt you are right.

Good job this is a mass build I would have made even more mistakes than normal wink

Low pass Pete05/03/2019 13:55:36
avatar
206 forum posts
118 photos
Posted by Chris Walby on 05/03/2019 13:10:57:

Hi LPP,

I thought II had measured from wingtip to dotted line and the wingspan was about right!

I'll redraw it tonight with the correct wing dihedral and see if it comes out where you indicate on your photo, no doubt you are right.

Good job this is a mass build I would have made even more mistakes than normal wink

Proves the point I made earlier Chris ref value of mass builds. Measure twice cut once I say again.

Cheers

Peter

Chris Walby05/03/2019 18:13:54
avatar
926 forum posts
222 photos

Hi LPP,

Taking your suggestion I think you are right that the centre line is not shown on the drawing.

If I take the various dihedral braces + the dowel plate and derive a new centre line then things look okay.

20190305_174424.jpg

Proof that we are correct is given by measuring the new wing span and calculating the with the wing dihedral of 3 degrees comes up with a wingspan of 54.09 inch.

As the model is advertised as 54 inch I am happy we are close enough!

Now next problem is that the small brace is not long enough to reach the second inboard rib so I am thinking of just moving the rib in a bit as per photo. Can anyone see a problem with that as I could just make a longer brace?

 

 

 

Edited By Chris Walby on 05/03/2019 18:26:54

Danny Fenton05/03/2019 23:42:14
avatar
9077 forum posts
3928 photos

Well done on sorting the issue Chris. I think moving the rib will be fine, the sheeting will help transfer loads

Cheers

Danny

Low pass Pete06/03/2019 06:45:24
avatar
206 forum posts
118 photos
Posted by Chris Walby on 05/03/2019 18:13:54:

Hi LPP,

Taking your suggestion I think you are right that the centre line is not shown on the drawing.

If I take the various dihedral braces + the dowel plate and derive a new centre line then things look okay.

20190305_174424.jpg

Proof that we are correct is given by measuring the new wing span and calculating the with the wing dihedral of 3 degrees comes up with a wingspan of 54.09 inch.

As the model is advertised as 54 inch I am happy we are close enough!

Now next problem is that the small brace is not long enough to reach the second inboard rib so I am thinking of just moving the rib in a bit as per photo. Can anyone see a problem with that as I could just make a longer brace?

Edited By Chris Walby on 05/03/2019 18:26:54

Looks like a plan Chris, well a slightly modified one anyway. Good job.smiley

Peter

Low pass Pete06/03/2019 06:48:13
avatar
206 forum posts
118 photos

Nice ruler Chriswink.  You can't have enough good tools.

LPP

Edited By Low pass Pete on 06/03/2019 06:49:15

Lindsay Todd06/03/2019 10:08:06
avatar
1678 forum posts
1666 photos

Gents image below is from the original plan sent into the mag, I have identified the centre line and position of first two ribs out, hope this helps clarify any irregularities found. Lindsren.jpg

tony oneill 106/03/2019 11:50:06
68 forum posts
49 photos

fuse3.jpgDid a bit on the fuselage over the last few days. No real issues apart from re sizing the doublers at the very front in the engine bay.fuse1.jpg

Chris Bott - Moderator06/03/2019 11:57:04
avatar
Moderator
6627 forum posts
1374 photos
1 articles

Lindsay many thanks for looking in, that appears to answer the questions.

Tony your progress looks excellent. Could you start your own thread on it in this section, please?

Chris Walby06/03/2019 17:20:27
avatar
926 forum posts
222 photos

RCM&E fly in this year at Buckminster on 14-15 Sept sounds a great idea and I'll make a weekend of it and camp up there.

Flew there with the pylon boys a couple of years ago and it a good venue with plenty of facilities, just need some decent weather.

Need to finish the model first, but if I haven't done that in 6 months I'll sit in the naughty corner. laugh

tony oneill 122/03/2019 09:41:25
68 forum posts
49 photos

this might be a daft question, but as i am not looking for aerobatic performance and this model has long ailerons would it be better to shorten these to about 2/3rd length, or just fit as they are and reduce the control throws? just a thought if anyone wants to pitch in

regards

tony.

Ron Gray22/03/2019 10:58:05
1414 forum posts
358 photos

Leave length as plan and adjust throws to suit your style of flying.

Chris Bott - Moderator22/03/2019 11:00:07
avatar
Moderator
6627 forum posts
1374 photos
1 articles

I agree with Ron as that's the choice that leaves your options open.

Chris Walby22/03/2019 11:58:48
avatar
926 forum posts
222 photos

+1 to stick with the plan...I don't know what the effects will be. Nice gentle plodder for me wink

Could always add split ailerons, then you could really play around with all kinds of configurations.... Flaps, crow brakes etc

tony oneill 122/03/2019 21:31:37
68 forum posts
49 photos

Thanks gents, looks like fit the ailerons full size and adjust the throws is the way to go.

Thanks for the help.

Tony

Chris Walby26/03/2019 22:26:25
avatar
926 forum posts
222 photos

Okay time to confess!

Mistake No 1

20190326_205044.jpg

Didn't use a single piece of wood for the elevators as at the time I couldn't work out the gap between each.

No2

20190326_204710.jpg

Servos in upside down and snakes fitted.

No3

20190326_205854.jpg

I haven't sheeted the wing, but fitted the dowels and more importantly the front dowel plate without the sheeting in place...I think this might be rework later on crying but I couldn't see how to fit them later once sheeted (perhaps sheet the top and then fit them)

There might be more, just not found them yet...but there is still time!

Low pass Pete27/03/2019 06:19:12
avatar
206 forum posts
118 photos

Chris Ref your issues

No 1

No problems with elevators. Just use wire joiner as per plan. However ref tailplane. Please ensure you join your 2 halves with a strong epoxy. Alternately remove the centre section and replace with a single piece. This would be much stronger.

No 2

I would remove servos and snakes and reverse as per plan. Just smile and carry on.

No 3

Make a centre section rib from 1/4in balsa and fit in the centre line. Sheet to this extra rib from each wing. This will have two bonuses. Extra strength and will make sheeting easier. One finished and covered all will be fine.

Hope this is helpful. Do not despair. The great thing about balsa is that errors are simply put right.

Cheers

Peter

All Topics | Latest Posts

Please login to post a reply.

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
Slec
Pepe Aircraft
electricwingman 2017
Revoc
Wings & Wheels 2019
Motion RC
Gliders Distribution
CML
Sarik
Advertise With Us
Latest "For Sale" Ads
Does your club have a safety officer?
Q: Does your club have a safety officer, or is the emphasis on individual members to each be their own safety officer?

 Yes we have a SO
 No, it's down to everyone

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us