Great Dane excavating co.

[Cooper]

[bigford]

WTF!!! thats huge!!!

[Cooper]

The diff is 11 on pinion and 33 on spur, so that is a 3:1 reduction I need to factor in correct? And the black motor is been living on a shelf for a few years , it's been begging for some electricity!! 1200 kv and the other out runner has a low kv, 256? But is a bit slow for what I was using it for direct drive in a springer tugboat. Probably too low of a kv (rpm/volt) for this use.

[doodlebug]

Originally Posted by Cooper

Question for you guys, the differential I'm using has x number of teeth on pinion and x number on the big gear. Is that a reduction I should consider into wheel rpm? Like if pinion has 25 teeth and gear has 100 is that a 4:1 reduction? After thinking about this beast and weights wanting to haul, I may be putting motor under cab like 1:1 machines using the reduction gearbox same as the 1:1 machines. Gives me more room in front of axle. Yes over engineering this heavyweight. I've been crunching the numbers and just thought of the differential aspect, I did not figure that into the final rpm. I'll go and count teeth on differential pinion and spur gear and find out numbers. Thanks guys.

Yes that's 4:1 ratio.
Cheers!

[jasonthekid]

Holy smokes! Now that's a motor!

[Cooper]

Got some work done on suspension.




Possibly making a true air ride,,, probably not but it could work. Was planing on springs with orings as guides. Breather hole will be hidden on bottom and between rod and cylinder.

Was pushing down as hard as I could to compress the trapped air. Almost could bottom but not quite.


And got this, I decided to place the motor ,yup the big black one, under the hood so to speak and have the planetary gearbox in front of axle with a transfer gear to motor. Just like the 1:1. Why make this simple?? Always like way engineers have done the hard work on the 1:1 machines. So copy that .

[DADSGARAGE]

Originally Posted by Cooper

Question for you guys, the differential I'm using has x number of teeth on pinion and x number on the big gear. Is that a reduction I should consider into wheel rpm? Like if pinion has 25 teeth and gear has 100 is that a 4:1 reduction? After thinking about this beast and weights wanting to haul, I may be putting motor under cab like 1:1 machines using the reduction gearbox same as the 1:1 machines. Gives me more room in front of axle. Yes over engineering this heavyweight. I've been crunching the numbers and just thought of the differential aspect, I did not figure that into the final rpm. I'll go and count teeth on differential pinion and spur gear and find out numbers. Thanks guys.

Hey Cooper....great job on the axle and susp. cylinders look great!! If you use a very small vent hole in the cylinders it might act a bit like a shock restricting the movement while the suspension is unloading...just a thought...

Something to remember/consider is the diameter of the tires when trying to figure out the ratio....my truck also has 8.5" tires and it is geared to turn the wheels at about 38rpm, 8.5 x 3.14159 = 26.7" circumference , 38x26.7=1014.7 inches per minute or 84.5 ft per minute. The banebots motor gear box actually turns at about 65-70rpm not the stated 90, at least the one I have turns at that speed, the 540 motor turns at 16800 divide that by 256 which is 65.6rpm on the output shaft. Here is a link that might also be helpful on calculating the needed power/torque....

http://www.robotshop.com/blog/en/dri...zing-tool-9698

Putting the motor up front and using a drive shaft will make it more like the real deal...should look great!!! I used chain drive for two reasons....easy to change gear ratios and the linear actuator is right in the middle of the frame rails so there was no way to run a drive shaft to the rear end. Did you do any more work/testing on the telescopic cylinders??? We have one in the shop at work, I think it's off a 789 not a 785 , one reason for the double acting telescopic cylinder is to decrease the time it takes to lower the box instead of just letting it drop under its own weight (time is money) , the other reason is it help hold the box down tight to the frame shims which helps add overall rigidity.
Looking forward to seeing the progress on this build...keep up the great work!!!

KP

[Cooper]

Some more done on shocks. So far they are just an air shock. Can push my whole body weight (as much as my hand can take) down on them without bottoming and they spring back. Maybe just go with air ride

[Cooper]

Ok got another gearbox today, a bit more robust, just a size comparison on planetary gearbox and motor along with one of our truck motors. gearbox is 4:1, 3:1, 3:1, and diff is another 3:1 reduction. Should end up around 90rpm. (Or 100) motor kv isn't an exact science) and with this gearbox I can make the last two or one stage a 4:1 if I need more reduction. I've settled on plans, rear with 3:1 differential, planetary gearbox with reduction in front of axle, two transfer gears to get driveshaft higher in frame, driveshaft to motor housed under hood. Very similar to the actual 1:1 machines.



All in my head at this point. I may start making some notes for reference

[egronvold]

[/QUOTE]

I guess "There's no substitute for cubic inches!"

[Cooper]

Build it bigger right? Lol!! I keep having to remind myself this is still 1:14 scale!!

[bigford]

what is this? and what are you going to do with it???

[Krewmember]

I'm pretty sure it's gear stock.

[Cooper]

Yes, I need to make a transfer gear to get the driveshaft higher before entering planetary gearbox. Now I can just cut the size shaft I need right from the gear stock, no set screws, nothing to come loose. The pinion gear on gearbox has a key way 1/16" I think? So all I will need to do is cut an external key way, that's easy.

[Cooper]

Merry Christmas everyone!! I hope everyone and family is well and Santa brought lots of goodies!!

Haven't had much time lately so everything is just rough parts/shapes. Details will be milled in once everything is proven to work/fit. Decided to make a new pinion shaft to allow gearbox to be as close to diff as possible. Also some 3d printed parts will be fitted to give more detail towards end. Cut the pinion and a shirt shaft, I will be brazing that together for strength.




Again everything is square chunky parts for now,,,,

[RCP57]

The pinion mod looks good! You and KP are giving me the itch to build something for myself but I must behave...

[DADSGARAGE]

Taking shape....looking good!! What gear ratio is that P80 gearbox?

[calum_scania]

Ok got another gearbox today, a bit more robust, just a size comparison on planetary gearbox and motor along with one of our truck motors. gearbox is 4:1, 3:1, 3:1, and diff is another 3:1 reduction. Should end up around 90rpm. (Or 100) motor kv isn't an exact science) and with this gearbox I can make the last two or one stage a 4:1 if I need more reduction. I've settled on plans, rear with 3:1 differential, planetary gearbox with reduction in front of axle, two transfer gears to get driveshaft higher in frame, driveshaft to motor housed under hood. Very similar to the actual 1:1 machines.

All in my head at this point. I may start making some notes for reference[/QUOTE]


This has maybe been asked before but there did you buy those motors from?

Calum

[Cooper]

Hey calum, I forget exactly where I got the motors or for what I was intending to use them. Had a boat project I had them for. This is one site I have frequented for boat supplies. Link is motors they offer.

http://www.offshoreelectrics.com/pro...ushless+Motors

I think they are a TP power brand motor.
Lmt, a German company makes some pretty high end motors,

https://www.mgm-controllers.com/cars/lmt-lehner-motors

[Lil Giants]

So that black motor is what diameter & what kv?