Cox Engines Forum
You are not logged in! Please login or register! Guests are limited to posting in the "General Questions (Guest Posting Allowed)" section only. Becoming a member is fast, easy and FREE!


Piston resetting  Babe_b10
Piston resetting  Pixel

Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Cox Engine of The Month
January-2021
Jason_WI's

"Bucket-O-Parts Cox TD .15 Special"



PAST WINNERS

CEF Traveling Engine

Win This Engine!
Forum Store
CEF Ear Savers
Gallery


Piston resetting  Empty

Piston resetting

Go down

Piston resetting  Empty Piston resetting

Post  Gordinir8 on Sat 15 Aug 2020, 06:12

One of my engines has a play and I need to buy a reset tool to make it true again it but I noticed that if you want to speak with numbers it's not very easy to hold this tiny piston and measure it. Things can be very easy with a piece of fuel silicone tube and a toothpic! This way you can keep the Conrod against the piston while at the same time you can compress it with the caliper or with the micrometer. In this case play is 055mm or .021in


Piston resetting  Img_2018

Piston resetting  Img_2019


Last edited by Gordinir8 on Mon 17 Aug 2020, 07:34; edited 2 times in total
Gordinir8
Gordinir8
Bronze Member
Bronze Member

Posts : 48
Join date : 2020-08-05
Age : 45

Back to top Go down

Piston resetting  Empty Re: Piston resetting

Post  balogh on Sat 15 Aug 2020, 07:42

A smart setup! I cannot measure the play though just keep knocking until there remains a hardly tangible one when you pull on the rod. I also spin the rod around to make sure it doesn't stick to the edge of the cup
balogh
balogh
Top Poster
Top Poster

2019 Supporter

2020 Supporter

Posts : 3271
Join date : 2011-11-06
Age : 62
Location : Budapest Hungary

Back to top Go down

Piston resetting  Empty Re: Piston resetting

Post  Iceberg on Sat 15 Aug 2020, 09:46

Interesting setup!
Please humor me. What is the perfect piston play?

Thanks
Ice
Iceberg
Iceberg
Gold Member
Gold Member

Posts : 322
Join date : 2018-11-03
Location : Bangkapi Thailand

Back to top Go down

Piston resetting  Empty Re: Piston resetting

Post  Cribbs74 on Sat 15 Aug 2020, 10:21

.002 is the number that is usually thrown around. Enough for the oil to creep into. To be honest though it isn’t super critical. At least not in my experience. I do resets mostly for longevity and not for performance. I measure play by feel. Some are tight and some are probably just right. After being run they settle out pretty even with each other.

I like the apparatus you made to measure.
Cribbs74
Cribbs74
Moderator

2019 Supporter

2020 Supporter

Posts : 11165
Join date : 2011-10-24
Age : 46
Location : Tuttle, OK

Back to top Go down

Piston resetting  Empty Re: Piston resetting

Post  Marleysky on Sun 16 Aug 2020, 11:50

How do you eliminate that Photobucket Black Stripe across your pictures?? [url=https://servimg.com/view/19103929/1131]Piston resetting  Acd45910[/url

Kinda ruins the view.
Marleysky
Marleysky
Diamond Member
Diamond Member

2019 Supporter

2020 Supporter

2021 Supporter

Posts : 2827
Join date : 2014-09-28
Age : 68
Location : Grand Rapids, MI

Back to top Go down

Piston resetting  Empty Re: Piston resetting

Post  Gordinir8 on Sun 16 Aug 2020, 12:24

By paying subscription I guess but I am not willing to do.
Gordinir8
Gordinir8
Bronze Member
Bronze Member

Posts : 48
Join date : 2020-08-05
Age : 45

Back to top Go down

Piston resetting  Empty Re: Piston resetting

Post  Surfer_kris on Mon 17 Aug 2020, 03:57

Just attach the original image to this forum instead.
Surfer_kris
Surfer_kris
Diamond Member
Diamond Member

Posts : 1754
Join date : 2010-11-20
Location : Sweden

Back to top Go down

Piston resetting  Empty Re: Piston resetting

Post  Gordinir8 on Mon 17 Aug 2020, 04:22

Are you sure? I thought that image has to be host somewhere! Gonna try it thanks.
Gordinir8
Gordinir8
Bronze Member
Bronze Member

