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G-Force Heli · 11-28-2007, 11:32 PM

For some time now the gimbals on my DX7 seem worn out and I have noticed some play. So I opened up the radio to check the tension springs. To my discovery, each gimbal only had a single ball bearing and a bronze bushing supporting it.

I have since replace all four bronze bushings with ball bearings. The radio now has quad bearings for each stick, two ball bearings for each axis.

It took me at least half an hour for each gimbal to be taken apart and reassembled. If you decide to do this, work very slow and carefully. There are a lot of wires to be aware of and don’t lose any screws or springs during the process.

All I can say is; it’s amazing how the sticks on the DX7 now feel more precise and smoother than it was new.

Garf

fogger · 11-28-2007, 11:54 PM

Nice, may have to try this someday. Got a bearing size for us? (OD x ID x Width)

Thanks for the info,

-Fog

Skiddz · 11-29-2007, 11:42 AM

Bearing part numbers would be nice

flyboy320 · 11-29-2007, 11:52 AM

Curious as to how long you had been using the TX for when the slop started to develop?

piwko4 · 11-29-2007, 12:17 PM

where did you get the bearings from?

Randallhurd · 11-30-2007, 04:01 PM

I guess I'm going to have to break out the Micrometer tonight and work on that.
I have dang near ever size bearing out there with as many crashes as I've had in my first 5 months of flight.
I'm sure I can get something to work out.
I had a bad orientation problem last night,, But I guess that's good,, 30 flights and one Unplanned landing. :o
It was kinda dark out. Heli was about 100 feet away I though it was coming down Head first, when I moved the stick in what I though was the right way, I was very dissappointed 3 seconds later.

G-Force Heli · 11-30-2007, 08:31 PM

The radio is a year old and gets heavy usage almost everyday. The sticks always felt loose since it was new. The bushing fit very loose on the gimbals so there no friction on the gimbals. The bearings fit snug onto the gimbals but are very smooth in operation, you can feel the difference.

Garf

Quote:

Originally Posted by flyboy320

Curious as to how long you had been using the TX for when the slop started to develop?

G-Force Heli · 11-30-2007, 08:37 PM

I am not here to solicit but to tell you all that the quad bearing gimbals are the way to go.

My HF id gives it away who we are.

Garf

Quote:

Originally Posted by piwko4

where did you get the bearings from?

th3tick · 11-30-2007, 08:42 PM

Quote:

Originally Posted by G-Force Heli

I am not here to solicit but to tell you all that the quad bearing gimbals are the way to go.

My HF id gives it away who we are.

Garf

Are you implying you'll be selling a set of bearings for this purpose?

Thanks,
John

G-Force Heli · 11-30-2007, 08:50 PM

John,

I am here to share with everyone my discovery how well the quad bearing upgrade works on the DX7. Keep in mind this has to be the most popular radio on the planet by now.

This simple upgrade is probably the best thing you can do for the DX7.

The bearings can be bought from any hobby store. We are not a hobby store.

Garf

Quote:

Originally Posted by th3tick

Are you implying you'll be selling a set of bearings for this purpose?

Thanks,
John

th3tick · 11-30-2007, 09:16 PM

Quote:

Originally Posted by G-Force Heli

John,

I am here to share with everyone my discovery how well the quad bearing upgrade works on the DX7. Keep in mind this has to be the most popular radio on the planet by now.

This simple upgrade is probably the best thing you can do for the DX7.

The bearings can be bought from any hobby store. We are not a hobby store.

Garf

Understood, although you must not know how awful hobby stores are around the Denver area for random parts like bearings

Any chance at all you could share the bearing size used so we can all go find some?

Thank you,
John

G-Force Heli · 11-30-2007, 09:22 PM

The bearing size is M4 x 7 x 2mm . I am sure any store selling micro helis would have this size. Some ball bearing servos use this size.

Garf

Quote:

Originally Posted by th3tick

Understood, although you must not know how awful hobby stores are around the Denver area for random parts like bearings

Any chance at all you could share the bearing size used so we can all go find some?

Thank you,
John

ping · 11-30-2007, 10:01 PM

M4x7x2 is kind of a weird size. M4x7x2.5mm is the trex 600 flybar seesaw bearing is it too wide to fit?

flyboy320 · 12-01-2007, 06:54 AM

Has anyone found out the correct bearing size/part number needed yet?

