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View Full Version : Haul of the day - PB GripTru(s) and other goodies



BadDog
11-12-2007, 11:59 PM
Well, I just did a little horse trading today and wound up with a pair of 5" 3 jaw Grip-Tru chucks, a Buck 10" 4 jaw, a PB 6" 4 jaw, a 14x14 lapping plate (at least I think that's what it is), a BEAUTIFUL 14x16 cast iron surface plate with some of the nicest scraping (complete with hard wood cover and some kind of rubber pad inside), 3 B&S 1x2x12 blocks (like 123s but longer) and a few other lesser goodies. The trade off is I have to build 2 rolling dollies to mount heavy toolboxes on. Basically a relatively simple welding job, and he's buying the casters.

Sorry, I'm pretty happy and had to gloat a bit...

Now the other side. Both of the Grip-Tru chucks are REALLY stiff. Not like rust, but like they are really gummed up. Looks like they sat for YEARS somewhere, but one still looks almost brand new while the other shows some general "patina" (but no rust/pit damage at all, probably coolant?). Anyway, I seem to remember seeing somewhere that the Grip-Trus take some sort of special attention to rebuild. Anyone know of anything I should be aware of before dissassembly? There are no signs of wear, or galling. No crash damage. Nothing that would endicate any sort of mechanical problem or wear.

Second question. I really only wanted one of them, but wound up with both. These are threaded chucks, not easily adapted to L00. So, I'm thinking I'll get a 5C blank (like the one John made into a ER adapter) and put it in my lathe, mark for orientation, and turn a spigot to mount the chuck on the 5C. It would still have near a 1" through hole. And I figure it will be handy (and can be accurate when adjusted) for those sizes that don't hit on the 32nds that my 5Cs cover. Not that I do any production work for which it would really pay off, but sometimes it would be nice to pop a chuck in without having to switch out the collet nose (even if it's not worth dialing in the chuck for that diameter)...

For the other, I've got a very nice shop made MT3 bull nose live center that came to me with a spare bearing. I'm thinking I may make a mount for the other GripTru to the MT3 using the spare bearing. Or, given the weight and length of the chuck, make up a whole new MT3 spindle with a pair of bearings for stability.

I dunno, just thinking what to do with my new prizes.

Oh, and the PB 6" 4 jaw is now mounted to my Hartford 6" indexer, while the Buck is going on my Troyke.

Fasttrack
11-13-2007, 12:10 AM
I dunno, just thinking what to do with my new prizes.



Send them to me ... ?


Unfortunantly i have nothing useful to say - but nice score!! I think i saw an article in several issues of the HSM that dealt with rebuilding set-true chucks. Might be worth doing some scrounging and see if you can dig them up. Otherwise i'll look for them when i'm back home.

BadDog
11-13-2007, 01:04 AM
As I understand it (based on Googled resources), the GripTru (PB) is a completely different mechanism that SetTru (Buck). But the function is similar, so perhaps at least some of the article is relevant, though I hope not needed. Anyway, thanks for the info and offer.

Your Old Dog
11-13-2007, 07:15 AM
Nice score! I wonder since you say the chucks aren't rusty but sticky if someone just poured automotive oil over them and that's what's causing the sticky action?

BadDog
11-13-2007, 04:25 PM
Not sure, the outside surfaces are definitely "tacky" to the touch. One is well "patina"d, the other appear very new(ish) and shiny, though still has a golden sheen/film. It's clearly been used, but maybe stored in something like cosmoline? In any case, I sprayed it with penetrating oil, soaking the scroll area, and left it sitting last night. It's still so stiff that I'm reluctant to force the scroll enough get them out. It's not gritty, it's not "locked", but it takes significant force on the key to turn, at which point it move smoothly, but slowly and then starts getting stiffer progressively (as if pushing up dried grease?) I'm kinda reluctant, but I may just hose them down with brake cleaner tonight to see if it frees up the scroll enough for disassembly. So far as I know, there are no seals and such that the Brake Cleaner would hurt. I've never fooled with a GripTru, but seen no reason to suspect it would have anything that would be damaged...

Rich Carlstedt
11-13-2007, 05:28 PM
The Grip-Tru Chuck use a sideways mounted tapered setscrew (s), rather than direct radial setscrew bearing on the mounting plate as in a Buck Adjust-true chuck. The taper makes the Grip-Tru easier to adjust in my experience and opinion. I would assume you need to remove these first to disassemble .
I am not aware of any restrictions on disassembly, but I am aware of differences of opinion on using both.
Both manufacturers recommend ( I believe?) to tighten the screws used to clamp the chuck on the back plate after adjusting.
Folks I worked with declined to do this,saying it screws up the adjustments when you want to "touch up" a part later .
This is a personal preference.

On my Buck at home, I always tighten the clamps after making a change

Rich

Timleech
11-13-2007, 06:30 PM
The Grip-Tru Chuck use a sideways mounted tapered setscrew (s), rather than direct radial setscrew bearing on the mounting plate as in a Buck Adjust-true chuck. The taper makes the Grip-Tru easier to adjust in my experience and opinion. I would assume you need to remove these first to disassemble .

Rich


Yes you must remove these screws as a first step.
The chuck itself is just like any other scroll chuck, all will become clear if you remove the adjuster screws and then the backplate.

I've put a scan of the instructions up at

http://web.onetel.com/~duttondock/Pictures/griptru-1.gif
and
http://web.onetel.com/~duttondock/Pictures/griptru-2.gif


edit to add a couple of pics of a griptru which had the backplate damaged by, presumably, overtightening of the adjusting screws.
I repaired the damage by building up with metal spray, it then took some judicious machining to get back to somewhere near the original profile.

http://web.onetel.com/~duttondock/Pictures/griptru-1.jpg

The adjusting screws are top left in the pic.


http://web.onetel.com/~duttondock/Pictures/griptru-2.jpg


Tim

Ken_Shea
11-13-2007, 07:09 PM
Nice catch BadDog,


Here is a really good deal at HGR. don't want any HSM'ers to lose out on a great opertunity for only $200

http://www.hgrindustrialsurplus.com/search-products/product-detail.aspx?id=20-889-075&searchtable=1&sortExpression=&SortASC=&pageSize=50&currentPageIndex=1

BadDog
11-14-2007, 01:32 AM
Well, the penetrating oil didn't do much good, but the WD40 seems to have worked. I got the jaws out tonight without any undue drama. I'll clean 'em up in the next few days.

Now to figure out how to mount them.