Spezzer Posted April 20 Share Posted April 20 (edited) So I'm working on a line of printable 1/32 scale models and an inexpensive chassis to go with it. Designing the printable body was the easy part. I also now just about have a working chassis. the problem is, the motor and response is a bit rubbish. Here is my set-up - I posted images as well:- FlySky GR3E Receiver MS18 Micro Servo Chinese 20A ESC 20x15mm 6v brushed motor 2x 3.7v Li-PO batteries In the past I used a set up that includes 4000mah 7.2v batteries and a much larger motor 35mm in diameter with ABSima ESC. With my inexpensive setup I am not getting the responsiveness I would like from my little motor. So, long story short, can someone recommend a suitable combo of esc/motor, and possibly battery for a small 1/32 model with proportional control and not loads of power but at least good response. Also, don't want to spend more than £20 😉 Edited April 21 by Spezzer grammar 1 Quote Link to comment Share on other sites More sharing options...
Spezzer Posted April 21 Author Share Posted April 21 I tried this little £6 motor - but when the ad said 100rpm I didn't think that was its fixed speed. Its a shame because for the size it is a great little torquey motor, responds well, and doesn't mess with the ESC. It will make an excellent crane motor! Quote Link to comment Share on other sites More sharing options...
Spezzer Posted April 24 Author Share Posted April 24 This little motor works quite nicely - its advertised as "3-12V, 15-1000 RPM (6V 500RPM)". The ESC is putting 8.6v max through it (or through the volt meter at least) and it achieves nowhere near 500RPM - more like about half. I think the part of the title I've put in bold are what was sold - the rest is the range of motors. The printed gears aren't too bad with a little silicon grease. I'm still not happy with the steering so on about the 5th design! Quote Link to comment Share on other sites More sharing options...
Spezzer Posted April 28 Author Share Posted April 28 This build is coming along nicely and have a working prototype with good level of control and response from motor and steering. All crammed into a PLA printed 1/32 chassis with printed steering gear, wheels and drive gears. Couple of things need improving, the motor works well with a good graduation from stop to slow and to full speed - the top end is a little lacking and would like at least a little wheel spin! The steering works well but just need to tweak it with a bit more lock. All in all, good progress. I'll have to calculate the cost of the radio gear but reckon its close to £20 excluding the transmitter. 1 Quote Link to comment Share on other sites More sharing options...
Yrkoon Posted April 29 Share Posted April 29 That looks pretty awesome 🙂 Quote Link to comment Share on other sites More sharing options...
Spezzer Posted April 29 Author Share Posted April 29 6 hours ago, Yrkoon said: That looks pretty awesome 🙂 Thanks - definitely making progress! Quote Link to comment Share on other sites More sharing options...
Spezzer Posted April 29 Author Share Posted April 29 These motors are a headache - cannot find anything quick enough to work with my 2x 3.7v 150mah Lipos. (charger reads 4.2v each) More power maybe? The steering on the other hand is working a treat - changed the geometry and the lock is now excellent. Cramming everything in to the chassis is a challenge. For the first model - a Ford Zephyr Mk4, I've designed a cover for the gear behind the driver/front bench seat/dashboard. The 2nd model is a Ford Transit Mk1 which should be easier to accommodate the gear. Quote Link to comment Share on other sites More sharing options...
ad456m Posted Tuesday at 15:47 Share Posted Tuesday at 15:47 (edited) I think from your result chart you want a motor with more rpm rather than more voltage. Have you played with a rollout/gearing calculator yet? That might help get an idea of where the right rpm range is. Edit - There are a lot of 130 size motors on eBay with 3500-5400 rpm, that might be somewhere to start and then mess with voltage. Edited Tuesday at 15:49 by ad456m Quote Link to comment Share on other sites More sharing options...
Spezzer Posted Thursday at 18:04 Author Share Posted Thursday at 18:04 (edited) On 30/04/2024 at 16:47, ad456m said: I think from your result chart you want a motor with more rpm rather than more voltage. Have you played with a rollout/gearing calculator yet? That might help get an idea of where the right rpm range is. Edit - There are a lot of 130 size motors on eBay with 3500-5400 rpm, that might be somewhere to start and then mess with voltage. These 130 motors are a little unpredictable. I tried a couple I had lying around. I couldn't measure the rpm but not very quick and low torque - probably 12v and therefore underpowered. The other just made the ESC twitch the motor rapidly as soon as I powered up the receiver/esc. I've got a cheap little pack of 8 ordered which operate up to 16500rpm at 3-6v so hopefully better suited to my 2x3.7v 150mah LiPos. Obviously it will need a gear reduction - maybe I should use meatal and not printed gears lol. Edited Thursday at 18:04 by Spezzer Quote Link to comment Share on other sites More sharing options...
ad456m Posted Thursday at 20:29 Share Posted Thursday at 20:29 Tamiya Mini4WD might be a place to look for gear ratio as they will be around the same size, there are some crazy rapid ones of them and they run on 130 motors. It might give you an upper end to work back from. Quote Link to comment Share on other sites More sharing options...
Spezzer Posted Friday at 18:36 Author Share Posted Friday at 18:36 (edited) The 3-6v 130 motors I bought are a disappointment. Fortunately 8 for only a £fiver! I hook them up and all I get is a fast pulse (maybe 3 or 4 per second) being sent to the steering servo. Not sure what that means tbh. I figured I would use a 130 motor but struggling to find the right one. I think I just need to find the right N20 motor which are the ones I put in the image above. edit - just connected a 12v scalextric (slot car) motor and got a pretty good speed from it. Thats a 130 size so compatible ones do exist but getting the right spec is so hit and miss. Edited Friday at 19:08 by Spezzer more info Quote Link to comment Share on other sites More sharing options...
Spezzer Posted 22 hours ago Author Share Posted 22 hours ago (edited) Success! Compatible 130 motor is spinning fast enough to spin the wheels and slide the car. Steering has good control with excellent lock. One more thing however, after a few minutes the battery drains and the throttle does not work same time as steering. The 2x 3.7v 150mah Lipos are not up to the job. I've wired the LiPos in parallel and getting just over 8v. Image attached. (Is that right?) I think I need to get closer to 12v although think the motor is fast enough. I suspect I just need more mAh. Volts and mah's confuse me!! Edited 14 hours ago by Spezzer Quote Link to comment Share on other sites More sharing options...
ad456m Posted 18 hours ago Share Posted 18 hours ago Yeah, Mah is what you’ll be after👍 Quote Link to comment Share on other sites More sharing options...
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