View Full Version : Rocking the HP-7.


grungerockjeepe
06-30-2009, 01:43 AM
Ok, so now as promised here are my tips and info on the Tyco HP-7:

Unlike the Curvehugger, the HP-7 has no real variations in the actual chassis design that Ive ever seen. Outside of some different motors over the years, and a different bend on the pickups, there's only one other development that I know of. So first off, a little info on these chassis:

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00133.jpg

Earlier HP-7s had the naked copper spring plates and pickups like on the left. These almost always had the greenwire motors as far as I know. The silver plated ones as on the right came on later. Ive seen every type of motor used in these, but unless you get it NIP, who's to say whats been swapped around. Speaking of motors...

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00134.jpg

The greenwire motors were what Tyco used pretty much exclusively in the first few years of HP-7 production. They seem to be the same type of arm used in the HP-2's and US-1 trucking chassis but with the commutator timing set for the leaf spring com brush setup and a longer rear pinion of the US-1. They are all widegap arms and are usually very strong runners. In fact Id say that my strongest running HP-7s are greenwire motored cars, but like with the HP-2s, there are some inconsistencies in these and not all of them are screamers. Some of these had one magnet marked with reddish orange paint, some with yellow. If there is any difference in magnet strength, its pretty much negligible.

The bottom center and bottom right motors have the more common goldwire motors, but these are widegap arms as well. These came after the greenwire cars, and were probably used up till the late 80's. I honestly have no idea what the difference is in the black endbells vs the milky white ones. But what I do know is that the chassis with black endbells seem fairly common on set cars from the 80s. The widegap copper arm motors are also very strong, and run comparably to the greenwire ones. They seem a bit more consistently fast, but it seems that the strongest green ones will edge out the strongest wide copper ones. Every widegap copper arm motor Ive seen has had one motor magnet marked with reddish orange paint.

Finally, the one on the bottom left is the narrow gap copper wire arm motor that was used from the late 80's right up to the mid 90's when HP-7 production ended. These dont have the bottom end torque as any of the widegap arms, but seem to do just fine on top end power. These all had either one magnet marked in reddish orange, or no paint markings at all.

All HP-7 motors use the same magnet can in galvanized steel and have the same strength motor magnets.

The chassis frames are all pretty much the same, I havent seen any variations on them. When getting ready to modify one for better performance, there are a few points of interest which Ive marked with some paint. *note that this frame is a junker, the rear motor bulkhead/front magnet mount is broken out of this one*

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00135.jpg

First thing you want to do is completely dismantle the chassis. The only thing that wont get in your way is the traction magnet so it can stay.

The yellow ridges under the front of the chassis go up under the leaf springs, and are meant to tension the springs against the pickups. The red dots help locate the spring plates, along with a couple little tabs just inside of the spring hangers. The white ridge on the inside right of the rear axle box is all that keeps your crown gear meshed onto the pinion. The teal gussets or 'wings' in front of the rear axle give a little stability to the rear axle box but also necessitate the excessively wide rear track.

The first mod is going to be to the ridges under the pickup springs. They are the reason why the tension is so hard to adjust and your car is always deslotting: they only allow the final 1/3 or so of the spring to have any flex at all. You want to take your razor scraper, and carefully shave that ridge completely off. Whatever you do, do NOT shave off the little round nubs to the insides of them, they locate the spring plates. Oh yeah, and dont go slicing up your fingers, either! In the foreground, you see what it should look like once you razor off the ridge, and in the back ground, how you'll shave them off:

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00138.jpg

Now, you can re-install the spring plates and guide pin. Now would be a good time to get out your dremel and use your rubber emery wheel to polish up any tarnishing on the spring plates, especially the full leaf springs and the rear tabs that contact the brush tabs on the motor. Also, you might want to ditch the stock aluminum guide pin for a steel one from a 440 since its a LOT more durable. Compressing your springs will show you how much more range of motion you now have.

