ceros motor ideas

[blazerbotics]

I wouldn't use the 150 sized Mags, the 400s would be best.

[maddox10]

2.3Hp =1700W=70 amps on the F30-150.

The heavier, fan-cooled Bosch 750gpa is rated at 40 amps.

Nominal torque @1700W for the F30-150=2.3 Nm.
Bosch 750 does 2.2Nm , but at half the RPM of the F30-150

In short. I'm not convinced the F30-150 is a suitable heavyweight drive motor.

I won't stop you from trying , and will eagerly look to the results. Getting small motors 1.8 kg less than the old style Bosches ain't something to sneeze at.

But gear down a lot... That's my advice.

[typhoon_driver]

Get a set of 800w iskras. Got a bunch here that were used in typhoon2. Same diameter as the magmotor just longer. Sealed as well. Nice motors.

[adz600]

Iskra sound ok what are the dimensions

[typhoon_driver]

2 seconds. I'll go measure

[typhoon_driver]

80mm diameter (give or take) and 150mm without shaft, 170mm shaft included.

These are rough measurements. I have had a bottle of wine this evening so they are plus or minus 5mm

[adz600]

too long I only haver 170mm max and must include all gearbox stages and mountings etc, its a tight space

[typhoon_driver]

Sounds a bit too tight. I'd modify the chassis

[adz600]

wish I could but the main chassis brace and cross brace sit on that bulkhead, along with the arm lower stop and when the arm shuts it sits 60mm inside the chassis as it has a ladder style brace construction in titanium so even if I removed the bulkhead the arm would then foul the motor. its a nightmare only the small mag motors would fit upto know with a small single stage box and a pinion output to the kart wheels

[maddox10]

Motor in wheel sounds like the only viable option.

[typhoon_driver]

Change the wheels. Typhoon 2 used wheels that were two inches wide

[adz600]

there is one last drastic option which means removing the custom buffer tank and installing the motors at the rear of the machine, this then allows the fitment of bosch motors or mags in the rear but leaves no space for a off the shelf buffer tank. the weight is then no longer centred over the wheels and the new buffer would be small, also I would need to move the esc but to were I don't think it will fit anywhere else

[Ellis]

Just playing devil's advocate, is there any viability to the cost of experimenting with some big brushless motors? It feels a bit soon tech-wise but in theory it should be possible? You'd want lots of reduction and a bit of slop in the transmission so the motors have the best conditions for starting up, but, certainly the power ratings are easily there in the brushless world. There are several large car ESCs that can be programmed to optimise them for robot drive use. In a heavy I don't think you'd notice any delay, as most feather and raptor size machines now running brushless drives are getting perfectly usable control.

It may simply be too soon/too much of a fuss with all that's involved, but if you intend to rebuild the transmission then the potential of experimentation is opened up. Again just putting the thought on the table.

If I remember right the wheels on Ceros are smooth and wide. As Gary says, they could be a lot smaller, giving you not only way more internal space, but less strain on the motors as less rubber has to be shoved around when turning.

[mattsdragons]

Another option could be change your wheels to something smaller in diameter and use the empty space above to mount some different motors? Yes it does mean a bit of messing around but it should open up your options more and still keeps the weight over the wheels

[Max]

Could you use a 90 degree gearbox?
Or rewind your perm motors with more/less windings (can't remember which) to decrease the number of amps drawn/power?
Or maybe use an electronic solution to reduce current eg. Massive resistor, or a large capasitor to reduce current spikes?