Quad bearing upgrade for the DX7 gimbals by G-Force

[G-Force Heli]

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]

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

Thanks for the info,

-Fog

[Skiddz]

Bearing part numbers would be nice

[flyboy320]

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

[piwko4]

where did you get the bearings from?

[Randallhurd]

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. :mad:

[G-Force Heli]

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

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

[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


where did you get the bearings from?

[th3tick]

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]

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



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

Thanks,
John

[th3tick]

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]

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



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]

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

[flyboy320]

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

[BarnOwl]

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]

http://www.vxb.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=bearings&Product_Code=kit7923&Category_Code=4mm


abec 3's 6 bucks each,just ordered 2:smokin:

[flyboy320]

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]

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]

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

[G-Force Heli]

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

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

[Randallhurd]

When installing bearings on mating surfaces,
.5 is a million miles off, I've been lucky in the past with accuracies at
.18 to .10 but never .50 or even .25.

[flyboy320]

Anyone know where you can buy these bearings (4x7x2mm) in Canada, perhaps online?

[th3tick]

Does anyone know what the X9303 has in this regard? Same setup? All bearings?

John

[G-Force Heli]

John,

Just open up the radio and look the gimbals. If one of the both end supporting bearings is silver, then it is full ball bearing. Other wise if it is bronze colored, it is a bronze bushing. I am pretty sure the X9303 and 12X should be quad bearing gimbals for each stick.

Garf


Does anyone know what the X9303 has in this regard? Same setup? All bearings?

John

[th3tick]

John,

Just open up the radio and look the gimbals. If one of the both end supporting bearings is silver, then it is full ball bearing. Other wise if it is bronze colored, it is a bronze bushing. I am pretty sure the X9303 and 12X should be quad bearing gimbals for each stick.

I understand how to check ;)

I just don't yet have my X9303 - waiting for it to arrive. If, however, they had bushings, then when I ordered a couple for my DX7, I'd order a couple more for the X9303, and save a bit on postage. Given the prices at that site, it would possibly even be worthwhile to order 10, and help out a few other folks here get them more cheaply.

$4 each for 10 vs. $7 each for singles is a big difference.

John