Here's the leaf spring at full compression on a stock, unshaved chassis:

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00142.jpg

And here it is laying flat against the underside of the modded chassis:

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00143.jpg


Now that you have infinite adjustability on the leaf springs, there will probably be an infinite number of opinions on how to bend and adjust them. Whats worked for me is the spring itself completely straight, and bent at an angle so that the tip is at the same height as the tabs that the pickups lock into:

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00141.jpg

The pickups themselves have had 2 different bends on them. The earlier design (some silver plated ones, and all bare copper ones) have a bend putting the peak of an angle as the only contact with the track rail--its the one in the background. It means smooth running over criss-cross tracks and intersections, but a poor contact patch with the track rails, and accelerated wear. The later design has the front 1/3 or so of the pickup bent so that its a nice flat contact with the rails as in the foreground:

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00136.jpg

With a pair of small flat nose pliers, one of these can be bent into the other, but I prefer the later design. Either way, if you cycle the installed pickup thru its range of motion on the modified chassis, you can see how much better tension it has and how easy this is to adjust. The tension is constant, and will keep your pickups planted but not so much to cause the front tires to lift up and cause your car to deslot. Your pickups will last much longer too, since they no longer support the weight of the front end, the front axle and tires do. I have done this mod on ever last HP-7 I own and it will be mandatory for every one I get in the future. I think once you try it, you'll agree that this is how Tyco SHOULD have made these.

grungerockjeepe
06-30-2009, 02:26 AM
The next mod is just a simple installation of a part that should have been there all along: a gear saver. Tyco may have saved a penny for every 25 HP-7s they built by deleting this part, but it was a bad move, since many HP-7s that get run end up looking something like this:

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00144.jpg

The stock HP-7 motor, especially ones with a narrow gap copper wire arm, dont put out a whole lot of torque. But leverage from the extended pinion, a chassis with some side to side flex, a tiny little ridge to locate the crown, and gears that are a bit soft equal a recipe for pulverized gear teeth. A stock 440 gear saver will fit right onto your axle with no clearance problems. The setup on the left uses the stock HP-7 wheels and axle but with a 440 gear saver. The one on the right has an aftermarket saver made by HT member rdm95, and has a set of wheels from a hotwheels real rider car able to fit by way of the next minor mod:

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00146.jpg

If you shave off the little 'wings' in front of the rear axle, then you'll be able to get a complete 440 X2 rear axle in there with the wide rear tires and wont widen the track much at all. The left side of the chassis is opened up for wider wheels, the right shows how you shave it off with a razor blade. You can clean this up with a set of needle files to get rid of any leftover 'wing':

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00139.jpg

The chassis with the HW wheels gives the right look to this unfinished Javelin I painted up:

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00149.jpg

After you shave the chassis wings, you can use a round needle file to open up the axle bosses a bit so that a Super G+ axle will fit, allowing for all kinds of AFX wheels to be installed on your HP-7. Dont use the Turbo's rear axle since it has knurls on the outer ends, which will be in the axle bosses and chew up your chassis. I was able to get AFX ansen sprints mounted to an HP-7. Mounted to a '98 Wrangler I resin cast some years back it just has that right look of badassery:

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00148.jpg


The final mod I do to quite a lot of my HP-7s is swapping out the motor magnets. The stock pieces are total weak sauce. You can harvest stronger ones from several sources, dead 440 X2s would probably be the most plentiful. Some of the magnet cans have little nubs on the inside edges, so the back sides of the stock HP-7 mags have little bevels along the edges. 440 X2 mags have sharp edges that you can knock off by doing a quick polishing with your rubber emery wheel. Another source of some comparably strong magnets and for cheap is the motors out of Ideal TCR racing cars:

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00147.jpg

Use a pair of end nippers to crack off the brass rear gear to harvest the armature for use in something else. The polished motor can will brighten up your chassis and the magnets will perk your car right up. These motors are pretty much the same thing as the Mabuchi motors from the later HP-2 chassis, which is good info for fans of those. You can also swap in the redwire arms from Tomy Turbo chassis since they too use a leaf spring endbell and with the stronger motor mags, your HP-7 will flat scream!

