Go Back  RCU Forums > RC Cars, Buggies, Trucks, Tanks and more > RC Tanks
Reload this Page >

Tamiya recoil problem help needed

Notices
RC Tanks Discuss all aspects of rc tank building and driving here!

Tamiya recoil problem help needed

Old 04-10-2015, 06:02 AM
  #1  
Tanker 10
Thread Starter
 
Tanker 10's Avatar
 
Join Date: Oct 2014
Location: Roseville, CA
Posts: 888
Likes: 0
Received 0 Likes on 0 Posts
Default Tamiya recoil problem help needed

Finishing up my JS-2 build and I've run into a BIG problem. I have no barrel recoil. Everything else works fine, there is cannon sound and barrel flash, and barrel elevation also works. Here is what I did, pulled trim down, pulled right stick down, gun fires-flash no recoil and I can see the gears coming from the recoil motor spinning but the large gear isn't. I did that twice and now the recoil motor won't spin but the flash and sound are still there. So some questions for you. Now that the turret is glued together, what do I do. I've checked for any obstructions, wires etc and I can't see anything. I see sites sell replacement units, but how do you change them out with the turret glued together? Thanks for the help guys, everything was going great until now.
Old 04-10-2015, 08:23 AM
  #2  
sergeantseabass
Senior Member
 
Join Date: Feb 2015
Location: Quakertown PA
Posts: 421
Likes: 0
Received 0 Likes on 0 Posts
Default

I'll take a look at mine when i get home to see if i could pull out the unit with out taking the whle turret apart but, i think you going to have to remove the turret pieces to access it I.E. unglue the turret. But you might be able to if you have a crookneck driver that can reach inside.
Old 04-10-2015, 08:37 AM
  #3  
Tanker 10
Thread Starter
 
Tanker 10's Avatar
 
Join Date: Oct 2014
Location: Roseville, CA
Posts: 888
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by sergeantseabass View Post
I'll take a look at mine when i get home to see if i could pull out the unit with out taking the whle turret apart but, i think you going to have to remove the turret pieces to access it I.E. unglue the turret. But you might be able to if you have a crookneck driver that can reach inside.
Yes, this is not going to be pretty.
Old 04-10-2015, 09:27 AM
  #4  
Ex_Pat_Tanker
 
Join Date: Mar 2008
Location: Peterborough, UNITED KINGDOM
Posts: 2,141
Received 33 Likes on 26 Posts
Default

Is the barrel free to move - i.e. can it get stuck on a lip of paint or something? My first guess would be that it jammed and blew the recoil circuit on the mfu (seen that happen a few times now).

If the barrel moves feely, then my second guess would be a bad motor - I've also had that happen to me, remove it from the mechanism and try it on its own by holding down the limit switch and triggering the main gun.

If the motor works on its own then, the slide on the recoil mechanism could be jamming - I had one where the the slot wasn't quite formed right some how, and it would stick at 3 o'clock and 9 o'clock as the mechanism rotated.

First part of this all it to remove the unit, and as I don't have the JS2, I can't help you with that one
Old 04-10-2015, 10:03 AM
  #5  
ausf
 
ausf's Avatar
 
Join Date: Apr 2005
Location: , NY
Posts: 3,084
Likes: 0
Received 1 Like on 1 Post
Default

You can get to the screws that mount the barrel from inside once you pull the turret ring.

Before anything, double check the connection for the recoil at the MFU. That one is in the corner and you should make sure one of the leads didn't slip out of the jst housing. For some reason, my recoil connector on the JS-2 likes to pop a wire.

It's probably not serious, these things are pretty hardy. Mine got jammed by being knocked off a table and landing on the barrel. It twisted the metal frame of the recoil unit. Bent it back and all was fine. When you get it out, first check around the microswitch to make sure it's in position and free, then check barrel alignment, obstructions. If everything's okay, pop the plastic gear cover and have a look that everything is in place. You can pop the motor then a bench test it.

Worse case scenario, you can buy a new unit from Jason for about $40.
Old 04-10-2015, 12:04 PM
  #6  
TheBennyB
 
Join Date: Jul 2010
Location: West Grove, PA
Posts: 3,146
Received 1 Like on 1 Post
Default

Once you have the recoil unit out also look at the bottom nut that holds the main gear in place. They have a notion of coming loose then the main gear will skip off the worm gear or drop gear depending on which unit the IS-2 uses. If it is off, look in the lower hull for it then screw it back on and use a tad of thread lock to keep in place.
Old 04-10-2015, 02:48 PM
  #7  
Tanker 10
Thread Starter
 
Tanker 10's Avatar
 
Join Date: Oct 2014
Location: Roseville, CA
Posts: 888
Likes: 0
Received 0 Likes on 0 Posts
Default

