New DBR member

[jimmyybob]

Hello, i have now took the plunge and purchased the tractor manual and i am about to compile a shopping list of things i need.
I am planning a few modifications to the rear end motor and drive system.

Wish me luck.

[markh15]

Hello there,
Finally some-one has bitten the bullet!
Congratulations, and welcome to the Toylander family. I'm Mark, and built a Toylander 2 earlier this year (Red S2 in the Gallery), before this forum was available.
We're a pretty friendly bunch, and will try to help-out in any way we can, be it with advice or parts solutions.
Don't be secretive, and please post pictures for us all to look at, we're all dying to see one of these built!

Keep Smiling,
Regards,
Mark (markh15).

[jimmyybob]

Cheers thanks.
I cant decide on the power, one motor or two.??
I also dont like the standard set up as the rear wheel looks to small in proportion to the rest, what do you think? the standard is 16" im thinking 20".
Im also thinking of coming directly out of the body with the drive instead of the underslung axle,has this been used on the toylander2 with a transaxle.?

[markh15]

Hi Jimmy, (hope that's right)
I can only guess at answers to your questions really, as I have no idea how the DBR is constructed.
All that I can say is that if you use two motors you get the differential effect when cornering.
As for larger rear wheels, one or two of us have gone for different wheel sizes in relation to those recommended in the build manual.
I have used a Motobility Scooter for the power-train, and trailer wheels and hubs on the axles.
Because the scooters only have small wheels, I have used chain and sprockets from a mountain bike to get a reduction in gearing, which works OK.

Other members have put me in touch with alternative suppliers (technobots.co.uk) of parts like gears, sprockets, chain etc, and I am in the middle of a re-fit at present, and will be changing of some of these parts.

One or two builders have placed the transaxle under the vehicle, and it seems to work, so your idea may be easy to do with a scooter type drive-train.
The problem we have, is the way the body tub is constructed on the Lanny types, so chain drive  is the easiest option.

You should spend some time checking out the build posts and members websites for the other models, and maybe this will give you some ideas.
Unfortunately you are the first to detail a tractor build for us all, although there are one or two others going at the moment, and details are promised.

Any other problems, just post a queerie, and although most of us are building Toylander 1 and 2's, someone will try to help out.

Keep Busy,
Regards,
Mark.

[multisync]

Hi
Glad to hear youre getting started, I've built the blue toylander in the gallery, nearly finished now. I used a mobility scooter drive train, but as the wheels were 3/2 times larger, I geared it down 2/3 to get the same speed and power as the original. I would suggest that if you use larger wheels you gear accordingly. As an example, if you double the wheel size, you will double the top speed, and half the available power, which may be a problem on hills.
I dont have any experience of the single motor drive but I'm sure that the two motor sytem will be far superior.
The mobility scooter has ample power and a built in differential, so will drive two wheels; but just like a car, it will spin one wheel if it lifts off the ground such as on uneven terrain. I think that the two motor system may overcome this! If you do go along the invalid buggy route, get the bits BEFORE you build, I built to the plans and then had to modify it to fit the buggy motor.
Keep us posted as you go and let us know if you need advce!
Get building and keep busy

[jimmyybob]

Hi all, ive now got a huge sheet of 12mm wood and a sharp saw....Grrrrrr

Does anyone know how best to work out the ratios, the only two things i will know for sure will be the motor rpm and the wheel size.
So from this how do you work out the gear sizes inbetween.?
Im pretty sure now that i am going from the motor to a diff (homemade unless you know of a small one) and then directly to the wheels.
I had briefly thought about a solid axle but it would end up like a go-cart with no diff.(see picture for example of layout)

[markh15]

Hi Jimmy,
You could solve all the problems in one go if you use a mobility scooter transaxle, like Walter (multisync) and I have.
The beauty of these is that the motor bolts directly to the diff / axle assembly.



This is the unit in mine,



it's quite big as it came from a large 4 wheeled scooter, but there are smaller scooters out there, I'm thinking of the lightweight 3 wheeled type.
 
The big plus side to the scooters is that some have lights and horn, and the control systems are all housed in one box, which is easy to locate somewhere out of the way.
You should keep your eyes peeled, and look in the local papers and on Ebay for a cheap example. You could probably pick up a complete, working example for what you would pay for one of the diffs alone.
With a bit of imagination, you could even fabricate a simple suspension system for the back without much trouble.

