sleeve pinching?
 

i got a pincher of someone used. it had no paper work with it. i know it is real easy to get it to tight so i pinched some sleeves in old motors first. i find myself asking if the sleeve should be in the pincher a certain way.any certain port to the gap in the pincher? and should i pinch rotate 180 degrees and pinch again? any body with experiance with this tool please give all the info possible. thanks.

you align the notch in the sleeve against the gap in the pincher then tighten it 1/8 of a turn then rotate 90 degrees and do the same just don't over do it since it will be irreversible but if it is still loose against the piston then you can always re do the process :nod:

thanks for the info. yes i know you can over do it. just didn't know if you should pinch one certain way. or pinch then rotate and pinch again. but you cleared that up for me. thanks again. didn't know if anybody was ever gonna answer .

clock
 

look at it as if it was a clock

12 3 6 9 move it a total of 4 times pinch slow do a full rotation 1/4 at a time

dont go nuts and pinch it to death :deathstar slide the piston back up into the sleeve
check the pinch ..

repeat a few times until you think it's about right

do they actually work?

of course it does and it'll give you a few months more life from p/s

but you can also loose the original performance of the engine but should be ok for pratice.

yea the motors i'm pinching have allready lost the original performance and are not really good for competitive racing anymore. good for practice or maybe backup motor.

just bringing an old thread back to life :sneaky:

anyone know a link of where to buy sleeve pinching tools? its just like a c-clamp, right? cant seem to find any info on a sleeve pincher that will work on an ofna .32. thanks in advance :)

thats because those dont work lol. (read on...)

You pinch it in a press, not with some 50 cent clamp... those 50 cent clamps used to sell on EBAY like crazy, and those i am referring to.

If you want your sleeve pinched the right way, send it to OSROCKET.

In 99%, the sleeves he pinched lasted longer and showed better performance than a new one.

That guy kinda invented sleeve pinching....

It's well worth the $15!!!

www.osrocketracing.com

my current engine is lasting longer and runs better after being pinched than it did new

thanks for the inputs :nod:

is there a difference between rayaracing's method and osrocket's method? pros and cons on each pinching service, from anyone who tried both?

I havent tried osrockets service, but I do have experience with Rayaracing. His service is very professional and well managed. In fact, I wrote an article in XRC some years ago about his resizing service.

I also own all his resizing fixtures for .12 engines. I still need to get stocked on .21 and .28 sizes.

This is definitely not the same thing that you get on ebay with some funky c-clamp from harbor freight!! Rays jigs are toleranced to the .0001" and have specific control measures to direct where in the liner the pinch is applied. Also most importantly, the sleeves arent clamped at all but rather swedged in a concentric fixture to retain perfect roundness (mucho importante!!!)

So I guess what I am saying is DO NOT USE C-CLAMPS!!!! THEY ARE BOGUS AND WILL RUIN YOUR ENGINE!!!

BK

#2 :nod:

RayAracing method is tooling designed JUST for sleeve resizing
 

First most RayAracing resizing method is with tooling designed just to resize sleeve cylinders. An alloy reconstruction process that reforms the sleeve alloys using internal and external control. state of the art equipment I spent 1 full year developing between late 2001-2002, that which has made it possible for many engine moders / clubs / hobby shops to resize rc nitro engine piston & sleeve sets. The guys out there resizing with success, are tooled by RayAracing.

You see in a previous post mentioned by Brian K contributing writer of XRC magazine he did an article on both my reconditioning-resizing work, and with tooling itself at hand to inspect and use himself. Thank you again BK and XRC magazine! Anytime you guys are ready to run another article on my reconditioning-resizing work as it is now in 2009 please feel free to call on me.

Finally, After inspecting thousands of piston and sleeve sets before servicing we have found that 9 of 10 sets are with from minor to moderately damaged surface finish conditions. As you guys know the sealing capabilities these 2 cycle ringless piston engines in both power cycle and mixing cycle are established (fit & finish) both cylinder wall to piston clearance/mated surfaces. Pinching is only half the job with renewing engine life. With that said we at RayAracing improve surface finish conditions before we resize. It simply provides better results than any other process/method used today.

Racers and hobbyists are encouraged to email me, text me with any questions. Please donot personal message me as I do not get a chance to sign on here as often as I'ed like.

Kind regards,

RayA
http://www.rayaracing.com/

ray's method is second to none..period.
as far as i am concerned and speaking from experience i will let no one else touch my engine internals.

keepin busy
 

Thanks helivaguy,
The group orders (6) and more sets keepin me busy more this year than past 7 years.improving poor surface finish conditions takes time.

RayA

a few guys at my track use a pipe cutter to circle around the oil rings on the piston. this gives increasedpinch when the engine is a litle tired.

all you need to do is pass the pipe cutter round cutting disk around the rings very lightly to increase compression. Suitable to do on an old engine that is a little tired, and needs some extra oomph.

you can get a pipe cutter from any hardware store;
http://www.electronicsnmore.com/imag...ing_Cutter.gif

please leave that poor piston alone
 

Thanks for the pic. I will post it on my website.
RayA

Got ripped off on ebay wish I read here first!!
 

