RF30 head elevation pinion gear slop?

[Howard E.]

I've got my RF30 partially torn down to do some mods & it seemed like a good time to pull the head elevation apart & check/lubricate things. I'm a little surprised to find there's about 3/16" end play between the pinion gear & the crank bracket ears.

Anyone know why there's this much space? I'm thinking of putting some fender washers in there to keep it centered.

Why?

Darned if I know.

 

[Dudemanrod]

Give us a photo of your situation there I have an RF-30 so I'm interested.

 

[pontiac428]

Maybe lots of play is needed because the rack is not well supported and prone to bow. It's not a precision elevator, nor does it need to be. Mine has at most 1/8 turn of play, and I've never even paused to think about it. If you can shim the pinion to your satisfaction without any binding through its travel, I'd say that's a win. Surely there's room for improvement, if it's worth your time. Whatever the case, please post your findings!

 

[Howard E.]

Here's some pics showing the amount of space between the gear & ears-





Interestingly I've noticed the gear assembly is not centered on the column where the slots in the head position the rack- it's set forward a bit, I'm assuming to make room the the clamping bolt recesses so it appears the gear must ride over against the plate's rear ear.



The rack however would appear to want to force the gear towards the front.



I know this is *probably* just a manufacturing dodge but has anyone got a good reason for me not to bush it? The gear itself is about 1" wide whereas the rack is closer to 3/4" so to truly tighten things up I'd need to turn the gear down to a narrower width. Doing this would most likely be just a pointless exercise but it is kinda gnawing at me

 

[Dudemanrod]

Oh ok yeah I used thrust washers to take it up when I replaced the spindle bearings. Your right it's way sloppy in there and it improved the location so as to ride in the center of the gear

 

[pontiac428]

I went and took a look at mine, and decided the play felt at the crank is actually from the rack moving up and down between the beveled ring at the base of the column and the retaining cap on top. Doesn't seem to be coming from gear play. Just thought I'd pass that on.

 

[epanzella]

I had to take the elevator assembly off to build my alignment system and noticed the backlash in that gear. I didn't bother trying to tighten it up because the weight of the mill head acts like an automatic backlash control. I did incorporate a locking collar in my alignment system that allows me to set a hard stop to return the head to exactly the same height after a tool change. That said, I've never used the hard stop because my tooling is really not repeatable in my ER32 collets so it's a moot point (so far)

 

[mickri]

You guys are so lucky that you can take the elevation gears off without removing the head. On mine I have to remove the head to get to those gears. Periodically when lowering the head on mine the head drops like there is a missing tooth on the spur gear. Doesn't happen when raising the head. Since I rarely have to move the head I am living with it.