What is the resistance of a stock Aurora T-Jet arm, and that of a stock Aurora slim line arm?

Thanks in advance.

Dan

The stock arms range from about 15 up to 21 ohms, not sure about the slim lines and if there is a difference there or not.

Marty

He is the Armature guy to go to. ( agghobby@hotmail.com )

Marty's right on the stock arms, though in my own experience less than 16 is few and far between. I have one, (1), uno little NOS slimline arm in the gearplate, it measures 8.1-8.2 @ 70° F.
If you're testing potential product, IMO you should be sure the arms are at room temp and record that temp with the results. :thumbsup:

...you should be sure the arms are at room temp and record that temp with the results. :thumbsup:
I'm doing exactly that...

So if you were developing a new 'stock' armature, what resistance would you make it, measured at 70 degrees...

Dan

I think it kind of depends on what you are going for....

Are you looking to replicate the feel on the original T-Jets? Run them at 18-20 volts? 12 volts? What kind of magnets? I would assume a new inline armature to be much more efficient that the older pancake arms, so if you wanted to match a 16 ohm pancake for instance, maybe look at an inline arm around 18 to 20 ohms?

My guess would be you'll need to experiment until it "feels" right, if you know what I am saying.

If I were designing a T-Jet chassis, I'd personally shoot for 16 on the finished armature. :thumbsup:

I've always thought that the ideal TJet arm would be in the 8-10 ohm range. TJets really need some torque to drive all the gears involved with its relatively primitive chassis layout. The 6 ohm arms are on the edge of being acceptable for use with race set power supplies, especially with more than one lane per power pack. The low resistance arms don't give you a lot of margin for error if you have heat issues. A nice set of polymer motor mags would alleviate some of the heat concern but the performance with wall warts may still be an issue. The original Tuff Ones had low resistance arms and weak magnets. Bad combination. They tended to run hot.

The 15-16 ohm arms work well with lower end power supplies but to bring them to life you need to take heroic measures in removing every bit of friction from the drivetrain because they are so lacking in bottom end torque. That's why folks like to run them at 20-24 volts. So something in the middle, 8-10 ohms, seems like a good compromise. The GJet serves as a good case in point for the viability of a middle of the road arm for a chassis that needs both a decent amount of torque and relatively modest power supply requirements.

Whether or not a mid range arm would be commercially successful depends on the market. The Fray TJet purists, i.e., Order of the Gray Lams, would probably avoid anything that deviates from their narrow template, but those of us in the much larger buying population who are looking for a very decent all around arm would appreciate an engineered solution as opposed to what Aurora produced. If the arm is built with a better lamination material (thinner too, to allow for 3-4 lams with the same thickness and mass), higher temperature wire, flatter comm, better comm material, better balance, etc., it would be attractive to me. If you're going to make the effort to build something that's already been done, try to improve it and take advantage of the advances in technology and material science that have occurred in the nearly half century since the original TJet was designed.

If I were designing a T-Jet chassis, I'd personally shoot for 16 on the finished armature. :thumbsup:
...why?

I've always thought that the ideal TJet arm would be in the 8-10 ohm range. TJets really need some torque to drive all the gears involved with its relatively primitive chassis layout. The 6 ohm arms are on the edge of being acceptable for use with race set power supplies, especially with more than one lane per power pack. The low resistance arms don't give you a lot of margin for error if you have heat issues. A nice set of polymer motor mags would alleviate some of the heat concern but the performance with wall warts may still be an issue. The original Tuff Ones had low resistance arms and weak magnets. Bad combination. They tended to run hot.

The 15-16 ohm arms work well with lower end power supplies but to bring them to life you need to take heroic measures in removing every bit of friction from the drivetrain because they are so lacking in bottom end torque. That's why folks like to run them at 20-24 volts. So something in the middle, 8-10 ohms, seems like a good compromise. The GJet serves as a good case in point for the viability of a middle of the road arm for a chassis that needs both a decent amount of torque and relatively modest power supply requirements.

