Creating a DIY Battery-Powered Toy Car Using DeWalt 12V Screwdriver: Mechanic's Insights Needed

Hello

I promised my daughter that I would make a toy car powered by battery next year.

I am good at electronics - I have been in it for over 20 years but this time I had to deal with mechanics and this is where the stairs begin.

I am asking the moderator to move to the appropriate section of this topic if I put it in the wrong section and I apologize in advance, please do not remove the matter important to me.

I am asking fellow mechanics who are more familiar with car matters.

I will describe my project from the mechanical side, how I would see it and what I was thinking - I am asking for advice if such solutions will work.

1. As a drive I intend to use a DeWalt 12V two speed screwdriver - or two screwdrivers.

https://www.google.pl/search?q=dw907&client=o...ved=0ahUKEwj43IXHycLWAhVDmbQKHQGTBKQQ_AUICygC

The screwdriver has two gears and 0-350 rpm or 0 - 1200 rpm, respectively

I'm going to use a stronger gear - lower speed.

I intend to drive the rear using 26cm wheels

http://allegro.pl/show_item.php?item=6680219694

I hope that the moderator will not remove the link but unfortunately I have not found a photo of these wheels anywhere else on the Allegro

Max load up to 40 kg per wheel quite light, of course you have to knock out the bearing and mount a rigid threaded rod fi 20mm with the sleeve and on the outside squeeze with washers and tighten well

Outside, I will use a cap nut closed on the other side, i.e. a bearing with a housing will be attached from the car side

https://www.wszystkodlarolnictwa.pl/moduly/sk...les/big/15705/-/Lozysko-z-obudowa-UCP213-.jpg

Of course, the bearing for a threaded rod fi 20 also bolted to the rod from two sides and screws housing to the chassis - welded from angles, but more on that later.

The second rear wheel is mounted in the same way on this rod - the shaft rigidly and through the bearing to the chassis between the wheels will be a gear wheel also bolted to this threaded rod (rear shaft)

http://allegro.pl/listing/user/listing.php?st...ch=ss-base-relevance-floki-5-nga-hcp-uni-1-4- 0905

Gear wheel with 20mm inner diameter and another one with a 10mm inner diameter on the bolt and also bolted

http://mixstor.pl/1340-home_default/101smgn6x40.jpg

The screw will have its head cut off and screwed tightly to the screwdriver - if necessary some of these elements will be lightly welded to avoid unscrewing.

So we already have the back and I see it more or less so I ask for opinions if it can be like this or possibly how to do it better and from what.

The next thing is the front swivel wheels and here the situation is a bit complicated - the front wheels have bearings in the wheels and the threaded rod will also be fitted from the outside with a dome nut and on the other hand the element will be used as below, unfortunately I did not find such things in Poland only on ali ...

https://pl.aliexpress.com/item/1-PCS-PHSAL20-...readed-Rod-End-Joint-Bearing/32811307444.html

afterwards this element from the bearing side will be fastened with a screw to the welded chassis structure. And in this way I handle the swivel front wheel - of course the second in the same way assembled and connected by a parallel rail to be able to turn two wheels at the same time.

Now the steering wheel remains - from the Tico car small and handy, on the other hand, I think here to tighten this rail for a 33cm long sliding gate on this crossbar - this is quite the type of teeth M4

http://allegro.pl/ar-met-listwa-zebata-z-tworzywa-odcinki-33cm-i6957431262.html

For this mode with the same tooth spacing put on the rod on which the steering wheel will now by turning the steering wheel will rotate the mode at the bottom and move the cross bar through the toothed bar and thus will change the position of the front wheels.



And the last thing I'm thinking about right now - depreciation

Depreciation will be made in such a way that there will be two stable and movable bases separated by springs installed on M20 bolts, bolts with incomplete thread and the spring will work, of course, where the thread is not

https://www.art-nierdzewne.pl/din-931-szescio...0x120-din-931-a2-szesciokatna-nierdzewna.html

and spring

http://allegro.pl/sprezyna-naciskowa-nr-162-wymiar-4x25-5x84-mm-i6921573867.html

I wonder whether to also give linear bearings from the bottom of the spring

https://www.google.pl/search?q=łożysko+liniow...ZVAKHYOACo4Q_AUICigB&biw=1024&bih=461#imgrc=_

Well, probably all ideas when it comes to mechanics please advice because if I order from China I have to think carefully

In electronic terms, the engine will be connected to a 12V 18Ah battery or two depending on the operating time and the engine will be through the PWM controller to regulate the revolutions, i.e. the speed of course the PWM potentiometer will be combined with the accelerator pedal - there is still the issue of braking but maybe the speed will not be dizzy and braking will be carried out by a gear in the screwdriver - just after releasing the accelerator pedal the speed will decrease quickly. Anyway, the assumption is that the vehicle will drive slowly - otherwise you will have to think about braking.

Once again, please do not remove the post, any transfer from the relevant department I care about answers and advice, because next year the construction of the vehicle will start and in the end there will be publication on the electrode, like my other designs.

Best regards and waiting for some advice solutions for which I thank you in advance and I am grateful ....

I would use a scooter engine for propulsion.
By buying 2 scooters you have engines, a chain, gears.
Simple and cheap.
In the case of screwdriver engines, mechanical work is a bit
- engine mount
-mounting the rack on the motor axis and it would be appropriate to support the axle from the other side.

See the steering system in the original.

