Transmission help or suggestions

[civicex5speed]

Hey all,

I’m looking for some input on a transmission for my first ever semi build
I am building a day cab globe liner delivery truck. So size of the transmission is not such a big deal. I will have room for about anything. However I have no experience with any transmission other then built in units from Tamiya Kits (CC-01, TL01, M05). So my question is this. I was looking at this guy for it’s small size and appearance of simple to install between frame rails.
http://store.rc4wd.com/Disruptor-Pla...ion_p_834.html
Then there is this guy, not sure of the difference beyond price, I believe both trans are 16:1 gear ratio
http://store.rc4wd.com/Disruptor-Ult...ck_p_1206.html
Of course there is for a little more money the ol 3 speed Tamiya unit. I would like to have the speed/gear options. But I don’t have a radio with channels for switching gears on the fly and really don’t care for a stick radio anyway. I however can bring the truck to me and switch gears. I am kinda new to the home built side of R/C hobbies and so likely don’t know something.
Anyone have suggestions? Maybe another one I don’t know of that is a good one? Price is an issue. I would like to stay in the $50 range, plus or minus, but much more then $80 will be an issue on the budget.

Also, I hear people refer to a company/store call “PMD” can anyone help with who or where this is?
Thanks

Clif

motor and tranny

http://cgi.ebay.com/ws/eBayISAPI.dll...e=STRK:MESE:IT

tranny single

http://cgi.ebay.com/ws/eBayISAPI.dll...e=STRK:MESE:IT

2 speed

http://cgi.ebay.com/ws/eBayISAPI.dll...e=STRK:MESE:IT

[civicex5speed]

Originally Posted by Semi Joe

motor and tranny

http://cgi.ebay.com/ws/eBayISAPI.dll...e=STRK:MESE:IT

tranny single

http://cgi.ebay.com/ws/eBayISAPI.dll...e=STRK:MESE:IT

2 speed

http://cgi.ebay.com/ws/eBayISAPI.dll...e=STRK:MESE:IT

Thanks Joe, your on my ebay fav sellers list. Can the pinnion gear be adjusted on the R2? Is the 2 speed worth the extra money? Or is the gear ratio so close together it's not worth it? I was looking at one trans that was a 2 speed, but it was some lame gearing along the lines of 1:1 and 1:1.5.

Thanks

Clif

[Espeefan]

Clif, PMD is Precision Model Distributors. Or www.gardentrucking.com.

As for the transmissions, planetary transmissions are perfect for the trucks. You really can't beat their small compact design. I'm going to run one in my own truck as well. The one I went with is a slightly larger design, for robotic use, but not much larger. Yes, you give up shifting gears, but you know what? I had a three speed truck and I never really took it out of 2nd gear anyway. I won't miss the shifting that much at all. Sometimes simpler is better too. The transmissions with multiple gears tend to have a lot of slack in them, or backlash. The dogs that slide into the gears need to have slots so they can slip in easier, but that's where all the slack comes from. A planetary will be nice and tight, without any noticable backlash. You notice the backlash most on a 3 speed, when you go forward to reverse, or when the truck rolls to a stop. Also when going down a hill. You stop, but the model rolls a little bit further then you expected. So nothing wrong with a single speed at all, in my book.

The only thing is, depending on what motor you run, and what voltage you run it at, 16:1 might not be enough of a reduction for you. What voltage and motor do you have in mind?

[civicex5speed]

Thanks Espeefan.
I am running a home made motor. It's probably about a 55 turn. If not then a 55 turn Novac motor. The diff might be from a CC01 chassie, so something with a higher ratio would be nice. I hear the CC01 is rather tall gearing.

Thanks for the PMD link, I'll check it out.

[FreddyGearDrive]

Aww...C'mon now Civic.Do er up right! Shift er 6 times.

Maker like the real deal!
FGD

[civicex5speed]

Originally Posted by FreddyGearDrive

Aww...C'mon now Civic.Do er up right! Shift er 6 times.

Maker like the real deal!
FGD

Honestly I thought of doing this, building a flywheel on the motor and a clutch too. You might ask why, but I thought it would be cool to actualy have to downshift and get into a low gear for hills and such.

Thanks gents for all the input. Anyone else have something they like?

[Espeefan]

A flywheel would help keep the momentum up, but if you really want the need to downshift, then you should make the truck underpowered and run a 375 or 380 sized motor in it instead. I've seen it done before.