Hardinge 5C speed collet chuck repair

[jbjoestjr]

I got this Hardinge-Sjogren NO5C Speed Collet Chuck given to me with a lathe I purchased. Tore it down cleaned it up, all looked good. Bought a set of collets for it, made D1-4 backplate to fit my lathe. Was tickled pink that runout was less than .001 at nose. First backplate I ever made.
I put a brand new collet in it and what do you know, it wouldn't tighten up no matter what I did. After the third collet I tried, caught and tightened up, I started measuring threads. Sure enough the third collet was .004 larger than the first two.
So back apart it comes and upon closer examination I figure out the threads in my center gear are shot even though about half of the thread depth is still there.
Cut me some slack though, this is the first collet chuck I have ever touched.
So now I am looking for a good deal on 5C Center Gear #0302 for a model 117 Speed Collet Chuck, which I learn after about 3 hours on the internet.
I have emailed Hardinge and waiting for what will probably scare me to death.
So if any of you out there want to get rid of one of these gears at a more reasonable cost than I am sure the factory will, please let me know.
Nothing like that feeling you get, when what you thought was a good deal, goes sour.
I know you all been there.
Thanks for listening.

 

[bjmh46]

Are you absolutely sure that you got the planetary gear "timing" correct on re-assembly? I had a similar experience the first time I disassembled/re-assembled a
Sjogren chuck. There are timing marks on the gears, and they must be aligned or the handwheel will lock up after a partial turn of the geartrain.

Regards
Bob

 

[OldMachinist]

Hardinge lists the outside thread on the 5C as 1.238"-20. What size are the threads on your new collets?

 

[jbjoestjr]

Hardinge lists the outside thread on the 5C as 1.238"-20. What size are the threads on your new collets?

Hi, Thanks for the input. Actually you both have good points, I did just learn about the timing issue in researching this, though that was not my problem unfortunately.
I am also glad you came up with the thread measurement, I could not find the specs on that thread in any of my charts. That is close to what my new import collets mic. at the threads because that was the first thing that popped into my head. No such luck, I had two or three collets that came in the "junk box" with the lathe and they were fairly good looking thread, kind of polished off, but measured 1.228 - 1.232. The imports ran around 1.230 -1.235.
Once I tore it back down and dug thru all my fresh new grease. Pulled the center gear out, all of the collets less than 1.230 would slide right thru what was left of the threads, 1.233 would just barely grab what was left of the threads in the center gear.
I emailed Hardinge that evening and had a answer by noon the next day, I commend them on their response time by the way.
Evidently there is a old and new style center gear and that is where I stand. I will call them today and figure out which one I have, everything seems to point to mine being the old style, and order the part. Either gear they quoted at 215 dollars, which I thought was reasonable compared to some of the gears I buy for my concrete cutting equipment in my business.
Don't know how long it will take me to get the gear but I really look forward to being able to use the chuck. So many of the parts I have to make are small round parts which this chuck should be ideal for.
Bye for now, will update as I learn more, I appreciate all your input.

 

[OldMachinist]

Your new collets sound like they're good on the threads. I checked several new Hardinge, Royal and Lyndex collets I have and they all were within 1.234"-1.236".