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irocdave12

New Monster Beetle Build Need Help and Advice Please!!

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Hi everyone, It’s been 10 years since I last logged onto the forum. I’m a former 1980 Tamiya kid as many of us were. I’m trying to get back into the tamiya cars again after a long hiatus to introduce my 6yr son to the world of RC. I built him a comical grasshopper as his first ride. I just bought the 2015 Monster Beetle kit. I desperately need help and advice on how to best build this thing right. I would really appreciate exact product recommendations and links. I’m looking to make it fast compared to the stock 540 motor but not insane where it breaking parts in the gearbox regularly. I think I’ll probably be buying and using the MIP ball diff. However what is the biggest mystery to me is what and if I can use a brushless set up ? If so what have others that have done similar Blackfoot/MB builds been using with success? Next question is batteries? Is there a Lipo that will fit in the MB? What should I be using for a good speed boost and long run times overalll? I know the ESC the MB comes with is brushless capable. I think it said 17.5 turn and up so I assume it means numbers higher than 17.5? I don’t have a grasp of how fast a 17.5 turn tamiya brushless motor would be. 10 years ago when I last played with RC Novak was still in business and they weren’t describing brushless in terms of motor turns like they always did with brushed motors growing up. I’m open to all thoughts and opinions including not using Lipo and brushless if thats going to be the better way to go. So please those that have been doing the Tamiya re-releases the past years with modern features please guide me and help me to make the right purchases and decisions. Thanks for any help and insight you can offer.

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Others will pitch in...

I’m using a 10.5 Tamiya brushless in my Frog with a Tamiya TBLE ESC. Way too fast. I have a TrackStar 17.5 in my Bush Devil with TrackStar ESC. Perfect speed and torque.

As for Lipo, the “standard” 2C 7.4v lipo fits very nicely. Take your car to your LHS and test fit. I found that I had to get a shorty for my Bush Devil bc the standard wouldn’t fit in through the side battery door with my nerf bars in place.  The standard MB has the bottom battery door so this won’t be an issue for you.

If you have more ORV questions, send me a PM.

Terry

 

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I’ll add that I am using the Frog dog bones and Vintage Frog gears in my Frog, with the MHeald transmission brace.  No problems with brushless.

My daughter’s Blackfoot has the same tranny setup but with the Xeostar tranny brace.  But here I’m using a slow crawler brushed motor.

Both braces have solved the ORV tranny issues for less than the MIP ball diff (or the Thorp I was using before).

Terry

 

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Thanks I wasn’t even aware of those braces. Where can I source a set of those to buy then? Is that something that was discovered to improve the gearbox after the redesign using the dog bones? I’m just kind of surprised something like that wasn’t figured out back in the 1980’s when the gearbox’s were even more fragile. I have read that with the more powerful motors and possibly related to the MIP diff being used that people have been popping dog bones out from the rear trailing arms splaying out under load reportedly so I’m a little concerned about that becoming an issue for me if I go ahead and buy the MIP diff to install in the initial build up of the kit

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The MIP diff is bulletproof but expensive,it was worth it for me though as it made the car reliable. I have no experience of the braces but have seen many poeple say they are great so would give them a go.

Brushless motors are great, loads of torque and no maintenance. The big issue with brushless and Tamiya rereleases is the gear ratios. As far as I know the Monster Beetle (one of the best Tamiya's ever btw) has only 1 option for pinion gear. It runs well with a silvercan on 2S, but would probably suit a 13.5T pretty well too. A 17.5T or higher would probably seem slow because of the gearing.

I run a gens ace round pack 4000mah 2S lipo which fits fine in the Monster Beetle but there are a lot of options. This battery is a bit too long for some chassis, Core RC make one that is slightly shorter and would be a better bet but its impossible to find for me. If you're in the UK then its easy

 

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To Jonathon remark about pinions and the MB, indeed the stock MB has only pinion option (10 teeth), but by using a CRP adjustable motor mount and extra long Thorp pinions, you can run up to 16 teeth...

Terry

 

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Here is the Xeostar brace:

The MHeald brace is out of production at the moment. But you can search for “MHeald” and find his info here. Send him a PM.

Terry

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Have a re-re Blackfoot and Monster Beetle.  The Blackfoot has the "Xeostar brace" mentioned above and runs a Superstock BZ motor.  Stock 10T pinion and CVAs as well and I have experienced no problems at all.  On a straight wide-open its as fast as I think this chassis can manage.  Also used anti-wear grease on the swing arm pivot points, seems to give smoother movement and much less signs of wear than kit supplied grease.  

