Vintage Tonka Winnibago

[bromvw]

Strap on a 4S LiPo fella and turn it into a Wheeliebago!

Heck NO this is a hauler not a dragster lol

[Daves956]

something like from the RC10 maybe?

[bromvw]

something like from the RC10 maybe?

A pair of those - 4 of the above - would be ideal Dave . Do you have a link to a vendor or are they from your parts stash ?

[berman]

I was going to suggest the battery trays out of a tractor truck but those rc10 ones are a better idea, especially if you are running square packs.

[bromvw]

think I'll go with the RC10 items Berman because thanks to a link from Percymon I can buy them quite cheaply from Wheelspin . As I will more than likely be running two 2s lipo hardcase packs they are almost made for the job .

[Daves956]

the picture was from an Ebay auction with a high bid of 99 cents for used ones, crossing the pond would have killed that price though.

[Skottoman]

Any Progress?
Cheers,

Skottoman

[bromvw]

Any Progress?

Cheers,

Skottoman

Yes . It now sports a very tasteful interior and Otto driver . And yes I WILL do some photos but right now I need to hit the sack having being on the nightshift .

[bromvw]

Guys I need some input . I need some form of reduction unit between the motor and transfer unit . What do you think of the HPI Wheely King gearbox ? It looks like a good strong and reliable item . It can also be bought fairly cheaply . BTW anyone got one for sale ?

Advice please and WHY for sale .

[Percymon]

Can you not simply go for a higher turn motor ?

65 / 75T ?

you could also limit battery voltage (6V pack ?) if you want to slow this hull down

[bromvw]

Can you not simply go for a higher turn motor ?

65 / 75T ?

you could also limit battery voltage (6V pack ?) if you want to slow this hull down

the problem I have David is the weight of this thing . I need torque and a lot of it . The driveline is essentially direct with no reduction at all through the transfer box or axels . Even with a high turn motor I just feel its going to be lots of wheel spin with no grunt .

[Percymon]

Did you not get the MFA unit ?

Confused !

[bromvw]

Did you not get the MFA unit ?

Confused !

no David - i'am not convinced its the way I want to go . Need to make my mind up basically - confused is the word

[Daves956]

If all you've got for reduction is the MFA unit 11:1 aint gonna cut it, especially with a brushed motor. With the weight your trying to push I don't think one of those per rear wheel would be enough. For a single brushed motor I think your looking at somewhere around 40:1 and that's iffy. I really think that your going to have to go brushless 4 pole and then reduce it.

[MadInventor]

Hi Arron,

I've quickly googled the t rex 60 axles (I assume that's what you used in the end), and found that the axle ratio is 2.53:1.

I agree with Dave that you will need further reduction.

I set my grapple skidder up with 34:1 (Standard ratio for a TXT-1), and that was with 168mm diameter wheels.

Wikipedia quotes top speed of a standard TXT-1 at 7mph, so if we used the same ratio (34:1) as that but with 98mm diameter tyres, you will be travelling at 58% of 7mph, which is around 4mph (Walking pace). I was aiming for around this speed for the grapple skidder, but didn't contend with the 3S and the mother of all boat motors.

If 4mph is where you are aiming to get, what about a TXT-1 box. It has a base ratio of around 12:1 with a 15tooth pinion, which with your axles would give a ratio of around 30:1. You can also have twin motors, and it will allow for dual crawler motors as well if you decide to go that way. (Personally, I would just use 12T instead of the standard 15T pinions in it, and have the increased wattage of the silver cans). A mammoth dump truck gearbox will allow for an even lower ratio, but only the use of one motor.

The downside is that the gearbox is quite tall, and will intrude on your interior.

If you're still thinking about MFA, they do 540 based reduction boxes with a base ratio of 47:1 (I picked this one at random after a quick scan of the catalogue.

If you had one of these going to each axle, you would have 2 motors and a final reduction ratio of 119:1, more than enough slow I think.

They also do a massive 975 sized motor for £40, with a reduction ratio of 49:1, but it has an output shaft that is 8mm diameter, so you would need a custom UJ to connect to any transfer case.

I don't think there will an easy answer to be honest, if you want off the shelf to use 540 sized motors, it will have to be a monster truck box of some sort I think.

[bromvw]

Martin I'm no trained engineer and to be honest find all this ratio stuff really confusing . By chance I was in Maplin's this evening and I can currently buy a MFA 540 5 pole based unit with a 100 : 1 ratio for £19 . Would that do the job driving through a rc4wd transfer box or would you go for two and forget the transfer unit ? . The transfer is 1:1 .

