NSR Drop Arm broken. Anyone else?

[Loan Shark]

Hey guys. In the process of building my Porsche 997 Proxy NSR 997 I encountered a problem. I have broken the NSR guide drop arm twice. I was using the green extra hard chassis and the red drop arm. I was also using a height trimmed & shortened Slotting Plus SP101004 deep wood guide. In the process of testing I have broken the round head off of 2 of the red drop arms. My guides were on the longer side. I broke one on my fairly tight routed track and another at Cgyracer's Mid-BC routed track. Both happened during a snap swing of the back end of the car.

The drop arm was fully secured with the NSR screw as supplied.

Has anyone else broken a drop arm? If so, what guide did this happen with?

As an aside I've also broken a Scalextric Legends chassis using the same guide. I also think I've broken another chassis as well but can't remember which one.

I'm wondering if this is a weak NSR part or if the guide is the issue? I've been using the Sloting Plus guide almost exclusively for 1.5 yrs. However am now not sure where the issue lies.

Any insight would be appreciated.

[Kevan]

Mine get glued up, I don't believe in drop arms unless it's on a Raid truck.

[Loan Shark]

As I mentioned mine were secured and had zero movement. I'm more looking to find out if this is a common problem, or only a Slotting Plus guide issue, or ?

[F1Fan]

Matt can you perhaps post a picture? I have broken a few guides, but can't remember breaking a S+ or a NSR drop arm. As you may already know different models of guides (even from the same manufacturer) comes in different shaft diameters and different slot car manufacturers have different size guide holes. Was the guide you used the correct dia for NSR? Did you have to ream out the arm?

Breaking two of these are a bit strange, a picture might be helpful the provide additional feedback.

Chris

[Mikeinclover]

Matt, I would think about trying the NSR deep wood guide NSR4859. We have been having great feedback on them. Another guide to try is the Scaleauto SC-1607 it is designed for a NSR so you shouldn't need to open the hole in the drop arm to much.
Mike

[Bal r 14]

I use the Slotting Plus SP101004 deep wood guide on all of my cars, which includes all NSR cars, two of which are 997 models. I have observed the opening for the guide post is a little tight on some NSR models, but that is easy to fix with a round file. The guide requires a bit of trimming for my track, as it has tight turns. I take about 1/4" off the back end and round both ends a little.

[Loan Shark]

Thanks guys. I'm not home til Monday. Will get into more detail then. In the end I had installed an NSR4859 thinking it might be best since its an NSR chassis. Thanks again for the help.

[Vision34]

Seams the guide might be a little tight OR it's to loose. As Mike from clover leaf said for my NSR's I use there deep wood guides. They work amazing! Remeber it's the steering on there car. There very important that they fit Perfectly in the guide hole.

[Kevan]

That's true for any guide in any car.

[chrisguyw]

I have broken the NSR guide drop arm twice. In the process of testing I have broken the round head off of 2 of the red drop arms. . Both happened during a snap swing of the back end of the car.


Any insight would be appreciated.

Hi Matt, I strongly suspect that your issue is neither the guide nor the drop arm, but, rather a lack of sufficient rotation in the guide.

You have said that both breaks occured during "snap" swings of the back of the car....if the guide does not have sufficient rotation, during a "snap" swing, the guide will hit the side of the guide post hole, and, one of 2 things will happen.......the guide blade will snap, or, the guide post hole will break. I have seen this happen to many many cars.

The cure is to file/grind the guide or the sides of the drop arm/chassis, to allow more guide rotation.

Below are a couple of pics. of this modification made to a Fly car......while the NSR guide is certainly different the idea is the same,...either the guide or the chassis/drop arm must be adjusted.

Cheers
Chris Walker


The first pic. shows the limited guide rotation allowed by the Fly chassis......if the car slides more that the allowable rotation, broken guide blades/guide post holes are inevitable.

While the NSR is admittedly different, the principle is the same,...a few more degrees of guide rotation will solve your problem.




A portion of the chassis/drop arm or guide must be removed to increase the degree of rotation......look to see where your guide hits the drop arm post hole, and modify either the guide or sides of the drop arm.

I have used a sharpie to indicate the piece that needs to be removed,....this obviously must be done on both sides




Use a file or burr in a Dremel to remove the bit of material..........



The modified chassis now allows the guide to rotate significantly more than stock




Each different manufacturers chassis requires a slightly different approach, but, I have done this type of modification to many NSR's, Scaleys' Slot-it's, Scaleautos, Flys' etc. etc etc. and have never had any issue whatsoever with guide or chassis breaks.

[Kevan]

I suspect you're right Chris.

[Loan Shark]

Hey guys. Thanks for all the replies. In the end I submitted the car with the NSR racing deep wood guide 4859. I also used a brand new red NSR drop Arm. Everything seems to work well. The 997 proxy will determine just how well.

On the original build I did have to take a small file to fit the Slotting Plus deep guide as it was too tight. After very close analysis of the fit of the slotting plus guide in the drop arm, I see there's a lot of leverage produced by the guide on the drop arm hole by its design. The guide impacts the arm 4mm behind the mounting hole instead of in the pocket of the hole and support thereby creating excessive leverage against the hole. At least that's my theory anyway

[F1Fan]

I think you have a reasonable theory and that combined with removing material most likely caused the issues. Good luck in the series and your first proxy.

[Loan Shark]

Thanks Chris. I'm excited and hoping to make the 27. Already have some mod ideas for the next one.