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Old Sep 18, 2012, 03:48 AM
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Portugal
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Another way to reinforce the hinges is to add some blenderm or clear packaging tape to the foam hinges... At least for me it works good
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Old Sep 18, 2012, 06:07 PM
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United States, NC, Hendersonville
Joined May 2010
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Hi HF,

Hinge lines were totally severed. No foam material left to cover. Your suggestions might have helped, but the basic problem remaines.

Thanks for your input,

Jack
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Old Sep 18, 2012, 06:18 PM
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Portugal
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Hello Jeff,

My comment was oriented to the public, sorry for not being clear about that...
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Last edited by HF_ATL; Sep 18, 2012 at 06:30 PM.
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Old Sep 29, 2012, 03:29 PM
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UK
Joined Oct 2001
118 Posts
Diamond 2500 motor

I have take the motor out of my Diamond 2500, to try and identify the stalling issue mentioned in my earlier post#977.
No obvious fault found , not sure if I should try and buy a new motor, so I may just put it back together.

Anyway the only difficult bit in dismantling is taking the clip of the back of the shaft since crash damage means I have attached the motor mount to the motor with hot melt glue (to avoid shorting since the insulation is gone there).
N.B. The two grub screws in the barrel at the front probably allow you to remove the shaft, but even with them removed the shaft stays fixed for me.
As the photos show, the stator is 37mm diameter and 20mm long.
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Last edited by mitchellj; Sep 29, 2012 at 03:58 PM.
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Old Sep 29, 2012, 04:03 PM
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UK
Joined Oct 2001
118 Posts
Spares in the UK

The following site lists spares for the diamond 2500

Note that I haven't dealt with these people, but while the price for the motor seems high that's standard for this unusual KV / size combination

http://www.elitemodelsonline.co.uk/P...h/Diamond-2500
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Old Sep 29, 2012, 04:06 PM
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Joined Aug 2006
379 Posts
mitchellj,
check the plugs of you motor leads. i had one break on an easy star and the motor would just cog and jitter. you'll need to cut off the heat shrink insulation, but this might reveal a problem with connectivity there.

or you coukd have a short in the motor it's self. if it getbvery hot, very quickly while it is stalled - this is an indication of an internal short as the wires/windings are just arcing with each other.

cheers,
Brian
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Old Sep 29, 2012, 04:48 PM
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United Kingdom, England, Taunton
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31 Posts
The Diamond's a tough old thing. After my repairs detailed in post 1029 I flew it today. After a few issues with initial trim it flies just as well as before. I suspect another crash will see it confined to the bin though.

I do find it a bit of a pig to land. I've got variable flaps on the bottom half of my throttle stick, and crow if wanted on ID1. It may be where i fly, but i find that having to clear some 50ft+ trees on certain approaches mean i struggle to get it down even though I've got 200 yds of landing strip! It just wants to float on, and slow it ain't...
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Old Sep 29, 2012, 06:16 PM
I'm a Registered User
Evansville, WI
Joined Dec 2006
3,689 Posts
Quote:
Originally Posted by mitchellj View Post
. The two grub screws in the barrel at the front probably allow you to remove the shaft, but even with them removed the shaft stays fixed for me.
To replace my bent shaft, I had to use a hydraulic press to push the shaft out. I supported the back side with a deep well socket to keep from bending the bell.

Also, take an ohm meter and check for continuity between the stator frame and the three motor wires. If you have continuity, the windings are shorted.
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Last edited by Bugman Jeff; Sep 29, 2012 at 06:23 PM.
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Old Sep 29, 2012, 06:21 PM
I'm a Registered User
Evansville, WI
Joined Dec 2006
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Quote:
Originally Posted by eddie currents View Post
I do find it a bit of a pig to land. I've got variable flaps on the bottom half of my throttle stick, and crow if wanted on ID1. It may be where i fly, but i find that having to clear some 50ft+ trees on certain approaches mean i struggle to get it down even though I've got 200 yds of landing strip! It just wants to float on, and slow it ain't...
I spent a whole battery just practicing landings. I found what worked best for me was to drop the flaps on approach, then ease into crow to slow it down more. I've got my Tx set so that at full crow, my flaps are down about 70 degrees, and the ailerons are up 60 degrees or so.
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Old Sep 30, 2012, 01:27 PM
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United States, CA, Camarillo
Joined Jul 2012
362 Posts
Wing Fitment Fix

