Tosh McCaber Posted June 1 Share Posted June 1 On my ongoing refurbishment of my old Aeromaster, (48" wingspan, 61/2 lb), I've changed the power supply from an HP 61, to, probably, a Mega 41/30/15 410kv donated by a pal in the club, (which is, I think , the equivalent of, say, a 4-Max P-O-5065-420),with a 6S battery. 50m dia- Much bigger than any of my small motors that I've been used to, since getting into electric! My latest question, (in a series on electrifying my old models!) stems from the Mega having the motor mount at the front, just behind the drive shaft. So I can't bolt it directly onto the bulkhead behind the motor, had the motor had a rear mounting plate. Rather, it will have to be fitted with approx 60mm standoffs from bulkhead to the front mount. So, a couple of questions: On a large motor like this, would standoffs be stable enough to keep the motor from wobbling/ vibrating? And are they going to withstand any light "dings" that may occur, with, say nose-overs on landings? Are some stand-offs better than others? Any suggestions appreciated! Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted June 1 Share Posted June 1 I wouldn't shy away from standoffs...... some quite large, vibratey petrol engines use them....... your Mega should be pretty much vibration free - if not, you probably have a bent shaft. They'll survive nose overs just fine - as well as, or better than, the motor shatf I'd guess. I can't recommend any as I don't use any motors of that power. 1 Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted June 1 Share Posted June 1 Tosh Stand-offs manufactured with threaded rod and aluminium tubes, readily available from the likes of B & Q, plus a couple of motor radial mounts ought to be fine for 4130 type motors. That's what I've used for my Kyosho Spitfire - pictures and description in the thread linked to below. Such stand offs are likely at least as robust as a liteply motor box with the mount bolted directly to it. As GG mentioned the relative strength of the threaded rod and your motor shaft is worthy of consideration - certainly on the old Ernie Moorcraft squirrel cage mounts, which had machined front and rear mounting plates and threaded aluminium stand off tubes the fact that in a heavy crash the motor mount tubes deformed, rather than breaking or bending the motor shaft wasn't a bad thing at all. 1 Quote Link to comment Share on other sites More sharing options...
John Lee Posted June 1 Share Posted June 1 An alternative to stand offs in this situation is the Axi motor mount. I fitted one on my Wot4 Pro in 2019 & it has worked fine ever since. https://www.electricwingman.com/axi-motor-mount 1 Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted June 1 Share Posted June 1 https://www.4-max.co.uk/adjustable-motor-mount-med-large.html Quote Link to comment Share on other sites More sharing options...
Adrian Smith 1 Posted June 1 Share Posted June 1 I have used up to 60 mm standoffs on some of my larger motors for some while, Tosh (60cc 100cc electric equivalent). Never had a problem and it is noticeable how little or no vibration occurs with electric motors. With petrol engines I was forever tightening up bolts after a couple of flights. Not with leccys. Just put blue thread lock on the bolts to the standoffs and motor wall and make sure you have a decent quality motor onboard. 1 Quote Link to comment Share on other sites More sharing options...
Geoff S Posted June 1 Share Posted June 1 I use 4mm s/s studding which allow for easy (though tedious) adjustment of both spacing for cowl clearance and thrust angles. My ARTF Wot4 (on 4S LiPo) Or 4mm high tensile caphead machine screws, as on my 60" ws DBS&S Sopwith Pup. In fact this did nose over on taxiing and what broke was the too flimsy (3mm) ply mount (from the kit), which didn't do the cowl much good. It took me a while to round to fixing it but I beefed it all up with 6mm ply and reduced the amount of lead in cowl accordingly. I'm still steeling myself to fly it but I'm confident the motor mount will be the least of my problems when I do. It's on 6S LiPo. 2 Quote Link to comment Share on other sites More sharing options...
Tosh McCaber Posted June 2 Author Share Posted June 2 As always, many thanks for your informative replies! I have used stand-offs (on Leccy's recommendation) on a smaller model. But, from all your responses, it looks like I'll go with 4mm studding in tubing stand-offs! Thanks again! 1 Quote Link to comment Share on other sites More sharing options...
Geoff S Posted June 2 Share Posted June 2 I'm not sure the tubing is necessary if you use decent-sized washers to stop the nuts sinking into the wood. Moreover, if you use tubing it has to be exactly the right length and you lose the ability to make minor thrust angle adjustments. 2 Quote Link to comment Share on other sites More sharing options...
Eric Robson Posted June 2 Share Posted June 2 (edited) On motors the size Tosh is using I use m5 threaded rod or m5 bolts similar to Geoff's method. A packet of m5 nuts is quite cheap from Screwfix as is washers. I tend to buy the nuts with a washer attached. It has always worked for me Edited June 2 by Eric Robson 1 Quote Link to comment Share on other sites More sharing options...
Tom Gaskin 1 Posted June 2 Share Posted June 2 Plus one for the threaded rod route. No tubing involved, just nuts, washers and spring washers. Tom 1 Quote Link to comment Share on other sites More sharing options...
Keith Billinge Posted June 13 Share Posted June 13 (edited) I buy the standoffs I need from firms on ebay. They are relatively cheap and you can get loads of different sizes. They come in aluminium and you can specify a larger diameter if you're worried about them being up to the job. I'm currently building a Wot4 and went for M5 Standoffs to accomodate M4 bolts and they work fine. I often include a hard rubber spacer behind the motor mounts but on the front of the standoff to give some vibration dampening. You can always add washers for more down/side thrust. KB Edited June 13 by Keith Billinge Quote Link to comment Share on other sites More sharing options...
Tosh McCaber Posted June 15 Author Share Posted June 15 Thank you for the heads-up Keith! Quote Link to comment Share on other sites More sharing options...
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