Posts : 48
Join date : 2020-08-05
Age : 45

Back to top Go down

Piston resetting  Empty Re: Piston resetting

Post  Surfer_kris on Mon 17 Aug 2020, 05:05

It will technically be hosted on the forum (or another service "servim"?), and everyone will be able to se it here. Just use the "Host"-button with a tiny floppy drive disc on it.
Surfer_kris
Surfer_kris
Diamond Member
Diamond Member

Posts : 1754
Join date : 2010-11-20
Location : Sweden

Back to top Go down

Piston resetting  Empty Re: Piston resetting

Post  Gordinir8 on Mon 17 Aug 2020, 05:35

Gordinir8
Gordinir8
Bronze Member
Bronze Member

Posts : 48
Join date : 2020-08-05
Age : 45

Back to top Go down

Piston resetting  Empty Re: Piston resetting

Post  roddie on Mon 17 Aug 2020, 21:33


Hi, I saved your photo and it previews fine for me with Windows Photo Viewer.

I have the Cox .049 reset tool. When I use it, I place the "cup" on a very solid surface. An anvil usually. I like to use a small hammer and tap very lightly on the tool; checking the ball/socket clearance after each tap. Being careful NOT to get heavy-handed; I rotate the tool approx. 120 degrees after each tap.. until the rod will not drop by gravity.. but will move if shaken. If your "setting" feels a little tight.. it might be fine. Some people here have mentioned that they set theirs' on the snug-side.

I'm led to understand that the ball-socket joint need only be reset "once".. as part of a break-in measure. Under normal operation, it shouldn't need resetting again and should hold it's setting due to work-hardening.
roddie
roddie
Top Poster
Top Poster

Posts : 7047
Join date : 2013-07-17
Age : 60
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

Piston resetting  Empty Copycat

Post  happydad on Tue 18 Aug 2020, 01:48

roddie wrote:

Hi, I saved your photo and it previews fine for me with Windows Photo Viewer.

I have the Cox .049 reset tool. When I use it, I place the "cup" on a very solid surface. An anvil usually. I like to use a small hammer and tap very lightly on the tool; checking the ball/socket clearance after each tap. Being careful NOT to get heavy-handed; I rotate the tool approx. 120 degrees after each tap.. until the rod will not drop by gravity.. but will move if shaken.  If your "setting" feels a little tight.. it might be fine. Some people here have mentioned that they set theirs' on the snug-side.  

I'm led to understand that the ball-socket joint need only be reset "once".. as part of a break-in measure. Under normal operation, it shouldn't need resetting again and should hold it's setting due to work-hardening.

roddie: That is exactly how I do my piston resetting. Always being sure to rotate the tool, and light to medium hits with a ball peen hammer. Anyone remember those??  My dad used those when putting rivets into sheet metal. WW2.  He was a single parent before he met my mom.

Happydad  RC Plane  Old Bugger  United States
happydad
happydad
Rest In Peace
Rest In Peace

I Support My Forum

2020 Supporter

Posts : 1592
Join date : 2012-05-28
Age : 75
Location : Escondido, CA

Back to top Go down

Piston resetting  Empty Re: Piston resetting

Post  Gordinir8 on Tue 18 Aug 2020, 04:05

Thanks for info, this is what I have in mind also. Tool is on its way.
Gordinir8
Gordinir8
Bronze Member
Bronze Member

Posts : 48
Join date : 2020-08-05
Age : 45

Back to top Go down

Piston resetting  Empty Re: Piston resetting

Post  gasface on Sat 05 Sep 2020, 16:15

Some really great info thanks. Very Happy
gasface
gasface
Moderate Poster
Moderate Poster

Posts : 12
Join date : 2020-08-10
Location : NV

Back to top Go down

Piston resetting  Empty Re: Piston resetting

Post  Tee Bee on Mon 07 Sep 2020, 07:12

That’s a neat measuring technique! Thanks for sharing.
Tee Bee
Tee Bee
Platinum Member
Platinum Member

2019 Supporter

2020 Supporter

Posts : 735
Join date : 2011-08-25
Location : Angleton, TX

Back to top Go down

Piston resetting  Empty Re: Piston resetting

Post  Sponsored content


Sponsored content


Back to top Go down

Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum