Repro Crosby Drum Alert

[PhilOhio]

I just had a conversation with Merle, who suggested that all of you who have bought these great drums should be alerted. Even if they are great, they need to be lubricated.

 

A board member here dropped one, damaging it, and Merle has been checking/repairing it. It appears that the factory never packed it with grease. As in "not any".

 

We don't know if this applies to all of them, but we are guessing it does. The Chinese manufacturer people have no experience with automatic weapons and no way of testing their product. They simply copied one Crosby, and did a pretty good job. But apparently, nobody told them the rotor cavity, housing the flat clock spring, has to be packed with grease.

 

A special fixture is available to do this. Not too many are around. Sometimes one is brought to a major Thompson shoot, and everybody gets their orifice packed.

 

Merle says Frank has one of these, as does Tracie, and probably PK, who made them. There's a thread on what these are, how you could make one, and how they are used. You clamp this thing on the drum and hook your greasegun (real one) onto a zerk fitting and pump 'er full. But without grease, you will have problems eventually. Probably sooner rather than later.

 

Merle says the grease choice is not critical. Any good bearing grease, such as the lithium greases from any auto parts store, are fine.

 

So I guess I have to get busy and make up this nifty little C-clamp type rig and pump my two Crosby repros full; and maybe treat my nearly 80-year-old Colt "L" drum to the same. It will have no way of knowing it should thank the Chinese for motivating me to do so.

[Elbow]

Pictures of this prossess would GREAT... Edited June 20, 2008 by Elbow

[hrt4me]

Thanks for the info. I recently sent all my stick mags and 2 repro drums to PK when he refurbished my WH 1928 TSMG, so I wonder whether he greased my drums for me? Is there a way I can check?

[PK.]

Hrt4me: I did not grease your new drums, never gave it a thought. They are, after all, ”new”.

 

You can’t really tell for sure from the outside. Remove the rotor assy from the case and look at the back of it; if it was greased, usually some will have leaked out of the junction of the spring cage and rotor.

 

I prefer to use a high grade of synthetic grease that is intended for “lifetime” applications that are not considered serviceable after manufacture. The stuff is expensive, but I figure I’d rather put something in there that won’t dry out or harden, even in the next 50 years. Once it’s in there, it’s there to stay after all.

 

[PhilOhio]

PK,

 

Could you recommend one or more of these "lifetime" type greases for guys who would like to pack their Crosby repro drums, to be on the safe side? And would there be different viscosities within the brands?

 

There have been at least three parties importing the recent repro drums, and I don't know if all came from the same manufacturing source. Brian Platt of Keepshooting.com brought the first ones in. Then either Sarco or Numrichs brought in a batch, after the "Thompson" marking was deleted. There was also another website business, mentioned by Merle, which sold them, but these may have come from one of the other importing businesses.

 

And PK, somebody may want to know if you have plans to make any more of these drum greasing fixtures in the near future, or if you still have any for sale from the last run?

[kruuth]

Is there a way to grease these w/o a special fixture? I have two of those drums from fortunelot.

 

PK,

 

Could you recommend one or more of these "lifetime" type greases for guys who would like to pack their Crosby repro drums, to be on the safe side? And would there be different viscosities within the brands?

 

There have been at least three parties importing the recent repro drums, and I don't know if all came from the same manufacturing source. Brian Platt of Keepshooting.com brought the first ones in. Then either Sarco or Numrichs brought in a batch, after the "Thompson" marking was deleted. There was also another website business, mentioned by Merle, which sold them, but these may have come from one of the other importing businesses.

 

And PK, somebody may want to know if you have plans to make any more of these drum greasing fixtures in the near future, or if you still have any for sale from the last run?

 

[Bridgeport28A1]

Any of the baord members in or near Minnesota have a drum greaser? If someone has one, I have several drums in need of grease.

 

Ross

[hrt4me]

Hrt4me: I did not grease your new drums, never gave it a thought. They are, after all, â€newâ€.

 

You can’t really tell for sure from the outside. Remove the rotor assy from the case and look at the back of it; if it was greased, usually some will have leaked out of the junction of the spring cage and rotor.

 

I prefer to use a high grade of synthetic grease that is intended for “lifetime†applications that are not considered serviceable after manufacture. The stuff is expensive, but I figure I’d rather put something in there that won’t dry out or harden, even in the next 50 years. Once it’s in there, it’s there to stay after all.

 

PK, do you have the proper fixture/jig for greasing these drums? If so, then I may want to include both my drums when I send you those other parts we discussed for re-bluing and wood work...

[PK.]

I use a product from Fuchs called Chempex 940, it is an NLGI 1 viscosity so it enters the close toleranced Colt drums easily. There may be something better, I have not made an exhaustive study of the subject, but It’s far superior to the run of the mill stuff, IMO.

 

I would be happy to make another run of drum greasers, if enough folks were interested to make it worth wile and keep the cost down. In any event, the price would be to high for casual use. Drums need only be greased every 10 or 20 years and the cost to have it done is marginal, or even free if you run into Merle at a show.