Just paid 9.99 plus 7.50 shipping for one of these stupid clamps last week for a trx 2.5 sleeve :( real upset about that now but what was I thikning I should know better than that. Anyways now that I read here I have cancelled the order I had for a 3.3 sleeve CLAMP not pincher like this liar states and I reported his item to ebay as this kind of crap doesnt need to go on and to take advantage of the uninformed like myself.

Anyways after reading here I will be sending my sleeves and pistons to either rayaracing or osrocketracing thanks for the info.
I did see that I could buy a setup from rayaracing and I may look into that but for the 450-500 it will cost I could buy alot of traxxas 3.3 engines for that :P though I did more so want to learn how to do it for myself as part of the hobby and plus being that I want to take up machining as I grew up with my dad owning a bridgeport and a clausing lathe in the basement I would like to get back into machining like I did a little of when I was a kid.

I am currentle experimenting with tools like these:

http://www.woodface.nl/cnc/spantangen.jpg

For less than 100 dollar you have the holder and the right fitting tool and it works.

Roelof, can you demonstrate it to me next national?

No problem

Roelof,
I suppose that's what you experimenting with ;)

The most important part is the brass ring, which is conical on inside by 0,02mm.
It's an nice setup, that can be used at the track as well, as long as a vice is available to hold it.

Oh, and sorry for the bad quality of the pics.

http://web138.sydney.webhoster.ag/im...nch/Pinch1.JPG
http://web138.sydney.webhoster.ag/im...nch/Pinch2.JPG
http://web138.sydney.webhoster.ag/im...nch/Pinch3.JPG

Thanx for the tip.

At this moment I am pinching the whole sleeve without a ring. Is does take some forces but when keeping it under pressure for a few minutes I do notice a difference.

Most .21 sleeves are 19.5mm and I have a clamp of 20mm. I have seen the .12 sleeves are 17mm for which I can make a ring.

IMHO, the brass ring is absolutely necessary to get a good result.
We tried to use the clamp by itself and it never worked.

The brass ring gives you the shape that you want, that why it is conical, just as the sleeve.

very interesting:nod::nod::D

that is one good tool u have there. i also experimented with a normal hose clamp. got half of my original pinch back and it performs well.

I have made my own pinching tool that works very well.
I used a collett from our bridgeport and machined a holder for it. I then mounted it on a flat piece of steel so I can hold it.
The collett is threaded at one end, It slides in the holder I made and I use a torque wrench to pinch it. Very easy to control.
I have done quite a few and am very happy with the results.
More people are finding that I have this and are asking me to pinch their sleeves.
Most of the time it does seem to give the engine a bit more life but it has lost a little bit of performance. Still good for practice or a back up engine if needed.
Greg Esser

Greg Esser's setup is quite nice. I like the fact that he has total control of how much pinch is delivered and doesn't go too far.

how long can i expect a pinch to last on a O.S. sleeve? Is it even worth it? I sent one off to rayaracing. I read somewhere that pinching a o.s. sleeve in particular is pointless because the liner o.s. uses is thiner, not like nova and picco.

But i always thought o.s. sleeve was as thick as a picco i have. Anybody pinch any o.s. motors? I have about 6 o.s. sleeves i wana pinch. Sent one to ray to see if it's worth it. They are all in good condition too.


and who is o.s. rocket? I keep reading about him but can never find him.

Duuuh,
I posted the link earlier:

http://www.osrocketracing.com/

he says he uses a cnc maching in two stages and that he doesn't pinch them but uses instead.

That does not make any sense. There is no way to get the sleeve smaller unless you pinch it.

I have pinched quite a few OS engines with awesome results....even my personal Ninja is pinched and running awesome...

He uses a cnc machine to pinch the sleeve rather than a mechanical arbor press like shown is Ray video's. I have engines pinched by both and they both do a steller job!!!

I did have a Novarossi 3sct pinched once and It was extremely hard to get the sleeve back into the crankcase. Not sure how this happen; maybe the die used to hold the sleeve left burrs on the outside.

Just remember to change the rod and maybe the bearings.


Pass you soon...

Those sleeve pinching ring/clamps are a joke. They out of round the cylinder and do not taper it at all. They leave some sides of your piston too tight in the sleeve then other parts loose. They feel tight but There is not a correct fit of the psiton/sleeve. Since RC engine rely on metal to metal sealing of the piston/sleeve if its not absolutly perfectly round. It will not run good and not last.

Resizing is not that much and the results are far superior.

Check out Rcrenew.com

Then you have to tell me why most people using these crappy tools do have good results?

We from rcrenew advise only rcrenew ?

may i know where can i get this stuff since i got alot of my old engine that is now being display in my room as they dont have new sleeve or being discountined..wish i can get 1 of those

?
 

I wouldn't suggest your purchasing any kind resizing equipment , and still that no matter which requires a reasonable amount experiences to learn craft , for your own personal use in doing only a few engines. Ask around your racing community and you may find someone that is tooled and experienced to do your engine models. I am tooled for resizing ALL car, truck, buggy, and truggy engine models. Feel free to email me with questions you may have.:nod: