Ohlsson & Rice: Tiny Tiger Rebuild

[CNew 404]

I decided it’s finally time I go through a Tiny Tiger. Seems a little strange that I haven’t done one of these yet.  Can someone point me to the Tiny Tiger rebuild thread that Wallfish did, I wasn’t having any luck finding it?  I didn’t get very far before I hit a roadblock. I’m trying to remove the generator section and it’s not pulling all the way apart. It moved maybe 1/8” before feeling like it’s got something else holding it in place. Is there a nut or bolt behind the little plug cover that is in the very center on the rear of the case (last photo)? It looks like someone has been in this one before as the little plug cover is bent up and wasn’t centered well when they put it back in so it’s all jammed up. If I have to remove this it’s probably going to be completely ruined after prying it out.

 

 

[factory 487]

11 hours ago, CNew said:

Can someone point me to the Tiny Tiger rebuild thread that Wallfish did, I wasn’t having any luck finding it?

 

The rebuild thread for the TT350 from @Wallfish is here;

Also the original Tiny Tiger manual (Model 5001-1, 5001-2 & 67) with service information can be found in the manuals sticky thread, it could also be useful for the older TT Model 300.

 

Quote

I didn’t get very far before I hit a roadblock. I’m trying to remove the generator section and it’s not pulling all the way apart. It moved maybe 1/8” before feeling like it’s got something else holding it in place. Is there a nut or bolt behind the little plug cover that is in the very center on the rear of the case (last photo)?

 

Could be the magnetism of the rotor, the rear section (with the connectors/socket) needs to come off with the middle section (alternator windings).

The little cover hides the screw & bearing for the rotor, I've never needed to remove the cover to separate the generator section.

 

David

[CNew 404]

Awesome, thanks David!

 

Some gentle taps and I was able to get it free. It was indeed the magnetism that was holding it on.  Now the fun part, removing the core section...

 

One of the wires has a crack in it with some corrosion. Should I go through the pain of pulling this apart to fix the wire?  Would it be a good idea to also replace the bearing on the end of the core shaft? Looks like a fairly standard 6201Z bearing. This one spins freely but there’s never a better time that when it’s all opened up...

[Wallfish 698]

It's the bearing in that seat of the rear cast piece which holds it on. Be sure to rotate the piece or tap around in different places to work it off the bearing.

You can also remove that cover to take out the screw that goes through the shaft. The pieces may separate by the shaft sliding out the center of the bearing or the shaft can separate from the taper on the engine shaft. Problem with that is it's difficult to not damage that cover to get it out

[CNew 404]

Finally got it all apart. The flywheel key was welded in place so that took more time than anything to finally dig out.

 

Any recommendations on whether or not to fix the wire and replace the bearing?

 

A previous owner also totally ruined the fuel pick up tube so I’ll have to make my own version.

[Wallfish 698]

Which wire? best to post a better pic. If it's not bad and you don't want to cut off the cap for covering with shrink tube, you can cover it with Plasti-Dip. That stuff doesn't glue itself to things so make sure you go all the way around the wire. It shrinks up tight when dry. Works good for fixing the old style coil wires too.

So far, never had a problem with the old bearings. They don't really have to take much side load so...

[CNew 404]

Yeah, I couldn’t really get a very good photo of the wire. It’s the black one and it look so like it has a single crack that goes all the way around the wire. I was thinking of maybe plastidip or liquid electrical tape but that would still leave the corrosion down inside the wire, maybe there’s not enough corrosion to cause problems...

[factory 487]

The wiring is your choice, as soon as you disturb/separate the rear section they all crack or crumble to bits.

 

The bearing should be fine as long as it is free from rust & spins freely, I can't imagine any of these got used for long enough to wear the bearings at all.

 

David

[CNew 404]

I’m tempted to avoid disturbing the wires and will use some plastidip or liquid tape first to see if it’ll work. 

 

Thanks for the thoughts on the bearing, I’ll hold off on it as well.

[CNew 404]

Well, so much for avoiding wire work. Upon reassembling today the power of the coil magnets yanked the coil section from the rear cover plate while sliding it on and pow, there little shards of dried out wire started falling out. I’m going to attempt multiple coats of liquid electrical tape to see if I can build up some thickness. Bummer...

[factory 487]

Oh dear, the wires with old crumbly perished rubber insulation, the last one I worked on was so bad I ended up sleeving all of the alternator wires with heat-shrink tubing. The wiring for the 110V outlet isn't made from rubber & didn't need sleeving.

 

 

 

 

David

[CNew 404]

13 minutes ago, factory said:

 

 

Ahhh yes, that’s a familiar looking sight. Mine isn’t quite that bad but the wires are now cracked and exposed like that.  I used some liquid electrical tape yesterday but I’m tempted to go all the way and open it up to add heat shrink tubing.  My biggest fear is the point where the wires go into the copper coil and if that area breaks...

[Wallfish 698]

28 minutes ago, CNew said:

 My biggest fear is the point where the wires go into the copper coil and if that area breaks...

Cut those caps off so you can work on the wires without being restrained by the connections to the cover. You'll find it much easier to work on without breaking off all of the old insulation plus you can now use shrink tubes to cover the wires. Once the shrink tube is done it can easily be handled without as much worry of damage to those areas of the wires.

I used gray size wire nuts to connect and cover mine but soldering as David did is a much better connection.