Like the barrel brush endbells on CH/HP-2 chassis, you can vent the endbells on HP-7s for better cooling and allowin commutator soot and crud to escape. Just carefully razor off the areas over top of the brushes but be VERY careful not to damage the leaf springs inside; theyre pretty fragile:

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00154.jpg

Once you get these techniques down, you can experiment with some different arm/magnet combos:

http://i77.photobucket.com/albums/j71/grungerockjeeper/HP7%20101/DSC00150.jpg

Stock narrow gap goldwire motor is up top, center left is wide gap goldwire with polished can and HP-2/TCR mags, narrow gap redwire Tomy arm in the same seup center right. Lower left is a wide gap goldwire arm with 440 motor mags, stock can and vented endbell, lower right is a green wire arm with vented endbell, HP-2 can and vented endbell.

Bill Hall
06-30-2009, 03:21 AM
'Tanks Jeeper!

So cool you got the new camera now!

NTxSlotCars
06-30-2009, 08:33 AM
Great info on the shoe springs! :thumbsup:

slotcarman12078
06-30-2009, 11:27 AM
This is too cool!!!! After looking at these threads I'm still wondering if pressing the comm shaft through a bit if a "Video Jimmy" specialty motor can be had with these. The longer shafts appear to be the correct length to do a centering slide and have enough meat to get wheels on the ends.. I'll keep these threads locked in my memory banks and when I have the chassis to play with I will definately revisit these threads and go to town. Nice work Jeeper!!! :thumbsup::thumbsup:

partspig
06-30-2009, 01:15 PM
Slot, A guy named Ed Bianchi was making cars he called direct drive cars a few years ago. He did a how to article with pics, but I was unable to find it. He used a wheel puller or some type of press he made to move the armature stack to the center of the armature shaft so he could mount tires on the protruding ends. He does still have a website here; http://www.horacepro.com/index.html

ebi
07-01-2009, 08:55 AM
Thanks a lot for sharing your resarch results!!!

Kind regards

Ebi

grungerockjeepe
07-01-2009, 06:54 PM
No problemo, dudes. When you try this stuff out be sure to post your questions, comments, and insults.

Wildstar
07-10-2009, 02:23 PM
Awesome tutorial, Grunger! A well set up "7" is one of my favorite chassis to drive. I've tried a lot of these mods before, but the pick-up spring nub is new to me -- it looks like a good idea and should solve a lot of pick-up wear problems. I'll have to give that a shot.

Does anyone else out there have any other mods for the HP-7?

NTxSlotCars
07-10-2009, 06:24 PM
You can install a Tomy Turbo can motor into the HP7. The exposed magnets seem to make it handle with more downforce. The shaft is shorter, but still works with the Tyco gear. The Turbo can motor seems to be stronger than all my Tyco can motors. Gjeepers, you have any info on the Tomy Turbo can motors?

Rich

videojimmy
07-10-2009, 08:45 PM
Really great info there, thanks!

I use H7 motors all the time when I slam a custom chassis togther.. never knew the
440 magnets would slide right in. I'm gonna give that a try for sure.

Pomfish
07-11-2009, 12:23 PM
Awesome tutorial, Grunger! A well set up "7" is one of my favorite chassis to drive. I've tried a lot of these mods before, but the pick-up spring nub is new to me -- it looks like a good idea and should solve a lot of pick-up wear problems. I'll have to give that a shot.

Does anyone else out there have any other mods for the HP-7?

I like to put the Magnets from a Marchon car on top of the stock HP7 bar magnet, it gives much better traction without being "Glued" to the track and they are removable if not desired.

Thanks,
Keith

grungerockjeepe
07-11-2009, 04:15 PM
You can install a Tomy Turbo can motor into the HP7. The exposed magnets seem to make it handle with more downforce. The shaft is shorter, but still works with the Tyco gear. The Turbo can motor seems to be stronger than all my Tyco can motors. Gjeepers, you have any info on the Tomy Turbo can motors?