Whether or not a mid range arm would be commercially successful depends on the market. The Fray TJet purists, i.e., Order of the Gray Lams, would probably avoid anything that deviates from their narrow template, but those of us in the much larger buying population who are looking for a very decent all around arm would appreciate an engineered solution as opposed to what Aurora produced. If the arm is built with a better lamination material (thinner too, to allow for 3-4 lams with the same thickness and mass), higher temperature wire, flatter comm, better comm material, better balance, etc., it would be attractive to me. If you're going to make the effort to build something that's already been done, try to improve it and take advantage of the advances in technology and material science that have occurred in the nearly half century since the original TJet was designed.
I have 100 arms here that range from 2 ohm to 15 ohms. There are roughly a dozen of 7 different resistance levels. The magnets I had made are on par and possibly a bit stronger than the JL/AW mags. Even stronger magnets are in the works, especially for the lower ohm arms, and for the Dash version of the Magna-Traction chassis.

The arms are currently tri-lam and the lams are made of silicone steel sheet. I've inquired about thinner/more lams. The number of laminations is meaningless if the material they are made of is garbage. The purpose of multiple laminations is to reduce what are called 'eddy currents'. Eddy currents reduce the efficiency of the motor by creating an opposing force to the magnetic field. Due to space constraints of the pancake design, 4 or 5 laminations are probably the upper limit. The comm is copper.

Here is my plan so far.

Since this is the feedback I've been getting (and since the supply of original T-Jets is running out), the T-Jet was going to be recreated as close to the original as possible. There would be exceptions, like the magnets, which would be stronger. There would be armature and magnet 'upgrades' available.

The shoes would be as close to Aurora original as possible. It seems the material and the shape of the shoes is 'ideal'. If this is a mistake, let me know.

I would like input as to what the optimum material and shape would be for the brushes.

I've been told to keep the pinion gear at 9 teeth, instead of the JL/AW 14 tooth gear. I'd like pros and cons regarding the different gears, not just 'this is what it should be because that's the way Aurora did it'...

Seems brass gears are 'desirable'. Why? Low friction, light weight, durable Delrin or Nylatron gears seem to be better suited for this application. Do people just like the look of brass or is there a technical advantage that brass gives you? Brass gears weigh more, have greater friction and raise the center of gravity, which are all negatives.


This is your chance to speak up. I'm not looking for a laundry list of everyones esoteric wishes, but I do want input backed by solid reasoning (if possible).

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The Dash Magna-Trac chassis would allow me to be more 'creative' and incorporate changes that might eventually find their way into the T-Jet. Like a snap in rear axle, poly mags (notched so they sit closer to the track), along with lower ohm arms...

The sleeper in this whole thing is the slimline. With decent magnets to go along with even the 'stock' 9 ohm arm, this platform could really take off!

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Perhaps I should open a separate thread or create a google discussion group for these chassis topics.

I firmly believe that the brass gear on the top of the gear plate will last a lot longer that the plastic ones. You can hog out the brass gears to make them lighter buy milling out pockets or make a big grove in one side of the gear. The CNC machined gears mesh much better, so the need to lap in the gears is not necessary. I understand is more expensive for this would make a great option along with different armature resistance’s and stronger magnets. While on this subject venting the side of the chassis to allow the heat to escape would be an excellent option like the Magnatraction chassis. Also domed brushes with a notch so they do not rotate are a good upgrade. Or my personnel favorite the Super II brush cups. Lower the gear plate into the chassis also helps handling as well. The Tjet purist will hate these Ideas. But in my opinion sorting through hundred of chassis to find the perfect set of matched components is so costly & time consuming. The same thing happened in stock class drag racing. That is what prompted Bracket racing. I very good friend of mine worked at Chrysler dealer he was racing a stock class Dodge Demon 340 CID. He ordered 10 set of cylinder heads head them flowed to see which ones out of the box flowed the best but he was able to send the rest back. If the parts are made to tighter tolerances from the begin it will reduce the cost to the racers & level the paying field.