Thank you guys for all of the help. I'm happy to report all is well and working. Here is what I found. On the large black gear for the recoil there is a large brass nut right in the center. When I activated the cannon, the carriage that the barrel attaches to starts to go backwards right, as the carriage moved backwards, it was getting hung up on that large nut. I tried to raise the gear so it was level with the top of the nut but couldn't. So I ground down the top of the nut so if was flat/even with the top of the gear. Prior to this I removed the recoil motor and found it was working when I hooked a battery and alligator clips to it. Also, having the motor out allowed me to manually slide the carriage and barrel reward. Thats how I saw it was getting hung up on the nut.
Old 04-10-2015, 03:07 PM
  #8  
sergeantseabass
Senior Member
 
Join Date: Feb 2015
Location: Quakertown PA
Posts: 421
Likes: 0
Received 0 Likes on 0 Posts
Default

I'm Glsd to hear that you got it working and that it was nothing major.
Old 04-10-2015, 03:14 PM
  #9  
Ex_Pat_Tanker
 
Join Date: Mar 2008
Location: Peterborough, UNITED KINGDOM
Posts: 2,141
Received 33 Likes on 26 Posts
Default

Originally Posted by Tanker 10 View Post
Thank you guys for all of the help. I'm happy to report all is well and working. Here is what I found. On the large black gear for the recoil there is a large brass nut right in the center. When I activated the cannon, the carriage that the barrel attaches to starts to go backwards right, as the carriage moved backwards, it was getting hung up on that large nut. I tried to raise the gear so it was level with the top of the nut but couldn't. So I ground down the top of the nut so if was flat/even with the top of the gear. Prior to this I removed the recoil motor and found it was working when I hooked a battery and alligator clips to it. Also, having the motor out allowed me to manually slide the carriage and barrel reward. Thats how I saw it was getting hung up on the nut.
That does concern me a little with Tamiya's quality control - that brass 'nut' (I think it's actually a shoulder bolt?) is supposed to clear the recoil slide Sounds like my recent problem with the slide slot not being formed properly? (bad stamping?)

Just for science (and great justice!) is the slide peice bent and hanging down, or is the brass head sticking up too far? Might help Tamiya determine which part is actually at fault...
(I suspect the arm to be honest?)
Old 04-10-2015, 05:31 PM
  #10  
thecommander
Senior Member
 
Join Date: Feb 2008
Location: hillsdale, NJ
Posts: 3,143
Likes: 0
Received 1 Like on 1 Post
Default

It is sad to see so many having trouble setting-up and/or programing their new tanks. As for Tamiya electronics and quality control, I have had very few problems over the years. My biggest complaint would be the slipper clutches are too loose. I weld most of them solid anyway except for first time tankers. Many issues with recoil and barrel trouble are alignment issues. Usually it is the recoil unit bracket on the rear of the mantlet is not parallel with the tank barrel bore. If it is too high or too low the mantlet bracket needs gentle bending. The barrel recoil mount tends to hang up on the front edge of the recoil unit or the offending center bolt mentioned above (Helpful Hint: Put a dab of glue or tape over the nut on the bottom of recoil unit. When it does come loose it falls into the tank often to disappear or even worse...enter an uncovered gearbox). I also pretest all the electronic strobe and motors before I assemble the tank. When would you like to find out you have a defective part...just when you need most (or when it is all assembled) or when you have time to get a replacement. Here is a video of some pre-testing:
Old 04-10-2015, 05:31 PM
  #11  
thecommander
Senior Member
 
Join Date: Feb 2008
Location: hillsdale, NJ
Posts: 3,143
Likes: 0
Received 1 Like on 1 Post
Default

It is sad to see so many guys having trouble setting-up and/or programing their new tanks. As for Tamiya electronics and quality control, I have had very few problems over the years. My biggest complaint would be the slipper clutches are too loose. I weld most of them solid anyway except for first time tankers. Many issues with recoil and barrel trouble are alignment issues. Usually it is the recoil unit bracket on the rear of the mantlet is not parallel with the tank barrel bore. If it is too high or too low the mantlet bracket needs gentle bending. The barrel recoil mount tends to hang up on the front edge of the recoil unit or the offending center bolt mentioned above (Helpful Hint: Put a dab of glue or tape over the nut on the bottom of recoil unit. When it does come loose it falls into the tank often to disappear or even worse...enter an uncovered gearbox).

I also pre-test all the electronics, strobe, recoil and motors before I assemble any tank. When would you like to find out you have a defective part???...just when you need most (or after it is all assembled) or when you have time to get a replacement.
Here is a video of some pre-testing: https://www.youtube.com/watch?v=Pgc-vuQmaTE

FYI: If anyone would like to borrow (free) a Futaba 4YF radio & receiver system to test or set up a new tank.... please PM me. It is customized for RC tanking with self centering joy-sticks and a remote fire switch for the main gun and machine gun. K.I.S.S. Just return it when you are done.