 

I routinely grease drums sent for service, but normally not new ones. Who would of thunk it? I will be looking hard at the Crosby repros from now on. Of course Hrt4me, I’d be glad to grease your drums.

 

[hrt4me]

I use a product from Fuchs called Chempex 940, it is an NLGI 1 viscosity so it enters the close toleranced Colt drums easily. There may be something better, I have not made an exhaustive study of the subject, but It’s far superior to the run of the mill stuff, IMO.

 

I would be happy to make another run of drum greasers, if enough folks were interested to make it worth wile and keep the cost down. In any event, the price would be to high for casual use. Drums need only be greased every 10 or 20 years and the cost to have it done is marginal, or even free if you run into Merle at a show.

 

I routinely grease drums sent for service, but normally not new ones. Who would of thunk it? I will be looking hard at the Crosby repros from now on. Of course Hrt4me, I’d be glad to grease your drums.

 

OK, then I'll resend them with the other parts. I'd also be interested in a drum greaser of my own, if we can get a group buy together.

[Mike Hammer]

How about a group of us purchasing 1 fixture splitting the cost among all and then mailing the fixture to the next person on the list? If we had 20 people the cost should not be too great. Any body wishing to use the fixture after all payees have used it, would then have to make a donation to the board, we could keep the thing in perpetual motion and also raise some money for Nick...wadaya say?

 

Mike Hammer

[hrt4me]

How about a group of us purchasing 1 fixture splitting the cost among all and then mailing the fixture to the next person on the list? If we had 20 people the cost should not be too great. Any body wishing to use the fixture after all payees have used it, would then have to make a donation to the board, we could keep the thing in perpetual motion and also raise some money for Nick...wadaya say?

 

Mike Hammer

 

That sounds like an idea, but I got the impression PK wasn't going to make just one. Also, the cost of shipping my 2 drums and paying to have them greased may be less than the rental cost discussed above.

 

[kruuth]

I'm a little concerned about the two I have from fortunelot. Is there a way to see if they're properly greased?

 

I use a product from Fuchs called Chempex 940, it is an NLGI 1 viscosity so it enters the close toleranced Colt drums easily. There may be something better, I have not made an exhaustive study of the subject, but It’s far superior to the run of the mill stuff, IMO.

 

I would be happy to make another run of drum greasers, if enough folks were interested to make it worth wile and keep the cost down. In any event, the price would be to high for casual use. Drums need only be greased every 10 or 20 years and the cost to have it done is marginal, or even free if you run into Merle at a show.

 

I routinely grease drums sent for service, but normally not new ones. Who would of thunk it? I will be looking hard at the Crosby repros from now on. Of course Hrt4me, I’d be glad to grease your drums.

 

[hrt4me]

I'm a little concerned about the two I have from fortunelot. Is there a way to see if they're properly greased?

 

Already asked and answered:

You can’t really tell for sure from the outside. Remove the rotor assy from the case and look at the back of it; if it was greased, usually some will have leaked out of the junction of the spring cage and rotor.

 

 

[PhilOhio]

I think the first thing for all of you would be to find out how much a greaser would cost, then decide if you might want to buy your own, as a few here have done in the past. It's not like buying a Thompson.

[PK.]

IIRC, the last batch went for about $80

[mgdoc8307]

I'd like to buy a drum "greaser tool" if PK makes them again. I'm sure alot of us would like to have their own.

[PhilOhio]

Knowing the way PK makes things from steel, this may be the best $80 any of you spend on a Thompson accessory.

[hrt4me]

I use a product from Fuchs called Chempex 940, it is an NLGI 1 viscosity so it enters the close toleranced Colt drums easily. There may be something better, I have not made an exhaustive study of the subject, but It’s far superior to the run of the mill stuff, IMO.

 

I would be happy to make another run of drum greasers, if enough folks were interested to make it worth wile and keep the cost down. In any event, the price would be to high for casual use. Drums need only be greased every 10 or 20 years and the cost to have it done is marginal, or even free if you run into Merle at a show.

 

I routinely grease drums sent for service, but normally not new ones. Who would of thunk it? I will be looking hard at the Crosby repros from now on. Of course Hrt4me, I’d be glad to grease your drums.

 

OK, then I'll resend them with the other parts. I'd also be interested in a drum greaser of my own, if we can get a group buy together.

 

PK, I just mailed the package to you this past weekend, please let me know when you get it. Thanks!

[PhilOhio]

Yesterday I built a drum greaser, parkerized it today, and just had fun successfully greasing my two Chinese repro "L" drums and original numbered Colt drum. Based on what I learned, I would strongly advise all of you with the new repros to grease them ASAP. My Chinese drums are from two different generations (before and after Kahr's groundless threats about the markings), and after carefully examining all the joints where at least some traces of grease should have been evident, there wasn't any. As in not one bit. This confirms what Merle Bitikofer found in one he opened up for repair, because it wouldn't run or wind right; POSITIVELY BECAUSE OF NO GREASE INSIDE, CAUSING GALLING, he told me.