Dan, First, let me Thank You for all your efforts to this hobby. Second, let me warn you (not that you already do not know) that you will and cannot make everyone happy.
I only want to opine on the gears with the experiance of the JL/AW chassis and the Thunder+ chassis. I would rather have brass gears as they seem more durable as well as seem to be more concentric. Some of the plastic gears we have all seen have been pretty lop-sided, malformed, or just junk. If the quality of plastic gears was the same as the brass ones I wouldn't mind them, but would still rather have brass.
Again, Thank You for all you are doing to further this hobby.

sorry to hear your dropping the inline tjet. i would have bought lots, promise!

as for shoes, most of the people i know who race t-jets use aftermarket shoes. BSRT, Wizzard, and Slottech all make aftermarket shoes for T-jet. Those shoes are ski shoes, in that they do not have the step of the original shoe. no one at the fray (80 plus racers) used original shoes.

i think high quality delrin gears would be fine. especfially if they were made from a different color so you could tell them apart frrom the crappy JL/AW plastic gears.

I will echo Mike Kings thoughts that it's too bad you're not doing the inline arms.

That being said though, I think doing a new chassis that mimics the performance of the original would be a great thing, there are enough super fast cars out there. Those of us that don't have stockpiles of the originals to go through would love to get a hold of a chassis that is/has:

snap in rear axles, #1 in my book
straight every time (no #4 chassis equivalents :) )
runs well out of the box
can interchange parts with the originals (bodies, arms, shoes, brushes, etc)
brass gears are great, but a high quality delrin would be good as well
I would vote to keep with the 9 tooth gear, not because it's the original, but because they just seem to run better


Overall it would just be nice to not have to spend a great deal of time matching the right top plate with the right chassis, gears, etc. Ideally it would be like the G-Jet, you put your stock parts together and know it's going to run well. That is something I would happily pay for.

Just some of my desires, I'm sure you'll do a great job whichever direction you go...

Parts interchangeability with multiple gear ratios and a variety of axle settings is what made the T-jet great conceptually. Versatility and reliability were part of the original draft.

Coupled with some decent QC they are still rattling along with gusto. As said previously you wont be able to please everyone. We all have seen the second coming of the T-jet with applied voodoo economics. Needless to say they are well short of the mark.

Given the monsterous start up costs I would think that adhering tightly to the basic template would be the ticket. The target market is a very narrow window so it has to appeal to as many disciplines as possible. Be you a NOS putt putt guy, a NAS-FRAY racer, the average Joe gomer modeler type; the t-jet works. The t-jet is firmly plopped in the middle of the road. My concern would be that too much deviation in any one direction would leave odd men out.

Crawl before ya walk and walk before ya run. Over time we saw the original design recieve many successful tweaks. It worked because it was a methodical progression based on a solid platform.

I would agree with AFX Too on the arms... in principle. A hair less than a Tuff ones wind...wild ones or speed wound would be my personal choice. However the inherent flaw is that it would deviate from the original template. A well made 16 is probably the ticket. There is no reason that in time one couldnt develop a speed part line of your own.

Plastic gears suck plain and simple. Pretty much a one use deal and toss them. The beauty of the brass gears was their potential for re-use and setting up multiple ratios. Coupled with some of the more modern high tooth count crowns the three available cluster ratios offered some huge variety. When you also start playing with tire profiles the tunability is myriad. IMHO the brass gears also provide the nifty flywheel effect that make a stock t-jet coast like an eight day clock because of their weight. Something that the spastic plastic pancakes lack. I would say start at nine teeth. Appeals to the Fray boyz and the idea that the fourteen tooth is arguably unuseable for most home/short tracks.

We could blather on indefinately on wishes and haystacks; but the bottom line is QC. Is it round? Is it straight? Is it square? Is it plumb? Answer yes to these questions and your well on your way to a winner.

