Tug Posted May 27, 2014 Author Share Posted May 27, 2014 I don't know to what you are referring! Sell it, you've no need of a poor mans 5ive, you have a 5ive! Sell it and use the cash to get your MGM swapped for a newer version that works! My work here is done, I'm off to buy more unnecessary motors! Quote Link to comment Share on other sites More sharing options...
Tug Posted May 28, 2014 Author Share Posted May 28, 2014 So, three months ago I bought an ally servo saver for my Savvy/S5. It duly arrived and was put to one side ready for when I had time. That time arrived 48hrs ago. So out came the tools. The new saver looked superb in its bubble packs, all shiny and blue. I paid little heed to it, why should I? I stripped down the front end of the S5 in preparation. I started examining the bits and pieces of the new saver and things weren't tallying up. Not even close! This was never going to fit! It was completely wrong! I reassembled the S5 and put it away. I studied the saver and pondered it for a while before putting that away too. It troubled me, there was something about it, something familiar. Got it! It's not for a Savvy! It's a Maxx saver! Beautifully made, finely engineered! Just for a different bloody car! So tonight, out came the Budget-Maxx and the tools, in went a rather nice servo saver! Perfect fit too! I'm very happy with the quality of the product, shame it was for the wrong car! So the hunt for an ally saver for the S5 continues. The Budget-Maxx is well sorted though! 1 Quote Link to comment Share on other sites More sharing options...
Popular Post Noj Posted May 29, 2014 Popular Post Share Posted May 29, 2014 I have sold my S5 (all being well)!! Not buying another mgm with the monies tho....serpent cobra, as I fancy a truggy 4 Quote Link to comment Share on other sites More sharing options...
Tug Posted May 29, 2014 Author Share Posted May 29, 2014 Truggy's are awesome, some of the toughest bashers I've seen. I'll get one eventually, but not til I've finished sorting the current fleet. Quote Link to comment Share on other sites More sharing options...
Tug Posted June 3, 2014 Author Share Posted June 3, 2014 Gave this a thorough spanking the other day, running on 6s she's incredibly fast. It's hard to explain what it feels like to have a car that big (even a faux 1/5), charging towards you at over 40mph! It's awesome! A proper smile inducer! The ammeter recorded a high of 137 amps. The meter is only rated to 130, so not sure how accurate it is at that level, close enough though, I'm sure. It was all on high traction ground, dry grass about 2"long and then dry tarmac. On the tarmac she was popping wheelies! Temps were high, but stayed inside the limits set by the manufacturer. The high kv (in a 1/5, 1600kv is high!)The motor eats batterys pretty darn quick! OK, I was doing repeated speed runs (the novelty is yet to wear off!), but I reckon I barely reached 15 minutes from 5000mah! If I stick to 4s,8000mah cells, then obviously the runtime will increase, especially if I ease off the throttle occasionally! I'm starting to have faith in the set-up now, so maybe it's time for a trail walk around Black Park in Iver? If it fails to make it round, I'll need my leash for it, I'll drag it back, but I ain't carrying it! That's about it for now, I'll have her out again ASAP and keep updating the thread. I'm at the stage where I want to push the motor hard and see if it really can handle this size of car, I know I'm near the upper limits of the 1717, but am I pushing it too much? Only one way to find out! Latazz. 1 Quote Link to comment Share on other sites More sharing options...
Mr. Doktor Posted June 3, 2014 Share Posted June 3, 2014 maybe a dumb suggestion, but if I had a heavy big truck powered by a relatively small motor, the first thing I would do, would be a wheel/tire combo change. I would try to reduce the rotational mass by replacing the stock tires for something lighter and even smaller. That will bring the temps down and allow you to push the 1717 harder. Just my 2 cents 1 Quote Link to comment Share on other sites More sharing options...
savagejoe Posted June 3, 2014 Share Posted June 3, 2014 but if you change the wheels for something smaller the car wont handle as well and also it will change the gearing, and they have a 24mm hex so what could you change them to. ok so you could change them for a different wheel and tire set but how much difference would it actually make on something so big because how much weight is actually in the stock wheel and tire set Quote Link to comment Share on other sites More sharing options...
rcboylive Posted June 3, 2014 Share Posted June 3, 2014 yes lighter wheels would help but the stock rodeo tires are quite light. i tried hpi terrapins ie savage xl tire setup n it did not turn out well. the weight of the truck tore the *hex* part of the wheel. 24mm hex can easily be swapped with 17mm or 14mm hexs for tire options later i switched them with proline bowties 1:5 on all four corners. theses tires r heavy and i think they played a major role in destroying my motor. Quote Link to comment Share on other sites More sharing options...
