Ohlsson & Rice: Little Wonder Trimmer

[CNew 404]

I received my Little Wonder Trimmer this afternoon. It needs a fair amount of clean up work and probably a few parts replaced that are missing. I have a couple general questions: is the metal handle supposed to flex when you pick it up? There looks to be a rubber bushing on each end to allow it to wiggle but I would have expected it to be a rigid handle.  Also, what is the little red plastic bottle that sits between the gas tank vent tubes? This one is cracked, will it still serve its purpose?

[Webhead 95]

The bottle allows the tank to vent in all different positions without leaking fuel.

[CNew 404]

Ahhh, makes sense - thanks!

[Wallfish 698]

And yes, the handle is mounted with rubber mounts, vibration dampers.

At least you got the little vent bottle. Most are missing because the nipples broke off.

[CNew 404]

One of the nipples looks like it’s barely hanging on. I’m guessing it will probably break off completely if I try to replace the fuel lines, which are hard as rocks.  I think it was in good condition prior to shipping. In the photos when I bought it everything looked in the correct position and when it arrived the bottle and bracket had been jarred loose. The unit also got a pretty good dent on the edge of the tank during shipping. O’well...

[Wallfish 698]

9 minutes ago, CNew said:

One of the nipples looks like it’s barely hanging on.

2 part epoxy, Not sure if that will hold up to gas over time but I'm assuming you're not looking to trim your bushes with this, just collecting

[factory 487]

Here are the relevant Little Wonder manuals, if you haven't already found them;

 

8 hours ago, Wallfish said:

8 hours ago, CNew said:

One of the nipples looks like it’s barely hanging on.

2 part epoxy, Not sure if that will hold up to gas over time but I'm assuming you're not looking to trim your bushes with this, just collecting 

 

The little red plastic bottle is described as the vent tank on the parts list and has a tiny hole in it to allow the trimmer to operate in different positions (as Wallfish said).

Most of mine are either missing or broken apart from this one (which I collected in person from the seller); 

 

I have thought about making a replacement for the others from a section of brass tubing with some flat ends soldered on, with two smaller brass tubes for the vent tubing to attach to.

 

David

[CNew 404]

David, John,

   Thank you both for all the great advice and suggestions. It’ll be fun to go through this tool. I noticed another odd thing today which I’m not sure if original to he unit. It appears someone drilled and tapped a hole on the side of th gear box housing. There isn’t a screw head on the outside so I’m curious to see what this is for once I take he base plate off th gear box. There is something partially threaded in the hole but no idea what they did this for. Thank you for the links to the manual as well, that’ll be really helpful!

 

Maybe if I can ever get some time I can have a buddy CAD up the vent bottle geometry and then it 3D printed with FD! T I chnology in ABS, ASA or PPSU material.

 

Clint

Sorry, some bad typos in the last message. That should have been “3D printed with FDM technology”...

[Wallfish 698]

2 hours ago, CNew said:

Maybe if I can ever get some time I can have a buddy CAD up the vent bottle geometry and then it 3D printed with FD! T I chnology in ABS, ASA or PPSU material.

Now we're talk'n. That's a great idea!

Not sure about that hole, I'd have to take a look at mine. But it appears it's a bolt from the other side and not sure why it wouldn't just be a blind hole.

[CNew 404]

Well I just happen to be a R&D engineer for a 3D printing company so I have access to the tools, just don’t ever seem to have enough time to have fun with the technology.

 

I think you’re right about the hole- it definitely looks like it was drilled from the inside of the gearbox. Seems very strange and I’m hoping it’s not some odd attempt to repair something inside.

[factory 487]

There are a pair of parts ones here, which I bought for the missing bits on another (and the option of changing to the longer cutter bar), I did pull the cover off of one when I got it, but can't see the area your interested as it's obscured by grease, don't think any of mine have the tapped hole going through the casing.

