Science Buddies: "Ask an Expert"

I helped a friend gather the material for her science project. She’s very excited and is having fun building the motor.
She searched the https://www.sciencebuddies.org website to obtain the material for a Reed Switch Motor listed below:
Materials and Equipment

Electric motor Kit #1; available from www.simplemotor.com, click "Ordering Information" on the left, and select "Kit 1."
Newspaper, scrap
Ruler, metric
Cardboard (1 small piece)
Safety goggles
AA batteries, new (4)
Optical tachometer; available from online retailers, such as Tower Hobbies at www.towerhobbies.com, model # LXPT31
Lab notebook
Graph paper
As you can see the motor kit recommended is Motor Kit #1.

www.simplemotor.com Motor Kit #1 consists of the following https://www.simplemotor.com/kit1contents.htm:
Heavy duty reed switch (rated 1A @ 110V DC)
Spool of magnet wire (50 ft or more of 27 gauge insulated copper wire)
2 magnets with South pole marked
Glossy magnet labels
Heavy duty board (approx. 5" x 6") with stands position color marks
Reed switch stand (marked with yellow star)
Electromagnet stand (marked with green star)
Rotor stands (marked with blue and silver stars)
Rotor core with 2 flat surfaces
4" precut nail with prewound tape for the electromagnet
2 caps with a center hole
T-pin
Wooden insert
Pushpin
Rubber plug that allows you to attach disks, propellers, etc.
Super glue
Piece of sandpaper
Self sticking felt pad
ZNR surge absorber
Rubber band

My question is how does she measure the various voltage without a battery holder?
We purchased one but it’s a total of 12v holder (8 AA Batteries).

Should I look for various battery holders? As you can see, we purchased the requirements but looks like it is difficult to complete the testing requirements.

Could you let me know what the best options for her to complete the project?

inquisitive - The design of a reed-relay motor seems like a nice experiment. One of the problems with some simple motors in these kinds of experiments is the design of a reliable "commutator" or device that switches the power into the coil at the precise rotational positions. The reed-relay accomplishes this handily. The experiment as written up in the simplemotor.com site takes readings at 1.5, 3.0, 4.5 and 6 volts. In essence, 1,2,3 and 4 battery cells connected in series. You might be able to use your 8 cell battery holder to work well. If you can simply install 4 cells in series, you can fashion a contact using a wire and perhaps a paper-clip to introduce between the battery positive contact and it's next cell or connection. The "negative" or common connection to the pack remains connected to the coil. That way the holder holds the 4 cells reliably, but you can "tap" it off at 1.5 volt increments as you read your data points. Having a multimeter to measure and verify voltage seems valuable. These can be obtained, often for less than $10, at many hardware stores. Perhaps it could be borrowed from a friend or neighbor. Another part of the experiment you can evaluate is the position of the reed switch relative to the magnets at various speeds. The position will likely vary the speed to a great degree, owing to the timing of the switched current and the duration of the switched pulse. There are a lot of mechanical, electrical and magnetic activities going on here, and you can make several hypotheses after you experiment a little. Good luck.

Rick Marz