M20k gear adjustments

[goodyFAB]

Well, I’ve come across another question I have not been able to get a clear answer for. 
 

have any of you possibly during an annual or while complying with the Eaton actuator SB noticed that in the retracted position the front nose wheel can be pushed up until it contacts the little foam tire skids in the front wheel well? 
 

potential on a bumpy ride the front nose gear will be bouncing up and down. Putting un necessary stress on heim joints and etc. 

The extension seems to be in perfect adjustment. The mains are perfect with no play, symmetrical, etc. 
If we lengthened the front push rods then then we would lose the spring tension on the rods in retracted position. 
no? 

anyone ever have this issue ? 
 

im using a condor front tire. The easiest fix seems like a bigger tire skid but this doesn’t seem right. 
 

thoughts ? 

[1980Mooney]

8 hours ago, goodyFAB said:

Well, I’ve come across another question I have not been able to get a clear answer for. 
 

have any of you possibly during an annual or while complying with the Eaton actuator SB noticed that in the retracted position the front nose wheel can be pushed up until it contacts the little foam tire skids in the front wheel well? 
 

potential on a bumpy ride the front nose gear will be bouncing up and down. Putting un necessary stress on heim joints and etc. 

The extension seems to be in perfect adjustment. The mains are perfect with no play, symmetrical, etc. 
If we lengthened the front push rods then then we would lose the spring tension on the rods in retracted position. 
no? 

anyone ever have this issue ? 
 

im using a condor front tire. The easiest fix seems like a bigger tire skid but this doesn’t seem right. 
 

thoughts ? 

I hope you and your A&P have a copy of the M20K Maintenance and Service Manual are following the landing gear rigging instructions religiously.  I see you have a "305" designation meaning a Rocket conversion which adds a lot more weight than the K nose gear was designed for.

You should be able to adjust the nose wheel travel up into the wheel well.  See the instructions for both K and J. They have the same body.  The J instructions explain it a little better. Note that the nose gear overcenter preload has to be rechecked after adjusting travel.

  

Edited September 23, 2022 by 1980Mooney

[goodyFAB]

16 hours ago, 1980Mooney said:

I hope you and your A&P have a copy of the M20K Maintenance and Service Manual are following the landing gear rigging instructions religiously.  I see you have a "305" designation meaning a Rocket conversion which adds a lot more weight than the K nose gear was designed for.

You should be able to adjust the nose wheel travel up into the wheel well.  See the instructions for both K and J. They have the same body.  The J instructions explain it a little better. Note that the nose gear overcenter preload has to be rechecked after adjusting travel.

  

Of course, 

I was checking over the rigging adjustments made. (I like to confirm things are right before i assume anything, especially when it comes to airplanes)

i found the mains and the nose gear to be within limits prescribed in the manual. 
 

but …..

 

I didn’t see anything about how far the front wheel should be in the wheel well or how much “free play” the wheel should or should not have in the retracted position. 
It’s possible I need to do more reading but in the meantime i thought I might ask here. (I’m away from the plane for a few days and it’s in my mind) 

When I reviewed the landing gear operation without adjusting anything. it seems like if it wanted to get the wheel tight to well, I would run out of adjustment on the bungee / over center shims. I may be wrong- so I’m asking if anyone has experience with what is acceptable for nose wheel play up and down in the well? 
obviously , it’s more important the extended position is in perfect adjustment, but I don’t like the way the nose wheel moves in retracted position, figured someone here may have an answer / experience. 

[LANCECASPER]

On 9/23/2022 at 6:30 AM, goodyFAB said:

Well, I’ve come across another question I have not been able to get a clear answer for. 
 

have any of you possibly during an annual or while complying with the Eaton actuator SB noticed that in the retracted position the front nose wheel can be pushed up until it contacts the little foam tire skids in the front wheel well? 
 

potential on a bumpy ride the front nose gear will be bouncing up and down. Putting un necessary stress on heim joints and etc. 

The extension seems to be in perfect adjustment. The mains are perfect with no play, symmetrical, etc. 
If we lengthened the front push rods then then we would lose the spring tension on the rods in retracted position. 
no? 

anyone ever have this issue ? 
 

im using a condor front tire. The easiest fix seems like a bigger tire skid but this doesn’t seem right. 
 

thoughts ? 

The biggest mistake on these adjustments is not having someone do this that has done it many times before. Don't assume that you and your mechanic, who may never have done a Mooney M20K configured as a Rocket, will get it right the first time. This and rigging the control surfaces are areas for a Mooney expert. In this case it is Rocket Science.