Bob, rctankcommand.com NEAD CO

Last edited by thecommander; 04-10-2015 at 05:51 PM.
Old 04-10-2015, 07:13 PM
  #12  
Tanker 10
Thread Starter
 
Tanker 10's Avatar
 
Join Date: Oct 2014
Location: Roseville, CA
Posts: 888
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Ex_Pat_Tanker View Post
That does concern me a little with Tamiya's quality control - that brass 'nut' (I think it's actually a shoulder bolt?) is supposed to clear the recoil slide Sounds like my recent problem with the slide slot not being formed properly? (bad stamping?)

Just for science (and great justice!) is the slide peice bent and hanging down, or is the brass head sticking up too far? Might help Tamiya determine which part is actually at fault...
(I suspect the arm to be honest?)
The shoulder bolt, as you say, was the problem. I looked again and the slide is not hanging down.
Old 04-10-2015, 07:30 PM
  #13  
Tanker 10
Thread Starter
 
Tanker 10's Avatar
 
Join Date: Oct 2014
Location: Roseville, CA
Posts: 888
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by thecommander View Post
It is sad to see so many guys having trouble setting-up and/or programing their new tanks. As for Tamiya electronics and quality control, I have had very few problems over the years. My biggest complaint would be the slipper clutches are too loose. I weld most of them solid anyway except for first time tankers. Many issues with recoil and barrel trouble are alignment issues. Usually it is the recoil unit bracket on the rear of the mantlet is not parallel with the tank barrel bore. If it is too high or too low the mantlet bracket needs gentle bending. The barrel recoil mount tends to hang up on the front edge of the recoil unit or the offending center bolt mentioned above (Helpful Hint: Put a dab of glue or tape over the nut on the bottom of recoil unit. When it does come loose it falls into the tank often to disappear or even worse...enter an uncovered gearbox).

I also pre-test all the electronics, strobe, recoil and motors before I assemble any tank. When would you like to find out you have a defective part???...just when you need most (or after it is all assembled) or when you have time to get a replacement.
Here is a video of some pre-testing: https://www.youtube.com/watch?v=Pgc-vuQmaTE

FYI: If anyone would like to borrow (free) a Futaba 4YF radio & receiver system to test or set up a new tank.... please PM me. It is customized for RC tanking with self centering joy-sticks and a remote fire switch for the main gun and machine gun. K.I.S.S. Just return it when you are done.

Bob, rctankcommand.com NEAD CO
I can appreciate the fact that I should have "plugged in the common sense" before starting my first Tamiya build. Maybe Tamiya should have you test the electronics as step 1 in their instruction manual instead of having you do it after the turret is built. I think it makes a lot of sense to follow the manual step by step unless of course you've been doing this for twenty years.
Old 04-10-2015, 08:37 PM
  #14  
thecommander
Senior Member
 
Join Date: Feb 2008
Location: hillsdale, NJ
Posts: 3,143
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by Tanker 10 View Post
I can appreciate the fact that I should have "plugged in the common sense" before starting my first Tamiya build. Maybe Tamiya should have you test the electronics as step 1 in their instruction manual instead of having you do it after the turret is built. I think it makes a lot of sense to follow the manual step by step unless of course you've been doing this for twenty years.
I have been stung too, just like you and many others before both of us. I have been building Tamiya RCs since the mid 1980's. I cut my teeth on the Bruiser, Lunchbox, Grasshopper etc... I had to learn many RC facts the hard way...no internet or forums back then. I got into the habit of testing certain components as a car mechanic & cop. I always checked the radio & flashlight before I left HQ. It has served me well. Even when I go fishing I start the boat at my house first before I drive to the launch ramp 45 miles away....just in case. I have learned much here on RCU and I am sure it will never stop. We are all sharing information here. Tamiya shows you the easiest way to build the tank ...but it is not always the best way to build a tank. Case in point: Why put the MF unit under the speaker in the Tiger tank? It is easier to adjust, service and test in the open paired with the DMD. It works best for me.

Good luck with the recoil and check that alignment. Bob

Last edited by thecommander; 04-11-2015 at 07:42 AM.
Old 04-10-2015, 09:40 PM
  #15  
rocyizhen
Junior Member
 
Join Date: Apr 2015
Posts: 5
Likes: 0
Received 0 Likes on 0 Posts
Default

You can get to the screws that mount the barrel from inside once you pull the turret ring.
Old 04-10-2015, 10:20 PM
  #16  
Tanker 10
Thread Starter
 
Tanker 10's Avatar
 
Join Date: Oct 2014
Location: Roseville, CA
Posts: 888
Likes: 0
Received 0 Likes on 0 Posts
Default

There's one thing for sure Bob, I won't make the same mistake twice.