Hope this helps,
Keep busy,
Regards,
Mark.

[multisync]

Hi again
By the way, are you jimmy, or bob?
What part of the UK/world are you?
Walter

[jimmyybob]

You can call me what ever you like, jimmyybob is good for me.
Im from peterborough.

MARK does that unit have a proper differential inside.?

[markh15]

Hi Jimmybob,
Yes, It's a fully functioning differential. The motor drives direct to a crown wheel (of sorts) inside. I took mine to pieces, because we were look at extending one of the driveshafts and tube, and they are beautifully engineered, no slack in the gears or anything. A proper miniature differential, and they work well.
 
Mine drives the rear wheel via cycle chain and sprockets, but these are due to be changed for something a little stronger, as they're not quite upto the job in hand.

I would seriously look into these for your tractor, visit a dealer and have a good look and a measure.

Keep Busy,
Mark.

[brian]

Hello JBob, welcome to pensioners anonymous.

Looking forward to following the story of your build on the forum.

Have you checked that 20" wheels are available with knobbly tyres.  You may well have gearing problems with the available wheelchair/ mobility scooter motors and 20" wheels unless you are going to throw some serious money at it or have extensive workshop facilities available to you.

I don't think any of the regular contributors on here have built a model anything exactly like Richard's original concept, we have all put our own stamp on it, and clearly, from you previous post's, you are all ready planning some major changes.

Good luck with your build, any help we can give, we will give freely, just keep the post's and pictures coming.

Regards,

Brian.

[jimmyybob]

Wheels and rims are available in all sizes if you buy them from a supplier of rotovator parts (ebay).
I work as a engineer (large marine diesel engines) so we have a machine shop if i need things making.

[multisync]

Hi Jimmyybob
You asked about gear ratios
I posted a reply with some info for you but it seems to have disappeared!
Basically, if you want to move at a fast walking pace, and invalid buggy maximum speed, thats 4 mph.
That equates to 21,120 feet per hour, or 352 feet per minute, or 4224 inches per minute.
Now measure around your tyre and find the circumference. My wheels are 50 ins, so the car moves forward 50 inches per revolution. Divide 4224 by 50 (or whatever your wheel measures), which gives 84.48. So you need to achieve about 85 rpm at the wheel axle.
If you have a motor that does 250 rpm, you will need a reduction of about 3:1; if the diff is 1:1, you'll need, say 10 tooth on the diff output and 30 tooth on the wheel. If your motor is 2500 rpm, you will need a reduction of 30:1, which may be much more difficult to achieve.
It makes sense therefore to find a motor with a built in gearbox, rather than a simple motor like the one from technobots which are about 2500 rpm.
I hope this all makes sense, if not just let me know your motor rpm, wheel size and diff ratio and I'll work it out for you.
Remember that the lower you gear the machine the slower it will be, but more power, just like low gear in a car.
Best of luck
if you want any more, just ask
walter

[multisync]

Hi again Jimmyybob
Like Brian, I used an invalid buggy setup. The motor unit  looks exactly like his. It has a built in diff and reduction, and automatic transmission brake, and was originally fitted with wheels with a circumference of 32 inches. I have fitted wheels with 48 inch circumference, thats an increase of 3:2, so of have used a reduction gear ratio of 2:3 to compensate. In other words< I have reduced the speed of the wheels to counteract the greater distance travelled per revolution.
Patrick in Malta (gremlin) used a similar motor but fitted bigger wheels direct to the axle, with no reduction, he gets more speed but less power, which may ba a problem on hills with a load on!
All the best
walter

[brian]

Hello again JBob.

Never thought about rotavator wheel's, good idea.

What about looking for a refurbishable rotavator and replacing the combustion engine with an electric motor, you would get the wheels, diff and a gearbox all in one, and with luck might find one with the right track width, or near enough.

Your access to a marine workshop gives you plenty of scope for a super engineered job, I realy do look forward to the build diary on this, keep us posted anyway.

Just as an afterthought, I believe the speed of these should not exceed 4mph [ approx 6Kmph] to be able to use them on the public highway so watch the gearing/speed.

Regards, 

Brian

PS, I think Walter has got me and Mark mixed up , my set up is a single wheelchair motor, although I did get a pair off EBay, but I thought that one would be enough for my 3 year old grandson for now.