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Aug 05, 2019, 01:25 AM
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Help!

Tamiya Bear Hawk fixup!


Hi everyone! I am new to this forum so I hope I post to the right sub. So I had this Tamiya bear Hawk some 25 years ago when I was a young lad and I recently got it out to fix it up "for my son".

I have got hold of a new speed regulator as the old one was missing a part and I was eager to try these ESC devices.

So to list the parts I have:

-Stock motor, silver can
-NEW hobbyking x-car 45a brushed car esc
-NEW Lipo 7.4v 2s
-stock servo for steering
-stock receiver (old AM crystal style)


The issues:

Installed everything and had quite a few hiccups with throttle specifically. Reverse works just about every time, but forwards is moody. It will suddenly just not respond at all, then it might do a little forwards jolt and then stop, but reverse seems to works fine more often. Some times I noticed that if I have been in reverse it won't go strait into forwards, but if I release the throttle and let the stick go to zero, and then go into forwards it will work. Some times though, nothing works and I can see the little light on the ESC blinking in time with throttle, so it seems to receive signals.
I have jiggled wires around and cleaned the motor. It basically is unstable.
Any thoughts?

Oh and if anyone can point me to best specs for the lipo: thank you! ( This one I just had lying around)


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Aug 07, 2019, 11:05 AM
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Any thoughts? Faulty ESC?

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Aug 07, 2019, 08:46 PM
ultra cheap pilot
ican3d's Avatar
Have you done calibrating the ESC to match the radio throttle throw? Else try troubleshooting narrow down the problem by testing on different brushed motor. However i suspect it should be on the ESC calibration part.
Aug 07, 2019, 11:22 PM
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Ok thanks . I didn't know I should do a calibration. How to do it?

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Aug 08, 2019, 12:05 AM
ultra cheap pilot
ican3d's Avatar
Go to this page and check the 'File' tabs to download the manual here: https://hobbyking.com/en_us/hobbykin...d-car-esc.html
Aug 08, 2019, 01:23 AM
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Thanks, but I don't see any instructions on calibration? You can set modes practice/climb and some lipo safety cutoff...but not calibration.

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Aug 08, 2019, 05:23 PM
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Ok I found a video for general calibration and tried holding stick in full throttle while turning ESC on. Seems to done the trick. I also realised that part of problem was the transmitter was reversed on throttle channel. Set it to normal and switched the motor wires around and now it feels like it should...need to take it for spin to check properly!

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Aug 09, 2019, 01:44 AM
ultra cheap pilot
ican3d's Avatar
Good to hear, hope it works well ahead.
Aug 12, 2019, 04:20 AM
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Ok it's all working perfekt now! So cool to be driving this again after 20ish years! Got used to the new breaking business that I never had back then, though I do miss seeing able to slam into reverse! I'm hoping some of you can help me find a good replacement for a couple of things that are needing attention.

1. New shocks: they seem to measure from screw to screw 100mm back and 75mm front

2. Wheels: rims seem to be about 50mm diameter. 20mm wide front and 40mm wide back. - would be cool to get some new type of rims and tires( off road ) but also I need to replace the original tires, they are super warn down.

3. Ball-bearings/ bushings: they have never been replaced..they are stock plastic bushings all round. Should I replace all with metal ball-bearings or rubber shielded?

4. Piston/gears: I'm getting a new 15t piston. out of steel is ok? Any point in getting 17t or will that even work? Not sure what the difference is. Anything else in the gear box/ driveline that is good to replace? It seems to make a lot of noise when driving..but it maybe just does that...I can't quite remember...just would of liked it to be more smooth sounding.

Picture: This is the body that I gradient spray painted in my youth. I have now added the stickers 20 years later and it's looking good..will post full car pics soon. Oh and I had mounted some cind of cap gun capsules or what you call them on the top there as a cind of mohawk... hahaha.


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Aug 12, 2019, 07:44 PM
ultra cheap pilot
ican3d's Avatar
Super nice! i hope you restore it to original condition. This buggy no longer in production so i don't know if any Tamiya parts compatible with this. You might need to check at www.tamiyabase.com for more info and compatibility stuff.
Aug 29, 2019, 03:54 AM
Registered User
1 Hobby king sells turnigy track star shocks in various lengths and are good .
2 wheels seem easy to get on eBay
3 ball bearings are a great upgrade and rubber shields help keep more dust and grit out , they do have slightly more friction than metal shielded ones but last ten times longer , its only worth getting metal shielded for gears inside the gearbox where there is no debris or if your racing and every tiny advantage helps .
4 steel pinions are good , way better than the cheese alloy pistons that just wear away , I'd stick to the 15t , your already running on lipo and a 7.2 v lipo is the equivalent of an 8.4 v NiMH from back in the day plus the lipo will run the car for half an hour and the old NiMH only lasted 5 min so the motor is going to get way hotter than it did without gearing it higher !

Hope that helps .
Sep 03, 2019, 02:27 PM
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Thread OP
Quote:
Originally Posted by dadio
1 Hobby king sells turnigy track star shocks in various lengths and are good .
2 wheels seem easy to get on eBay
3 ball bearings are a great upgrade and rubber shields help keep more dust and grit out , they do have slightly more friction than metal shielded ones but last ten times longer , its only worth getting metal shielded for gears inside the gearbox where there is no debris or if your racing and every tiny advantage helps .
4 steel pinions are good , way better than the cheese alloy pistons that just wear away , I'd stick to the 15t , your already running on lipo and a 7.2 v lipo is the equivalent of an 8.4 v NiMH from back in the day plus the lipo will run the car for half an hour and the old NiMH only lasted 5 min so the motor is going to get way hotter than it did without gearing it higher !

Hope that helps .
Thank you for this! I ended up buying quite similar of what you suggest. I have bought Tamiya hop up shocks, metal ball bearings, steel 15t pinion and new tires from eBay. The back tires are the same as original but I went for a more retro look on the front. The back rims are unknown origin and I can't remember we're I got them. I painted the front rims to match the back. The mohawk is something I did when I was a boy, and I think il leave it there.
The gear box seems a lot more quiet now the ball-bearings are in place!

I'm quite pleased and looking forward to take it for a proper spin!

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Sep 03, 2019, 07:26 PM
ultra cheap pilot
ican3d's Avatar
That driver inside the cockpit needs new paintjob. It will help increase the face value.
Sep 04, 2019, 02:05 AM
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Haha. Yes he never was given much attention.

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Sep 05, 2019, 08:36 AM
Registered User
Hm could those be perhaps Tamiya egress rims & tires for the rear ?
Can't quite see the pattern of the rim here, mind taking a picture of one laying down on a white background ?

(Ofc outside facing towards the camera.)
any serialnumbers or markings on the rim ?

If the rear rims are a 12mm hex you can put in essentially anything that is clearing the a arms in terms of height and width.
When it comes too the front they should roll on ball bearings as well, there are plenty of rims for biggies & stadium trucks that does that if you look around a bit.

The mohawk kind of reminds me of the cars from carmageddon & deathrace, perhaps something you watched or played plenty of back in the day ?


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