BarnOwl · 12-01-2007, 08:14 AM

Quote:

Quad bearing upgrade for the DX7 gimbals by G-Force

Would G-Force be marketing those in a complete set with step by step instructions to do the conversion? I would buy such a set without thinking.

aristo · 12-01-2007, 02:25 PM

http://www.vxb.com/Merchant2/merchan...egory_Code=4mm

abec 3's 6 bucks each,just ordered 2

flyboy320 · 12-01-2007, 03:00 PM

I see those are 4x7x2 bearings. My local HS has 4x7x2.5 size ones for half that price. Anyone know if they would fit?

ping · 12-01-2007, 03:02 PM

Those are open. I haven't found a source for a sealed 4x7x2's yet. I might try the 4x7x2.5 the next time my Trex head is apart.

aristo · 12-01-2007, 03:12 PM

its inside your radio a sealed clean environment,sealed vs open makes no differance in this application.

G-Force Heli · 12-01-2007, 07:45 PM

The 4x7x2 open bearing is fine. That is what I used.

The other ball bearing that is on the gimbals are also open.

11-28-2007, 11:32 PM	#1 (permalink)
G-Force Heli Join Date: Jun 2007	Quad bearing upgrade for the DX7 gimbals by G-Force For some time now the gimbals on my DX7 seem worn out and I have noticed some play. So I opened up the radio to check the tension springs. To my discovery, each gimbal only had a single ball bearing and a bronze bushing supporting it. I have since replace all four bronze bushings with ball bearings. The radio now has quad bearings for each stick, two ball bearings for each axis. It took me at least half an hour for each gimbal to be taken apart and reassembled. If you decide to do this, work very slow and carefully. There are a lot of wires to be aware of and don’t lose any screws or springs during the process. All I can say is; it’s amazing how the sticks on the DX7 now feel more precise and smoother than it was new. Garf Attached Thumbnails Last edited by G-Force Heli; 11-29-2007 at 12:51 AM..

11-28-2007, 11:54 PM	#2 (permalink)
fogger Registered Users My HF Map location Join Date: Jul 2006	Nice, may have to try this someday. Got a bearing size for us? (OD x ID x Width) Thanks for the info, -Fog __________________ This heli stuff is a pretty deep Rabbit hole, you just have to decide how deep you are willing to go...

11-29-2007, 11:42 AM	#3 (permalink)
Skiddz HF Support My HF Map location Join Date: May 2006	Bearing part numbers would be nice __________________ -Kevin No helicopters were harmed in the creation of this post. AMA CD # 7309, Turbine Waiver# RW 890 Click Here For Bergen Intrepid Turbine Build Videos

11-30-2007, 04:01 PM	#6 (permalink)
Randallhurd My HF Map location Join Date: Sep 2007	Bearings/ I guess I'm going to have to break out the Micrometer tonight and work on that. I have dang near ever size bearing out there with as many crashes as I've had in my first 5 months of flight. I'm sure I can get something to work out. I had a bad orientation problem last night,, But I guess that's good,, 30 flights and one Unplanned landing. :o It was kinda dark out. Heli was about 100 feet away I though it was coming down Head first, when I moved the stick in what I though was the right way, I was very dissappointed 3 seconds later.

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11-29-2007, 11:52 AM	#4 (permalink)
flyboy320 Registered Users My HF Map location Join Date: Aug 2007	Curious as to how long you had been using the TX for when the slop started to develop?

11-29-2007, 12:17 PM	#5 (permalink)
piwko4 Registered Users My HF Map location Join Date: Sep 2006	where did you get the bearings from?

11-30-2007, 10:01 PM	#13 (permalink)
ping Registered Users Join Date: Jul 2005	M4x7x2 is kind of a weird size. M4x7x2.5mm is the trex 600 flybar seesaw bearing is it too wide to fit?

12-01-2007, 06:54 AM	#14 (permalink)
flyboy320 Registered Users My HF Map location Join Date: Aug 2007	Has anyone found out the correct bearing size/part number needed yet?

12-01-2007, 02:25 PM	#16 (permalink)
aristo Registered Users My HF Map location Join Date: Dec 2006	http://www.vxb.com/Merchant2/merchan...egory_Code=4mm abec 3's 6 bucks each,just ordered 2

12-01-2007, 03:00 PM	#17 (permalink)
flyboy320 Registered Users My HF Map location Join Date: Aug 2007	I see those are 4x7x2 bearings. My local HS has 4x7x2.5 size ones for half that price. Anyone know if they would fit?

12-01-2007, 03:02 PM	#18 (permalink)
ping Registered Users Join Date: Jul 2005	Those are open. I haven't found a source for a sealed 4x7x2's yet. I might try the 4x7x2.5 the next time my Trex head is apart.

12-01-2007, 03:12 PM	#19 (permalink)
aristo Registered Users My HF Map location Join Date: Dec 2006	its inside your radio a sealed clean environment,sealed vs open makes no differance in this application.

12-01-2007, 07:45 PM	#20 (permalink)
G-Force Heli Thread Starter Join Date: Jun 2007	The 4x7x2 open bearing is fine. That is what I used. The other ball bearing that is on the gimbals are also open.

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