[factory 487]

Those wire nuts aren't used much in the UK and the crimps originally used would need expensive tooling for a reliable connection.

 

I'm not sure if it shows in the picture, but I make a ring out of solid tinned copper wire to use for the soldered connections, then put the wires in this before soldering, it helps make a much stronger connection, I can take some pictures if needed.

Also they may be a pain to solder if you don't clean the tarnish from the wire ends before soldering.

Two layers of slightly larger heat-shrink sleeving cover the join, use a longer piece for the first layer & fold it back on itself back before sliding the second piece on and this will cover the exposed end.

 

David

[CNew 404]

David, John,

   Thank you for all the helpful suggestions.  I think I’m tracking with the ideas but additional photos are always helpful.

 

Thanks,

Clint

Also, it looks like there is a rusty red paint coating on the copper wiring on your coils - did you add that or was it original to your unit?  Mine isn’t just bare exposed copper.

[CNew 404]

That was a little nerve-racking trying to remove the old plastic wire caps and then remove the crimped metal to free the wires without snapping off the little wire tabs.  Got it all free, now it’s time to get some more shrink tuning and stuff to do the soldering.

[CNew 404]

Now that I’ve got everything exposed it looks like a few of the wires are worse off than I thought. There isn’t t much insulation left.  Is it possible to re-sleeve the wires by breaking off all the last bits of old cracked wire insulation and then just using heat shrink tubing as “new insulation”?

[Wallfish 698]

Just be careful. I covered mine since there's no need to be pretty in there and it's completely hidden once assembled. My priority was to make sure nothing was damaged and stopped the operation of it. The shrink tube holds the old insulation once it's on there. It shouldn't be a problem to remove it all either and shrink tube it.

[CNew 404]

Sounds good. Looks like mine may have been store in a humid environment, the wires that are severely cracked also have blue-green corrosion permeating the entire wire.  I think if there were more insulation left I would just simply cover it with heat shrink but I think in this case it might make sense just to finish removing the last bits and re-sleeve. Not what I had planned to do with this one but o’well, it’s good learning!

[JUST O&R 237]

looking good I would like to see finished product sense I have one of this to do in the future 

I imagine  there all that way.

[factory 487]

22 hours ago, CNew said:

Also, it looks like there is a rusty red paint coating on the copper wiring on your coils - did you add that or was it original to your unit?  Mine isn’t just bare exposed copper.

 

That's how it was when I bought it, it could be pigmented varnish similar to what we used at work for traction motors, but is probably just lower cost red paint. Rather annoyingly they painted over the wire colours, but this isn't too much of a problem as measuring the resistance confirms which windings are which.

Yours just has lacquer on the coil wire, but it does allow you to see the sleeved connections to the coils better.

 

17 hours ago, CNew said:

Looks like mine may have been store in a humid environment, the wires that are severely cracked also have blue-green corrosion permeating the entire wire.

The corrosion of the copper is due to chemical reaction to the rubber insulation, copper wire used is normally tinned to prevent this, nothing else on your TT looks rusty/corroded. If you look at mine the socket clamp & diodes were very rusty.

 

David

[Wallfish 698]

The couple/few I have opened up had that orange crap on there as well. Don't remember seeing them like Clint's.

Yeah, those wires you should totally strip and cover. Thought they would've been in better shape from your first description

[factory 487]

On 5/17/2020 at 4:29 PM, CNew said:

David, John,

   Thank you for all the helpful suggestions.  I think I’m tracking with the ideas but additional photos are always helpful.

 

I took some pictures earlier today to show the technique I use to join the wires & leads of the diodes together, I'll get them edited & uploaded tomorrow as it's quite late now.

 

David

[CNew 404]

3 hours ago, Wallfish said:

Yeah, those wires you should totally strip and cover. Thought they would've been in better shape from your first description

 

Well they were in slightly better condition until I was re-assembling the unit and the magnet sucked the coil off the back plate. That sudden yank pretty much did the rest of the insulation in...

[factory 487]

On 5/18/2020 at 11:16 PM, factory said:

On 5/17/2020 at 4:29 PM, CNew said:

David, John,

   Thank you for all the helpful suggestions.  I think I’m tracking with the ideas but additional photos are always helpful.

 

I took some pictures earlier today to show the technique I use to join the wires & leads of the diodes together, I'll get them edited & uploaded tomorrow as it's quite late now.

 

David

 

Here is how I made the join for the wiring in my TT, demonstrated with wire from a scrap wiring loom, the technique used for the wire loops dates back a very long time, I first saw it used in a pre-war radio for joining multiple wires & components together (before printed circuit boards existed).

 

The wires before & after tinning with fresh tin/lead solder (note: do not tin wires if using crimp or wire-nut connections).

 

To make the loops I use standard tinned copper wire (aka fuse wire), I have a few different wire gauges for joining different thickness cables, choose a drill bit or something else that is a bit larger than the cables to be joined, wrap a few turns of the tinned copper wire around & cut to length.

 

I've shown a couple of sizes I made and if you leave a length a wire as shown they can be used in other things for extending component leads. Slide the loop over the tinned wires to be joined (for a continuous length of wire slide the sleeving on before soldering).

 

The whole lot soldered together with tin/lead solder and here are some finished joins ready for sleeving.

 

Hopefully this will be useful to others.

 

David