Much fuss has been made over affordability and while it is a primary concern, I would gladly pony up for a solid contender in the t-jet realm. There is no way to appeal to "lil Johnny's gotta have it Mattel crowd" and the "grizzled and grumpy slot veteran". It's apples and oranges.

I see no reason to guild the lily. We've all managed to cobble along with the originals. The point is that the NOS Aurora stuff is a finite resource. There's a mountain of aftermarket stuff available. Build a solid versatile platform and they will come.;)

sorry to hear your dropping the inline tjet. i would have bought lots, promise!

It's not being dropped, just pushed back...

no one at the fray (80 plus racers) used original shoes.
This is the problem. I'm not making this chassis for 80 guys.

What's the best shoe for 95% of the people out there?

What are the best brushes for 95% of the market? What is the best arm for this same 95%??

When the non-frayers buy an original T-Jet chassis, do they yank the Aurora shoes off because they're garbage? When a home racer buys a T-Jet chassis, do they replace the shoes and put on an aftermarket shoe? Do they pop out the brushes and put in something else? I'm not dissing the Fray people but they are a very small part of the market. If I build an arm at 16 ohms per pole, will it make the fray guys happy but alienate everyone else?

Are the AW brushes good or are they junk? The factory will charge me the same for a 16 ohm arm and a 2 ohm arm. Perhaps there will be different 'flavors' of the same basic platform but one will have stronger mags/lower arm.

A snap in rear axle has to be just about the easiest mod to this chassis, but in doing so it would be deviating from the original. Is this a bad idea?

What's the best shoe for 95% of the people out there?

I think there are a few types that stand out, the slot techs are great, as are the American Lines, and the BSRTs, they all do the job quite nicely

What are the best brushes for 95% of the market?

JB's and Wizzards are both pretty darn good

What is the best arm for this same 95%??

I'd say the standard gray lam arm that everyone is using now, not just the fray guys

When the non-frayers buy an original T-Jet chassis, do they yank the Aurora shoes off because they're garbage?

No, it's just that some are better. That being said, those siler plated things on the AW and JL cars are just plain awful...

When a home racer buys a T-Jet chassis, do they replace the shoes and put on an aftermarket shoe? Do they pop out the brushes and put in something else? I'm not dissing the Fray people but they are a very small part of the market. If I build an arm at 16 ohms per pole, will it make the fray guys happy but alienate everyone else?

I would guess your typical home racer would do absolutely nothing, and if the car is a bad build quality, like some of the newer releases have been, they will run them around their Tomy track, get frustrated with them, and never buy them again. I agree that you shouldn't be building a car for fray guys to alienate everyone else, but you should probably be building them for groups like ours here on this board and for newer folks into the hobby. Make it so a new guy can throw it on the track and get some laps in and have fun with his kids, but also so a guy that wants to tweak the crap out of it can do so as well.

Are the AW brushes good or are they junk? The factory will charge me the same for a 16 ohm arm and a 2 ohm arm. Perhaps there will be different 'flavors' of the same basic platform but one will have stronger mags/lower arm.

A snap in rear axle has to be just about the easiest mod to this chassis, but in doing so it would be deviating from the original. Is this a bad idea?

No, it's a phenomenal idea, again, relate it for the masses. A new guy wants to try a new rear end set up, he clicks the old one out and pops in a new one.... no searching for the right tools to get everything out and then try to balance everything just right to get them back in. It's a bonus for the tweakers as we can have multiple setups for different tracks, lanes, you name it, that is a win-win for everyone. If you don't change anything else from the original, change the rear axle to a snap in.

Dan,

First a great big thanks for the chassis you are going to make.

As for the Slim-Line a 7-8ohm range is good. The magnets are the waekest link if you can double the strength on them you will be doing good. The chassis had one defect from the factory. Many had one pickup spring nub to big and it affected the pickup springs. A qick trim down to normal size fixed this. Ther other defect was either the chassis was too narrow on the rear axel inside area or the crown gear boss was too large. I believe it was the chassis as its the same crown gear used with the 12 Tooth hop up. Also some chassis had the alignment between the aramature top hole and bottom hole off. Not sure if this was a gear plate error or chassis.

