Low current HPR motor starters

Does such a thing exist?

I'm looking to test fire some 38 mm sugar motors (behind a protective barrier), but I don't have a relay launch system. I was hoping to just use a PSII launch controller.

I have successfully launched quite a few composite G's using a standard Estes controller. Admittedly the green takes a pretty long button mash, but it gets there.

Energizer Ultimate (LiFeS2) AA's really pack a punch, even more so 14500 LiPos ( 3.7-4.2 V/ ea. ) from a vape shop.

If you're using the old NiCad controller it should pack plenty of wallop. Give it a whirl without the motor on, see how it goes

The PSII controller uses six C cells....and has a port inside with an orange JST connector where you can connect something else - such as a 3-cell LiPoly.

I've fired several kinds of composite motor igniters with a PSII controller including a Copperhead.

You could use a car battery.

BEC said:

The PSII controller uses six C cells....and has a port inside with an orange JST connector where you can connect something else - such as a 3-cell LiPoly.

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Bat-mite said:

You could use a car battery.

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So it sounds like the advice is MORE POWER. I suppose that's fitting for a forum dedicated to rocketry.

It seems to me that a low-power e-match or Q2G2-ish igniter could be coated with layers of pyrogen to make it suitable for igniting a HPR motor. I've never messed with this kind of stuff, so I guess I'm out of my league here.

Time to buy a 3S LiPo or a long wire for my car battery.

As others have said, the controller doesn’t matter. The battery does. Use nicad, nimh or lipo and you’ll get all the current you need.

I’ve been using homemade igniters with very simple slow black powder (fine ground and mixed but unmilled) mixed with nitro lacquer over a few turns of nichrome wire. 100% success in smaller composite motors... I got sick of $3 aerotech igniters failing. I’ve found these light knS very reliably. I also dip my Estes igniters in this mix which makes them less useless.

BDB said:

So it sounds like the advice is MORE POWER. I suppose that's fitting for a forum dedicated to rocketry.

Click to expand...

I have two PSII controllers. One has six Duracell C cells in it, the other a 1250 mAh 3 cell LiPoly that's quite a few years old. I get better (faster ignition) results with the LiPoly-powered one (and it's much lighter) but both will do the job for just about any single motor for which the 30-foot setback distance is appropriate. Both have been used for CTI and several different sorts of Aerotech igniters (including a Copperhead) with success. I've also used them for Quickburst homemade igniters with no problem.

The only thing I wouldn't feel comfortable trying would be a three or more motor cluster using Estes igniters.

So it looks like this 1000 mA 3S battery would be the easiest and cheapest solution for my PSII controller. Any other suggestions?

https://hobbyking.com/en_us/turnigy-1000mah-3s-20c-lipo-pack.html

That 1000 mAh pack should do fine. The 20C rating implies that it can comfortably source 20A. The real limit on current delivery in this setup is those little orange JST connectors. Fortunately, for the fraction of a second the power needs to be delivered they can take it. To use a bigger battery you'd wind up needing an adapter to go from whatever connector it had on it to the little orange JST. Doable, but fiddly.

Be sure you have an appropriate charger as well. It looks like that battery has the most common balance plug on it, so there are lots of inexpensive chargers that would be suitable.

I've loaned my PSII controller with the LiPoly in it to TARC teams and had them fly all day and only need to put a low single-digit percentage of the total charge back into the battery afterward. Likewise if I go out for a day of flying on my own. (I use an FMADirect [now RevoLectrix] Cellpro 4s charger, which gives me this info).

With 1000mah, you’re going to run out of money to buy motors long before you run out of battery...