Transmissions

[Aero 9000]

What transmissions are available for tractor trucks ?

Has anyone used a RC4wd 3 speed ? What are they like ? Has anyone disassembled one, i'm curious to know are they a crash gearbox like the old Tamiya hilux diecast gearbox or are they a dog box like the current tamiya plastic box...??


Also what are everyones thoughts on this 9 speed transmission...?? it has 3 ranges and 3 gears in each range and is full metal...??

[scalelover]

The Rc4wd 3 speed is not the greatest out there. I asked this same question not long ago and it ls said to have some hard shifting issues and the actual shifter is very tight requiring a high torque servo, and it's only 4x4 in first gear and 2wd in all others. With that said their 2 speed and single speed trannys are great but if course not as fun without all the gears.
Pricing also seems a bit steep on it compared to other 3 speeds.

As for the nine speed I've never seen it before so I can't give you any real input on it. Whose the manufacturer of it? And what's the cost?

--Dan

[Aero 9000]

Hi Dan,
when you say the RC4wd 3 speed has "hard shifting issues" do you mean it is difficult to shift without grinding gears or that it is physically hard to move the shifting mechanism ...?

The 9 speed is made by HGM in Australia.....don't know the cost....is the concept good...??

Thankyou.

[Michael S]

Originally Posted by Aero 9000

Hi Dan,
when you say the RC4wd 3 speed has "hard shifting issues" do you mean it is difficult to shift without grinding gears or that it is physically hard to move the shifting mechanism ...?

The 9 speed is made by HGM in Australia.....don't know the cost....is the concept good...??

Thankyou.

Do you have a web on HGM?

[Aero 9000]

Originally Posted by Michael S

Do you have a web on HGM?

No web, but a email: lkhanley@optusnet.com.au

[scalelover]

Originally Posted by Aero 9000

Hi Dan,
when you say the RC4wd 3 speed has "hard shifting issues" do you mean it is difficult to shift without grinding gears or that it is physically hard to move the shifting mechanism ...?

The 9 speed is made by HGM in Australia.....don't know the cost....is the concept good...??

Thankyou.

I was wondering the same as above do you have a link to the trans maker
Id like to look into a bit more and see what it's all about

--Dan

[Aero 9000]

Originally Posted by scalelover

I was wondering the same as above do you have a link to the trans maker
Id like to look into a bit more and see what it's all about

--Dan

Hi, email lkhanley@optusnet.com.au , no web address.

[mack kid]

I e mailed him and he gave a great response and info. i gave him the forum info and told him to join and share his build. its designed to fit into trucks in replace of tamiya 3 speed.

[scalelover]

Both, shift shaft is very hard to move requires alot of torque does not feel super smooth and I've heard when shifting it tends to grind if the servo is not setup just right on the shaft (it can be finiky) also with shifting on the fly, but this you'd kind of expect with any trans seeing as they don't have clutches

--Dan

[mazdaparts]

Its a shame the didn't make the case look more like a scale engine and tranny combo. Did the email list the gear ratios?

[Tamiya Cowboy]

I am with Jammer I would go the 6 speed first as for the cost does not warrant the extra 3 gears. And I have a truck set up with a 6 speed and it was cool at first but now when ever it gets driven i only still run 3 gears at most. But you are also right not everything is needed that is on a truck a item like this will come down to what options a guy would want on there truck and it is a very nice piece you have built.

[SonoranWraith]

Yeah I think the transmissions are one of those things that doesn't translate from the 1:1 to scale modeling. Diesel engines work in a narrow range so the transmissions are geared to keep them working in that range. The electric motors we use provide a lot more range and at small scale you need slow with power so a low gear and a high gear really provide all you need.

[Aero 9000]

Originally Posted by SonoranWraith

Yeah I think the transmissions are one of those things that doesn't translate from the 1:1 to scale modeling. Diesel engines work in a narrow range so the transmissions are geared to keep them working in that range. The electric motors we use provide a lot more range and at small scale you need slow with power so a low gear and a high gear really provide all you need.

You are quite correct.
The RS540 is quite a broad range and torquey motor.
If someone was seeking scale realism in perfomance (as many do in railroad models) a electric motor of narrower performance range could be selected to simulate the diesels performance. Perhaps the RS555. It is likely that such a motor would draw considerably less amperage than the average RS540 so far greater running times may also be achieved along with the more realistic performance.