Here’s an update on my wing fitment fix. I replaced the plywood pieces with parts made from carbon fiber sheet. Shaving the foam on one wing by 2mm and reusing the plywood shims might be the easier solution, but I didn’t have confidence in doing that very well.

I purchased one 100mm x 300mm sheet of 1mm thick carbon fiber from HobbyKing.com ($10.79USD plus S&H from Hong Kong).

To avoid carbon fiber dust from grinding or drilling, I cut the pieces to shape using a nibbling tool. Used a thick steel rule and box cutter to scribe lines for cutting the shapes with the nibbler tool. Carbon fiber is pretty brittle, so it will easily crack or splinter, but the nibbler does a great job of cutting without such problems.



For cutting the holes…. I measured the plywood holes to be 10.2 mm inside diameter. The nylon pins measured 9.78mm outside diameter.

I don’t have a drill press, so I made a custom 10mm drill guide from two aluminum ground bars I purchased from the local home improvement store (Home Depot) for less than $5.00USD each. Without the a drill guide the drill will wander off, so you’ll likely have a problem precisely positioning the holes. Also, you need to clamp the carbon with a backing plate to prevent splintering when the drill breaks through.



Plan to return the ground bars in as good as new for a refund later. The ground bar has 3/8” holes which is very close to 10mm. I also purchased one 9.8mm drill ($5.00USD with shipping) from a seller in China on eBay. So, I actually drilled the holes in the carbon at 9.8mm.

For the drill guide, I used two screws to keep the two ground bars in alignment. The carbon fiber was positioned and clamped with to C-clamps for drilling. And my caliper’s depth gage was used to position the hole. I actually pre-punched a 9/32” hole with a hand punch to reduce the drilling dust.



Here’s the carbon pieces positioned for fit-up prior to gluing.



I also purchased carbon fiber tubing (12mm OD x 10mm ID x 750mm long) from HobbyKing.com ($4.66USD plus S&H). So, next I cut two lengths of this using a Dremel tool and carbide cut off rotary blade.



The pins are just under 10mm OD, so the pins fit the tubing as a slip fit.

I bored the foam pin holes to just under 12mm using a circular rasp and hand drill. Same could be done with sand paper taped to and wrapped around a wooden dowel.



Here’s what it looks like with the pins installed. I still need to glue the tubes in place. The carbon will keep the holes from widening larger. I have the lanyard is tied to the plywood tray under the canopy, so the pins can only get lost with the plane.



Update



I had a change of heart. Decided the radio wave aspects of these large pieces of carbon fiber might degrade the 2.4GHz Rx reception. So I fabricated and installed new pieces from plywood. Used 1/16" (1.6mm) thick birch plywood stock. Bored the holes using a 10mm diameter auger bit with plywood sandwich to avoid splintering the plywood. Holes were first drilled with 1mm pilot holes on top waster plywood and also finish piece, drill bit used to align holes for clamping sandwich. 1/16" Plywood finished pieces were then sanded to 1.5mm thick, holes and edges were hardened with CA glue, then glued to wing foam using foam safe glue. Finally, plywood was sealed using water based polyurethane varnish.
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Old Sep 30, 2012, 04:01 PM
.: Looking for Thermals :.
Ricardo RW's Avatar
Chile, Quinta Región de Valparaíso, Los Andes
Joined Jun 2002
861 Posts
Today I have a very nice flying session with my Diamond. After fit it with a HTS-Blue Sensor Station from Hitec with GPS and 50Amp current sensor, I sent her to the air.