Tug Posted June 3, 2014 Author Share Posted June 3, 2014 I think the stockers were designed specifically to be the right size, but lightweight. Anything else of comparable size is just too heavy. They don't offer masses of grip, but they're OK and they look the part. Anything heavier will just eat the drivetrain. I'm happy. Quote Link to comment Share on other sites More sharing options...
Tug Posted June 5, 2014 Author Share Posted June 5, 2014 Blew a bearing last night, the one that supports the output shaft from the centre Diff at the front. Was I unlucky or was it always going to fail? It was probably caused by my 6s run the other day, which was all speed runs. I think I'm going to have to watch it closely, because even with 500,000k oil, the fronts still spin up a lot! This means that bearing is taking a beating. A bigger bearing would cope better, but that would mean asking Dejan to machine a new mounting plate to hold this bearing, a bearing that'd need to be approximately 20x10x5. Not sure that's even possible. Peace. PS, picked up a dog egg, found it sat on top of the Rx box. Not impressed, it's a play Park, no dogs allowed. Plus, if it drops one, pick it up. Quote Link to comment Share on other sites More sharing options...
oodboo Posted June 5, 2014 Share Posted June 5, 2014 You need some of this in your diff mate: 1 Quote Link to comment Share on other sites More sharing options...
Mr. Doktor Posted June 5, 2014 Share Posted June 5, 2014 you should try 1000k http://www.ebay.com/itm/Tamiya-54419-RC-Silicone-Diff-Oil-1000000-/271509672007?pt=Radio_Control_Parts_Accessories&hash=item3f373cd047 or 2000k http://www.capricornrc.nl/Webwinkel-Product-30104945/Differential-oil-2000000.html or this http://www.redrc.net/2012/06/lmi-racing-silicone-oil/ 1 Quote Link to comment Share on other sites More sharing options...
Tug Posted June 10, 2014 Author Share Posted June 10, 2014 (edited) Tonight I gave her a thorough spanking! It was only on 4s, but the grass was long and I'd recently fitted a mesh over the ESC fan to keep the grass out. It thermalled! I'm not worried, it's never done that even on 6s, so clearly the mesh grill was to blame. The mesh is made from some old tights I'd cut up, so I've swapped it over to some lighter denier and will test it tomorrow. Edited June 10, 2014 by Tug Quote Link to comment Share on other sites More sharing options...
Tug Posted June 17, 2014 Author Share Posted June 17, 2014 Today I took delivery of my 58110, 780kv motor. It's basically the Leopard version of the 2028. It's not that the 1717 couldn't cope with the car, but a large motor like the 1717 being pushed to its limits, is very thirsty and the runtimes were just not good enough. Although this is an even larger can, I'm hoping that its much lower Kv will help with runtimes. No point fitting it yet, the pinion has yet to arrive. I'll be back once I've got all the bits and done some testing. 1 Quote Link to comment Share on other sites More sharing options...
Noj Posted June 17, 2014 Share Posted June 17, 2014 I know nothing about that motor, it has never appeared on my watch list, no PayPal transactions are associated with it, and I have never taken receipt of it, or, passed it onto a third party. Are we all clear on that? Carry on....... 2 Quote Link to comment Share on other sites More sharing options...
Tug Posted June 25, 2014 Author Share Posted June 25, 2014 So, tonight I finally got to fit my new Leopard motor, the monster that is the 58110, 780kv. I decided I would start on 5s. I had a guess on gearing based on previous experience. I settled on a 25 tooth pinion, this was virtually double what I was running on the 1717, but at half the kv I figured that'll do. The gearing choice seems about right, good acceleration and respectable top speed. The ESC was running warm, getting into the fifties, but the motor barely changed temperature! However, the test run was cut short because the rear diff decided "enough!", and pretty much exploded! The diff cup (ally) has a large split in it. Three of the four screws that hold crown gear on have sheared off! I found bits of screws poking out through the diff housing! Now, what went wrong? Hard to tell, but looking at the bits I'd say brute force played a large part. The diff screws could've started backing out, then been snapped off when they'd backed out far enough to touch the diff housing. However, all the snapped screws are basically just heads, which is why I think they were snapped off in situ, but if they were snapped off in situ, why not the fourth screw too? I'll get a complete new diff when I can, then start testing afresh. Was it just the new motor? Or was the diff on its way out anyway? Only one way to find out, fit a new diff and go again! That's all for now. Quote Link to comment Share on other sites More sharing options...