 

The Monster Beetle has the MIP diff and a Brushless 21.5T  sensored setup, but it's probably slower than a stock silver can but can run all day it seems on a 5000mah 2s pack.  I crawl up grassy hills and foot trails with it, and again have no issues whatsoever.  I used kit supplied  grease on the rear swing arms here, but when it's time to do a general clean I'll replace with anti-wear grease as well.  

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With my Monster Beetle build, I wanted durability as a priority, so I went with the MIP diff which so far has been working flawlessly. It is supplied with metal shielded  flanged bearings, but I wanted more reliability so replaced these with rubber sealed ones from RCBearings.co.uk instead, along with rubber sealed bearings throughout the rest of the car too. To prevent the cracking and twisting of the rear swing arms where the shocks attach, I fitted AmPro sintered steel braces (link https://www.shapeways.com/product/U4ZQNUV9H/tamiya-orv-swing-arm-shock-brace?optionId=58402519&li=shops) and to reduce wear on the pivots I used a dry wax-like lube designed for bicycle chains and derailleurs which is plastic-safe and doesn't attract dirt or turn into grinding paste (link https://www.halfords.com/cycling/bike-maintenance/bike-lube/muc-off-dry-lube-bike-lubricant---120ml-955310.html). To prevent issues with the universals popping out of the drive cups over jumps, I built the shocks with internal spacers to reduce the droop to the point that they stay put even when the wheels are off the ground. To prevent cracked plastic rear wheel adapters in cold-weather running I fitted alloy ones from Miniature Manufacturing (link https://www.ebay.co.uk/itm/Tamiya-Hornet-Grasshopper-Monster-Beetle-CNC-Machined-Alloy-Wheel-Hubs/264750155307?hash=item3da456c62b:g:CW4AAOSwwBRewnmd). Finally, I sourced a lightweight polycarbonate shell from Kamtec which I use for running (link https://www.kamtec.co.uk/epages/BT4645.sf/en_GB/?ObjectPath=/Shops/BT4645/Products/K0043). This is lighter so lowers the CoG resulting in fewer rollovers, and it also flexes when it does roll over, reducing stress on the body mounting points.

20210117_133055

 

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Thanks for the great info guys. Here’s what I’ve learned recently in regards to using a Lipo battery. I basically get all my stuff through Tower Hobbies here in USA. In shopping for a Lipo I keep reading customer reviews that say they can’t find anything Lipo to fit in a MB or other Tamiya buggies etc. I’m looking at options from Venom and others in a 20-25c rating and 5000mah and below. Every battery has specs saying they are 138mm in length. That’s seems to be standard for most part. However tamiya users are leaving reviews that anything over 132mm in length won’t work and that there just isn’t a Lipo short enough to fit in a Frog MB BF chassis. ?? I’m at a loss at this point. Does anyone have a link I can simply click and buy a battery that will definitely fit? Or should I just give up on the Lipo option and just get a very best in a Nimh?

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@irocdave12 The length shouldn't be too much of a problem on the MB chassis. You know those bushings that everyone hates? The metal 850-sized ones can be used to extend the battery retaining plates to give more room.

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On 4/19/2021 at 5:44 AM, irocdave12 said:

Thanks for the great info guys. Here’s what I’ve learned recently in regards to using a Lipo battery. I basically get all my stuff through Tower Hobbies here in USA. In shopping for a Lipo I keep reading customer reviews that say they can’t find anything Lipo to fit in a MB or other Tamiya buggies etc. I’m looking at options from Venom and others in a 20-25c rating and 5000mah and below. Every battery has specs saying they are 138mm in length. That’s seems to be standard for most part. However tamiya users are leaving reviews that anything over 132mm in length won’t work and that there just isn’t a Lipo short enough to fit in a Frog MB BF chassis. ?? I’m at a loss at this point. Does anyone have a link I can simply click and buy a battery that will definitely fit? Or should I just give up on the Lipo option and just get a very best in a Nimh?

I use even Square Lipos in my Monster Beetles. This beauty takes everything, using a simple trick: On the chassis parts tree are the 2 red spacers intended for the old mechanical speedo. You take these and fit them underneath the left sideplate for the battery with longer screws. 2 benefits: You balance out the hanging out motor on the right side by setting off the battery sligthly to the left. And you can fit any battery you like!;)

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img34024_20012013232455_5_1100_.jpg

Here you can see on the very left the nuts and the red spacers I talked about. You can already see the square battery pack a little...

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7 hours ago, ruebiracer said:

img34024_20012013232455_5_1100_.jpg

Here you can see on the very left the nuts and the red spacers I talked about. You can already see the square battery pack a little...

Whoa~ Quite a lot going on in this photo.. a slipper clutch mod?  plastic insert shape that follows the shape of the transmission..  threaded rod and nuts suggest a different motor mount position(perhaps larger pinion) as well.  Do tell us more!

