hp 41 82104A card reader repair

[dave PLS]

Seems like a lot of us with these are having the "gooey roller" syndrome. Just this morning I received a pair of emails inquiring as to my repair using the model airplane fuel tubing. I know some of you like the O ring method, but I stand behind my fuel line! After 25 years+ in the model airplane hobby, believe me, I have plenty. So what I guess I am asking, is if there is enough interest in repairing these jewels, I'd almost be willing to put together a photo documentation of MY methods, and perhaps the webmaster Dave H. here may provide the link to my website for all. I would consider it my contribution to this fine site and all that are HP. Anybody interested?

[John Robinson]

Sounds like a great idea to me.

[Les Bell]

Yes, please do! I don't have gooey roller syndrome yet, but it's only a matter of time. . .

--- Les [http://www.lesbell.com.au]

[DaveC]

Dave- I cannot believe that anyone would repair rollers with fuel line after trying o rings! But I'll ask anyway - what are the advantages other than extreme cheapness?

[dave PLS]

Dave, think about it. The material that hp originally used was a solid piece, the width of the axle of the driven gear. The cross sectional area of an O ring is a circle. You use a pair of O rings so now you have the area of two circles. The cross sectional area of the tubing is a rectangle. Furthermore, the contact area of the O ring is a small area tangent to the circle. Thats why you need a pair of them. I realize we are not trying to peel a bannana with this thing, but I think you see my point nonetheless.

As to the fuel line slipping, I have yet to find that happen. Surgical tubing sounds fine, that is if you have a source for it. The fuel line IMHO is rather indestructable, I suppose we could put a pair of 82104A card readers, one with my fix and one with the O ring fix on the dash of a volkswagen on 100 degree day for 12 hours in the sun and then see what happens. :)

[DaveC]

Well I dunno about leaving any calc out in the sun in a car, (excepting a 6S!) *I* wouldnt, is this a sort of 'who melts first' competition? The tube your using is much harder (less compressible) than the original rather springy rubber, eventually causing greater wear to the mechanism. The O ring approach does have less contact but I see this as an advantage causing less damage to the cards - which are not getting any younger! Dirty cards - these will eventually leave a deposit right around the hose causing slippage, O rings because they change shape while reading dont suffer as much, dirt crumbling off (probably to get lost in the switches :) Preparation of the hose is a pain, getting 2 parallel cuts, if you dont get that right you end up with an uneven drive, pretty dodgy in the hands of the inexperienced. O' rings provide a sure fire - off the shelf solution, having used hose as well I'm not so sure it comes up to the mark.

[Andrés C. Rodríguez (Argentina)]

Very good idea, and if possible please supply dimensions in both English and Metric units, to accomodate people in countries or places where "fuel line" or "smallest o-rings" may be a little diffuse specification.

[DaveC]

O'rings: Size 006 2.9mm Outer 1.78 inner

[Dave]

Fuel tubing or vinyl tubing is too smooth, I'm sure orings work well, but 1/4" OD surgical tubing has the right surface texture & grip & works well.

[Ed W.]

I have one of these card readers, which has not yet suffered the gooey roller. Photo documentation would be greatly appreciated!!!

[steve]

I fully support the idea of having a pictorial turorial on how to repair the card reader roller.

Where people have different ideas on the material to use, then perhaps they can create little addendums (addenda?) so those of us with no idea at all :-) can look at all approaches.

Also if anyone is fixing anything else...

[dave PLS]

Ok guys, this morning I found the time to take care of getting my repair procedure on my site. I also re-repaired a reader using the O rings. See my comments at the site. Take the trip to http://community.webtv.net/lostrabbit and meet the hare and his vintage Porsches, the card reader instructions are at the bottom. Enjoy and let me know what you think! Dave

[Randy Smith]

Hey Dave, how about seeing if you can get Mr. Hicks to put your address in a permanent place in the museum or putting your instructions in a permanent place. I think that would be a good thing to do. I found myself smiling as I read your instructions remembering my frustrations trying to get the card track back together and the two halves back together. Nice Porsche, but I am a Corvette guy myself. Take care, Randy