55 turn still too fast!

[Brian in PA]

Hi guys and girl. My current build is employing a 55 turn crawler motor with no reduction. It seems still too fast (did some bench testing with the battery to the motor direct). My last 2 builds used a PMD 4:1 and a RC4WD 4:1. I was told that the 55 turn was the way to go. Now I really don't have any room to put a reduction in this truck. Is there a different (slower) motor that I could get?? Any help is greatly appreciated!!

Thanks!
Brian

[rc_farmer]

Hey Brian, did you change the stock pinion to a 6th pinion?

[Brian in PA]

No, I think it is still stock.

[fhhhstix]

First off a smaller pinion such as a 6 tooth will help. I tried a 6 tooth and a 55 but it is still not as slow as a 4:1. Next if it is still to fast you can go to a 65 turn or a 75 turn with the smaller pinion. Are you planning to use an MFU or similar unit in this truck, if so I think you could still get by with an Integy 4:1 which would put the motor up over top of the servos with no modification.

Travis

[rc_farmer]

Originally Posted by fhhhstix

First off a smaller pinion such as a 6 tooth will help. I tried a 6 tooth and a 55 but it is still not as slow as a 4:1. Next if it is still to fast you can go to a 65 turn or a 75 turn with the smaller pinion. Are you planning to use an MFU or similar unit in this truck, if so I think you could still get by with an Integy 4:1 which would put the motor up over top of the servos with no modification.

Travis

True-that!

[Brian in PA]

Thanks Guys! Where would I find that integy unit at?

Brian

[ihbuilder]

brian I'd go with the integy box like travis stated ,thet're not expensive , but use a 55t or 65t unless you want it sllloooowwww like my 5900 which is 75t 3.9:1 integy w/stock pinion + tami 3 spd .

[fhhhstix]

You can order it directly from Integy or I know a guy who has a couple. Here is the part # C22726SILVER for some reason the silver one is half the price of the blue one but they are identical other than color. The package says 2.5 ratio but it has a second gear in it for 3.9:1.

Travis

[CustomRCmodels]

hey guys ,
keep in mind , in case you are using a Tamiya MFU , the better choice is a gear-reduction and using a motor not much slower when like a 35 turn crawler motor ,
otherwise you are messing up the power-settings of the MFU unit , especially when you drive your truck without a trailer ( power-selector-switch in the 5th wheel )
For the guys been in Indy this year , my yellow Knigh Hauler is equipped with a 35 turn motor and a 5:1 reduction , which seamed to be just the right speed , even when driven in 3rd gear . And I also “timed” the 35 turn motor about 10 degrees fast , means I do have faster speeds in forward as in reverse.

[Brian in PA]

Thanks guys. I will be using the MFU.

Brian

[DieselKid]

Brian,

After seeing and operating Travis' rigs at Indy I'm hooked on the Integy reduction he has mentioned! In fact I ordered 2 off the bay last night...

http://www.ebay.com/sch/i.html?_from...All-Categories

-Alex

[SuperDutyScaler]

i have a 65T and a 6tooth pinion and its still too fast. im saying up for a gear reduction now

[Juganought]

Have you guys taken weight into the account? I have both 55 and 65 with six tooth. I am assuming, after you load it with a trailer or other, this should slow it down some more. Front and rear wheels are loaded with lead amounting to approx, 3 to 4lbs.

[CustomRCmodels]

To get a nice operating ( drivable ) truck there is now way around a gear-reduction .
Just lower RPM motors or limiting the power to the motor via endpoint-settings on the transmitters , adding weight and such is just cheating and you want be happy with it .
It would be like on a real car or truck in which you are trying to take of in the highest gear with only applying very little throttle . You don’t have power plus you sucking up the fuel .
The idea behind gear-reductions is not only the slower more powerful , plus much more efficient ( less current draw from the battery ) driving , but also the braking .
We saw this again this year at Indy , driving up and down the bridge , you could tell right away who had gear-reductions in his truck . A higher gear-ratio gives you also better braking .
As for the Tamiya drive-train based trucks , I used to use my self-made 55 turn motors
( way before the lathe-motors and crawler motors were available ) in combination with a self-made 3:1 gear-reduction . This resulted in a actual speed-reduction of about 6:1 ,
since a 55 turn motor creates about ½ the rpm as a stock 27 turn motor ( 8000 rpm vs 15000 rpm ) .
This type of reduction was just the right speed for the Tamiya 3 speed based trucks .
When Carson introduced there original ( plastic housing ) 4:1 reduction , that alone wasn’t enough , but a good start , even thought a lot of guys used them , some also with the combination of a 55 turn motor which gave you about a 8:1 speed reduction .
Back then , together with RIC from PMD , we created the stronger , aluminum casing , modified Carson gear-reduction and I made some changes to the gearing ( additional ball-bearings ) . This GRU is a nice choice if you don’t have the room inside the cab , but room in your frame .
Now with the introducing of the Tamiya MFU unit , the idea with the lower rpm motors doesn’t work so well anymore , since the MFU is tailored for a 27 turn motor and if used with a higher turn motor ( lower current draw ) the effects , down/up-shifting , sound-effects , drivability , just don’t work as good .
The choice here would be to stick with a 27 turn motor and do the speed reducing via gear-reduction only.
Since I never was a friend of these cheap Mabuchi motors , I went with 27turn motors in a modified motor-can ( adjustable brushes / timing and ball-bearings ) , either self-made , by using the guts out of a Mabuchi motor and installed in a modified motor-can or using the Orion 27 turn Rush series motors , which are now hard to come by .
Therefore I am using now the 35 turn Integy crawler motors with a 5:1 gear-reduction ,
which seams to be just the right speed .
Besides the ready to install gear-reductions from PMD or RC4WD , there are plenty of options these days to make up your own gear-reductions from air-plane gear-reductions ,
or gearboxes from crawlers and such .

Maybe we should make a “sticky” out of this , since I would have a bunch of info’s to contribute to this subject , including website links , since I have a bunch of these info’s cluttered all over my website and these questions about motor’s and gearing seam to keep popping up regularly.

[SuperDutyScaler]

that would be nice custom, i need a gear reduction but PMD isway too expensive. im picky so i want something that looks good, is strong, and wont kill me in price

[Bsorenson79]

I never used these but this might help you out.

http://store.rc4wd.com/search.asp?ke...=18&search.y=9

[Brian in PA]

Update! I got the Integy GRU installed. It is a very nice piece and perfect for this application. it is also very affordable! Thanks for the tips!

Brian

[Juganought]

Can we please see it action Brian....Please

[Brian in PA]

As soon as my MFU and radio comes in I'll get a vid up.

Brian