It would be a matter of individual taste....

[Cossett]

I think the all in one 9s is a great idea, but it's a little on the large side for the guys that want a interior, a day cab, a tipper on the back or other,
If it was smaller/more compact I think there would be a bigger market for the guys that want all those gears and were willing to fork out over a grand for a gear box,
For most people it would come down to cost, how much room it takes up as there are alot of cabs out there that are crammed with electrics when the body is off and for most a 3 speed is plenty...
Just my thoughts...

[Aero 9000]

Originally Posted by Cossett

I think the all in one 9s is a great idea, but it's a little on the large side for the guys that want a interior, a day cab, a tipper on the back or other,
If it was smaller/more compact I think there would be a bigger market for the guys that want all those gears and were willing to fork out over a grand for a gear box,
For most people it would come down to cost, how much room it takes up as there are alot of cabs out there that are crammed with electrics when the body is off and for most a 3 speed is plenty...
Just my thoughts...

Thankyou for your thoughts on the matter.

Many things do not go from 1:1 down to scale. This is a real problem. this is why the trans is a lot larger than a scale model of a real trans would be. The gears inside are around Tamiya size. And there are a number of technical reasons why Tamiya went for that size of gears.
If you did a scale model of a real trans the gears and shafts would be tiny. It would be like watch making, it would be fragile and prone to breakage and bearing failures and the gears being so small would need to hardened steel and then ground...
OMG....if you think 1300 bucks is over the top, a minature scale gearbox with tiny hardend and ground gears would cost more than the national debt....

This monster 9 speed can be mounted further forward in the chassis with some inginuity reducing the overhang at the rear of a day cab to 1/2 inch.

Everything in engineering is a compromise, what one person will trade off another won't.....As i say it is a matter of individual taste...

[Aero 9000]

Originally Posted by Cossett

I think the all in one 9s is a great idea, but it's a little on the large side for the guys that want a interior, a day cab, a tipper on the back or other,
If it was smaller/more compact I think there would be a bigger market for the guys that want all those gears and were willing to fork out over a grand for a gear box,
For most people it would come down to cost, how much room it takes up as there are alot of cabs out there that are crammed with electrics when the body is off and for most a 3 speed is plenty...
Just my thoughts...

Size comparison:....

[Aero 9000]

Originally Posted by Cossett

I think the all in one 9s is a great idea, but it's a little on the large side for the guys that want a interior, a day cab, a tipper on the back or other,
If it was smaller/more compact I think there would be a bigger market for the guys that want all those gears and were willing to fork out over a grand for a gear box,
For most people it would come down to cost, how much room it takes up as there are alot of cabs out there that are crammed with electrics when the body is off and for most a 3 speed is plenty...
Just my thoughts...

9 speed alternate mounting positions..

[rc_farmer]

by the time you shift thru all 9 gears, it will be across the stateline.

[Aero 9000]

Originally Posted by rc_farmer

by the time you shift thru all 9 gears, it will be across the stateline.

It would not allways be necessary to shift through all 9 gears.

As shifting is concerned i would forsee that the 9 speed would essentially be shifted by selecting a range (high, mid, or low) with the right stick on the control in the vertical plane (right horizontal of course being steering) and then shift the gears 1st, 2nd and 3rd as normal with the left stick on the control in the horizontal plane, only changing ranges as the overall situation requires, rather than starting in 1st / low and shifting all the way through all the 9 gears to top. So in some situations you would start in High range / 1st and not even look at the 6 gears below that. In a crawling situation you may decide Low range is suitable and then start in either 1st, 2nd or 3rd and the same for Mid range. Choose a range then choose a gear. Having said that you can also start in low range and shift up through the ranges to high range selecting 1st, 2nd or 3rd at the same time. Almost endless possibilities.

[scalelover]

Originally Posted by Aero 9000

9 speed alternate mounting positions..

Even with these pics you can see its nearly impossible to have an interior, especially in a day cab. I really dont even see a way in a conventional or an extended sleeper without figuring out a way to lay it on its side.

--Dan