 

 

One of them also had this very nice glued-on replacement fin bodge on the flywheel (now gone for recycling, without the starter dogs of course).

 

 

On 1/23/2019 at 11:15 PM, CNew said:

Maybe if I can ever get some time I can have a buddy CAD up the vent bottle geometry and then it 3D printed with FDM technology in ABS, ASA or PPSU material.

 

Sound like a great idea too, maybe even make the vent tank walls a little thicker so that it's less likely to get damaged.

 

David

 

P.S. Me and CAD programs don't seem to get on, I've wasted many hours trying different ones for electronics PCB design but can't find one I can get on with. I did also use AutoCAD many many years ago at college but only for 2D drawing.

[CNew 404]

David,

  Thank you for the photos, now I’m really intrigued to open up my trimmer gear box to see what that hole is all about. Seems like a very strange place to drill and tap a through hole. At first I thought maybe they wanted a simpler way to add grease or something but since there isnt a way to access the inside from it and there’s no screw head or zerk fitting, that theory went out the window....

 

ps I fired up the little green military engine this morning. It doesn’t have a muffler or air cleaner so I only ran it for a few seconds. Ran really strong and loud!  I think it was used very little or not at all prior to me getting it. The original carb diaphragm was even still functioning.

[CNew 404]

I opened up the Little Wonder gearbox cover and unfortunately I still can’t see the hole. It looks like I’ll have to remove the entire mechanism inside in order to gain visibility to that area of the box. More investigating ahead...  I may decide to work on the engine first and make sure I can get it working before going much further on the gearbox.

[Wallfish 698]

As with most of these old tools, you should just go through the whole thing anyway. disassemble, clean and re-grease everything.

My gearbox on the little wonder does NOT have that hole so it appears someone has been in there before. That means you should definitely get into it and have a look. Just do it over a clean surface or lay out a towel or something. Those little roller bearings enjoy taking off and it's a pain in the @$$ to find them after they do. It's probably something you're aware of by now but just in case since there aren't replacements available.

[CNew 404]

Good advice- I’m anxious to see what this hole is all about!  Good suggestion on using a towel to help catch those bearings....

 

Clint

[factory 487]

18 hours ago, CNew said:

I opened up the Little Wonder gearbox cover and unfortunately I still can’t see the hole. It looks like I’ll have to remove the entire mechanism inside in order to gain visibility to that area of the box. More investigating ahead...

 

I think I've sussed out what has happened, the tapped hole is where one of the two screws that attach the fixed part of the cutter bar to the gearbox casing is, I think the thread has become stripped (or the screw head broke off) and a previous repairer has drilled & tapped it for a longer replacement screw.

 

Pictures of a partial strip-down of one of my parts donors to follow when I get them downloaded & edited from my camera.

 

David

[CNew 404]

David,

    I think you’re on to something there. Given the location of the hole it is right above the mounting of the bar as you suggest. I bet you’re right on about the repair.  I was hoping to spend some time getting in there today but it didn’t happen. Maybe this week I can get it cleaned out and get some photos. I need to stare at it a bit to figure out how the components come out - and as Wallfish pointed out, not lose any of he bearings!

 

 Nice work coming up with the theory, I suspect I’ll prove you right once I finally get in there.

 

Clint

[factory 487]

Here are the pictures of the gearbox I stripped down last weekend, as per the instructions the jam-nuts need to be removed first to allow the blade bar screws to be removed. I don't think topping up the grease will be enough for this one, it needs cleaning out completely later in the year when the weather improves (but it's no where near as cold over here at the moment compared with how Minnesota has been this week ).

 

 

And here are those two threaded holes for the cutter bar.

 

Hope this helps anyone with one of these.

 

David

[CNew 404]

Hello David,

   Thank you for taking the time to open one of these up- this is extremely helpful. Now I know what to expect along the way. I’m hoping I can get some time this weekend to start working on my trimmer.

 

We finally warmed up to +20F here today so massive improvement over -31!

