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Post by pceng on Feb 23, 2013 11:48:46 GMT -7
All NTRA race classes that I know of have color requirements for tires (black). Since the MM/PS is new to me, and if I'm right was added to the NTRA line-up. Do the rear tires have to be black? Seems that would require a custom tire since different size sili-foams are not all ways available in different colors.
Looked through the ISRA MM/PS building tips and was curious about the 22t crown. Has anyone tried different size gears and tires (saw something about tires also).
Perhaps this is more for Sam, since I believe him to be the most familiar with this class. How close to the minimum weight do most cars come. Have two been working on, one is below weigh and the other way over.
tia ......... PC
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Post by jjwallace on Feb 23, 2013 18:44:16 GMT -7
Pceng this was posted Feb. 3 so it is current. There are no restrictions on tires. I believe this is the only class that has no restrictions.
Post by SKR on Feb 3, 2013 at 3:36pm
MM/PS
MM/PS Mountain Motor Pro Stock
Pro Tree Light
Body: Only Resin or Hard Plastic bodies allowed. No Styrene or Lexan. Windows & Wings may be made of Lexan. Balsa wood Hood Scoops are allowed. Bodies must be of a 1980 Model/Make or newer. All bodies must have a Front Window, Rear Window, Hood Scoop, Rear Air Spoil or Wing. Each body must have a front and rear bumper.
Armatures: 2.6 Ohm minimum. Any Armature that retails for $20.00 or less are allowed. DeWinding of Armature or Advancing/Retarding Commutator is NOT allowed. No homebuilt armatures. Balancing is allowed. Armature must be readily available.
Magnets: Only two motor magnets per car. Ceramic motor magnets are only allowed. Polymer traction magnets are allowed. Only a total of four magnets per car. Two Motor and Two traction magnets. No extra magnets allowed.
Electrical: No Restrictions on Pick Up Shoes, Springs, Brush Barrels, & Motor Brushes. Must be readily available. Shunts and Braids are allowed.
Gears: No Restrictions. Must be readily available.
Wheels & Tires: No Restrictions.
Chassis: All available inline chassis are allowed. No scratch built chassis. Chassis can be Cut, Drilled, Sanded and Braced to stiffen. Wheelie bars are allowed.
Weight: 22 Grams: Cars are subjected to weigh in before and after each run.
Update:
These armatures from Lucky Bob's (LB) ARE legal. BSRT had marked their prices up to LB's by 20% so LB's did the same. These armatures retail for $18.00 on BSRT's site.
Listed at Lucky Bob's:
BSRT140 G+, G3 & G3R
HIGH POWER ARMATURE
EPOXIED, CUT & TIED COMM &BALANCED
APROX. 3.1 TO 3.4 OHMS
$21.60
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Post by SKR on Feb 23, 2013 19:43:27 GMT -7
All NTRA race classes that I know of have color requirements for tires (black). Since the MM/PS is new to me, and if I'm right was added to the NTRA line-up. Do the rear tires have to be black? Seems that would require a custom tire since different size sili-foams are not all ways available in different colors. Looked through the ISRA MM/PS building tips and was curious about the 22t crown. Has anyone tried different size gears and tires (saw something about tires also). Perhaps this is more for Sam, since I believe him to be the most familiar with this class. How close to the minimum weight do most cars come. Have two been working on, one is below weigh and the other way over. tia ......... PC No restrictions on tire colors for this class. Tire selection would be too limited if we only went with black. As far as gearing, some of us run 22T and some run 21T with a 8T Pinion. I've been having better luck with the 21T if I'm using these motor magnets:
277 |
G3/G3R BONDED MOTOR MAGNETS CERAMIC GRADE LEVEL 4
HIGH DOWNFORCE |
As far as tires, I've been going a little bigger (.465-.470"). Locally, Dan has the E/T record and is using somwhere around .458-.460", I'll find out for sure and post later. Weight: You want to be running right at the class minimum of 22 grams. Taking a dremel to the inside of the heavier bodies will get you down to weight. Hope this helps. Sam |
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Post by pceng on Feb 24, 2013 11:43:35 GMT -7
Knew it had to be something, was using MM/PS info from build guide on home page. Was thinking min.weight at 21g's, is 22 now the number? Guess I missed something again.
But thanks for the info. guys! that was quick -
Hey Sam, should have called them MM/BRICKS, just joking did I go to far. But why the increase, if 22 is right? Remember seeing, and admiring the paint jobs done on lexan bodies, when I first started visiting the site. I guess I just find this unexpected from you.
.......... Peter
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Post by SKR on Feb 24, 2013 12:04:54 GMT -7
Rule revisions were made for this year and posted in other sections. This class has always been a hard body class. Thanks for the compliments on the lexans. Kim still races a few in brackets, I just don't like the detail or lack thereof on those bodies. By increasing the weight to 22 grams, its much easier to achieve with out pulling bumper off or hacking the body up. You didn't go to far, it's all a matter of opinion and what you like. These are the current rules as JJ posted above: MM/PS
MM/PS Mountain Motor Pro Stock
Pro Tree Light
Body: Only Resin or Hard Plastic bodies allowed. No Styrene or Lexan. Windows & Wings may be made of Lexan. Balsa wood Hood Scoops are allowed. Bodies must be of a 1980 Model/Make or newer. All bodies must have a Front Window, Rear Window, Hood Scoop, Rear Air Spoil or Wing. Each body must have a front and rear bumper.