Now as to the TJET aramatures. I would recommend you stay with the dual lam and 16 ohms or greater for your stock chassis so they will be legal for the existing major races across the country.

You also might want to think about your own Dash-One TJET chassis with the 3 lam 8-10 Ohm aramature, stronger magnets and a 12 Tooth rear pinion and some cool new TJET wheels of your choice:)

Whatever you decide on I wish you the best of luck and great success

Roger Corrie

Dan one other thing I would consider if I was making the slimline would be two versions. One original and one longer sa up to 1.7 - 1.9 inch wheelbase. The number of bodies that would fit would almost be unlimited. Almost all the HOt Rods and American Muscle cars and all the Vintage NASCARs that are out there would fit. Not to mention all the Vintage Indy and Grand Prix cars :)

Roger Corrie

...why?

Bill pretty much said it all.

Some other thoughts:

Fray t-jet racing is hardly just "The Fray" anymore. This style of T-Jet racing is prominent across the country with little variations, especially in the chassis. While true Fray rules tend to be borderline psychotic, the madness has produced probably the finest variation of a basically stock Thunderjet chassis. A testament to this is that in open T-Jet racing, Fray-legal cars generally WIN. Against JL T-Jets and their 14-ohm arms and wild gearing, Fray legal cars generally WIN. There's half or better of your R&D right there.

Let's not forget VHORS, NITRO, and the others who run fined tuned originals.

From a business standpoint, again Fray "style" does come to mind. With the demise of the Aurora chassis, there will ultimately have to be a decision made to allow a replacement. That replacement does not have to be necessarily better (thus possibly costlier) than the original but consistency with the original will weigh heavily on it's wide acceptance. There is already chatter about legalizing JL/AW arms, if this happens I highly doubt a third choice would even be considered.

Lenny, If you are going to make a tjet, then by all means make a tjet. Critical factors will include parts interchangeability with older chassis and bodies, acceptance by racing groups is another factor to consider, plastic gears are just fine, as long as they are of good quality. Plastic gives you less weight on top and less rotating mass. They worked fine on my TYCO 440X-2's and others, and could be lapped with a Bic lighter. Plastic gears are a cheap upgrade that will give you more power. Plastic gears are one reason why most race groups ban Johnny Lightnings. Two other items to address are pick-up shoes and brushes. I favor the just a tad longer BSRT style pick-up shoes, reason; delivers more juice to the motor and is a cheap upgrade. The brushes I would recommend would be notched on one side so they will not spin, much like the old Faller? Another cheap upgrade for more power. I would offer snap in rear axle chassis, armatures with different ohm ratings and laminations, stronger magnets, silver electricals, etc, as after market parts, or hop-up upgrades. If you are going to make a chassis, support it with after market parts. Don't do like Tom Lowe and just make chassis. Support from racing groups will be weak because he is not providing replacement parts. Enough said.............

from a marketing stand point, here is How I look at.

Many folks run VHORS or FRAY or STOCK aurora t-jets.
That rule is (1 think) is 16ohm, so I would shoot for 16.2ohm 2 lam arm to cover the variance. make it look as close to the AURORA gray lam arm as possible so that groups include the arm in their rules instead of trying to tech it.

make the chassis the same as aurora, parts can interchange willy nilly
use the same metal gear plate gears.

The closer it is to the original aurora, the better it will fill the need of the t-jet'ers

Yes there are those who want improvements, but thats the magnatraction, and SG+:wave:



If you looking at the magnatracion type car, then go with the mean green type arm. ie 5.6 to 6ohms. So people can add the hot arm to their t-jet if needed.

Starting off on a project like this, you do not want to spread yourself to thin.
You need bang for your buck!
A t-jet clone will give you that.

