brush cutting help

[boborc]

whats up i was thinking of buying the xipp brush cutter from integy.is it worth the investment,will it help brushes last longer?will i see better performance?i race an oval & always seem to heat up the brushes causing loss of power will cutting help?thanks for any input

[rcguy2477]

It all depends how hot the motors get. If the brushes get so hot to the point of discoloration, than it won't make a difference. If the brushes look fine after the run, than yest it will help, but you still won't be able to achieve the performance you got with brand new brushes. Axxis (http://www.axxis-racing.com) is making a brush cutter that should be one of the best quality ones available.

[gizmoguy303]

Serrating your brushes will not prolong the life of your brushes but in most cases it will give you an increase in power. If your brushes are discoloring because of excessive heat, make sure that your geared correctly/no binding/etc. Having freshly serrated brushes would probably make a noticeable difference in oval racing since you would gain RPM.

The Integy unit looks very nice and would work well for serrating brushes. AXXIS will be offering something similar as well. I would concentrate on having good batteries, chargers, and motors before spending that much money on a brush serrator. Make sure you buy the stuff that makes the most difference first: TIRES, batteries, good motors, etc. Hope this helps! :)

[boborc]

thanks guys,i'll probally go with the integy hoping that i will get more than 2 or 3 runs out of a set of brushes.Now that i buy the xxx le mans brushes at $13 a pair it can get expensive quick.as for the gearing it is a little over geared but it still winds out on the straight & i am at 1/2 speed if not more thru the turns thats why my brushes take a beating any other tips appreciated thanks again

[gizmoguy303]

If you run the Trinity XXX brushes I don't think you need to serrate them.

[boborc]

yeah i'm using the xxx brush but they still fell off after 2 battery packs, enough that i would notice & i'm no pro.i'am just trying to get good power for a longer time without shelling out 4 or 13 bucks after every 2-3 runs.the cutter will pay for its self after a while i hope.i know the xxx come flat w/no serrations but i wonder if it would help since there are no slow corners to come out of, just the start & after a kart wheel down the straight ha ha

[gizmoguy303]

If the XXX brushes come with no serrations and you say they are falling off after two runs, how do you think that serrating the brushes will provide more power with less power loss? I am not positive, but I think the XXX brushes work better with no serrations. If you are losing power after two runs, it is the comm that is causing the power loss, not the XXX brushes.

[highroller]

What I've found to work well as far as brushes and springs kinda depends on motor power levels, and type of motor you are using. Plus it depends on whether you are using a Monster Stock or the Epic Roar stock, or racing in the 19turn class so I'll give information on what I'm using.
Stock: Reedy 767, or Putnam Green/Blue shunt brushes, some motors use a Purple/Red combo or 2 purple (kinda depends on the amp draw and other things). Monster Stocks rollout 1.95 to 1.98 you can miss the gearing a little and motor still runs decent, the Epic ROAR Stock rollout 2.01 you have to be right on the gearing for this motor to work great on all sections of the track.
19turn mod (adjustable ARCOR style motors) Epic or Yokomo makes good power with the newer Cobalt cans making a tab better. For brushes the Putnam X brush with Purple springs (most guys use 36 degrees of timing, while others use 24 to 30 degrees) and rollout varying depending on track and motor 2.20 to 2.48. Some do use the Trinity 4383 or XXX brush even the Reedy 728 or Plutonium but for the great wear, price don't always seem to make as good of power on the track - dyno numbers may look great - but on the track motor doesn't always produce the same results.
Modified- Brushes Putnam X, Trinity 4383, Reedy 738 or 728 normally with Purple springs timing varies from 20 to 32 degrees depending on turn/winds,runtime and rollout.
With 19turn mod and regular mod most run a full face serrated brush while in stock some use different brush cuts to get more power, Hollow, slotted and timed or 1/2 cut are used or reserrating the brush face. Reducing the surface area of brush face increases rpm at a slight decrease on torque ( or low end punch). Altering spring tension also helps, what I look at is how long it takes a motor to reach a certain amp output and alter spring tension accordingly. If amp draw increases in a short time but drops off increase spring tension a little - present tension may not be adaquate as motor reaches it operate rpm levels, then if it rakes a long duration for rpm levels to build I reduce spring tension a little. Dyno pulls a done only to get a relative idea of where each motor is making power not as a perfect means of saying one motor is better than another. Sometimes I've had a motor that was making way less power than another go out and set track records while the motor with superb numbers ran like a dude.
Also tweaking and setting up chassis has been key. Selecting right tire compound, using just enough traction compound, vary shock spring and oil, finding the right front spring combo (grn/red, black/grn wolfe) along with using small amount of tweak to no tweak. To help setup up your chassis, let us know what chassis you are using, along with the track layout and possible drive line length.