Joe
Old 08-26-2015, 10:03 AM
  #17  
JH81187
Junior Member
 
Join Date: Jun 2010
Location: Campbell, CA
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Default

Hello, I just finished building the same model and am having the same clicking/grinding sounds with the recoil and the gun not really recoiling. Also my turret is completed. How do I unglue the turret and fix the problem? I used superglue to glue the turret together. Any help is appreciated.
Old 08-26-2015, 01:53 PM
  #18  
Tanker 10
Thread Starter
 
Tanker 10's Avatar
 
Join Date: Oct 2014
Location: Roseville, CA
Posts: 888
Likes: 0
Received 0 Likes on 0 Posts
Default

This is what I've learned to do with the Tamiya turret and it's many wires. If I develop a problem, I remove the turret from the tank, then try the recoil and elevation units. I've found that if they work fine with the turret removed from the tank, I better look at my wire routing again. Usually, that is the problem. As far as ungluing the two turret halves, I can't offer anything to help with that. I did learn my lesson about using ca to glue turret halves together, I won't do it again. On my recently finished M-51 kit, I used a glue called Aleene's original Tacky Glue. It reminds me of Elmers white glue and is water soluble. I haven't needed to try and separate it yet and it is holding fine. Since I cleaned up the wires on my JS-2, I've had no problems with my recoil unit.

Also, I've made it a point to count my turret revolutions (usually only one) I then will return the turret in the opposite direction and just not leave it. That has helped also.

Last edited by Tanker 10; 08-26-2015 at 01:58 PM.
Old 11-30-2015, 07:11 PM
  #19  
JH81187
Junior Member
 
Join Date: Jun 2010
Location: Campbell, CA
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Default

Hello there. I'm having the same problem here. The past few days, the tank was working fine, and then the recoil unit started acting up today. I opened it up and took a look inside but I can't seem to see anything wrong. What is the best way to resolve this issue. The wires are not in the way so I know it is not that flash cable. The motor works but seems that the slide gets stuck 1/4 way on the big gear wheel. I have to push the barrel to help move it a long.
Old 11-30-2015, 07:45 PM
  #20  
Jeff489
My Feedback: (12)
 
Join Date: Jul 2005
Posts: 1,316
Received 4 Likes on 4 Posts
Default

Your recoil bracket is bent most likely. You should check the alignment and hand bend it back into alignment.
Old 11-30-2015, 08:49 PM
  #21  
TheBennyB
 
Join Date: Jul 2010
Location: West Grove, PA
Posts: 3,146
Received 1 Like on 1 Post
Default

Also check the nut on the bottom of the unit that holds the main plastic gear that rotates and moves the barrel. It will come loose and the gear will wobble and bind. Just tighten it and put a dab of thread lock to hold it place. I've had it happen to where the nut came completely off and had to go searching in the lower hull for it.
Old 11-30-2015, 09:25 PM
  #22  
JH81187
Junior Member
 
Join Date: Jun 2010
Location: Campbell, CA
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Default

The nut seems to be in place. How do I tighten it since it lies so flush with the surface of the gear? Also how do I hand bend the recoil bracket? Do I have to take apart the turret to do this, and how does one take apart a turret? What should I use to remove the CA glue that I used to glue the turret together?
Old 11-30-2015, 09:34 PM
  #23  
TheBennyB
 
Join Date: Jul 2010
Location: West Grove, PA
Posts: 3,146
Received 1 Like on 1 Post
Default

What tank do you have? Yes, you'll have to get into the turret to bend the bracket. If it's a tammy tiger just hold the mantlet/trunion area and slightly bend the recoil unit/bracket slightly up or down. You could possibly do this from the underside of the turret as well. Take the turret off the tank and go at it from the inside, the bracket that holds the elevation unit may be in the way though. To tighten the nut you can use the "T" wrench supplied and tighten from the top on the brass hex screw.

Last edited by TheBennyB; 11-30-2015 at 09:37 PM.
Old 11-30-2015, 09:37 PM
  #24  
JH81187
Junior Member
 
Join Date: Jun 2010
Location: Campbell, CA
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Default

It's the JS-2 tank.
Old 11-30-2015, 09:46 PM
  #25  
TheBennyB
 
Join Date: Jul 2010
Location: West Grove, PA
Posts: 3,146
Received 1 Like on 1 Post
Default

Originally Posted by JH81187 View Post
It's the JS-2 tank.
EEKS, yea that's the one tammy turret that is poorly designed on having to glue it together. Best bet is to go from the underneath to bend it a bit. Could try torquing/twisting the turret a bit to try and loosen the CA up but that could end bad too.

Last edited by TheBennyB; 11-30-2015 at 09:49 PM.

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.