Her is an intresting mod to A Tjet. http://www.howorld.net/archives/howto/conversions/tj_chmod/chassmod.html Maybe at least two versions of the Tjet one stock on a hotter version with a lower ohm arm stronger magnets vented chassis brush cups etc.

My thought are this: Don't try to please everyone: do your best to stay true to the stock original solid rivet T-jet chassis. The original T-jet design was a good design that was durable, and highly adaptable. Brass gears, brass metal contacts and brass shoes are all must. Plastic gears are often warped an are less modifiable as compared to brass. A 16 ohm arm is the best "stock" ohm rating, lower ohm ratings are not for everyone. 14 tooth gears make a car too twitchy for a home set. I avoid the JL chasis because of the gearing. Stock T-jet brushes were admittedly a weak point. The point is that everyone will make their own changes and part swaps. The most important thing is that the chassis work straight our of the box on Aurora lock and joiner and AFX track, with no more tweaking than a little lubricant. Quality non-warped parts, that interchange from chassis to chassis are also a must.

Phred

I would be interested in testing some of the lower OHM arms & your magnets. I have some AG arms to compare them too along with Super Two arms as well. Besides track testing using a chassis Dyno would also help.

Boy O boy with all the wants and desires i can think of ... the best thing in my opinion is to run ! Run as fast as you can away from this whole idea . I say that half serious and half joking. Truth is while i love the tjet , it has been the downfall of many an idealist who thought he could build a better mouse trap ! OK so you just gotta make it right ? Ok then do yourself the biggest favor you can and make it EXACTLY like the original period . Then do what all the others did not do and oversee the project from start to finish like no other before you.
Harrison learned the lesson of not being there and trusting that the prototype would be what he had for the end product. Well we seen the disasterous results that had. JL came along and decided the better mouse trap was the way to go. Again we seen how that went when QC was left behind and they went on the cheap for materials. AW was next and while the jury is still out on some aspects , they too decided to go with the burgerKing approach and have it thier way with less than stellar results ! You still wanna try this project ? Well then the formulary Aurora followed as old and antequeted as it is still worked enough to keep all us old kids begging for more 40+ years later. Make the chassis as original as possible in every aspect then offer your up grades. That would give the baseline guys what they want and give the racers / builders what they want since ALL parts could be interchangable ! You got a pretty good dialog going here for aftermarket items , upgrades and hop up items so a suggestion would be to focus in 2 distinct and separate areas. 1st the ORIGINAL DUPLICATE chassis where discussion should be DONE and second the after market items / options. Not only will that get the guys buying but i would suspect you would get the high praise that others had hoped for just by following a 40 year old formula.

Good luck , Dennis Rutherford Road Rage HO

My take on a new chassis would be start with what works. I would want to see an arm ranging from 15-18 ohms with complete parts interchangeability. The only major change I would want is the quick change rear axle. I play with my cars, but seldom race them in competition. I want four cars that run will together, and if the arms and magnets are in the standard NOS Tjet range, the easier it is to make them into IROC type sets.

My $.02 worth.

Make it as close to the original as possible. It is a good work horse that responds well to modifications. The heavier, more friction brass gears are the tradeoff for the poor quality and low life expectancy of plastic gears. If you can find a material that is durable and can easily be made consistantly good, go for it!! Again follow Aurora's lead. Make a standard T-Jet and later upgrade to a Tuff-Ones version.

I don't want to offend anyone here, this is my opinion only!! I don't care for Fray style cars at all!! In my opinion they are plain ugly. I would not make a chassis that meets their secifications, let them do that themselves.

If you make a base T-Jet chassis it can be fun for a lot of people. Fun for the guys like me that want a car to run decent right out of the box. Add some slip on silicones and go! When I was into modifying cars for racing, it was a ball tinkering with them to get the best performance. Taking the stock chassis and making it my own.

Dan,
Let me echo the statement that I appreciate your efforts and the nergy you put into our hobby.

