Dash 4 lam teamed with Dash magnets drag test

[BIG E]

At my buddy Tom Stumpf's table (his are always back to back with mine) I was handed a bunch of DASH magnets at the HO slot car show in Parsippany, NJ this past Sunday. They were a bright silver finish and VERY strong. Are those the magnets you're talking about here?
-- Thanks, Ernie :>)

[Ecbill]

It's been a long time since I had any of the old Quadralam arms in my hands but I seem to recall that they were very torquey.

We used to run them on a 16 x 4 Daytona like tri-oval in AFX chassis. They had strong torque and good brakes.

[Ecbill]

The difference between the Dash 4 lam and the Aurora QLam may be the windings more than anything else.

[Ralphthe3rd]

I had bought a couple of the DASH Quads, and have tested both in various style chassis and have been very pleased, and have about the same results as Dave posted. And I too just used standard (matched) Dash ceramic magnets for the testing. I didn't order the Neo Mags, although I did finally order some of the Dash Poly's, which are pretty wicked strong in their own right. As a matter of fact, the Dash Poly's are so strong, that my power supply doesn't provide enough AMPS to make then run very well, and were slower with my individual(one per lane) LapTop power sources. So I'm a bit disappointed that I cannot use them to their best abilities :( , and certainly could NEVER use the Neo's on my Home Track. But I'm fairly pleased with the DASH Quads :text-bravo:

[SpeedyNH]

has anybody ever measured the total stack height/ lam thickness on any of these? just wondering if the lams reduce in thickness as the number increases so the stack stays relatively similar, or they don't and there's more core area (and weight) as you go more. having more core area (given the same material, and assuming that the lam stamping stays the same) would allow a stiffer wind. number of lines of flux and all that.
speedy

[Ralphthe3rd]

[SpeedyNH]

thanks Dave!

[RichD]

At 20 volts with a 4 ohm armature the stall current will be 5 amps or a bit less. Nobody ever talks about magnet strength having an effect on stall current however. Once the car gets rolling I would expect that a car with stronger magnets would make more back EMF and that could reduce the current draw. On the flip side stronger magnets will give you more downforce and increase mechanical drag, causing the car to draw at least a little more current. I only have one pancake car with polymer magnets and I had not run that for a long time. The car has a Magnatraction chassis, so the magnets are the tall ones. I had never bothered to check the magnets, so I just did that. I was surprised that they only measure 800 gauss in the middle, but they are 1700 gauss at the ends. The ceramic magnets that I put in T-Jets are always at least 850 gauss. The armature in the car is a Daniel Cardinale black and that measures 4.1 ohms. The motor brushes are silver and the pickup shoes have shunts. On the track the car drew as much as 1.5 ohms when it was moving and I saw 1.7 amps when I did a drag start. I really need to get a meter with a peak hold feature to take measurements of this sort. If I was really ambitious I would put in a Dash 4 lamination arm to see what happens. As it is the car is as fast as a decent inline car, but it does tend to get rather warm.

[RichD]

Measuring magnets is a tricky business because the magnetic field is not uniform. Two people using the same meter will often get different readings for the same magnet depending on the technique that they use. If I am interested in how the magnets will work with the armature with pancake magnets I fish around in the center of the side that faces the armature. I note the highest reading. I now also take readings at the ends of the magnets, often those readings are not equal. Possibly the poles will see a stronger field as they approach the magnet and a weaker one as they leave it, or the opposite might be true. If you tinker around with the magnet orientation, say by turning one of the magnets upside down you can sometime squeeze out a little more speed. In most cases it is not the absolute reading that is important, you have to use a technique that get you the same reading all of the time. The gauss meter that I use has a probe and is more versatile than a "magnet matcher", but the magnet matcher has the virtue of giving more reproducible readings.

[RichD]

It is difficult to get duplicate readings with a probe. For one thing you need to keep the probe itself oriented the same way every time. I am very careful to hold the probe the same way each time I take readings and repeated tests of the same magnet always give me readings within 5 gauss, which I think is close enough. I have considered making a holder for both the probe and the magnets, that would factor out the orientation effect and make the meter more like a magnet matcher.