Armatures: 2.6 Ohm minimum. Any Armature that retails for $20.00 or less are allowed. DeWinding of Armature or Advancing/Retarding Commutator is NOT allowed. No homebuilt armatures. Balancing is allowed. Armature must be readily available.
Magnets: Only two motor magnets per car. Ceramic motor magnets are only allowed. Polymer traction magnets are allowed. Only a total of four magnets per car. Two Motor and Two traction magnets. No extra magnets allowed.
Electrical: No Restrictions on Pick Up Shoes, Springs, Brush Barrels, & Motor Brushes. Must be readily available. Shunts and Braids are allowed.
Gears: No Restrictions. Must be readily available.
Wheels & Tires: No Restrictions.
Chassis: All available inline chassis are allowed. No scratch built chassis. Chassis can be Cut, Drilled, Sanded and Braced to stiffen. Wheelie bars are allowed.
Weight: 22 Grams: Cars are subjected to weigh in before and after each run.
Update:
These armatures from Lucky Bob's (LB) ARE legal. BSRT had marked their prices up to LB's by 20% so LB's did the same. These armatures retail for $18.00 on BSRT's site.
Listed at Lucky Bob's:
BSRT140 G+, G3 & G3R
HIGH POWER ARMATURE
EPOXIED, CUT & TIED COMM &BALANCED
APROX. 3.1 TO 3.4 OHMS
$21.60Read more: nitroslots.com/thread/3159/page/1/mm-ps#scrollTo=29817#ixzz2LqQfeoy5 |
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Post by pceng on Feb 24, 2013 12:54:42 GMT -7
Hey Sam,
Actually did go to far, the PS4 mounted on finished chassis 21gs. But now I get to choose where the weight goes ...... mmmmm.
See you at the races ..... Peter
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Post by mike11422 on Dec 30, 2014 15:17:11 GMT -7
Has anyone taken any readings on viper scale motor magnets? Sorry if this was discussed else where.
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Post by pceng on Dec 30, 2014 16:25:41 GMT -7
Has anyone taken any readings on viper scale motor magnets? Sorry if this was discussed else where. Intresting thought, had not thought about it. Since measuring devices vary.......... Measurements comparing Viper mags to BSRT 290's or 77's would be helpfull. SHOULD ANYBODY TAKE THIS UPON THEMSELVES...... be sure to post results......... Peter |
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Post by Deleted on Dec 30, 2014 17:44:12 GMT -7
Interesting question regarding the Viper magnets!
However to what do we compare them too?
In addition if compared to brand XYZ with what equipment and method were the readings taken?
If I get readings with my equipment they could be way off to another set of readings taken?
Or is there a standard?
ALan
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Post by dave632 on Dec 30, 2014 18:21:03 GMT -7
I have some Viper magnets on order. I will try to compare them to BSRT magnets to see which reading are higher.
Since there is no standard check we can make we can only say which is stronger.
I will most likely get a gauss meter in the future.
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Post by Deleted on Dec 30, 2014 19:56:40 GMT -7
ALan,
many folks use an inexpensive small digital postal type scale that has a clear protector lid (which can be used as a catch all for loose parts when turned upside down on the scale) using an indelible pen(sharpie?) mark a spot on the center of the clear plastic and with the scale on place the magnet on the center spot, record the reading. maybe even write it on the magnet with a silver paint pen.
now ...
all readings you take in this manner (which will probably appear as negative because you are pulling on the plate instead of pushing it) will give you the ability to compare your magnets with each other and match magnets strength for ultimate balance usage.
likely the numbers will not be comparable to other folks results.
further, you might drill little holes over the on/off button and reset button for ease of use.
I have one from Harbor Freight (about $10.00) for strictly this purpose.
matching magnets for strength is very important in tuning all types of slot cars.
this method can help determine and understand down force of traction magnets installed in chassis too.
hope this helps somewhat.
Happy New Year,
allan
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Post by dave632 on Dec 30, 2014 21:15:27 GMT -7
That is the kind of gram scale I use with the cover cut away in this case to allow access to the buttons.
Works good for matching but it would be hard to compare to someone else's magnet checker since the pull might be different. Since height etc. might not be the same.
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Post by pceng on Dec 31, 2014 8:05:22 GMT -7
Comparison of magnets using different measuring devices will show a common difference. That is percentage. Tried this with scale (like Al, mentioned) and a Hann's device (hope I got the name right). Though readings on both were different things. The difference shown on each was almost the same thing percentage wise.
Keeping a record of readings for different magnet types will help for reference in future.
......... Peter
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Post by Deleted on Dec 31, 2014 9:15:31 GMT -7
Road Trip to Harbor Freight. Problem is I go for a $10.00 item and $100 later !!!! - - - --
Thanks Al
ALan
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Post by kdog on Dec 31, 2014 9:43:14 GMT -7
Road Trip to Harbor Freight. Problem is I go for a $10.00 item and $100 later !!!! - - - -- Thanks Al ALan I think the Surgeon General needs to put a warning label on Harbor Freights front door! BAD FOR YOUR WALLET |
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