MOO
Marty

My thought are this: Don't try to please everyone: do your best to stay true to the stock original solid rivet T-jet chassis. The original T-jet design was a good design that was durable, and highly adaptable. Brass gears, brass metal contacts and brass shoes are all must. Plastic gears are often warped an are less modifiable as compared to brass. A 16 ohm arm is the best "stock" ohm rating, lower ohm ratings are not for everyone. 14 tooth gears make a car too twitchy for a home set. I avoid the JL chasis because of the gearing. Stock T-jet brushes were admittedly a weak point. The point is that everyone will make their own changes and part swaps. The most important thing is that the chassis work straight our of the box on Aurora lock and joiner and AFX track, with no more tweaking than a little lubricant. Quality non-warped parts, that interchange from chassis to chassis are also a must.

Phred
If I don't use solid rivets will I be ostracized?

I agree with all who want a purely original, as in stock Aurora, chassis. With one exception. I also agree with Marty Bauer about the snap in rear axle. The biggest pain in working on a t-jet is removing the rear end to fit a new gear, add spacers, or even just change the sili/sponge tires a lot of us use. Have you ever managed to push a brass spacer through the rear axle hole? I've done it and now a good racing chassis is a shelf queen holder. Heck, if you ONLY built a quality stock replacement chassis with the snap in axle option I would by MANY.

Later, The former Fray racer and Seattle Fray team Captain Rockinator

I would not make a chassis that meets their secifications, let them do that themselves.

Under that...."look"....and except for the magnets is very much a stock Aurora chassis, again, it's a shining example of how far you can go with a stock configuration. You could probably apply 90% of the fray chassis rules to box stock T-Jet racing. So a stock type chassis would work for you and them. :thumbsup:

Fray racing isn't for everyone, but every T-Jet racer can learn from it.

Gene,I'll bring some to you the next time I'm out your way.I don't want to have to borrow one of Bill's junkers.Tom

I also agree with Marty Bauer about the snap in rear axle

Absolutely fabulous idea. This alone would eliminate one of the most tedious impediments to testing & tuning TJets. Brush cups w/springs would be high on my list as well.

If I don't use solid rivets will I be ostracized?

I don't see why you would be, it certainly doesn't "make a winner". I don't see how they could create any difference electrically or mechanically. As an argument, hollow rivets do provide a ventilation path through the motor box.

Gene,I'll bring some to you the next time I'm out your way.I don't want to have to borrow one of Bill's junkers.Tom

http://images.yuku.com/image/gif/12b15a4375f8c19f74fb0e74040a02844f39428.gif

If I don't use solid rivets will I be ostracized?

No way, I have just as many good open rivet t-jets as I do solid ones, I don't think for a second that the solid rivets is what makes the t-jet great.

I do also like AFXToo's recommendation for the brush cups....

Hey Dan - Make a real TJet replacement, please! I'd like to see between 15-17 ohms, and a hop-up arm similar to the Wild Ones arms, though I'm not sure off the top of my head what that would be. I have a couple Wild Ones cars from my youth that have both Mean Green and Tuff Ones Speedwind arms - so, around 6 ohms and 7-8 ohms respectively? My guess...

Gene Hedden

$9.99 and everyone
will buy them...

I agree with all who want a purely original, as in stock Aurora, chassis. With one exception. I also agree with Marty Bauer about the snap in rear axle. The biggest pain in working on a t-jet is removing the rear end to fit a new gear, add spacers, or even just change the sili/sponge tires a lot of us use. Have you ever managed to push a brass spacer through the rear axle hole? I've done it and now a good racing chassis is a shelf queen holder. Heck, if you ONLY built a quality stock replacement chassis with the snap in axle option I would by MANY.

Later, The former Fray racer and Seattle Fray team Captain Rockinator
Would a snap in rear axle get FRAY approval?

I tell you what, they get made straight every time, with a snap in rear axle and I can swap old t-jet stuff in and out, I'd pay double that....

Would a snap in rear axle get FRAY approval?

