PDA

View Full Version : Springs ...Clock type



lynnl
03-07-2005, 07:33 PM
Is "clock spring" the right term? i.e. for those coiled, flat strips ..that go "sproin-n-n-g".

Whatever the name, I've got a problem with one that maintains the retraction/takeup tension on the quill of a Rockwell drill press. The inner crimped end that engages a slot on the end of the handled, geared shaft which lowers/raises the quill is broken off.

I'd think these would be available in generic form as standard hardware items, but I can't find any in the MSC big book. (this is 3/8" wide)

I've thought about trying to anneal/normalize just an inch or so and bend a new crimp in this one. But it's so stiff it's doubtful that I'd be able to stretch it out enough to keep the rest cool enough to maintain the spring temper in it.

Any thoughts/ideas/suggestions appreciated.

John Stevenson
03-07-2005, 07:48 PM
We used to bend some spring stock similar to this by gripping using two pairs of heavy pliers.
The handles of the pliers were fastened to either side of a big 5 vot transformer but mucho amps.
We just grapped the strip where we wanted to bend it between the pliers, waited a few seconds and then bent it, let go and threw the strip in a can of oil.
Not very technical but it worked.

We also used the same transformer with the carbon sticks out of old batteries sharpened up to engrave cutter details onto HSS

John S

Tinker2
03-07-2005, 07:55 PM
If we are Not being very technical

I have punched a hole in the end of the spring and riveted a new end on it.
?????

Have fun
Be Safe http://bbs.homeshopmachinist.net//smile.gif

lynnl
03-07-2005, 08:02 PM
I guess that would tend to keep the heat affected zone between the pliers, with the mass of the pliers serving as sinks for most heat being conducted outward from that zone.

That gives me an idea. I'll try to clamp a couple of inches or so between two thick strips of steel, which (hopefully) will keep it straight enough to work with, AND sink off some of the heat.

lynnl
03-07-2005, 08:08 PM
Yeah, that would work too, Tinker, but annealing a spot for drilling a hole is the problem. Or more specifically keeping a section straightened out to work with is the problem.

Tinker2
03-07-2005, 08:27 PM
You don’t need to anneal the spring to PUNCH a hole, that is why I
have repaired or mounted springs that way.
I use a flat piece of any steel, drill a hole the size you want. take a center
punch and put a dimple on the spring where you want the hole in the
spring. Set the dimple in the spring on the hole in the flat piece of steel.
Take a punch set it on the dimple take a big hammer and smack it.

Have Fun
Be Safe http://bbs.homeshopmachinist.net//smile.gif

darryl
03-07-2005, 08:54 PM
I did that same repair many years ago on a flat wound spring on my drill press. I used a propane torch, and some aluminum sheet to keep heat off the rest of the spring. Bent a new end on it, refitted it, and forgot it until you mentioned it.

Jim Luck
03-07-2005, 09:21 PM
I could'ent find one in the MSC catolog, but I'm sure its a standard item. USA or import, they may all be the same, if its a small DP. If not, just order one thru a dealer. It would be a lot easier to just replace it -- Good Luck!!--

lynnl
03-07-2005, 11:06 PM
It's an old drill press. I'd tried once before to buy another part for it. Forgotten the exact details of the search, but the Rockwell service agency I found (I think maybe Porter Cable) couldn't cross reference it to anything they had data sheets on.

Turns out that I was able to bend a little crimp on the end which will work. (The two ends seem to lack the normal spring temper) However...
I'm now having a devil of time getting it coiled back up into its little cylindrical housing. My arthritic hands don't have the strength they used to, and hurt so much it's hard to get it wound down tight enough to fit back in there. After 3 or 4 bloody gouges by that hooked end I've given it up for the night. I'll sleep on it and maybe come up with some brilliant scheme that'll make it easy. HA..Ha!