Spektrum DX7 Ball Bearing Upgrade for Gimbals

[Jeff Morgan]

All,
 
Yesterday a comment was made about how smooth the gimbals on my DX7 were.  The DX7 comes from the factory with four bushings and four ball bearings supporting the two gimbals.  When I started flying helicopters back in the spring, I noticed the gimbals felt a bit notchy, so I decided to work on getting them a little smoother.  The secret is a ball bearing upgrade which replaces four bushings with ABEC-3 ball bearings; it's cheap and makes a nice difference.  It's a straightforward process, but you need to allocate about an hour to complete.  While I was in the radio, I regreased the existing ball bearings, sanded the indentations on the throttle and greased it as well.  For me, it was worth the effort.
 
http://www.helidirect.com/abec3-high-quality-4x7x2mm-dx7-gimbal-bearings-upgrade-kit-p-6607.hdx
 
http://www.rchelimag.com/forum/showthread.php?t=6343&page=1&pp=1
 
For those inclined, there are two other modifications of which I am aware:
 

• A custom (good quality) backlight assembly available in a couple of different colors.  This isn't a DIY put-in-a-radioshack-LED modification, but a complete modification which surrounds the LCD screen.  http://www.dfxhobbies.com/spektrum-screen-backlight-p-146.html

 
 

• A different voltage regulator which will improve battery life substantially; however, there is talk about noise.  http://www.dimensionengineering.com/DE-SW033.htm  This company also has other goodies that might be of interest (see the home page).

 
 
 
Jeff
 
 
 
 

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[wb4...@teara.org]

>Yesterday a comment was made about how smooth the gimbals on my DX7 were.
The DX7 comes from the factory with four bushings and four ball bearings
supporting the two gimbals. When I started flying helicopters back in the
spring, I noticed the gimbals felt a bit notchy, so I decided to work on
getting them a little smoother. The secret is a ball bearing upgrade which
replaces four bushings with ABEC-3 ball bearings; it's cheap and makes a
nice difference. It's a straightforward process, but you need to allocate
about an hour to complete. While I was in the radio, I regreased the
existing ball bearings, sanded the indentations on the throttle and greased
it as well. For me, it was worth the effort.

Jeff,

You wouldn't happen to know the part # on the bearing itself, would you? I
might be able to order those directly from one of our bearing sources.

Dave

Dave Hockaday WB4IUY
aka "Tweek", VROC #940
AMA 119484, IMAA 31979

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www.eQSL.cc/Member.cfm?WB4IUY
Motorcycle Parts: www.ScootWorks.com

[Jeff Morgan]

Here is the only specific part number I could find (obviously from a different mfr.): 
 

• GWS EPSC-2A4C (4x7x2mm).

 
Boca has a few 4x7x2 bearings and buying in a ten pack and repackaging may be a good option:
 

http://www.bocabearings.com/main1.aspx?p=quicksearchbearing

 
 
Jeff
 

 
> Date: Sat, 2 Jan 2010 20:45:21 +0000
> To: rd...@googlegroups.com
> From: wb4...@teara.org
> Subject: Re: [RDRC] Spektrum DX7 Ball Bearing Upgrade for Gimbals

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[Jeff Morgan]

It might go without saying, but I probably should have mentioned that I have a heli version of the DX7...otherwise I would not sand the indentations from the throttle.

 

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From: mtnbi...@hotmail.com
To: rd...@googlegroups.com
Subject: [RDRC] Spektrum DX7 Ball Bearing Upgrade for Gimbals
Date: Sat, 2 Jan 2010 10:57:02 -0500

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[Bill D'Epagnier]

The DX7 comes with both throttle straps- ratchet and smooth.  The extra one is on the little bag that has the servo hardware. It just takes a minute to change.

[Jeff Morgan]

You're correct Bill.  However, even with the smooth tension strap and grease, the throttle was a bit notchy.  So, I sanded the indentations from the plastic on the throttle slider itself.  Starting with 150 and ending with 320+.  The process makes the throttle buttery smooth.  Note that you can still use the tension strap, but it will not have the ability to ratchet any longer.   

 
Jeff

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From: bi...@nc.rr.com
To: rd...@googlegroups.com
Subject: Re: [RDRC] Spektrum DX7 Ball Bearing Upgrade for Gimbals
Date: Sun, 3 Jan 2010 07:12:34 -0500

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