Using a battery drill as motor for a Mayfair

[Tore]

When I started my Mayfair project, I was determined to build it completely stock.  No improvements or alternations that would only make the build take a lot longer...

For power, my plan was to use motors from RLT.  But, Richard suggested I should try using a battery drill instead.  At first, I was skeptical.  Would a drill be powerful enough? 

The Mayfair is small and only weights approx half of a Toylander.  It only have place for one kid, while the Toylander often has one grownup and 3 kids onboard, plus 2 kids in the trailer...

A battery drill has gearing, it has electronic speed control and reverse...  It might work.

I decided to try.  The drill would have to be a quality one, not a ?19 Chinese thing.  DeWalt drills are plentiful on eBay, and I got a 12V DC727 for... ?19.  Brand new, it even came with a manual and guarantee card.  Boy is that guarantee going to be void.

The donor drill on the altar, ready to be sacrificed:


Slightly in pieces:


The drill has a speed of 400rpm in the lowest gear.  The specifications claims it has an output power of 230W.  I will use a small sprocket on the motor and a large one on the wheel, giving an additional gear ratio of 5:1 (1:5?).  That should give a top speed of 4-5km/t.  Quite suitable for a 2 year old driver.

Status for the project now is, I'm waiting for the wheels to arrive from RLT.

To be continued... someday.

-Tore

[jock]

Hi Tore,
I am looking forward to seeing how the drill goes, I am thinking of building a mayfair in the future, I think I may be tempted to use two motors as I'm not keen on the idea of the power to one wheel.

Jock

[Tore]

Hi all,

I'm happy to say the wheels arrived from Richard today, and they look really nice!  Now I can make the necessary measurements and start making the axles and figure out how to mount the guts from the drill...

This is how the motor and gearbox looks with all the unnecessary plastic removed:



A closeup of the gearbox and output shaft:



In the upper picture, you also see the drill's trigger and the speed controller.  The unit has a "plunger pot" which should be fairly easy to use for the throttle.

But the first task in hand is putting a layer of glass fiber cloth and epoxy resin on the Mayfair's body.

-Tore

[Robert]

Hi Tore,

I'm really curious to read how it all works out with this motor.
What about the cooling of it?
Don't you think that it can get overheated ?

anyhow, it's a challenging idea!

[Tore]

So Brian, you're a skeptic?  That makes two of us.

I was planning to use motors from RLT in the Mayfair, but Richard suggested I try a battery drill.  Consider it R&D.

Fitting the drill motor and gearbox has proved *very* simple - the sprocket will screw right onto where the chuck was, and the clutch provides a simple place to attach a bracket.  Pictures will follow.

I will make the bracket attach to the car body in the same way as the RLT motors, so if the idea (and drill motors) fail I have a backup plan.

-Tore

[brian]

Hello Tore,

I hope it works out ok. 

I know you will get motion, but it is the longevity I was concerned about.

Regards,

Brian.

[Tore]

An minor status update from me today:

I've made most of the front suspension bits and motor mounts for the Mayfair.



The front suspension is ready, part from the steering arms.  Basically, I'm waiting for my new plasma cutter to arrive, and the steering arms will be a great first job for it.  I'm making all the bits and pieces from stainless steel - not because it's needed, but it's what I have at hand.  And they look nice and shiny.  Those of you who know the Mayfair might notice I've used larger dimension box steel for the front member.  It's not that I think it is necessary, but I had some 25x25mm left over from the Toylander.



Now to the interesting part.  Motor mount.



I've made a mounting plate from aluminum that attaches to the DeWalt gearbox, where the adjustment for the clutch used to be. Most of the gearbox is hidden inside the MDF, and is well supported.



The sprocket is threaded onto the axle and locked by a left-threaded screw, just as the chuck used to be. The axle from the gearbox is supported by a large ball bearing, I hope it will withstand the lateral forces from the chain.



You may notice I'm using small #25 chain and sprockets.  This is because the drill has an output speed of 400rpm, and needs to be geared down to less than 100rpm on the wheel.  A 1:4-1:5 gear ratio would be difficult using bicycle chain.  The Mayfair is a lot lighter than a Toylander, and will only carry one child, so I hope the #25 chain will be strong enough.

So far, the Mayfair has been a thrill to build. I "forgot" to make the rear axle last time I had access to my lathe, but I hope to go back to make it sometime in february.

-Tore

[brian]

My word Tore, that's a lovely bit of engineering and joinery, well done.

What line of business are you in that has a lathe, welder and plasma cutter at your disposal??  Do you take in weekend guests?

Keep up the good work and keep us up to date, even if it is only to envy you your skills.

Regards,

Brian.

[Tore]

Thanks, Brian.

I'm actually a computer programmer.  I just inherited my father's lust for expensive tools.  And his tools.

-Tore

[brian]

And his abilities too Tore from the looks of the quality of your work.

Regards,

Brian.

[Tore]

He was a great teacher.

-Tore

[Richard]

What a fantastic job you are making Tore.

Have you seen my friend Joakim lately? Please give him my regards when you do. I think he is planning a Toylander meeting at his Land Rover camp this year.

Best wishes Richard

[Tore]

The Mayfair had it's maiden run under own power today.  That drill motor is powerful.

[jock]

Hi Tore, I would love to hear more on how the drills are coping, any idea on the range they would achieve? I am planning a mayfair in the future after I am finnished the TL2.

Where about in Norway are you from? I spent 8 years working offshore of Norway. Crew changing from Bronnoysund and kristiansund and Flora. I have attended courses in Drammond, Stavanger, Trondheim, Bergen and Sandefjord. A beutiful Country, just a petty about the prices.

John

[Tore]

Hi John,

I know for sure it will do at least 3 meters - that is the space available in my workshop, and is what we have tested so far...

Hopefully, the drivetrain won't be too ineffective, but I will measure the current draw when we take the car out for it's first drive in the street.  Then I can calculate a theoretical range at least.  Problem is, the street is filled with some cold, white substance...

My impression so far, is that the drill motor is very powerful, and very noisy.  The car sounds like an airplane during takeoff!  I am concerned by the durability of the gearbox, though.  It does not handle being driven by the car very well (when you slow down, and the car is "pushing" the motor).  But, I still have to test it on the road.

If I could choose freely, I would have used one of the motors supplied by Richard at RLT, but with a gearbox having a built in differential enabling it to drive both rear wheels. Perhaps, if there was enough demand, Richard could supply them (but we all know the Mayfair isn't exactly his best selling model...).

You are going to enjoy building the Mayfair.  It's size makes it a lot more handy in the workshop, and you can actually carry it under your arm if needed.  The downside is that a grownup (me) cannot fit inside it, even if my butt isn't that big.  Since most of the Toylander builders I know build the cars to use them themselves (using the kids as an excuse), this is a showstopper  I wish I had build mine before the Toylander, it is the perfect "starter" model.

-Tore

Oh, BTW I live in Sandnes, 15 minutes south of Stavanger.  And yes, Norway is an expensive country.