Two screwdrivers will exceed the value of the finished car, as I would have used wiper motors. After that, seeing the materials you want to use, it looks like it would be an armored car. For example, screw No. 20, it probably doesn't even have a passenger car.
Is it not better to buy ready e.g. damaged or not complete and then tune it?, There would be some base.

I made the kids a tricycle from an old car seat, a pram axle and a piece of a bicycle. Front-wheel drive, high maneuverability and no differential. I used the rear bike wheel on the front because of the "free wheel". I welded to the original rack matched to the engine. I bought the electric motor, chain, gears, controller and shifters in the online store. Supply of two 18 ah gel batteries. 500w motor The car is flying, I think it reaches 25km / h. Batteries last more than an hour.

Hello

Engines are left from screwdrivers for 30 PLN on scrap metal, you can buy a box of screwdrivers for batteries - of course efficient without battery so the drive will be like for free.

Mounting as I wrote the mode on the main shaft + the other on a small shaft 10mm screwed from two sides into two screwdrivers, unless I use one on the other supported on the bearing. The screwdriver will be called an amortized surface, so the forces will act more on the main shaft than on the screwdriver shaft - I will probably make some housing for these two modes in such a way that I pour oil on the bottom to lubricate the modes. In the case of two screwdrivers, of course, the motors will be connected in opposite way, i.e. for one right it is for the other left and without electronics in the screwdrivers directly under my PWM system.

As for engine mounting, they will be mounted on entire screwdrivers with gearboxes used in the screwdrivers. There will be a roller on the heads and, if needed, the heads will be slightly caught by welding to a small roller.

As for the costs of screwdrivers I gave above where to get cheap screwdrivers cheaply, as for the whole finished Chinese car - it falls off due to trash and plastic wheels. In addition, probably two children will be crazy about it so it must be "armored" of course in the test phase daddy will be a load (about 60kg) so also must withstand I try to choose materials so that they are the lightest roller on the rear axle must be thick so that it does not bend everything especially since there will be a main load - sitting.

Besides, as far as I know, Chinese vehicles of this type have no depreciation or are very poor - let's call it "the better"

In summary, the costs will not be cosmic at all
- screwdrivers - scrap
- welded construction - angles - scrap
- the purchase remains - shaft - bearings - bolts - springs - wheels - modes
- I have electronics and battery.
- Parts from the car type gas pedal steering wheel.

A colleague Daras41 raised an important issue of the rear differential - the fact I did not think about it and you will have to think about it - on the other hand if you can't do it on the ground (ground) it should not be an obstacle - I think I lose power for swallowing and wear of larger wheels - the worst after the cobblestones would be felt well depending on the load.

For the materials used were given as an example and probably during construction there will be one thing you will need to change maybe the cupid screws will be smaller.

As for the steering system in the original is made on the principle of a lever turning the wheel turning strip - this solution is unsatisfactory for me - the mode and strip seems better.

Now I have a new topic for thinking - differential system - how and what to do easily - of course with rear-wheel drive - two wheels remain front - four in total because the car must have 4 wheels

Regards ....

Engine life will be short.
The load on the screwdriver is axial.
Turning off the power will cause engine braking, the transmission will not withstand.

Added after 16 [minutes]:

If you use 2 motors, a differential mechanism will not be needed.

Hello

I wasn't there a bit and the concept and approach to the subject changed

Screwdrivers probably would not be better suited such drive systems equipped with a differential system.

https://pl.aliexpress.com/wholesale?catId=0&i...ive_id=SB_20180212045955&SearchText=transaxle

I purchased one used together with the 24V frame

The frame is on the steering springs will need to be redone and the whole thing looks like this

As soon as the weather is freezing and it can be done outside, I start the project



As for now, I started the engine with a voltage of 12V and you can drive on it, but a little slow at 24V should be OK

Regards ...

How's the car? Show off the effects.

Hello

The toy car in the basic version without equipment is made.

In short, I will tell you but I will put the whole project as a separate topic.

Mechanical construction - photo frame + aluminum frame added to not add too much kilograms. Floor panel from the outside. The front lamps of the kanlux luminaires are rear with a car brake light. Steering wheel pedals ignition from Tico, seat from some chair.

Electrical system consisting of relays to activate the lights and power the car and change the direction of travel. Switching functions is only the ignition switch does not have a stick as in a traditional car.

PWM 20A motor controller for speed regulation - gas pedal mechanically coupled with a slide potentiometer.

Electromagnetic brake which is connected to the brake pedal.

In addition, there is a cable for charging the battery under the seat - 2x12V 18Ah gel battery

It cost a little work - it is a lot of fun, but as it happens with my daughter, everything gets boring quickly so during the summer she went and slowly goes into oblivion but I still have a son of 1.5 years and when he grows up a bit the car will improve by then and will be as he found.

For charging I use a 24V 1A charger to charge gel batteries and I have a 24V 30W panel with a solar charge regulator - as it was outside the sun was connecting the panel under the car and charging was for free.

Here are photos of my project - panel car

I would forget to write about the speed - about 12km / h so if I try I will catch up with the car running. Working time of the car on full batteries - it's hard to say - it is fun all day long, but it is known that the car does not drive all the time, but my daughter drives a little, she parks and drives again - you would have to do a test on a straight road on full batteries which distance will cover. But I can't do such a test.

The current consumed by the system is heavily dependent on gas depletion and reaches 10A with the weight of the daughter - the weight of the person in charge according to the manufacturer's data is about 100kg. Only the power consumption increases.

Engine and drive system module manufactured by ASI Technologies.



I will leave the photos of the interior for publication when setting up a separate topic.

Regards ....