Dragster motor is HUGE compared to Xcelerator

This isn't quite news, but you should check out the photos CP just posted of Dragster's cable drum and motor assembly. This thing is absolutely huge. I had no idea it would be so much bigger!

Here are the photos (2/5/03)

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Jeff - Webmaster/Admin - CoasterBuzz.com - Sillynonsense.com
"The world rotates to The Ultra-Heavy Beat!" - KMFDM

Are there pictures that show the same scale for the Xcelerator motor?

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--George H
---Superman the ride...coming to a SF park near you soon...
Currency tracking experiment... http://www.wheresgeorge.com (Referring to The "George" on the $1 bill - Not Me)

Jeff...that doesn't appear to me to be much larger than Xcelerator's motor at all.

Moosh

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"It looks smaller than I imagined, but still looks to be a great ride." -- CPLady

It does look huge. But then I don't know what Xcelerstors looks like. Does anyone have a pic of Xcelerator?

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-Sean Newman

Compare the two:

Xcelerator vs. Dragster

That guy in the Dragster photo could sit inside of that motor, and the drum is certainly bigger.

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Jeff - Webmaster/Admin - CoasterBuzz.com - Sillynonsense.com
"The world rotates to The Ultra-Heavy Beat!" - KMFDM

Wow, does this have to do with higher speed or that the fact that the cable has to be so much longer?

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Da Poodle

Coming in 2003-The Spawn Of Magnum!

Not only is the drum bigger on Dragster, but the number of motor modules on the drum is greatly increased.

Yep, the Dragster one is a lot bigger.
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-Sean Newman

What exactly are the "modules" anyway? I know how the system works but don't really recognize the pieces other then the cable drum.

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Da Poodle

Coming in 2003-The Spawn Of Magnum!

*** This post was edited by MagnumForce 2/7/2003 1:51:40 PM ***

OK...you're right. Its bigger. Thanks for the link, Jeff ;-)

Moosh

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"It looks smaller than I imagined, but still looks to be a great ride." -- CPLady

I was hoping Dave could answer the question about the "modules." Obviously the cylinders in the pits are the accumulators, so what happens from there through the hoses to the drum?

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Jeff - Webmaster/Admin - CoasterBuzz.com - Sillynonsense.com
"The world rotates to The Ultra-Heavy Beat!" - KMFDM

They may be injectors for the hydraulic fluid. But where is the turbine?

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Da Poodle

Coming in 2003-The Spawn Of Magnum!

*** This post was edited by MagnumForce 2/7/2003 2:00:56 PM ***

Yeah, that is definately bigger than Xcelerator's. Is it me or are certain parts on the motors painted to match the colors of the ride? Why would that matter when they're covered up? Aside from that, I bet the spool's bigger since it will be spinning faster and more than Xcelerator, so it's bigger so there's a larger radius. That means the TTD's will have less rotations than Xcelerator's to hit that speed.

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I was asked to describe X in one word. The word? -- OhmygoshwhathaveIgottenmyselfintothisisthescariest
thingintheworldhelpmeIamgoingtodieAHHHH!!!

We're getting somewhere, anyway...

With regard first of all to the painting on the motors...the yellow bits appear to be plugs where the hydraulic hoses will be connected. Have a look at this photo to see what I mean.

Second, I am wondering the same thing about the little units, and so far have not got any answers. I have done some searching, though, and come up with a few things...

At least one person has suggested that those are small hydraulic motors connected to a ring gear. But the problem with that explanation is that if we assume the cable drum to be 6' in diameter, the top speed of that drum has to be about 560 RPM. If each of those pinions is 6" in diameter, that's a 12:1 reduction which would mean those pinions are going around at 6,726 RPM. Now, 6,000 RPM isn't in itself unreasonable (the head drum in my camcorder runs at 9,000 RPM), but it seems a little bit unreasonable for a hydraulic motor.