[MadInventor]

Martin I'm no trained engineer and to be honest find all this ratio stuff really confusing . By chance I was in Maplin's this evening and I can currently buy a MFA 540 5 pole based unit with a 100 : 1 ratio for £19 . Would that do the job driving through a rc4wd transfer box or would you go for two and forget the transfer unit ? . The transfer is 1:1 .

Basically, the ratio is the number of times the motor has to turn to rotate the wheels once. To combine axle and gearbox ratios together you mutiply them, so the MFA unit with 100:1 and the axle with 2.53:1 will give a final ratio of 253:1, which means the motor will rotate 253 times to turn the wheels once.

Basically, the larger the gear ratio number, the more torque you will get at the wheels, but the vehicle will be correspondingly slower.

I'm assuming that the motor you can get from maplin is the 919D1001LN, a 5 pole 540, 100:1 ratio, with an enclosed gearcase and an offset output shaft. At 7.2V (no load), the gearbox rotates at 33.6rpm, which translates into about 2.45Km/h, or ~1.5mph, which equals *&%$*"^%$ slow.

With such a low ratio, the model will move fine on one motor I think, but it will seem very very slow.

The 3 pole motor version (MFA 919D1001) has roughly double the RPM (79) with the same ratio, and would give a top speed of 5.77km/h, or around 3.6mph, which I think would be a bit more usuable.

Re - Would I use 2 motors and no transfer case, or 1 motor and a transfer case, that's a tricky one. The transfer case will give better traction as the axles cannot rotate independently of each other, but using 2 motors will give twice the power output, and more power is always good .

I think you could get away with one motor at that ratio, especially with the 5 pole motor as it has extra torque. If you compare against my 6x6 truck, that barrels along ok with a single 540 on a much higher ratio (Around 30:1 in 1st), and that's got to be 6-7kgs of weight (Steel chassis, aluminium walking beam cases, aluminium bodywork, steel log frame, steel trailer, log load, 3 speed box etc), although I am using an 8.4 or 9.6V battery in it. (I can't remember which ).

Hope this info is of some help with your decision making.

[Daves956]

I think that given the 20ish pounds your trying to push a pair of 50:1s would do you just fine. Unless your planning on off roading it a lot I'd skip the transfer case. There's a lot of ways to tone it down if it's too fast but if it doesn't have the power to start with you don't have many options to fix it.

[MadInventor]

I think that given the 20ish pounds your trying to push a pair of 50:1s would do you just fine. Unless your planning on off roading it a lot I'd skip the transfer case. There's a lot of ways to tone it down if it's too fast but if it doesn't have the power to start with you don't have many options to fix it.

I'd agree with you on this Dave, that seems a sensible ratio to go for which will give a good comprimise between toorque and speed.

[bromvw]

Being thinking about this a lot . Having twin motors makes a lot of sense . Firstly there is no problem with having to find or make custom prop shafts . I can just move the motors to suit off the peg items . The MFA motors/gearbox's are easy to maintain and mount directly to the steel Tonka .The extra pulling power will really help when its pulling my CC-01 and trailer too . Having done a Wild Dagger I know of a suitable reasonably priced ESC I like as well .

Mind made up . As soon as I can I'll order a pair of MFA motors with 50:1 gearbox's

thanks Fellas

[MadInventor]

Being thinking about this a lot . Having twin motors makes a lot of sense . Firstly there is no problem with having to find or make custom prop shafts . I can just move the motors to suit off the peg items . The MFA motors/gearbox's are easy to maintain and mount directly to the steel Tonka .The extra pulling power will really help when its pulling my CC-01 and trailer too . Having done a Wild Dagger I know of a suitable reasonably priced ESC I like as well .

Mind made up . As soon as I can I'll order a pair of MFA motors with 50:1 gearbox's

thanks Fellas

Glad you've decided on what you're doing Arron, looking forward now to seeing some fast progress on it

[bromvw]

Gentlemen ( and lady's if Jenny reads this ) . Has anybody got a complete set of leaf spring shackle mounts available for sale ? What i'am after is the type that bolt to the chassis rails . Used or new - anything considered as long as all the nuts and bolts are there . I was thinking of buying some from rc4wd but with customs and import duty they work out very expensive .

Make a offer Guys

[MadInventor]

Try contacting this seller on Ebay:

catmand11r

He sells a lot of tamiya truck parts and sold me some spring hangers without having to buy a whole bag, just the pressed parts I wanted, so if you can use tamiya parts, he might be a cheap option.

[emory70]

Pardon me, but when I see that thing, I immediately think of National Lampoon's Christmas Vacation.

I also see a totally clapped out but fully capable crawler

[matman]

Also , what has happened to this Bromvw ??????? .