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25 minutes ago, Killajb said:

Whoa~ Quite a lot going on in this photo.. a slipper clutch mod?  plastic insert shape that follows the shape of the transmission..  threaded rod and nuts suggest a different motor mount position(perhaps larger pinion) as well.  Do tell us more!

Hi Killajb, thanks for your kind words! I took the pic of my showroom. It´s my Monster beetle runner I built around 2011 and modified quite a lot. I had a Brat as a kid, so I knew the weaknesses of the ORV´s. But I never had a Monster Beetle, which I liked very much in the Tamiya catalogues. I also never run a Monster truck before, only buggies and onroad from 1997 on. I was quite surprised, how well this ORV monster from ebay drove. Since then, I´m deep in the rabbit hole. That´s the background of my yellow one. 

It features a DF03 slipper clutch in a2mm widened gear box, Reinforced front shock tower, body braces, lower chassis front part. Furthermore centered steering, zero bumpsteer mods, 17,5t Brushless engine with a little timing program, Aluminum wheels, modified CVA shocks etc. 

You can find it in my showroom here: (There are some more posts for it while making progresses, was my beginning here, and I forgot to make a nice build thread out of it)

58060: Monster Beetle from ruebiracer showroom, My Monster Beetle Runner - Tamiya RC & Radio Control Cars (tamiyaclub.com)

If you have any questions, let me know.

Kind regards,

Matthias

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Regarding your question: I think I have a 16t pinion module 0,5 on, giving 13,95:1 ratio with the 82t spur gear. Diff carrier is original MB (you could also use Frog one with 49 instead of 59T). Motormount is a homemade Alu plate, but nowadays there are some adjustable mounts around, which save work.

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Thank you Matthias!  Your build is very nice!  Even more impressive considering this was done awhile back.  Consider me a big fan of your work sir!  

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Thank you so much, with the Rere parts around and the latest new tuning parts, it´s a little easier to build nice Monster beetles. MCI does much better custom stickers than the paper based ones I used back then. Colors faded out, and they are not really that waterproof. And I´m getting the feel at the moment, that I have to build another Monster beetle with a 13,5t brushless setup, an easier slipper mod and some Alu shocks next year. And a nice livery to sit beneath my yellow one...:)

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My Blackfoot seems to be at it's chassis' limit with a SuperStock BZ motor.  That is considering as well, I drive it somewhat gently.  

Bluefoot.jpg

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20 hours ago, Killajb said:

My Blackfoot seems to be at it's chassis' limit with a SuperStock BZ motor.  That is considering as well, I drive it somewhat gently.  

Bluefoot.jpg

That looks very cool, are these Tamiya aeration dampers you used for it? Would be interested in your setup/springs you used for them.;) 

And very nice wheels!

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Why yes, those are aeration dampers..   Overkill for sure, but well.. y'know:rolleyes:.  I used all the stock supplied blackfoot springs and Tamiya "soft" oil as shown.  I did switch the lower spring retainers to blue alloy ones,  but it was mostly for the looks.  They work great for what I do.  Truck squats under acceleration and lands flush off a 25cm curb without a bounce afterwards.  Wheels are RPM revolvers that were scarce 6 months ago, so I opted to get 4 12mm hex wheels and use adapters for the fronts.  Blessing in disguise as it widens the stance a tad and makes for less of a chance of a rollover when driving on the street.

TRF Damper Large Spring Retainer (4 pcs) (RC Model) - HobbySearch Mini 4WD  Store Tamiya #42198 - RC TRF Buggy HL Aeration Damper Set

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Thank you very much, actually, I recently came over a set of those, and plan to use it on my Super Monster Beetle, too.:lol: Yes, it´s a bit overkill. But you can never have good enogh dampers!:P

Cool to hear, that the stock spring diameters work. I find the Rere front springs a good match for driving, but the rear springs too long in length, and a little to hard on the MB. Doesn´t help for the trailing arm bend/popout drive shaft problems.

But it fit´s your body very well, together with the blue spring plates.

Actually, I was always surprised, how well my yellow beetle handled over the my nephews and my second stock beetle on the street, and when doing more ambitioned driving. In the end I came to the conclusion, that the aluminum wheels I use bring some more weight on the axles. That seems to help for Cog like on a crawler with weights. I´ve never rolled mine as quickly as the std. ones! It´s really nice, because I decided on the wheels just fr looks and because spares wher not so easy to get 2011, before the Rere´s. I playing with the thought to put wheel weghts all around on the kit rims of my nephew, to get the same effect. (for small money).:rolleyes:

Somehow it seems to have some "gyro" effect, too, lol. Sounds like a joke, but I built both beetles with the same shock/spring setup and the same batteries/servos/steering. So the only difference is my brushless motor, while he uses a Cupmachine silvercan...

 

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