[goodyFAB]

I do appreciate that very much. This is exactly why I’m asking this question. The last person to rig the gear was a well known Mooney service center. 
front wheel had play in retracted position. 
 

Fast forward , comply with Eaton SB 

we have the same exact free play in front wheel retracted position. 
 

is this an oversight? Is this normal ? 
Before I seek out someone who is a rigging expert I’m looking for some insight. 
 

this might be yet another instance where “the experts” left something undone. 

[Will.iam]

Call don maxwell at maxwell MSC? I’m sure they would have an opinion on whether free play in the retracted position is acceptable or not. 

[bmcconnaha]

6 hours ago, LANCECASPER said:

The biggest mistake on these adjustments is not having someone do this that has done it many times before. Don't assume that you and your mechanic, who may never have done a Mooney M20K configured as a Rocket, will get it right the first time. This and rigging the control surfaces are areas for a Mooney expert. In this case it is Rocket Science.

Yikes, I hope we're not making a mistake.  My usual SC couldn't work with my schedule this year, and I am working through an owner assisted annual, one of the nose gear springs is ever so slightly out of spec , and one of the mains over center was light and not within the 10 inch pounds of the other MLG that is required in the manual.  It seems easy enough to adjust.  Manual says nose first, then the mains.  Recheck the nose.  Verify mains don't take over 325 inch pounds after electric extension.  

[Guest]

I’ve never seen any dimensions for nose gear retracted height in the wheel well. They have to go high enough to pull the doors closed fully.  It’s easy to get them out of adjustment and get the doors rubbing or catching on the tire.  Tire size and tread design have an effect on fit and clearance.

[Stetson20]

On 9/24/2022 at 6:15 PM, M20Doc said:

I’ve never seen any dimensions for nose gear retracted height in the wheel well. They have to go high enough to pull the doors closed fully.  It’s easy to get them out of adjustment and get the doors rubbing or catching on the tire.  Tire size and tread design have an effect on fit and clearance.

Would a new MLG tire be a possible cause for gear retraction cycle to pop the circuit breaker? Just got mine out of annual and twice (actually 3 times) now, the MLG cb popped during retraction cycle. Avionics tech thought it was a stray ground wire crossing an unshielded portion of the gear wiring behind the main panel. I found out that wasn't the cause when I retracted the gear on climbout.

My local A&P is scheduled to swing the gear tomorrow to see what may be the cause. He also told me that circuit breakers "get old and tired" and sometimes need to be replaced. He's going to check the amperage draw through the retraction cycle while swinging the gear.

Anybody have any insight? Thanks!

[EricJ]

4 minutes ago, Stetson20 said:

Would a new MLG tire be a possible cause for gear retraction cycle to pop the circuit breaker? Just got mine out of annual and twice (actually 3 times) now, the MLG cb popped during retraction cycle. Avionics tech thought it was a stray ground wire crossing an unshielded portion of the gear wiring behind the main panel. I found out that wasn't the cause when I retracted the gear on climbout.

My local A&P is scheduled to swing the gear tomorrow to see what may be the cause. He also told me that circuit breakers "get old and tired" and sometimes need to be replaced. He's going to check the amperage draw through the retraction cycle while swinging the gear.

Anybody have any insight? Thanks!

Yes, and this is why you're supposed to swing the gear after a tire change.    Gear swing should show wether clearance is the issue or not.

[Guest]

6 hours ago, Stetson20 said:

Would a new MLG tire be a possible cause for gear retraction cycle to pop the circuit breaker? Just got mine out of annual and twice (actually 3 times) now, the MLG cb popped during retraction cycle. Avionics tech thought it was a stray ground wire crossing an unshielded portion of the gear wiring behind the main panel. I found out that wasn't the cause when I retracted the gear on climbout.

My local A&P is scheduled to swing the gear tomorrow to see what may be the cause. He also told me that circuit breakers "get old and tired" and sometimes need to be replaced. He's going to check the amperage draw through the retraction cycle while swinging the gear.

Anybody have any insight? Thanks!

It’s certainly possible that a tire change could cause issues.  Raising it on jack to look for any signs of binding is a good first step.

[carusoam]

There are also a few tire recaps with extra tread that are known to cause fit challenges….

 

So…

If the gear is set up properly… it passes all of the tests for transit and being locked down….

 

Why would we want another spec for it being hidden in the wells?

If it misses a hidden in the wells spec…

Would the only option be adjust the wells to match the final tire location…

There is only soooo much you can engineer an affordable mechanical device…. Before it gets too heavy, too expensive, or too complex to maintain...

