Cheap, EASY modding of the GD600

[RCMFMaxxMan]

Well i was told by twisted[creations] to share this with you all. It is a quick simple way to mod a GD600. It is more precise than a file and cheaper and easier than a lathe.
1. take the spur shaft and put the short end into a drill collet as you do when you file the shaft.
2. take a large vise grip and look at the teeth on it. the first few rows of teeth are bumpy and then the rest are just straight across the jaw of the vise grip. Use a motor shaft as a measurment by resting the shaft in between the first straight tooth and the second one. like this:
V 'V ' V # note: the ' is there for spacing purposes only.
/\ /\O/\# The v's represent the teeth and the # represents the bumpy teeth and the O represents the motor shaft. It is obviously not to scale but that will give you the idea i was goin for.

clamp the vise grip (loosely) and tighten the adjustment screw "finger tight." This will make the first pair and 2nd pair of teeth 1/8" apart.
3. turn on the drill and as it is spinning use the vise grip like a lathe's cutter. squeeze the 5mm shaft with the first pair and second pair of the visegrip's teeth (that were set to clamp at 1/8") until the visegrip clamps and then the shaft will be 1/8" because the vise grip was set to 1/8". The vise grip will cut pretty quickly and easily so thats why it is important to set the vise grip ahead of time so you don't over cut.
4. Test fit the pinion and shave a little as necesarry.
5. Grind a flat on the shaft for the pinion set screw and you are done!

When i did mine the shaft was much straighter (no noticable off center-ness) and was a much much cleaner cut than a file. This took me just a few minutes and was free for me. If you don't have a vise grip, regular pliers will probably work too.

If anyone wants clarification i can get some pics. just let me know.

[snakeman]

Awesome, makes perfect sense to me! I have one on the way, and just happened to get a drill press so I'll have to try it out!

Thanks for the tip.

[totalxbadass]

Well duh...no really, that is a great idea....Just got my gd today, so here goes nothin.....

[JasonInAugusta]

You'd be surprised how much run-out ("off center-ness") you'll get this way.

When I set up a GD in the lathe, I stick the dial indicator on it and work the chuck until I have less than .001" run-out at the farthest point from the chuck. (this means there's even less run-out the closer you move the dial indicator towards the chuck)

Why? Because when you set gear mesh the common standard is to stick a sheet of paper between the gears, squeeze'm together, lock the motor in place, then rotate the paper out from between the gears. This mesh happens at the farthest point from the spur on the output shaft of the GD.

For those that don't know, a standard sheet of inkjet paper is .004" thick. (Yes, I measured)

So, if you've got .001" run-out your mesh is constantly changing as the pinion rotates. This may not seem like a big deal, but if you end up with .004" run-out your mesh will be all over the place.

And when you're done cutting although you may not see run-out on the area you cut, think about once the spur and shaft are back in the reduction housing riding on those bearings...that's when things will go out of whack.

It's also much easier to cut the shaft down to exact dimensions for the pinion on the lathe...much more precise.

Twisted did his first GD this way (pliers)...he got his second from me. ;)

[RCMFMaxxMan]

well the problem with a lathe is the price. I mean the pliers worked great for me and when i spin the tranny spur with my finger there is not any noticeable mesh change as the pinion rotates. And i have driven it without any problems. Maybe i was just lucky...But it seems like it would work every time. I just thought i would let some people know who cant afford lathe work.

[Davkin]

But it seems like it would work every time

Nope, you were just lucky. There is nothing to guide the pliers but your hand, so why would you think if would work every time? At least with using a file you are working slowly and can compensate for errors. Maybe a compromise would be to use the pliers first but not use them to cut all the way down to 1/8" and then use the files to finish it off.

David

[mazdaparts]

Actually, provided your vice grips or pliers jaws are straight you shouldn't have any problems.

[radishkid]

Originally Posted by mazdaparts

Actually, provided your vice grips or pliers jaws are straight you shouldn't have any problems.

That is assuming that the collet of your drillpress is perfectly centered

[TwistedCreations]

UMMMMMMMM, :?


this is the 1st i heard about vice grips and pliers.( at least that i remember) but looking at the date on this post- hard tellin :? .. i used a dremel and a dial indicator on my 1st one i did.. using the dial indicator is about the only way i knew to keep it ideal to being straight. if not, you would screw up your gear mesh

[RCMFMaxxMan]

QUOTE=Davkin]Nope, you were just lucky. There is nothing to guide the pliers but your hand, so why would you think if would work every time?[/QUOTE]
sounds like you have never tried it so you are in no place to contrdict me. The thing with the vice grips is that the teeth are always straight and flush with the pinion shaft unlike a file controlled by your hand. The pliers put equal pressure on each side of the shaft which makes the cutting more accurate. I have seen some terrible file hack jobs but the vice grips look like a lathe cut minus the smooth look but i suppose you could get it smooth and shiny with sand paper but its not necessary.

[Davkin]

sounds like you have never tried it so you are in no place to contrdict me

Well, I've never jumped off a cliff, so I guess I'm in no place say it might kill you. I don't care how equal the pressure may or may not be to either side, you can't guarantee the pliers will go down the shaft straight, simple common sense, just like knowing better than to jump off a cliff.

David

[RCMFMaxxMan]

Originally Posted by Davkin

Well, I've never jumped off a cliff, so I guess I'm in no place say it might kill you. I don't care how equal the pressure may or may not be to either side, you can't guarantee the pliers will go down the shaft straight, simple common sense, just like knowing better than to jump off a cliff.

David

hahaha. thats a very poor comparison because jumping off a cliff has been proven many many times that it kills people. But using pliers to reduce a pinion shaft has only been tried by me and maybe one other person. And for me it has proven to work very very well for the nice price of free.

But i don't even see why this sould be a debate. All I was tryin to do is give the less fortunate folks a tip that worked great for me.

[Davkin]

All I was tryin to do is give the less fortunate folks a tip that worked great for me.

And I'm just warning that using such a method will be hit or miss. Less fortunate folks can't afford to keep buying gearboxes until they get it right either. No way it could work every time, in fact I still say the percentage chance for success is quite low and you just got lucky.

David

[RCMFMaxxMan]

i didn't have any doubts that it wouldn't work everytime so thats why i posted it. I suppose theres a chance it may not work everytime so if anyone else tries it let us know how it goes or if i ever have to do it again i will post my results.