Help - MM252 wire hub NOT compatible with Lincoln L56 plastic reel 12-1/2 lb. -

[BukitCase]

Yeah, it DOES seem like a simple fix; til you actually DO it - this is at least a "2-part problem" - I found a piece of leftover 2" PVC conduit last night and made some spacers. So far, so good - except the actual HUB on my MM252 has a radius where the 2" part of the hub transitions to its back flange, and that lets the spacer kind of "hunt around" for center.

So I chamfered the inner end of the spacer that's needed BEHIND the wire spool, which helped...

Then I discovered that the "locator pin" that's on the hubs back flange didn't wanna STAY in the 8" spool's "too shallow" locator HOLE, because the machine's locator PIN is kind of "bullet shaped"; probably so it can "find" the hole and self-center. Works FINE with WIRE spools, and I found that NON-Lincoln 8" PLASTIC spools have REAL holes in them, DEEP enough and on two DIFFERENT distances from center, so ONE of those holes would work FINE with the MM252's "bullet-shaped" pin...

The 252's manual is ZERO help; all it says is you need to add the (included) SPRING on the OUTSIDE of an 8" spool to make up for the difference in the WIDTH (about 1.5")

That would have worked FINE, if the 8" Lincoln-type spool was MADE RIGHT (with a full-depth hole) but it's NOT. I don't know (yet) if this is also true of LIGHTER WEIGHT (10 lb) spools of Lincoln wire, if they exist.

ONE part of the problem (the pin not staying in the hole when there's tension on the spool) may go away when I get the spool TENSION dialed in for the smaller diameter spool; the "end of spool" radius on the 44 lb. wire spool is ALMOST as big as the BEGINNING of spool radius on the 8" spool, PLUS the 44 pounder has a LOT more INERTIA, so tension for it needs to be even HIGHER to eliminate slack in the wire, especially under high feed rates...

When I finally gave up and went to bed around 2am, I had made a SECOND spacer to go between the spool and the outer spring (which is ONLY used on the narrower 8" spools) - it looks like that change will help keep the "bullet-shaped" pin on the machine from jumping out of the "not deep enough" pin hole in Lincoln's 8" spool, especially since the TENSION adjustment (part of the INNER hub on the 252) will be a LOT less when set for the smaller spool.

This isn't over for me; after the holidays, at least ONE of us (Me, Miller, Lincoln) will know MORE about it before I'm done - but for NOW, I'm fairly sure I have a workable (if a bit Rube Goldberg) solution...

Thanks everybody for chipping in, especially Carl for jarring me out of my "let's play with MORE toys rather than simplify this" mindset - also the show of moral support didn't hurt, thanks for that too - Hope everyone has a great New Year... Steve

 

[BukitCase]

Update - the MM252 is back together, and appears to feed OK with the crap spool, 3/8" inner spacer added along with a 3/4" spacer between the stock spring and the retainer collar - I set the spool tension to be the same as the (working) MM211 with the 8" (full) spool, using some "fish scales" left over from my audio and video recorder repair days.

Measured the pull on the MM211 at 26-27 ounces, then put that spool and scale on the MM252 and set it's tension the same. Several high speed starts/stops while feeding the wire thru the 15' torch, no birdnesting and almost no "runover" - maybe 1/8".

Yeah, I know; the manual says, "when a slight force is needed to turn spool, tension is set..." - Sorry, but I'm NOT WIRED that way, too much time working on PRECISION stuff... Besides, "slight" by WHOSE STANDARDS? I've worked with guys who put a nut on "finger tight" and I needed at LEAST a pair of Channel locks to get it loose, and I'm 6'0" and 190

Final test after supper, finishing the welds on the pliers holder/tacking nuts on for the caster "anti-slop" mods, add a front stop to the welder cradle and a small table for nozzle gel, etc - More about that later on the "container weld shop build" thread in BuildItYourself forum. Way it's going so far, that'll probably be manana... Steve

 

[CincyFlyer]

I have, in the past, chucked up an empty spool on a bolt in the drill, and ran stuff from one spool to another. Not ideal (especially if it gets loose on you!) but certainly quick and doable.

 

[BukitCase]

Thanks; yeah, I'd considered that - same reservations as you.

For now, the 8" L56 spool seems to be working OK with the spacers (if not ideal), so I'll probably use up this 8" spool (got 3 more from Zoro before I found out) - When I run this one out I'll just get either a 33 or 44 of L56 for the MM252, got the 8" ones stored inside along with the 2# spools for the 30A gun - the smaller spools work fine in the MM211, so between the two machines I probably won't need to buy wire for the next 3-4 years. (The last 44# went in the 252 not quite 4 years ago)

On the spool that's in the 252 right now, I set it up on the DP, chucked a 3/8 center cut end mill and (gently) deepened the pin hole til I just barely saw copper - so now I'm thinking that the problem might be trying to get 12-1/2 pounds of wire on an 8" spool. At least some of the lighter 8" spools look like they have a full-depth pin hole, probably 'cause they don't need that extra space near the center for extra wire... Steve

 

[yomax4]

That pin issue was common a few years back. Like you said, Many machines had a 2 pin option to make all spools work. including the metal basket spools. Miller and others used to send a 2" x 4" coil spring to help hold the 12# spools against the pin. The MM250 didn't offer the 2 pin option and they said to use Hobart wire and the problem would be solved. That Ploy didn't work. ESAB too had a fiber spool that the holes were too small for the pin and they had bought a bazillion of them and wouldn't fix the problem til the fiber spools were gone. Only option was a brand switch. I'm not sure of the cost but a new Lincoln plastic hub might fit the miller without too much adaptation.

 

[BukitCase]

Yomax, thanks for the history lesson, much appreciated - so far my "bandaids" are working OK - the outer spacer I added gives the stock miller spring (for 8" spools) enough extra compression, and I tweaked my inner spacer's width so that there's enough engagement of the stock pin that it stays in the slightly deepened spool hole WITHOUT the spool wobbling -

That'll have to do for now - at the rate I use wire, that 12# spool will probably last about 8 months. At that time, I'll just go back to full-size WIRE spools, or at least make sure the pin hole on a (full size) plastic one is gonna work.

If all else fails, I have a milling machine, a rotary table and lathe chuck for it, boring bars, etc, and a stubborn streak that runs wide and deep -

Again, thanks for the info... Steve