Still Bill

iTrader: (16)

I purchased a unique tool to sand diff rings that is made in Japan. It came with instructions that are in Japanese.

The very fine grit sandpaper used in the tool is on a plastic film backed disc that is exactly cut to the size of a CD (at 4-1/2" diameter with a 5/8" center hole). Looking for a resource to get some 400/600 grit sandpaper disks. Does anyone know the Japanese manufacturer of this diff sander tool?

I have a scanned PDF file of the instructions; but, not sure I can attach it to this posting.

Bill

jjfo80

iTrader: (1)

hey bill yeah racing make the magnetic block to hold ur diff ring and then on a flat surface you put any sand paper on the flat surface and sand away... but I would be using like 1200 grit and then like 2000 grit to finish off as your polishing not trying to take metal off the diff ring... cause if ur trying to take that much away using the sand paper your using you need to throw the diff rings away and put new ones in.

In saying this I dont polish my diff rings at all and I have never had any tight spots and they never have a problem.... the thing is if you always keep your diff clean by rebuilding them after EVERY race day or test day you will have no problem.... Very important tho when setting your ball diff up make sure you tighten and spin the diff at the same time when setting the diff up after rebuild and you will never get flat spots on the balls or dents in the plates.... use good silicon lube mate and your set....

I wasnt being rude as I know you have been on the forum for years as of how many pots you have but I have been doing rc for over 15 years myself just never knew forums like this was around til not so long ago haha....

Hope this helps and not rude to you.
Fordy

jjfo80

iTrader: (1)

but in saying all that you could go to a automotive paint shop and buy stick on sanding disks for a air operated sander that have a film backing that once removed is sticky.... I forgot to mention that.... any grade sand paper you need they make wet or dry and just cut your own hole in the middle with anything....

Sydewynder

Your diff ring sanding tool is 4-1/2" dia?

BrodieMan

iTrader: (3)

a fellow RCTECHer enlightened my on diff ring polishing. Eraser and 1200 sandpaper. works great, my diffs are silky smooth

jjfo80

iTrader: (1)

yo brodie man is that the ink eraser not the lead pencil eraser yeah?? sounds like a dumb question but just making sure???

do you use the eraser first then the 1200 sandpaper after or the other way round??

Fordy

Still Bill

iTrader: (16)

Fordy,

No problem mate. Not taken as rude at all. An interesting post and I follow your logic because I went that way for 5-6 years.

Used to make my diff rings very smooth; but, since brushless motors came out, I experienced too much slip upon initial takeoff from the starting line in a race.

Now, I intentionally scratch up my diff rings to help the balls achieve a higher level of grip to the rings. The scratches cannot be noticed when checking the smoothness of the diff. Been doing it for a couple years after a pro told me about it.

For my WGT pan car, I probably go for a couple months of weekly racing on carpet without even thinking about rebuilding my CRC diffs. A Slapmaster Thrust Bearing setup helps too. Do have to rebuild for outdoor racing conditions a bit more often.

And I should have indicated 600/800 grit sandpaper in my previous post.

I will look up the Yeah Racing tool; but, your description is vastly different from the sanding tool I bought.

Cheers!

Bill

jjfo80

iTrader: (1)

Wow didnt think along those lines at all..... so the rougher they are the better but do you use steel balls as they are cheap and they can cop a flogging and well throw them away and who cares.... Or do u use ceramic balls and do they last longer with the rougher diff rings??

Good thinking tho I am so going to try that cause thats such a great idea.

Do ur diff's still feel smooth or they feel rough after having slightly rough diff rings or they still smooth by using more lube???

This has made me think so much more now shit..... I have been doing the same things for so many years and its worked but I am wondering this whol diff thing the way your going with it is a good thing.... I will never go gear diffs cause they are just shit in my opinion really.... just no were near as tunable as a ball diff and I like the fell of ball diffs anyways
If gear diffs were so good they would sell them in kits..... they wouldnt bugger around with ball diffs thats for sure....

Anyway keep this thread going as this is VERY interesting

Fordy

Still Bill

iTrader: (16)

It is a 4-1/2" square piece of plexiglas that supports the 4-1/2" round sanding disk.

It has multiple metal parts that hold the sanding disk to the plexiglass and the diff ring.

A very trick tool. Leave it to the Japanese...LOL

Previously used a diff ring holder made by Irrgang Racing Services; but, it would cramp my hands badly.

Bill

Still Bill

iTrader: (16)

Thanks for all the input guys.

Fordy, The scratches are noticeable to the eye; but, you cannot feel them on the rings. They are very fine.

jjfo80, I looked up those auto body disks previously; but, could not find any finer grit ones. Do you know that they get down to 600/800 grits?

Bill

PFKAOG

iTrader: (12)

Home depot has 600

Sydewynder

I know there are 4" dia x 1/2" centre hole wet dry 800 grit paper. These are used for disc sanders.

Have you talked to OD or Crashby about prepping diff rings? Polishing them is a no no because you have to tighten down too much for the diff not to slip.



@ Fordy

Didn't you post you have special way/ lube for building a diff but didn't want to divulge what it was?

jjfo80

iTrader: (1)

Yeah mate here in australia they do..... I will do some research for you and could post some over to you once I check it out.... I will not be home til the weekend so first thing monday morning my time which will me sunday night for you I will see what I can come up with for you and let you know

Still Bill

iTrader: (16)

With a plastic film backing?

Still Bill

iTrader: (16)

I have 5 circular sheets of fine grades to play with for now. Just want to try something courser to match closer to what I was doing previously. No hurry because I have six prepped diff rings that are ready to go.

Have a great weekend.

Cheers!

Bill