Rich

Ive tried to put a tomy type motor in an HP-7 but the block just doesnt seem to want to fit right. Far as I know there are 4 varations on them: Gold wires are the first ones, much weaker than the redwires. Redwires came on Turbos and SRTs, SRTs seem much faster, but that could jsut be the neos. Then there are those greenwire hop up motors. Any of the arms will fit into an HP-7 motor block then you can put in 440 Magnets, it seems to have the same amount of grunt as the turbo motor. I dont think the motor magnets are doing much for downforce either way though.

gonegonzo
12-09-2009, 05:56 AM
Bumping this up with the rest of the HP7 posts.

Great post.

Gonzo

slotnewbie69
12-16-2009, 06:04 AM
just another thanks here for some great tuning tips from you guys.as my small ho collection grows,i want to expand my buddy's interest in tyco,lifelike,etc.i am not a purist,and like all things slot.so if i can tune these little suckers up and show their potential.maybe i can expand the interests of my afx buds.i like the tycos ihave,and think they were great innovators in the field when aurora was still tinkering with pancake arms.i like those too,but inline is so much more efficient.i welcome any tips and info on breaking down inline motors,as i am scared of taking them apart.one thing about the pancake motors,they are easy to breakdown and wrench.thanks agaain guys for the awesome tips and tutes!

RacerDave
12-19-2009, 11:27 AM
This is a great thread. Thanks for all the HP7 info, especially about the mods to the pick-ups. Dave.

XracerHO
12-24-2009, 04:25 PM
Grungerockjeepe, Thank you for the HP7 modifications, what a great difference even used TCR magnets & polished motor can producing fantastic Torque!! Off to get some braid & follow the Curvehugger postings for the next chassis projects! :thumbsup: :thumbsup: ..RL

Jeepm@n
01-08-2012, 11:42 PM
Ok I have a few chassis that I did the spring mod too. That worked great. I had some old chassis that the contact area for the motor was broke off years ago.

Where can I get the spring assemblies for the HP7?

I'm also looking to get more of these chassis. Any good sources to buy these?

Thanks for the tips GrungeRockJeeper.:thumbsup:

mtyoder
01-09-2012, 10:20 PM
I have some old neo's that fit in those can motors. one set is in a modified ho monster truck. you can swap out the silver parts from a tomy super g+ bulk head right into a hp7 bulk head and a tomy turbo or super g+ arm or lifelike m arm. Shaft length might be an issue on that lifelike arm. With a few more mods n tweaks you can install an old tyco bulkhead with threaded tyco 440 brush barrels and a tyco 440 arm. This is a lot of work but if you are a lover of the hp7..... there are some good design ideas there.

sumoldfool
01-11-2012, 02:53 AM
This was a great thread for me to edumacate myself...Thanks a lot !!

Sir Slotsalot
01-11-2012, 12:54 PM
You can greatly improve the HP-7 performance by installing a Fyrebox-1 hi-perf replacement motor available from Slot Car Express:

http://www.slotcarexpress.com/Power-Drive-Train-Wheels---Tires.html

Hope this helps.

1976Cordoba
01-11-2012, 03:27 PM
I dunno - part of the charm of the HP7 for me is how they run NOT hot-rodded or nailed down to the track. But this has been an interesting read.

Sir Slotsalot
01-11-2012, 03:57 PM
If you're open to other cars like the HP-7, Tomy SRT is a actually a better performer right out of the box. There are still plenty of new ones available.

1976Cordoba
01-11-2012, 05:25 PM
If you're open to other cars like the HP-7, Tomy SRT is a actually a better performer right out of the box. There are still plenty of new ones available.


The SRT is way, way to stuck down for my tastes. So is the Turbo. The bar-magnet original Tyco 440 is about as planted as I like in a non X2 or SG+ platform. :)

Sir Slotsalot
01-11-2012, 06:53 PM
Doba,

Understood. It's all about the preferred driving style. I'm also racing 1/43 which has less "stick". I'm beginning to like that style as well.

gonegonzo
01-11-2012, 07:18 PM
I think the HP7 has many of the 1/24th scale pan chassis handling chracteristics .

The ony od I do is add gear savers to the rear axle . I will say that the pickup braid looks like a good move .

Gonzo