Sorry I just replied, been away from here for awhile.

[TEM]

Hey Highroller, those rollout numbers you got there is for pan car(in inches), right? Cause for touring car, offroad, etc; you're looking at a lot lower.

[highroller]

yes that is for pan cars.
to get into a ballpark multiply the 2.01 x transmissions ratio of the vehicle and consider the diameter of tires. Most pan cars run tires sizes between 2.30 to 2.19 that is they true them from the normal 2.45 down so you run chassis lower and tires usually don't chunk as much.

that's was another reason it makes it easier in suggesting things if people would mention vehicle type, track surface or layout and other information. The 1 or 3 times I did race TC on oval I broke more parts in those two races than I did in the 30 races in onroad. Not because of my driving but because of someone spinning out and having no place to go and you are caring more speed - almost can run full throttle the whole track.

[boborc]

guys this is with an epic 9t single flat wire motor.its a bat out of hell with new brushes but after 10 to 15 minutes (2-3 runs)they fall off, i run a 12t and & i get good power for 15 runs with a set of brushes.maybe its just the expensive of running hot mods or is there something else i could do; besides gear it down so far that a 17t has the same top end?its a t3 stadium truck with with stock size tires

[TEM]

guys this is with an epic 9t single flat wire motor.its a bat out of hell with new brushes but after 10 to 15 minutes (2-3 runs)they fall off, i run a 12t and & i get good power for 15 runs with a set of brushes.maybe its just the expensive of running hot mods or is there something else i could do; besides gear it down so far that a 17t has the same top end?its a t3 stadium truck with with stock size tires

Are you bashing or racing on a track? You definately do NOT need a 9t in an offroad truck. Yes, brushes(standard kinds, never tried them plutonium's, etc, etc yet) are only good for a couple runs in a hot mod motor before you feel a drop in performance. I'd say go with a higher turn motor. Also consider using a lower silver compound, less performance but better for wear. And if you do need the performance, it is going to cost you.

[highroller]

When running a true modified motor it's important to find the setup that gives the best balance of power and wear - sometimes there isn't you have to sacrifice one for the other. More maintenance comm truing, brush replacement to achieve the performance you need. The selecting a motor in a turn and wind area that works for the track conditions a vehicle.

Since you've already purchased the motor there are some things you can do to reduce the raw low end power and possibly reduce some wear but not all.
Gearing may be help by dropping a pinion or two more inline tailoring gearing to motors potiential power level. Timing either decreasing or increasing again changes the power a little, if motor produces too much acceleration but you need more low end power then decrease the timing starting with 2-10 degrees it may also give you better runtime. Depending on certain conditions racers may use 6-36 degrees of timing for certain uses, the higher equals more wear and less runime. Brushes and compounds used can again aid in either reducing some wear with very little decrease in performance either use a high silver brush on the positive, while using a low to medium content silver on the negative. Spring tension is another misconception you want a spring heavy enough that it keeps brush in contact with the comm as motors develop or produce higher rpms most springs aren't providing adaquete tension. Motors in the 13 turn range start with 2 reds or slightly heavier on the positive, then all the way up to purples with more tension on the positive (making the bend between 2-5 degree).

The most I run any modified (racing) is three runs no more than 5 for 4cell racing before tearing down and truing the comm. If brush looks good it gets cleaned and reserrated so all surfaces are free of glazing. After each heat normally a shot of motor cleaner, then cleaning the comm and brush face with a comm stick.

A cheaper alternative that many modified racers use is buying a couple of replacement armatures in different turn and winds sometime the same if you find the one that works. This does two things, the armature is cheaper than buying a complete motor using different replacement armatures then allows you to tailor the motor power to track conditions and can allow you to reduce wear. The armature you use if racing must be of the same motor manufacturer, that is the armature must be made for a Epic (Trinity). Going to something like a round wire 10 or 11 double may help reduce some wear but produce better acceleration that the 12 turn. The round wire should also give runtime or run a little longer into the race.