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theRightRearTire183
move the box forward on the rails. Also, how come the same sleds that let runs of 350ft during the summer, can stop runs at 220 indoors?

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theRightRearTire183
then why can't we stop at 320ft outdoors? Oh wait we can

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dieselsmoke
There is an easy solution but people won't like it much....

Sleds are linear devices....meaning there is a gear ratio that stays constant (even though you can choose different gears) though the run. You move X feet, you get Y travel on the box. Simple.

Solution: drop the gearbox and use a linear motor or encoder and ballscrew and servo drive. The box travel can now be anything we want it to be, whatever shaped curve you want. No longer are you tied to a simple mathematic equation. I think what is needed is a much heavier box that comes out slow and lets guys get going, and then really comes on fast further down the track.

Why everyone will hate it is because there will be all kinds of "witchcraft and voodoo" suggested by pullers who arent winning....you can hear the moaning now...."sled operator had it in for me and selected the wrong curve".

Non-linear sleds are the answer. The system could be designed in a day and built in less than a month. Who will answer the call?

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The Original Michael

There is an easy solution but people won't like it much....

Sleds are linear devices....meaning there is a gear ratio that stays constant (even though you can choose different gears) though the run. You move X feet, you get Y travel on the box. Simple.

Solution: drop the gearbox and use a linear motor or encoder and ballscrew and servo drive. The box travel can now be anything we want it to be, whatever shaped curve you want. No longer are you tied to a simple mathematic equation. I think what is needed is a much heavier box that comes out slow and lets guys get going, and then really comes on fast further down the track.

Why everyone will hate it is because there will be all kinds of "witchcraft and voodoo" suggested by pullers who arent winning....you can hear the moaning now...."sled operator had it in for me and selected the wrong curve".

Non-linear sleds are the answer. The system could be designed in a day and built in less than a month. Who will answer the call?

Hello. 2 questions about this idea-1
1) Would the sled look the same as the current sleds, and
2) Would the sled be required to carry as much weight as current sleds, or would the transfer be more efficient? Would this idea allow an unlimited mod to be stopped with the weight that one semi can haul to the track?

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dieselsmoke
There is an easy solution but people won't like it much....

Sleds are linear devices....meaning there is a gear ratio that stays constant (even though you can choose different gears) though the run. You move X feet, you get Y travel on the box. Simple.

Solution: drop the gearbox and use a linear motor or encoder and ballscrew and servo drive. The box travel can now be anything we want it to be, whatever shaped curve you want. No longer are you tied to a simple mathematic equation. I think what is needed is a much heavier box that comes out slow and lets guys get going, and then really comes on fast further down the track.

Why everyone will hate it is because there will be all kinds of "witchcraft and voodoo" suggested by pullers who arent winning....you can hear the moaning now...."sled operator had it in for me and selected the wrong curve".

Non-linear sleds are the answer. The system could be designed in a day and built in less than a month. Who will answer the call?

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The Original Michael
As a spin-off topic for the If you were NTPA president topic where the discussion changed to speed-

The basic sled design has not changed in years. Is there a new type of design that may be more efficient? Ideally, one that could stop the high horsepower classes with enough weight that could legally be hauled by one semi, and at a distance of 300-320'?

Has anyone ever thought "what if?" about a different type of sled design that may work as well or better than current designs?

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S'no Farmer
I had a thought years ago about using a smaller sled with a fixed weight and no moving parts but then hooked to a cable on its back side. The cable would then be on a large drum that would have a resistance similar to a Wheel Dyno. This Dyno and drum would be fixed at the starting line and feed out cable as the tractor goes down the track. The fixed weight would give enough hitch weight to give the tractor traction. The cable could then be used to pull the fixed weight sled back to the starting line. The Dyno apparatus could be on a set of beams to slide to the desired spot on the track that each puller wants.

I know it's out there but it could solve some issues but creates others. You wouldn't be able to start grooming the track as quickly and the issue mentioned earlier about pullers not trusting the system. I've not convinced myself that there would be enough weight transfer to the hitch of the tractor with this type of system.

S'no Farmer

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Mo
I have a friend in western PA who knows a guy with a blue semi that is a sled with the cab at the front. I could get info from them if you want about the pros and cons of having that particular type of sled.

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Dick Morgan
I am going to think way outside the box on this question. I am not sure if it's strictly of weight for the sled, rather is it a distribution of the weight? I realize this may sound crazy, but what if the cab of the sled was relocated to either the middle or the front of the sled. Raise the cab up and let the box pass under it as it travels to the front of the sled. By moving the cab forward the weight box could move farther to the back of the sled allowing the pulling vehicle to have good speed leaving the line and when the box travels all the way to the front of the sled there would be both the weight of the box and the cab now applying full downward pressure to the pan. I would also see if it's possible to move the sled motor forward of the sled wheels. I realize that dirt and possibly stones could hit the cab, however with proper shielding this can be minimized. This also would give the sled operator a better view of the vehicle hooked to the sled.

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The Original Michael
As a spin-off topic for the If you were NTPA president topic where the discussion changed to speed-

The basic sled design has not changed in years. Is there a new type of design that may be more efficient? Ideally, one that could stop the high horsepower classes with enough weight that could legally be hauled by one semi, and at a distance of 300-320'?

Has anyone ever thought "what if?" about a different type of sled design that may work as well or better than current designs?

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theRightRearTire183
so you are saying that they should add a second set of grousers to the sled? Three (potential) problems.

1) If it does drop at say 20ft, it would destroy the track, especially after the pan grousers drop. Guaranteed hook track

2) How are you going to back up this "trailer"? Do you have to unhook it from the sled to a courtesy tractor? Or does the sled operator get to back that up himself?

3) The whole idea of this topic is weight, how will this contraption be transported?

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TWaite
Not sure if this idea is even feasable but what about adding another set of axles? Make the sled a triple axle instead of a dual axle. It would add some additional weight to the sled but also would have the ability to haul additional weight down the road. But, does that additional weight going down the road require different licensing/permits. Maybe that 3rd axle would "float" instead coming off the ground adding some rolling resistance or have braking applied to it. Maybe I'm thing way outside the box lol

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cpr
Could well be. Speaking of the towed attachement idea, what is going on here?

CP