The day wasn't promising, a very cold and foggy day. About 11.30 the fog went away and the sun started to shine.

Threw my Diamond 2500 at full throttle and went as a rocket with my 4S Lipo 2,200 mAH.

I did the diving test to know if I have the correct CG, was nice, didn't tug under or go up, near the neutral point.

I have to try the programming settings as Crow, Camber and Reflex. Soon I realized that the air was pumping thermals, so I went hunting.

I was about 20 or 30 minutes up playing with camber to get the sweet point and catching several thermals, I took her more than 1,000 feet.

Nonetheless, I have some To-Do's waiting. I need to replace all foam hinges with some tape, foam hinges tend to wear out and I'm not willing to lose a control surface on air.

Need to put some fiber glass on the belly to make it more scratch resistant.

Need to cover the wings with tape to make them more durable.

A very nice sailplane.

Regards.
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Old Sep 30, 2012, 07:15 PM
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Evansville, WI
Joined Dec 2006
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Quote:
Originally Posted by Ricardo RW View Post
Need to put some fiber glass on the belly to make it more scratch resistant.
I simply used 2 layers of packaging tape on the bottom of the fuse. Unless I land on something very hard and sharp, it's protected the foam great so far. I do get the occasional dent, but no holes in the foam
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Old Sep 30, 2012, 07:23 PM
.: Looking for Thermals :.
Ricardo RW's Avatar
Chile, Quinta Región de Valparaíso, Los Andes
Joined Jun 2002
861 Posts
Quote:
Originally Posted by Bugman Jeff View Post
I simply used 2 layers of packaging tape on the bottom of the fuse. Unless I land on something very hard and sharp, it's protected the foam great so far. I do get the occasional dent, but no holes in the foam
I'll try that, faster and cheaper
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Old Sep 30, 2012, 11:07 PM
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Sweden
Joined Jul 2010
186 Posts
Thanks Ricardo for nice post. Our weather in Sweden now is off season...!
And about CG. I did not know that stable flight without lift change with speed change was sign of correct CG. Sound correct. Have to check myself.

Thaks Barry and all other also for keeping this thread alive with very good posts.

BG
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Old Oct 01, 2012, 07:47 PM
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United States, PA, Lebanon
Joined Oct 2007
211 Posts
Diamond 2500 Issues

Great Thread on the Diamond. I currently have been flying a Diamond 2500 and its a great glider.

I thought Id ask for some advise from other flyers for a two problems I have been having with the airplane.

First I am using the stock 60 ESC with the airplane. I have a Spectrum DX 7 and have the receiver Dual range receiver that is also also a spectrum. I have recently noticed after completely putting the power down the engine continues to keep running at a very slow speed while my throttle stick is completely down. I then have to push the power up slightly and back down for the motor and props to quit spinning. Motor is running uncontrolably at slow speeds.

Is it the ESC or motor?

Second when I hand launch the airplane it sometime veers to the left suddenly. I have to correct with hard right rudder to straighten out the airplane and it rights its self? CG with 2200 to 4000 lipo batteries has been fine. Does the motor have to angled to the right for thrust or does it fly ok with it straight?

I use a large 4000 MA lipo in the nose ane wonder if the CG might be off? My flaps quit working so I taped them up. One isnt down to cause loss of lift during hand lauching to cause a stall. Unknown what the problem is.

All servos are working correctly. No servo hum to indicate a bad servo. Just a note I have used gorilla glue for a few repairs on the nose and tail and I dont think that should effect the weight.

I also use lights on the airplane for flying at dusk and have used Ram lights running directly into my receiver. Also smaller lights on each wing tip and top of rudder.

I never had any problems with the airplane and properly hand launch it. Maybe the lipo is too large? I cant seem to fix the problem and would like to keep flying the airplane. I seems like it tip stalls suddenly. I have had zero problems with airplane until now.

Thanks for any inputs.

Chris
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