82104A card reader coupler slipping

[David Hayden]

TL;DR: Can I use something other than super glue to hold the dampening couple to the motor axle?

I repaired my card reader, gummy wheel and dampening couple about 4 years ago. Recently, it started making a horrible noise and not pulling cards through. I opened it, cleaned it again, including a tiny bit of crud between the tiny plastic roller and its housing. After reassembling, it worked for about a dozen cards, and it's failing now.

I'm pretty sure that the couple is slipping on the motor axle. I've seem people using super glue to hold them together, but it seems like there's no going back if you do that. Is there anything else people have used to provide some friction between the couple and the axle? Hopefully something that can be removed if necessary?

Thanks,
Dave

[Raymond Del Tondo]

IMHO the fastest and easiest replacement for the coupler/dampener is to use the isolating tube of a suitable electric cable.
This works without any glue, and is reversible.
Of course the tube has to have a tight fit, so it may take some trials to place it on the wormgear rim.
                   
HTH:-)

[teenix]

I have a method described in my Classic Notes file starting on page 42. If you have some basic tools in the garage waiting for something to do, it is a nice little job. Once set up, it doesn't take long to make each one so you could make a few and store them until needed.

cheers

Tony

[Johnboy]

Nice method Tony. I have a bunch of 82104 readers to repair, so this will come in handy.

I was recently thinking about a similar but simpler method to make new 41c screw posts from round ABS plastic rod. I have discovered this wonderful stuff called liquid plastic cement that I will used to attach the new posts.

Cheers,
John

[David Hayden]

Thanks for the suggestions Tony and Raymond. My current repair for the coupling uses wire wrap and shrink wrap as I recall. I have a drill press and RG-58 cable. so it's tempting to make some couplings using Tony's method.

Still though, that method calls for super gluing the coupling to the helical gear, which is something I'd prefer to avoid in case I need to redo it again at some point.

Dave

[John Garza (3665)]

I've had good results with 'gasket maker' and RTV sealant. Good grip, but axle can be pulled free and the sealant scooped out if need be - so it isn't permanent in any way. And SO much easier than fiddling with cable insulation. Just clean out all the old remnants, and push small amounts in like you're filling an ice cream cone. Get it level with the top and slide in the axle. The axle mates with a hole at the bottom to ensure it's straight. Let it dry overnight before putting cards through it.

-J

[teenix]

(11-07-2023 02:35 AM)David Hayden Wrote:  Thanks for the suggestions Tony and Raymond. My current repair for the coupling uses wire wrap and shrink wrap as I recall. I have a drill press and RG-58 cable. so it's tempting to make some couplings using Tony's method.

Still though, that method calls for super gluing the coupling to the helical gear, which is something I'd prefer to avoid in case I need to redo it again at some point.

Dave

Hi Dave,

The super glue holds it in position and prevents slipping but the coupler and gear will still come apart because Super Glue adheres but does not stick with a bullet proof bond to the cable inner.

As will the gummy repairs, Super Glue comes off the gear easily with acetone.

cheers

Tony

[David Hayden]

(11-07-2023 04:33 AM)teenix Wrote:  The super glue holds it in position and prevents slipping but the coupler and gear will still come apart because Super Glue adheres but does not stick with a bullet proof bond to the cable inner.

As will the gummy repairs, Super Glue comes off the gear easily with acetone.

Thanks, Tony. Yes, it occurred to me that my whole premise might have been wrong. I assumed that super glue would create an permanent bond that would prevent future repairs if needed.

Your method with the coax cable insulation looks really nice and would create a much neater solution compared to my current wire insulation and shrink wrap hack. I may try it this weekend. I especially like the idea of making several extra couplings for future use. Hmm. If I could only find that piece of surgical tubing I got from Geoff Quickfall, I'd have all the parts to repair other card readers.

All the best, and thanks again.
Dave