It would eventually, like everything else, it took time for the BSRT shoes to get approved but they did. The RTHO gears got approved among others. There are only a finite amount of these old chassis left, they will definitely need to allow something new. If they don't, then they will die off just like everything else that doesn't want to change, and something new will come in. But the great thing about the fray is that they are using the 40 year old chassis as a platform and using some newer technologies to enable them to go faster. The majority of us that don't have the overstock, would be enough pressure I think to make changes to just about anything...

Please replicate the original T-Jet chassis as close as is humanly possible! It is a unique piece of work with unique qualities for the hobbiest. Improve only the motor brushes and possibly the quality of the arms. The rest is perfect. Let the aftermarket parts makers take care of all the preferred racing needs. When we run out of the originals we will wish they were back in their original form. Thanks.
Tjetjunkster

I agree,
if they want snap in axles, run a inline:freak::woohoo:
:roll::roll:

again, if it is a tech headache for those that run the org t-jet, it will be accepted faster.

If they want snap in axle, they can cut the chassis:rolleyes:

If I don't use solid rivets will I be ostracized?

Nope
we run both solid and open.
I think the solid rivet chassis is like because it was an earlier mold, so it worked better (in general).

Shoes

take a look at the slottech shoe.
It works the best for me.

I am for a stock spec Tjet with better brushes. While the brush cups are a cool idea its just another part I have to get. While I am not a fan of a snap in axle I can see it as a plus. I think that top gears made from better quality plastics would be a plus as long as they are still interchangable with NOS gears. I think the biggest insurance for acceptance and success is quality control which to date has been great on all your other products. Myself, I can't wait for a slimline replacement! Again using quality and materials equil to or better than the origonals.

Hey Mike :wave:

Shoes

take a look at the slottech shoe.
It works the best for me.

Me too. :thumbsup:

But for a rolling product I'd make the window taller, the Slottech shoe's natural restriction can be a problem with stock-size tires and low rails.

I would say that sticking close to the original would be the best bet. Arms in the 16-20 range. Axle spacing, topplates, all shafts, gear center spacing. Chassis is useful right out of the box, good or not. Offer upgrades down the road. A quadralam would be nice down the road also.
Making sure that parts are interchangable with the original would also be wise. It doesnt matter if you're a dedicated racer or collector, most into tjets tinker to an extent and mixing and matching parts is a big part of it.
Perfect example of what not to do is the Thunderplus chassis, it doesnt interchange, wasnt very good, so they never became useful other than to collect dust. If everything had interchanged then it wouldnt have been as much of a failure. It was of good quality (the arms sucked!), noone was able to do much with them due to lack of interchange with the original.
There are several different forms in which these chassis are used and all the purveyors of the different uses will try to sway you to what they think is the best way to produce them. Just remember, the original started it all, and everything else was developed from there. Build the base (and do it well), hop it up from there. Smart business also.

If I was serious about this project, I would test the waters before I jumped in head first.

If you're going to do this, try making only a gearplate. This a VERY simple mold, so tooling costs would be minimized. If you get good responses to that, then try the chassis. This a MUCH more complicated mold, and much more pricey. (but you probably already know that.)

Then there is the electrical components. You will need to find a good Multi-slide shop or tool and die shop to produce these tools. Remember that copper is at an all time high and will continue to go up.

You need to optimize all of your tooling costs, so I would think about offering a "Rebuild Kit" This would include the new electricals, rivets and instructions to replace the electrics on an original t-jet. This would give at least some of your tools a second life and more options for ROI.

When it comes to being legal for the FRAY?
I would'nt count on anything. They have no sense of the amount of money it takes to produce this stuff. When BSRT pruduced their t-jet shoe, they were'nt legal for three years. A pure copy would be the only shure way.
Just keep asking yourself, "would I buy this" and you should be fine.

I would be happy to design any tooling you require, or help in any way I could.

Tim Leppert
journeyman tool and die maker (22 years)