Daimler

[Chrysanthos Kanellopoulos]

I've finally built a Daimler as 1:6 , 77 cms long and about 7 kgrs heavy with batteries (12V, 7 A).

It is built around pneumatic wheels and the front parts is hinged to the rear and suspended. It is temporarily constructed out of 15 cm thick plywood and I hope to eventually have it built out of 4mm thick laser cut aluminium.

 

My question is: Are the 7 kgrs going to run on 12 V, 14.4 or 18 Volt right angle drills at 400-500 RPM and 1200-1500 RPM (fast gear) ? This translates to 15 kms/h and 45 kms/h with 80% performance on the motors.  Anybody knows if it is going to "jump" a little over bumps and do stunts ? with the fast gear I am supposed to have all teh speed I want, but very little torque.

If not, I will consider mounting a gas engine.  I know from Bajas 5B, you can have 12 kgrs run and jump .

I'll post images during teh weekend.

Chrys

[Chrysanthos Kanellopoulos]

So, these are the photos I promised.  I still have to work on the suspension of the other side. but just to give you an idea.   it seems to me like a heavy construction . I doubt that two 12 Volt drills can make this 7 kgr heavy thing roll and run.  I better go with two 18 Volt drills - one on every rear wheel- and see what happens.

It'll be sightly lighter if the ply walls were made out of 4 mm thick aluminium sheet.

Chrys

 

 

-----

 

I've finally built a Daimler as 1:6 , 77 cms long and about 7 kgrs heavy with batteries (12V, 7 A).

It is built around pneumatic wheels and the front parts is hinged to the rear and suspended. It is temporarily constructed out of 15 cm thick plywood and I hope to eventually have it built out of 4mm thick laser cut aluminium.

 

My question is: Are the 7 kgrs going to run on 12 V, 14.4 or 18 Volt right angle drills at 400-500 RPM and 1200-1500 RPM (fast gear) ? This translates to 15 kms/h and 45 kms/h with 80% performance on the motors.  Anybody knows if it is going to "jump" a little over bumps and do stunts ? with the fast gear I am supposed to have all teh speed I want, but very little torque.

If not, I will consider mounting a gas engine. I'll post images during teh weekend.

Chrys

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[Chrysanthos Kanellopoulos]

Sorry it's just over 11 kgrs heavy.  What kind of motor/s will make it run? Any advice is  greatly appreciated.

Chrys

[Odyssey...@aol.com]

very interesting floor layout.

 

Chris,
Odyssey Slipways

---

AOL Search: Your one stop for directions, recipes and all other Holiday needs. Search Now.

[Odyssey...@aol.com]

just wondering, but since this is a single axle vehicle, is it really necessary to use 2 motors?

 

how will you be getting the power to the rear wheels?

 

Chris,
Odyssey Slipways

[Odyssey...@aol.com]

just thought of something else, your front wheel axles, will you be shimming them up, further from the plywood floor? will the current mounting for them be sturdy enough vs the spring suspension - will they tilt and dig into the wood when running over rough terrain?

 

are you going to be using a large servo and connecting it directly to the steering linkage or will you be putting something between them to give the servo output more torque (from the arm to the steering arm) and also to help prevent feed back from bumps and hard turns/terrain (to help prevent extra strain/wear on the servo)?

 

i'll have to look again, but is the gun going to be permanently mounted or will it have a tilt (up/down) function, just wondering as if your shooting while driving, your front end will take some of the shock, but the rear chassie will still move up and down as to the hinging of the forward part.

 

Chris,
Odyssey Slipways

[Chrysanthos Kanellopoulos]

The floor of teh front part will eventually be constructed out of laser cut aluminium sheet. Only a plywood dummy for now, to test my systems.

just thought of something else, your front wheel axles, will you be shimming them up, further from the plywood floor? will the current mounting for them be sturdy enough vs the spring suspension - will they tilt and dig into the wood when running over rough terrain?

 

----- They won't dig into the aluminium, plus I am planning to have them installed and rotated on a big roundel.

 

are you going to be using a large servo and connecting it directly to the steering linkage or will you be putting something between them to give the servo output more torque (from the arm to the steering arm) and also to help prevent feed back from bumps and hard turns/terrain (to help prevent extra strain/wear on the servo)?

 

---- Just a 25 kgr/cm servo with a steer arm as in teh attachment. That will translate to 6 kgrs on the end of teh 4 cm long steer arm. Like what can I do to prevent the extra strain on the servo?? any help?