 

Clinr

[CNew 404]

Hello David,

    I was able to get the Little Wonder all disassembled today and opened up th gear box.  Turns out the odd threaded hole is as you suggested. Either it was tapped too deep at the factory or someone extended the hole at a later date, maybe to try to get the bar held in place tighter. The hole in question was indeed the front main hole that holds the cutter bar.  Now the fun part, degreasing this thing.  From what I can tell it has the original grease, and lists of it - pretty nasty stuff.  I’ll try to get some photos once I get things cleaned up enough to really see what is going on in there.  After taking the engine and gas tank off I’ll probably do a full tear down on those as well. I noticed the exhaust collector was loose enough to swivel a little so I’m guessing that means the cylinder is not on tight or a gasket has worn out.

 

Thanks again for the photos, those were really helpful as I was pulling things apart.

 

Clint

[CNew 404]

Hello David,

   Do you think there is a special grease recommended for the trimmer gear box when I go to put it back together? I was thinking perhaps some general purpose wheel bearing grease but I thought I’d see if you knew if there was a recommended viscosity or special lubricant that might be better suited for this application.

 

Clint

[factory 487]

The original grease used by Little Wonder was Lubrico (or is it Lubriko?) M3-3K-9K, I get very few results if I search the web for that, so I guess it's no longer available. I will be using the same grease I use for the engine rebuild in mine (LM2 Lithium based), or use Lubriplate as recommended in the engine rebuild thread.

To clean out the old grease I used an old dining knife to remove the bulk of it and will be cleaning the rest out (outside later in the year) with an old toothbrush & gas/petrol same as I do with any other part, with a alu/foil takeaway tray underneath to catch the crud.

 

23 hours ago, CNew said:

I noticed the exhaust collector was loose enough to swivel a little so I’m guessing that means the cylinder is not on tight or a gasket has worn out.

 

With new gaskets & O-ring seal you can just about turn the exhaust collector ring after the cylinder has been tightened, this allows you to move it a little for alignment to fit certain tools. If it's really loose then it's probably been apart for decarbonising & not had the gaskets renewed, if the starter housing doesn't fit properly then the cylinder is not screwed in far enough (I had this problem with one of my rebuilds, due to the new O-rings I bought being to thick).

Note: The slots in the cylinder should line up (or be at right angles) with the crankshaft.

 

David

[CNew 404]

David,

   Sounds like a good approach with the grease. The junk in mine was a really thick dark grey mess. I’ve used Lubriplate on other engine builds, great stuff. It definitely a lower viscosity than the stuff I’m scraping out.  I’ll see if I can find anything similar to the LM2 Lithium based grease you mentioned as well. I did some more degreasing today and I think I’m going to have to go a similar route to what you suggest with gasoline to get everything really clean. I also couldn’t quite figure out how the main gear is removed. It appears to be held in with the pivot fork that connects to the engagement lever. I was hoping to avoid dismantling the lever fork but that might be necessary for the rest of the parts to be removed.

Also, thanks for the clarification on the exhaust collector.  Mine certainly isn’t super loose but with some pressure can be made to move slightly so maybe that’s more normal.  I’ll check the position of the cylinder slots.

 

Thanks,

Clint

 

 

[CNew 404]

Slowly making progress on the Little Wonder. Starting to get into the engine, it’s definitely a dirty one.  Found that the previous owner made an air filter out of a dish cleaning sponge pad...

[Wallfish 698]

See you already have the essential dental pics and Q-tips out. Another good thing to get is a set of hole punches for making new gaskets. I like the little plier type rather than the type you hit with a hammer. They make quick accurate work for making new paper gaskets. Just search around the web for a set with all different sizes.

Example

https://www.amazon.com/Darice-1201-14-Circle-Punches-3-Piece/dp/B000WWK8US/ref=sr_1_5/146-3815977-4936629?ie=UTF8&qid=1549421562&sr=8-5&keywords=hole+punch+set