Noj Posted June 25, 2014 Share Posted June 25, 2014 Torque FTW! Piccies of the can and damage please Quote Link to comment Share on other sites More sharing options...
Tug Posted June 26, 2014 Author Share Posted June 26, 2014 I'll get pics later. I've won two diffs from jennysrc, in the meantime, all I really need is a diff cup and gasket and she should be good to go. 1 Quote Link to comment Share on other sites More sharing options...
DeadMeatUK Posted June 26, 2014 Share Posted June 26, 2014 Your diff screws might have come loose. If they did all of the torque would be transferred to the flexing then back and fourth under acc/brake until they work harden and break. When the screws are tight most of the torque is transmitted from the crown gear to the housing via friction between the two parts and gasket so the screws are only subjected to tension. Quote Link to comment Share on other sites More sharing options...
Tug Posted June 26, 2014 Author Share Posted June 26, 2014 Your diff screws might have come loose. If they did all of the torque would be transferred to the flexing then back and fourth under acc/brake until they work harden and break. When the screws are tight most of the torque is transmitted from the crown gear to the housing via friction between the two parts and gasket so the screws are only subjected to tension. Cheers for that, as I'd just swapped to a far larger motor I was head-scratching as to why it had happened. Was I to blame the diff or the new motor. I think it probably was diff failure, I've had problems in the past with threadlock not holding screws into ally cups. BTW, getting the diff out is a mission! Yes, it was my first go, but that's not an easy diff to get out. It actually makes the Maxx arrangement look easy! 1 Quote Link to comment Share on other sites More sharing options...
Tug Posted June 28, 2014 Author Share Posted June 28, 2014 Right, yesterday I picked up the parts needed to repair the wrecked diff. I went to Monarch Models in South Harrow, owned by a great guy called Mayoor, and got what I needed. So last night I sat and figured out the correct method for getting these diffs in and out, it's easy! Even easier with a screw-gun. Buoyed with this new found knowledge, I set about removing and inspecting the front diff. All seems OK, but changed the oil to 60k and re-threadlocked. What I have noticed is how much play there is at the rear compared to the front. I think the failing rear diff has damaged the rear housing, so now the repaired diff is back in with new bearings, there is more side to side movement than at the front. I'll probably try to shim this out this morning, but I'm also on the hunt for a cheap replacement housing, I'd prefer that option. In short, really impressed with HPIs diffs, good solid equipment. Unlike Traxxas and there plasticine crown gears! This HPI diff only failed due to a lack of threadlock, that's human error and not the diff's fault. I'll get back to motor testing ASAP. Yours faithfully, All my love, Blah blah blah, Tug. Quote Link to comment Share on other sites More sharing options...
Tug Posted June 30, 2014 Author Share Posted June 30, 2014 A quick blast at the park yesterday and all is running nicely. The motor temps hit the high forties, I can live with that. The ESC hit low fifties, but that was mainly where the motor cables exit the ESC, should I permanently solder them in to ensure the lowest possible resistance? I'll sleep on that irreversible decision. The heatsink was low forties. I'm happy with these temps, nothing is cooking, that's all that matters. She still gets through batterys in double quick time! 5000mah in less than ten minutes! Still, for the fun factor, I'll live with that! Quote Link to comment Share on other sites More sharing options...
Noj Posted June 30, 2014 Share Posted June 30, 2014 Mine has changed hands again!!! Do I miss it? Nah, happy to watch your progress fella 1 Quote Link to comment Share on other sites More sharing options...
Tug Posted June 30, 2014 Author Share Posted June 30, 2014 Progress is in the final stages, there's little else I feel needs attention. I'll go for a 6s run soon, rude not to! Really enjoying this truck. It's becoming a pleasure to work on, looks great on the move, jumps beautifully! For runtime improvements, I'll probably do what others have done and fit my own battery boxes. This will allow 5s to be carried on both sides, connect these up in parallel and have 10,000mah of capacity. Sorted! Quote Link to comment Share on other sites More sharing options...
ts4n Posted July 1, 2014 Share Posted July 1, 2014 Its mine now! Time for a power quest ! Lol where do I start tho ? Never done a large scale brushless before Quote Link to comment Share on other sites More sharing options...
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