 

Also check to see if there are any rubber, springs, or other bearings in the system that are loose, worn, damaged or are in need of repair or replacement…

PP thoughts only, not a mechanic…

Best regards,

-a-

[Stetson20]

On 9/27/2022 at 11:48 AM, EricJ said:

Yes, and this is why you're supposed to swing the gear after a tire change.    Gear swing should show wether clearance is the issue or not.

The tire change was during the annual. They also swung the gear. I assume the gear was swung *after* the tire change. My local A&P is set to swing the gear today.

[N201MKTurbo]

I don't know about you guys, but I have to jack the plane to change a tire. Once on jacks, swinging the gear is nothing.

[Stetson20]

Not to hijack the thread but my A&P swung the gear several times last week. There seems to be an electrical issue. When all my avionics and lights are turned on, the amperage draw is over 55A, then the screen display will just blank it out. (Attached pic of the display in flight a couple weeks ago. You can see the blanked out Amps in the lower right of the display)...

They're still troubleshooting and I hope to get it resolved soon, as I am enrolled in the MAPA PPP in Reading, PA later in the month. Crossing my fingers, as I wasn't able to make the Mooney Summit because the plane wasn't done.

[1980Mooney]

On 10/4/2022 at 9:01 AM, Stetson20 said:

Not to hijack the thread but my A&P swung the gear several times last week. There seems to be an electrical issue. When all my avionics and lights are turned on, the amperage draw is over 55A, then the screen display will just blank it out. (Attached pic of the display in flight a couple weeks ago. You can see the blanked out Amps in the lower right of the display)...

They're still troubleshooting and I hope to get it resolved soon, as I am enrolled in the MAPA PPP in Reading, PA later in the month. Crossing my fingers, as I wasn't able to make the Mooney Summit because the plane wasn't done.

 

Per your model year and serial number I assume you have a 14 volt system.  At 17.1 volts charging (if accurate) your twin batteries in tail per Rocket conversion are toast.  Your regulator must be bad.

 

Edited February 25, 2023 by 1980Mooney

[Ragsf15e]

4 minutes ago, 1980Mooney said:

Per your model year and serial number I assume you have a 14 volt system.  At 17.1 volts charging (if accurate) your twin batteries in tail per Rocket conversion are toast.  Your regulator must be bad.

Or it’s a 24v system and 17.1v is also bad.

[1980Mooney]

46 minutes ago, Ragsf15e said:

Or it’s a 24v system and 17.1v is also bad.

No - his serial number is 25-0872.  28 volt started with 25-1000

Edited October 7, 2022 by 1980Mooney

[Fly Boomer]

1 hour ago, Ragsf15e said:

Or it’s a 24v system and 17.1v is also bad.

Not sure, but all Rockets may be 28-volt.

[1980Mooney]

49 minutes ago, Fly Boomer said:

Not sure, but all Rockets may be 28-volt.

Rocket Engineering, back in the day, took the airframe that you brought them (J for Missile 300 - IO550 and K for Rocket 305 -TSIO520)  and essentially did a firewall forward modification.  They did not gut the plane of existing 14 volt electronics/wiring if you had a pre 1986 K or a pre 1989 J.  They did not touch the 14 volt vs 28 volt relays, breakers, landing gear actuators, or avionics/panel. They did relocate the battery and put 2 in the very back of the tail essentially for ballast to counter the forward CG of the new heavier motors and props.  I have the last Missile they did in 2001 and it is 14 volt.

Edited October 7, 2022 by 1980Mooney

[Fly Boomer]

9 hours ago, 1980Mooney said:

They did relocate the battery and put 2 in the very back of the tail essentially for ballast to counter the forward CG of the new heavier motors and props.  I have the last Missile they did in 2001 and it is 14 volt.

So the 14-volt Rockets and Missiles have the two batteries in parallel, and the 28-volt airplanes have the two batteries in series?

[1980Mooney]

3 hours ago, Fly Boomer said:

So the 14-volt Rockets and Missiles have the two batteries in parallel, and the 28-volt airplanes have the two batteries in series?

No they are all in parallel.  Planes that were originally 14 v are still 14 v and those that were 28 v are still 28 v.  They just have 2 Concord Recombinant XC batteries wired simply in parallel in a box that slides all the way to the back of the tail.  They give you a special board that you use temporarily to slide them because of the weight and difficulty getting back there.

Ovations have 2 batteries in parallel but have a more sophisticated wiring of the batteries so if one fails the other is still at peak performance I believe.  I have never had any problems with the Rocket approach

If he roasted even one he needs to replace both batteries with equal strength because of the parallel wiring - he is looking at about $1000 in batteries, new regulator and labor.  Probably an easy $2000 total if there are not other problems or damage.