Spinner Weapon Motor Discussion

[robjones]

Its a real struggle to keep microCHIP competitive against fast, well armoured, well designed and made feathers and although its made big improvements since Aberystwyth Uni earlier this year its weight is now the biggest problem. Its has always had a centrally mounted Evo Warrior run with two 7.2v 3600 mAh in series, belt driving the 1Kg blades/disk on a 1:1 ratio (see profile pic). The motor is about 65mm high and weighs about 1.3kg. It spins the blades to about 2900rpm really quickly.
Ive now got an Astroflight 940, which is 700g (big saving) but I dont want to fry it. Im thinking of a belt drive at a 5:1 ratio in the same configuration.
Any views on whether Ill get the same power/performance, is it worth modifications, experience with Astros. With the weight saving I can put in more cells or use a bigger disk.
Thanks
Rob

Hiya Rob, well you know what Scorpion Evil is like. They use their Astro flight at 24v using 3:1 ratio on their 6mm chain. So belt drive on 5:1 ratio seems quite safe. Faster spin up time as well since the more ratio used, not as fast but who needs speed if you can keep it going.
Little Spinner is only 2000rpm but keeps hitting with the diamter and weight behind it.

So yeah Rob 5:1 ratio is a good safe choice. and can run it up to 24v if you want to.

Mr Stu

[ewan]

Id invest the weight youve lost in extra battery cells if I were you. At 24v with 5:1 ratio the astroflight should give no load of around 3200rpm to the disc/bar - but at a push you should be able to run 4:1 giving 4000rpm or more - this is probably closer to the ratio used by scorpion jr at the moment. Currently I guess your getting about 3000rpm from the undervolted EV so you should see an increased KE with on your existing bars/discs at 4:1/5:1 ratio. As you dont want to fry your Astro, dont run it at 2:1 ratio like Ive done before

If youve got the weight to spare you should stick more weight into the weapon - but only if youve got enough weight after youve packed in a few more weapon battery cells. Ive seen microchip with the big long steel bar with hammer shaped bits on the end - I presume youve not had the weight to use this much but now perhaps you could use that? (is there any more weight you could take out of the ali base?)

From our bout at Norwich I think theres a big modification you should try to make with the height of the weapon bar/disc. Currently its right at the top of the axle but it should be quite easy to mount the astroflight upside-down in the middle of the chassis so that its possible to put the bar right down to the ground - maybe 2cm over the ground actually.

[robjones]

Thanks guys, maybe Ill go for a 4:1 @ 21.6v (3 packs) Ill need to make a new driver pulley. Ive already made some modifications to microCHIP and it will go with the 10mm ali base on top so the disk will be about 2cm off the deck. Im hoping to get it all together by the 4th Sept

Well personnally speaking, not a fan of astros. A drill motor is perfect for spinning up a disc. The astro is just overkill and as they are so small, producing so much power that they heat up rather quickly if used for a long period (a few min).

Although thats just my views......

[glen]

would any body have any downloadable videos of some of these latest UK featherweight spinners. it would be nice to see some in action

Hi folks- I thought Id add to this thread rather than start another.
Thanks to Eds heads up back in September (cheers Ed!), Ive acquired a pair of those RS pancake motors that were being sold on ebay. Rather than reinvent the wheel (or the disc), what would experienced spinner builders suggest is a sensible size of pulley and belt, and a sensible gearing ratio for this motor (24v, 75W, 3,600rpm, 19.7Ncm torque)? Itll be spinning one of those nice 10 Hardox discs of Christians. Also, what profile of belt do most folk use? Im assuming a V belt, but I have seen feathers using round section belts too.

Hi John On the original DragonStrike I used the round belt with a gear ratio of 1 to 1 but that was with a EV warrior. The only problem I found was that when it hit the belt tended to slip. On the New DS I will be using a 2kg Disc at 1 to 1 from a EV using 6 mm chain. At the moment most spinners are using chain or like Little Spinner a converted angle grinder gear box. For your motors I would probably go for a 1 to 1 Ratio.

Thanks Tony- It may wellve been DragonStrike I was thinking of with the round section belt. The reason I was thinking V-belts was to allow a little slip and avoid stalling the motor and transmitting mechanical shock to it. So, current thinking is that these arent significant issues?

It appears to me chains are often the achilles heel of spinners. They are always coming off in battle. On microCHIP I used a V belt (as used in pillar drills actually) because I wanted a little slip to protect the motor and other components. I used a 1:1 from an 18v driven EvoWarrior with two hefty pulleys. The belt was 10mm wide. On the latest microCHIP Im using an Astro which revs at 11,000 the ratio is 3:1, but Im using the same lucky belt that Ive had from the start. The weapon system has been microCHIPS most reliable part, I just wish the drive was as tough.