Espritmodel.com Telemetry Radio
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Old Jan 07, 2013, 05:06 AM
I don't want to "Switch Now"
pmackenzie's Avatar
Toronto (Don Mills), Canada
Joined Dec 2002
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Originally Posted by Julez View Post
Hi guys.

I took the liberty to take some images of the knit marks from the Hobbyking forum of the link above.
Knit marks (or knit lines) occur, when the flow fronts of the liquid plastic during the injection molding process meet each other in an unfavorable way.
They look like fine cracks on the finished product.
I just spoke with an injection molding specialist who happens to work in my department, and she confirmed that the reasons for this can be either excess moisture in the raw material, or some tweaking needs to be done concerning the injection temperature and speed.
I would call them weld lines, but that sounds about right.
Generally (particularly if you made the tool )you hope that processing tweaks would improve them, but sometimes you need to make tooling changes as well. In this case they would mainly be a cosmetic concern.
Often they are simply hidden behind paint or a surface texture and can only be seen if you look at the back side of a part.

Pat MacKenzie
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Old Jan 07, 2013, 05:22 AM
Proud to eat Kraut ;-)
Julez's Avatar
Germany
Joined Dec 2003
5,214 Posts
I agree that on a transmitter case, they are indeed not a big problem.
There was a case that a specific size of folding propellers of the otherwise perfect brand "Aeronaut" kept desintegrating. This could be traced back to a "knit line" at the base near the hinge.
But a TX case will most likely never experience this kind of stress.
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Old Jan 07, 2013, 05:54 AM
I ♥ OpenTX
H2SO4's Avatar
Australia, New South Wales, Sydney
Joined Jan 2011
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Originally Posted by Julez View Post
But a TX case will most likely never experience this kind of stress.
Speak for yourself

My Tx case bears the brunt of my frustration caused by my mediocre flying.
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Old Jan 07, 2013, 07:00 AM
Video Juggernaut
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FL
Joined Nov 2003
2,637 Posts
Wow, seeing lots of knit picky complaints about a 50 dollar 9ch tx. Anyway, the wire seems like you can hot glue and or add a molex extension? The case molding issue, is it really an issue? Seems superficial to me. What other "issues" did people find? Anyone have a list yet? I've been reading through here but that's about all I managed to find besides someone stating their frsky module doesn't fit right. Speaking of frsky, will the djt module send telemetry to the onboard LCD or will you still need to use an external?
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Old Jan 07, 2013, 07:08 AM
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cold wombat's Avatar
Australia, WA, Perth
Joined Jul 2011
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Also very ordinary buttons, unusual battery configuration with 'dangerous' charge port.

TBH I think the real bitch is about lost opportunities.
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Old Jan 07, 2013, 07:10 AM
Flying a Chipmunk in Portugal
jhsa's Avatar
NRW, Germany
Joined Sep 2010
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Problems with PPM at trainer ports not working correctly??

http://forum.turnigy9xr.com/9xr-problem-t342.html
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Old Jan 07, 2013, 07:12 AM
chicken nuggets
Joined Aug 2011
204 Posts
Knit lines and weld lines are the same thing. Painting over them can often make the look worse, as was found with a new paint processing unit was being commissioned where I worked.
Silver paint over a knit line ended up looking like the grand canyon! Heh heh!!

Never did have a moulding that could not have them rectified with adjustments in temps, speeds, packing and pressures.
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Old Jan 07, 2013, 08:01 AM
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LI, New York, USA
Joined Mar 2003
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So the general opinion is these are not cracks but cosmetic imperfections in the molding process. No need to drop some thin CA into them to reinforce them?

As long as they appear to be cosmetic and not structural breaks that will eventually open up, not a big deal. But this is why I would not buy the first batch of almost any product. There are usually "birthing issues" and bugs that come out in the first run. Later runs have these fixed.
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Old Jan 07, 2013, 08:22 AM
chicken nuggets
Joined Aug 2011
204 Posts
Without checking one and seeing the lines, impossible to say. Technically they could be as bad as 'cracks' or just cosmetic and limited to the surface. If they are 'cracks' run some thin CA on the inside. That will help.
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Old Jan 07, 2013, 08:44 AM
Video Juggernaut
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FL
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Quote:
Originally Posted by cold wombat View Post
Also very ordinary buttons, unusual battery configuration with 'dangerous' charge port.

TBH I think the real bitch is about lost opportunities.
dangerous charge port?
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Old Jan 07, 2013, 08:57 AM
FPV Crash Dummy
igorp's Avatar
United States, CT, Bloomfield
Joined Aug 2007
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Quote:
Originally Posted by jhsa View Post
Problems with PPM at trainer ports not working correctly??

http://forum.turnigy9xr.com/9xr-problem-t342.html
From reading those posts it looks like this may only effect those that want to use head trackers.
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Old Jan 07, 2013, 09:06 AM
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LI, New York, USA
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Originally Posted by Wingbreaker View Post
dangerous charge port?
The radio uses LiPoly batteries but the charger port is for a NiCd/NiMh charger. Hopefully it is not actually connected internally or there could be some radio fires.
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Old Jan 07, 2013, 09:09 AM
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United States, AL, Owens Cross Roads
Joined Jan 2012
111 Posts
I have a 9X at the moment. Should I look at replacing it with the 9XR? I have set mine up so I can use the module bay so not sure that is a big selling point for me. Buy the 9XR or just stick with the 9X for now?
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Old Jan 07, 2013, 09:11 AM
RC beginner
New York
Joined Oct 2008
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Quote:
Originally Posted by aeajr View Post
The radio uses LiPoly batteries but the charger port is for a NiCd/NiMh charger. Hopefully it is not actually connected internally or there could be some radio fires.
at least one member measured battery voltage there so it is connected. another actually suggested plugging in a wall wart to charge. "dangerous" may be understatement. but i suspect hk will profit from repeat sales of puffed lipos and fried radios so maybe not really bad engineering from their viewpoint.

reasons i passed:

1. with no module or rx extremely bad deal compared to original 9x.
2. incredibly stupid (for consumer) battery design.
3. menus buttons designed to fail within a year or two.
4. bulky "transformers (tm)" case

good for hk. not for me.
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Old Jan 07, 2013, 09:21 AM
Penguins can´t fly?
SKIPPER2384's Avatar
Germany, SH, Glückstadt
Joined Jan 2011
36 Posts
Why should it be so hard to change from mode 1 to 2?
That plastic pin must have gotten in there somehow, so it must probably come out somehow!
My 9XR is unfortunately still on the Way but I ordered a Mode 2 because they were in stock the time I ordered and I fly Mode 3 so the Spring will change it´s Place even if I have to drill it out and replace it on the other side!
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