 

i'll have to look again, but is the gun going to be permanently mounted or will it have a tilt (up/down) function, just wondering as if your shooting while driving, your front end will take some of the shock, but the rear chassie will still move up and down as to the hinging of the forward part.

 

---- The turret and gun will be mounted on a deck bolted onto the L-shaped beams that extend from rear to front. I am hoping that the rear does not move up and down a lot.  But that's like with all suspended or not vehicles. They all rock up and down.

 

---- And I basically want two motors in order to increase torque. My biggest concern is to make the 11 - 12 kgrs roll.  How heavy is Gordon Rapson's vehicle? It is electric.

 

Alternatively,  I could mirror the rear part to the front and mount four 12 Volt drills with tank/skid steering as in:

http://www.youtube.com/watch?v=BS9pGOxQ10Q

That's better for aiming. And then I can definitely run the motors on the fast gear = 1200 RPM or 45 kms/h! MOre weight, but without the pains of steer arms...

 

Chrys

[Chrysanthos Kanellopoulos]

Will a Sabertooth 2x25 take the 25 amps of two 12 Volt drills on every channel????

[Chris Malton]

According to the spec, it should be able to deliver 25A on both motor
channels. Shove some fuses in there, just in case, though.

Chris

[Chrysanthos Kanellopoulos]

That's my latest. lightly sprayed so you can tell hull from rubber and
steel.
I'll have to choose between two drills and a costly steering servo or four
drills and a Sabertooth 2x25

Chrys

[Chris Malton]

Looking good Chrys.

Chris

[Chrysanthos Kanellopoulos]

Thanks guys. If you helped me make this 12 kgr beauty run, I would be
eternally grateful.
Chrys

----- Original Message -----
From: "Chris Malton" <chr...@cjsoftuk.dyndns.org>
To: <rctank...@googlegroups.com>
Sent: Sunday, November 09, 2008 11:44 AM
Subject: [TANKS] Re: Daimler

>
> Looking good Chrys.
>
> Chris

[Chris Malton]

Why costly steering servo?

It shouldn't be too hard, surely?

Chris

On 09/11/2008 09:37, Chrysanthos Kanellopoulos wrote:

[Chrysanthos Kanellopoulos]

A servo with a torque of 25 kgr.cm and steel gears should cost about $ 78
plus shipping.
At the end of a 4 cm long servo arm the torque should be about 6 kgrs *only
*. Considering all teh bumps
Chrys

----- Original Message -----
From: "Chris Malton" <chr...@cjsoftuk.dyndns.org>
To: <rctank...@googlegroups.com>

Sent: Sunday, November 09, 2008 6:44 PM
Subject: [TANKS] Re: Daimler

>

> __________ NOD32 3434 (20080911) Information __________

[Chris Malton]

OUCH! I'm sure there must be a better way.

That said, I can't think what it might be at the moment.

Chris

[Chrysanthos Kanellopoulos]

This is the kind of servo used in Bajas 5B, if you know them. THey are
awfully heavy, fast and strong, 92 cm/ 1 yard long buggies, - they weigh 12
kgrs.
I've seen them being abused and thought that nothing less is acceptable.
Chrys

----- Original Message -----
From: "Chris Malton" <chr...@cjsoftuk.dyndns.org>
To: <rctank...@googlegroups.com>
Sent: Sunday, November 09, 2008 7:08 PM
Subject: [TANKS] Re: Daimler

>

[Michael Clark]

Have you looked at http://openservo.com/?

I was thinking something like this with a heavier duty motor driver would give servo control over larger motors.

I was looking at it for a linear servo, but I'm going another direction.

[HV]

I don’t have any advice on drill motors, but I built a similar
chassis, which weighs about 18 kg. It looks like you are using the
same wheels (25 cm) I am using. I am using 4 kiddie car motors, which
move the vehicle at about 5 - 6 km/hr. It is skid steered. It takes
less than 20 amps total in half-skid steering mode. I use half-skid
steering to limit current draw. I don’t have an ESC yet. The vehicle
is not very scale because of the wheel size and length/width ratio are
way off. It looks more like a bomb squad robot than an armored car.

On Nov 9, 5:32 am, "Chrysanthos Kanellopoulos" <xchr...@otenet.gr>
wrote:

[Chrysanthos Kanellopoulos]

Frank , would you consider adding my Daimler looking thing to the Pending Designation page?

You can lift off and paste as many photos as you like from the :

http://groups.google.com/group/rctankcombat/browse_thread/thread/8c8b17c600051ca9

and the only CAD screen shot attached here, if you like.

Tanks,

 

Chrys