 

I started with the second generation drum, without the "Thompson" or "Crosby" markings. I used my full size automotive greasegun, which takes the large cartridges...good quality lithium auto bearing grease which never ever hardens. I thought the drum might take six or eight pumps. After ten or fifteen, I thought my gun wasn't working or was out of grease. I took it off the zerk fitting, gave the lever a shot, and out came plenty of grease. So I kept pumping...and pumping...and pumping...and... Anyhow, I hadn't thought to count. But finally, on one pump, grease began coming out of all the right places at exactly the same time. So the thing was full. Clearly it had been totally empty.

 

Second came my first generation repro drum, with the markings which were included before Kahr management began making all their hollow threats about use of the word "Thompson". This time I counted; 36 pumps to fill 'er up.

 

On a roll, with my new greaser working O.K. and easily, I got out my Colt drum. It was evident that there was still plenty of fresh looking, live grease around the joint between the rotor face and the shaft. I've had the drum since 1969 and never greased it before. I'm sure it was not greased since leaving some factory, maybe around the mid 1930s. I thought it was utterly amazing that the grease was still soft and live after more than 70 years! Good stuff. But still...had to top it off. It took exactly 31 pumps.

 

Afterward, I was sorry I didn't think to take a pic of my fixture with a rotor assembly in it. I've never seen one of PK's greasers, but understand how it and the others work. You just have a "C"-clamp arrangement and force grease inside the spring housing through the tolerance between the hole in the face of the rotor and the shaft running through it. Here's what I made, welding my "C" out of 1" square tubing, touching up a few areas on the mill, and making a couple pieces on the lathe. In the pic, I have a piece of wooden dowel holding parts together, so I don't lose them; the dowel is in position where the rotor shaft would be. The round red piece is a standard hardware store 1" diameter garden hose rubber seal washer, 1/8" thick...makes replacement easy...no hunting all over for some odd size "O"-ring. It is recessed 1/16 into the face of the cup and captured there by a sharp edge. So it protrudes 1/16" to make the seal. And you DON'T compress it that much; just snug, and the grease is positively retained.

 

Notice how my press fit drill rod screw handle didn't take the parkerizing. Too much nickel, I guess. Cheap crap parks best.

 

 

Here is the greaser apart, below. The top cup with the seal is not permanently attached to the clamp. Its inside cavity is about 1/16" larger in diameter than the OD of the rotor shaft. The depth of the hole in this cup is about 1/16" more than the height the shaft protrudes from the rotor, so it doesn't bottom in the cup; the cup's rubber seal mates with the rotor face. I machined a rounded indentation in the top of the cup, so the screw stays centered in it when tightened. And then the cup and seal stay centered on the face of the rotor.

 

In the bottom of the "C" clamp, the anvil piece for the lower end of the rotor shaft has a recess about 3/16" deep, and seated in it is a 1/16" thick piece of rubber I cut from an old inner tube. This seals the shaft, so grease doesn't squirt out. The only place grease can go is in between the top part of the shaft and the hole in the rotor. ...I hoped. And so it did.

 

 

To use this, you slip the greaser cup over the upright top of the rotor shaft, move it into the "C", and hold the bottom of the shaft against the rubber seal at the bottom of the "C" while you snug up the screw against the top of the cup. Then pump away, watching for the first ooze that stays "stop".

 

So you do-it-yourselfers, I overengineered this, as usual. You can build something like this much more easily. All you really need to make is the grease cup that goes on top. You could do that with a Dremel tool and an electric drill. You could hold it onto the rotor assembly with any clamp or vise having the right reach, clamping a flexible piece of anything on the bottom of the hollow shaft to seal it.

 

And yes, you could make one of these to grease the drum without taking the rotor out of the shell at all. But it takes a very wide and special (expensive?) "C" clamp to start with. Or you have to make a much bigger deal. Also, when it's time to grease that coiled clock spring, it's also long past time to inspect and grease the camming surfaces of the winding ratchet. So the rotor should come out anyway. Thus I made a more compact fixture, for use on a removed rotor assembly.

 

In another 70 years or so, when these drums need to be greased again, I hope I remember where I stored the greaser...and what my name is.

Edited September 24, 2008 by PhilOhio

[hrt4me]

Nice work, Phil, thanks for posting the description and the photos!

[PhilOhio]

Nice work, Phil, thanks for posting the description and the photos!

 

Your welcome.

 

Does anybody know whether or where these are still being marketed, and at the same price around $200? It's a deal, for anybody who needs a decent shooter drum.

 

[Bridgeport28A1]

PhilOhio, Numrich is still selling the Crosby Co. Marked L drum.

 

Ross

[PhilOhio]

Thanks Ross. I've got my two, but just wanted everybody else to know where they could get them, if still available.

[dalbert]

The Sportsman's Guide also has them...

 

http://www.sportsmansguide.com/net/cb/cb.aspx?a=406536

 

David