11LikesTamiya TB04 Pro
10-22-2013, 08:15 AM
#242
Tech Master
Its about reliability of the car. The teeth that are on the bevels need to be of a certain pitch to be reliable in plastic (or most material) The sizes of the bevels have to be a certain size due to them fitting on shafts that have a certain diameter, so that also forces some sort of compromise. Also a lack of teeth can make the car not be that efficient and quite notchy.
I remember back in the early days of TC we used to sometimes file teeth of gears in the TA01/02 gearbox to reduce the IR to help gearing.. it kinda worked but the gears didnt last for long and the car was not as smooth to drive.
Also the way that the motor is mounted in the car ensures larger gears are needed. For example the A700 has an IR of 2.55 in the same configuration as the TB04 and an IR of 1.9 (ish) for the classic layout.
I remember back in the early days of TC we used to sometimes file teeth of gears in the TA01/02 gearbox to reduce the IR to help gearing.. it kinda worked but the gears didnt last for long and the car was not as smooth to drive.
Also the way that the motor is mounted in the car ensures larger gears are needed. For example the A700 has an IR of 2.55 in the same configuration as the TB04 and an IR of 1.9 (ish) for the classic layout.
10-22-2013, 08:57 AM
#243
IR is good, but the vehicle total weight(1570grams) is what's the problem !!!!
10-22-2013, 11:31 AM
#244
Tech Master
I've been looking at the car, and you can strip weight of the car quite easily and also choose the right electrics. The spool is not great as its heavy, running putty in the front diff might be best.
10-22-2013, 12:02 PM
#245
Tech Master
10-22-2013, 12:18 PM
#246
10-22-2013, 11:23 PM
#247
Tech Initiate
Do you use ball bearings in your gear diff?
Are there pros and cons?
Are there pros and cons?
10-23-2013, 09:34 PM
#248
I'm going to make my comments as I go along and build it.
*the diffs are easy to build. Be sure to get all the flash off the gears before assembly. Don't forget the gaskets!
*i used ride gum in the frnt, but 1000 cst in the rear. It's not enough, needs to be 1500 pr 2k.
*compared to the tbo3, there is a LOT more gear lash that needs to be done, and it's a lot harder to do then it looks. Put the kit described shims in, and then continue to add then till you get the lash out. Do one at a time.
*a assembled tbo3 diff w aluminum out drives is 18 grams, the spool with steel out drives is 19, and these gear diffs are a whopping 29 grams! They have some aluminum parts coming, hope they make some more.
Sacramento beat Golden State, I'm going to bed.
*the diffs are easy to build. Be sure to get all the flash off the gears before assembly. Don't forget the gaskets!
*i used ride gum in the frnt, but 1000 cst in the rear. It's not enough, needs to be 1500 pr 2k.
*compared to the tbo3, there is a LOT more gear lash that needs to be done, and it's a lot harder to do then it looks. Put the kit described shims in, and then continue to add then till you get the lash out. Do one at a time.
*a assembled tbo3 diff w aluminum out drives is 18 grams, the spool with steel out drives is 19, and these gear diffs are a whopping 29 grams! They have some aluminum parts coming, hope they make some more.
Sacramento beat Golden State, I'm going to bed.
10-24-2013, 04:06 AM
#249
Tech Master
I'm going to make my comments as I go along and build it.
*the diffs are easy to build. Be sure to get all the flash off the gears before assembly. Don't forget the gaskets!
*i used ride gum in the frnt, but 1000 cst in the rear. It's not enough, needs to be 1500 pr 2k.
*compared to the tbo3, there is a LOT more gear lash that needs to be done, and it's a lot harder to do then it looks. Put the kit described shims in, and then continue to add then till you get the lash out. Do one at a time.
*a assembled tbo3 diff w aluminum out drives is 18 grams, the spool with steel out drives is 19, and these gear diffs are a whopping 29 grams! They have some aluminum parts coming, hope they make some more.
Sacramento beat Golden State, I'm going to bed.
*the diffs are easy to build. Be sure to get all the flash off the gears before assembly. Don't forget the gaskets!
*i used ride gum in the frnt, but 1000 cst in the rear. It's not enough, needs to be 1500 pr 2k.
*compared to the tbo3, there is a LOT more gear lash that needs to be done, and it's a lot harder to do then it looks. Put the kit described shims in, and then continue to add then till you get the lash out. Do one at a time.
*a assembled tbo3 diff w aluminum out drives is 18 grams, the spool with steel out drives is 19, and these gear diffs are a whopping 29 grams! They have some aluminum parts coming, hope they make some more.
Sacramento beat Golden State, I'm going to bed.
My friend runs the awsomatix. The diffs are heavier than most cars. It doesn't seem to affect performance as long as the drive train is smooth
10-24-2013, 08:52 AM
#250
Almost there...and with any luck, will be racing this weekend 
10-24-2013, 10:38 AM
#252
I was about 20 grams away from minimum weight for TCS racing with the TB-03. That was with a lightweight NSX that is now discontinued. A Protoform LW speed 6 is another 30 grams heavier. That puts this cars weight 80 grams over ROAR minimum...anyway, that's a bunch and that's my concern. I'll know more when I get the car built 100%.
10-24-2013, 10:57 AM
#254
TRF (Tamiya Ready to File)
Not some of my finest work...it was late at night, too many rockstars, didn't have the proper dremel bit; stacked a bunch of sanding discs, and went to work. This did not take a couple of minutes
I sent a pic to the mothership for consideration as an allowable modification. Maybe they'll forward it to the appropriate designer as a proposal for an option part. Of course, Craig gets credit for the idea.
*edit* As pointed out by a fellow racer (ie. getting clowned for a hoopty job) I removed too much material. It's not easy holding a dremel steady while heavily caffeinated.
Not some of my finest work...it was late at night, too many rockstars, didn't have the proper dremel bit; stacked a bunch of sanding discs, and went to work. This did not take a couple of minutes
I sent a pic to the mothership for consideration as an allowable modification. Maybe they'll forward it to the appropriate designer as a proposal for an option part. Of course, Craig gets credit for the idea.
*edit* As pointed out by a fellow racer (ie. getting clowned for a hoopty job) I removed too much material. It's not easy holding a dremel steady while heavily caffeinated.
Last edited by rtypec; 10-24-2013 at 11:10 AM.
10-24-2013, 01:10 PM
#255
Users don't need to grind the radius that far back. Once you hit the screw holes, STOP. The motor screws are the limiting factor. I guess you could clearance the screw and make a 54 or 55 fit, but if you don't want to do that, just make sure it's wide enough for your pinion.
I made a jig to make these on a mill über sano, but I don't have a turntable (or access to one)so it's kind of a wasted effort. Will make it easier to hold still while using the die grinder.
Via PM, Fred said Tamiya was aware of the problem and this mod will likely be okay unless they make something else to address the issue.
I made a jig to make these on a mill über sano, but I don't have a turntable (or access to one)so it's kind of a wasted effort. Will make it easier to hold still while using the die grinder.
Via PM, Fred said Tamiya was aware of the problem and this mod will likely be okay unless they make something else to address the issue.