Kurly

iTrader: (2)

Now were talking.... I like what Im hearing about this car. Im also excited about finishing mine up and contributing to the thread. I ran into a snag when building mine and am waiting on some parts. Otherwise the one thing I have to say about it is that the suspension movement is extremely free. If the forward bite is good them Ive very excited to get the car outside. Keep up the input guys and I will do my best when Im done with mine to do the same.

B00t13g

iTrader: (9)

I'm curious why that is? Adding an additional belt and rearranging the rest of the drive train to fit would throw off the balance of the car, which is an advantage the gz1 currently has. I do not foresee gizmo ever getting away from the two gear setup unless they can figure out a way to do that without moving the motor from its centered position, and even then, why?

CristianTabush

iTrader: (13)

Correct. As a matter of fact, the 2 spur gear layout is patented by Gizmo. Adding a third belt would increase the drive train drag and weight of the car as well. The 2 spur gear system is actually really efficient. The car accelerates harder than any car I have ever driven, with a super smooth power delivery and increased traction over conventional designs. Wheel spin is super low and when running modified, I can run about 15-20 degrees more total timing (either turbo, boost, endbell but usually a combination.) since the car is just easier to drive. A 3 belt system would be a step back, and If I am not wrong, was tested by Gizmo in the early conceptualization days. This car was not just thrown together, it had been being developed in secret for about 18 months without leaking any information.

racer x 1

iTrader: (27)

Curious. Has anyone set the car up for stock? I remeber reading early on that you have limited spur choices due to lack of motor adjustment?

English365

iTrader: (128)

CT mentioned he ran 21.5 with success a few posts back.

CristianTabush

iTrader: (13)

You are actually unlimited in the spur gear selection. The vertical adjustment does not change the motor position, so while you can only use 3 (maybe 4 with a slight bit of filing to the moto mount screw holes) pinions per spur gear combination, you can use any combo spur pinion that you may want so long as the tooth count is 136-138 teeth (total number of teeth).

The Gizmo gear chart does not include spurs past 95, I had made one all the way to 80 tooth, but unfortunately lost it as it had not been finished. I'll have to do it again this week and I'll upload it. However I ran 88T spurs in USGT.

racer x 1

iTrader: (27)

Thats great to hear! I was worried it may not be a good weapon for stock racers!

niznai

You don't need to move the motor anywhere to add a third belt. In fact it can be done by the home fiddler with minimal modifications and with parts off the shelf. All you need is two identical pulleys of the right size on the two spur shafts, positioned where the spurs are right now, flip the motor pinion and have the belt run between the two pulleys over the motor shaft. Attach the spur on whichever side you want. Yokomo had a similar belt setup running around the motor shaft on the YR4. You could actually use one of those YR4 spur holders with a pulley on the back. All this would probably move the remaining spur out only about 5mm or so, so no big deal.

EAMotorsports

iTrader: (79)

Why? If they spent 18 months testing between 2 belt 2 spur and 3 belt 1 spur and released this one why would anyone want to waste their time? I would understand if the car wasnt good out of the box but everyone that has ran one says its great. I saw the prototype ones run at ETS race over seas when I was there in December and it looked great on their tracks as well. Just not sure why you would want to take a step back as Cristian said.

EA

daleburr

The three-belt setup is a pain in the ass to be honest. I made a prototype a few years ago as I wanted to centralise all the weight:



The handling was great, there's definitely mileage in centralising all the weight like that; it was a huge improvement over a standard TC6. But keeping the 3 belts correctly tensioned was difficult with the flexible chassis we run in TC. Fine on a 1/8th car with a thick alloy chassis I'm sure.

The Gizmo setup is probably the best compromise in that it centres the motor up, while still keeping good flex and belt tension. Plus it's more efficient than 3 belts.

foampervert

iTrader: (5)

its all about friction.

belts need tension, which creates friction, gears have dramatically less friction then belts.

This is the reason why shaft (gears) cars, were and still are, used in rc cars... cos in certain applications (such as 17.5t, 21.5t and to a degree... 13.5t, stock or spec type racing), they provide an advantage in speed and acceleration.

Belts are usually used in mod type touring cars because belts can "stretch" a little, providing the car with a little "give" upon hard accelerations (less tire wheelspin) and less transmission damage (mod motors can churn out insane torque).

in the case of gz1, the gears are spurs... so technically the torque of the motor is divided into 2 spurs, effectively halving the amount of torque on the spurs and potentially increasing the life of both spurs (but you need to pay for 2... so it might be no actual net gain... hahahha)

i still love the design and want to get one.

TryHard

iTrader: (4)

funny about the three belt thing... back in '09 came up with iterations of the below design whilst trying to get a good balance... centralised weight was the theme, as well as allowing for shorty and saddle packs.
Having the third belt on solid mounting off of the motor mount helped to combat the flex thing. Plus designed the bearing tubes to have eccentric adjustment to help tensions...

Never got off the CAD screen, and plenty I would alter now.. but still interesting to see the Gizmo and other developments have similar ideas

Airwave

iTrader: (1)

I totally understand the point, but with this system, spur gears are becoming the critical point of the car.

First you must have twice the number of spur gears however the ratio you are trying to achieve. Then, when you change the ratio, the number of compatible pinions per spur gears is very low. And finally, you must take care of what kind of spur gears you are using, I suppose molted ones are hard to use as they are not perfectly round...

I was indeed talking about a third belt to avoid that, no to re-think the whole car. It could be easily achieved by adding two identitcal pulleys on the opposite side.

By the way I agree, two belts are more efficients than three.

Chrissy C

iTrader: (1)

Nice work Ed. The Gizmo appeals to me for the outside of the box thinking.

Not wanting to hijack the Gizmo thread, but I've built and been running for a couple of weeks this take on a BD7. Again, focus is on central weight distribution.

So far it has been working well and given me ideas for the next steps.

gigaplex

iTrader: (2)

That brings new meaning to the phrase "a pinion as big as a spur gear".