I've done a little bit of research in the past hours, and it seems possible that what we are looking at may be an axial piston type hydraulic motor. Fluid is applied to the back end of a piston which pushes against a plate which then pushes the motor around. In that way, each of those (16?) boxes mounted around the rim would be a single linear actuator. Pressure applied in sequence to the cylinders would cause the motor to rotate, and nothing would have to operate at particularly high speed...at its fastest each cylinder would have to operate at about 9 strokes/second.

What I don't like about that is that it would require some complicated valving because the high-volume high-pressure lines on the back of each unit would have to serve as both supply and return lines. I suppose a large check-valve would do...but there has to be more to it than that to keep the single line from just dumping straight to the return...

The kinds of volume and torque requirements for this thing suggest the use of a piston-type motor. I'd say a radial piston motor would make sense, except that clearly isn't the layout of this motor, so it almost has to be axial. But what is missing is the return path for the hydraulic fluid. I wonder if the smaller tube coming off the units is a pilot line of some kind to control valving on the main supply.....

I'm still looking for more data on the motor; if I find anything I'll report back. :)

--Dave Althoff, Jr.
EDIT: I had the RPM right but the ratio wrong...
*** This post was edited by RideMan 2/7/2003 11:19:30 PM ***

Dave, here is my thought about it. I'm still thinking it uses the gears.

Now, the drum itself may be 6' in diameter, though the gears coming out of the individual motors are not touching the drum. Thus a shaft is coming out of the drum to the motor where a gear is attached to receive the torque from the motors. Now this gear that is attached to the motors does not have to be 6' in diameter as well, though it very well could be, going back to your numbers.

Say there is no ring gear like you mentioned but rather a sun gear with a series of planet gears around it that remain stationary. That sun gear will have the same angular velocity of the cable drum but just a much smaller diameter. So still with the 6" planet gears and say a 3' sun gear would mean that the individual motors will pump out 3360rpms.

I have no idea if that is right but its another look on that theory.

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Chris Tyson
Photographer
www.pkiunlimited.com

I would tell you for certain that it uses gears, per the descriptions with the photos that says "gearbox." So, Dave, the ratios you're considering might not be ridiculous if they're scaled down with whatever gearing is in that box.

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Jeff - Webmaster/Admin - CoasterBuzz.com - Sillynonsense.com
"The world rotates to The Ultra-Heavy Beat!" - KMFDM

Yow! I thought our Racer motor was huge... It looks like a miniature compared to that.

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If you could just see the beauty... these things I could never describe. Pleasures and wayward distraction; is this my wonderful prize? --Joy Division

Yeah, I agree. The Racer has a nice sized motor, but Dragster's is incredible!

BeastFreak, your planetary gearset was kind of what I was thinking, but consider this: If it is a planetary gearset, which it very well might be, you're still looking at a roughly 6' diameter sun gear because you can't get around the positioning of those modules around the perimeter of the motor assembly.

The two things I don't like about that theory are as follows:

1) Given the size of the hoses leading into the modules, there would be a hell of a lot of fluid pouring into each unit. Once it is in there, where does it go? Perhaps each of those units is a small gear-type or vane-type motor, but there would have to be some kind of output port capable of handling the very large fluid volume moving through each unit.

This is why i kind of like the axial shaft piston theory, because such an arrangement would only require one high volume hose for each unit: fluid comes in under high pressure to drive the motor, and eight steps later comes back out at reduced pressure through the same port. In essence it's like an 8-pole electric motor.

2) Hydraulic motors are generally not suited to high-speed operation. In fact, that is one of the advantages of hydraulic motors over electric motors for amusement rides: While an electric motor runs at 3,600 RPM and has to be geared down for most applications, hydraulic motors usually operate at much lower speeds

A larger pinion gear on each module would allow for lower speed, but the size is limited by the need to cram 16 of them around the center shaft.

I honestly don't know. In a brief web search today I was unable to find any assembly that looked at all like the Dragster or Xcelerator motors, which complicates the search just a little.

--Dave Althoff, Jr.

TopThrillDragsterWeiner said:
Yeah, I agree. The Racer has a nice sized motor, but Dragster's is incredible!

.....sigh..... It begins again.....