Upgrading / Repairing steering front engined Rover Rancher

[mixotricha]

Think I might go with a drive sprocket off a bike. I have lots of those about in a box somewhere with different size holes. Also lots of 420 chain to fit em. Found a smaller looking pinion on the fleabay that is also 420. Now just trying to remember where all my chain pin pushing tools and other sprocket related bits went.

 

[bertsmobile1]

420 might be a bit big to get a reasonable leverage but what the heck,
using what you have sounds like a plan Stan

 

[mixotricha]

So some digging about in my junk box found something interesting.

After looking at lots of drive sprockets and some bicycle cassette sprockets in my junk pile are all the same pitch as some cox steering chains I came across.

According to some blurb for a steering chain on ebay ...

Width between Plates: (inches) 3/16"
Pitch (inches) 1/2" (mm): 12.7mm
86 links including con-link

Or in other words lots of mowers about with that pitch but the chain is thinner. Thicker chain seems fine to me.

Sprocket I looked at off a bike was actually 19mm hole just splined to.

I think it will slide straight on to the secondary shaft thing'a'wazut and bolt on thar if I just braze in the existing holes on the thing'a'wazut and drill new ones.

Also looking at the ratio for the cox steering setup it doesn't really look to be all that much either.

So I can get a 420 at say 10T and another 420 at say 20T. I think it will do the jerb you know.

Then the aluminium base plate they go in to splits so it can move further.

That means the hole in the console for the thing'a'wazut also needs to shift.

Tomorrow I will take some pictures of what I mean.

 

[bertsmobile1]

I got you
If you asked I would have said the steering chain was 5/16 x 1/4 just goes to show it is good to check
I must admit I had never thought about doing this so it might get me enthused to get some of the colts I have sitting in the grave yard running & sold
I was thinking along the line of fabricating some gears when we get the Adcock running but sprockets & chains might just be the go
Just goes to show how helping others can help yourself .

 

[mixotricha]

Today I turned out the hole in the drive gear. The hole itself was 19mm but of course splines. Splines were hardened. Lathe is currently in pieces so I drilled it out. Think it tore up my nice Christmas tree bit to! What worked nicely was to just grind the splines away. Slips on the thing'a'wazut fine. Also plenty of room to put bolts through it in to the arm of the thing'a'wazut. Was also thinking about the ratio and how can probably come up with some way to shorten or lengthen that arm if needed. The plate that carries both shafts I am thinking about spitting. The thing'a'wazut shaft is in a rotating cam arrangement but it might be enough for keeping the tension nicely. Will have to wait till I put it together to see. I am still thinking about the stop for this. I am thinking it will be something on top of the thing'a'wazut shaft where it pokes through the top of the frame in the console. I've also ordered up a pinion that has a 19mm ID so hopefully it just slides on. If not I will be mowing my lawn by hand till the lathe is fixed

Also I have no idea about the twist in the thing'a'wazut. I think it was that way before this lot tore up.

 

[bertsmobile1]

looks like a goer
parts book shows the twist which is to keep the tie rod ends in a flat plane.
A simple U bolt over the top of the arm or something similar will do the job of a stop
If you are a dab hand with the welder then weld a bolt between the sprocket teeth to prevent the chain engaging, although this will tend to stretch the chain.
According to the wrong IPL for your mower the Wasit is called a Steering lay shaft .

 

[mixotricha]

As soon as the pinion turns up in the post I will come back and update this. Should be next week some time based on the tracking.

 

[mixotricha]

Sorry it has taken awhile to come back to this. Got the front end reassembled. It is almost good to go _but_ the ratio is not quite enough. Close but not quite. Now the main problem with all of this really is the placement of the engagement for the clutch for the cutter. I went in to the local mower shop and they said look at parts for a model 2300 Nova / Supa Nova and gave me a parts diagram and list for that. But before that I am just going to figure out how to move the engagement lever for the cutter clutch. If I solve that problem and I can put in any steering I want really. It interferes with the arm on the layshaft if I move the layshaft over any further See I split the plate that carries the steering shaft and the layshaft. I then put slots in it so I could slide it. I'll use some sort of adjustment like the wheel adjusters off an old bike. I'll take a picture of the fully assembly when I go back out to the shed again. I was about to quit on this before I thought of moving the engagement lever. But with the front end up in the air the wheels turn nicely. It just doesn't have quite enough torque to turn em nice on the ground. They turn but it is heavy. Needs about 10 more teeth in the driven gear I think.

 

[bertsmobile1]

That sounds very wrong to me
Cox Drive the deck from the rear double pulley so when you hit something hard with the deck or blades the deck goes back and the belt goes slack so it slips rather than breaking which is how the get away with a $12 std belt rather than a $ 100 kevlar belt .
It is one of the prime reason I use them for loaners , however they are Orions & Compacts, not Nova & Super Novas .
Novas & Super Novas also drive the deck from the rear so you engage the deck by allowing the springs to pull the deck forward to tighten the belt.

Rover drive the deck from the front double pulley so the deck is engaged by sliding it back to tighten the belt

So I don't see much from the two interchanging

 

[mixotricha]

Ah my explanation was not clear. What I was saying was that I looked at bigger drive sprockets like on the Supa Nova. This makes sense to because if one imagines the sector gear that came out of the Rover then it then it would be about 120mm in size as a full gear. Now I have space for the diameter of a bigger gear but when that happens the Layshaft needs to move over. It seems to me Rover was not entirely rubbish here. What they did was a very good way to get a large ratio in a small space. They understood you only need a small segment of the larger gear. However this could also be solved by me changing how the engagement for the cutter works. Since that is what is in the way. I am thinking a cable. But I can't quite place in my mind what that cable is out of. Pulls and twists and locks. I might be thinking of a parking brake in the dash board of some old car I once had. As soon as I remember what it is I am going to get rid of the engagement lever it has for the cutter and replace it with a cable and a handle in the console. It pulls an arm down below that swings the engagement pulley over. Bit of tension on it but not to much. Then will have space for bigger gear. At least this is my plan. See as it is now it 'just' has clearance and with the wheels off the ground turns nicely. Just not quite enough torque when on the ground to feel good. Can turn em but to heavy. Can feel the stress in it on the chain. Is a ratio of about 1.5 is to small. Needs to be more like 2.5.