We offer these because people ask for them. There's a school of thought we'd be better off as a company to not sell them at all because folks can get hurt using them. We do it anyway because we feel with some guidance reasonable people can use them in perfect safety - if - they exercise good judgement. So we'll try to provide some guidance but ultimately, it's on you to ascertain your risk to yourself and others and if you don't agree to hold us harmless, then don't buy it. Plain enough?
Point being, with a snug fit within the rubber adapter of a standard model airplane engine
electric starter, this tool may allow you to start model helicopter engines, also . . . without using tools to switch back and forth, with enough safety. True as long as you don't become complacent or careless.
- Friction fit into a model airplane starter cup is safe enough but a permanent installation is safer
So that's with regard to a tool-less installation using a friction fit, it's OK - but - a better way, for improved safety, we advise permanently mounting this adapter to an electric starter motor's shaft. Yes, then it becomes a foot-and-a-half of unwieldy and heavy tool. Yes, it's more expensive to own two starters - one dedicated to fixed-wing use and the other to rotary-wing model aircraft.
Honestly? We've heard all the reasons against a dedicated StartProbe-installation. We get it. But permanently coupling this StartProbe to your electric starter is better because it's safer. Has nothing to do with cheaper. Safety first, eh? Consider yourself the recipient of reasonable advice from the experienced modeler writing this for ProModeler customers with regard to using this device.
That warning aside, yes, you may use this with a Sullivan-brand (or an east Asian import) electric model engine starter by relying on a friction fit. There are even groves machined into the base to allow you to tailor the fit using rubber o-rings available from the hardware store. This is an attempt to make it more nearly universal-fit for purpose in all the variations on a theme available in electric starters for model engines.
Bottom line? So as long as a snug friction fit is to your satisfaction, it'll work fine. But please don't go blaming us if things go awry because we recommend a permanent fit. Heads up!
Basically, this tool is used to extend the start-motor's reach by using a ball-end extended hex shaft in order to couple with the engine start adapter, e.g. for starting up a model engine.
Note; 6mm is something of a standard in the model helicopter world, so this is what this one has. Further to this, there are other ways to skin the let's-start-the-engine cat. Hex is popular because it doesn't depend on the consistency of another shaft's machined surface. Basically, the hex works like a giant Allen head bolt and key to provides a positive lock that's easy to engage and disengage.
However, since once the engine starts, it's unlikely the RPM of the engine and of the electric starter are the same, when you disengaged them parts may be spinning and because of physics, sling themselves away at high speed.
You must be careful because torque could very easily wrench the whole device if not just the adapter and throw it a long way - maybe 50' (so you don't want to be anywhere near that, believe me). Major point being, carelessly handled, especially if poorly fit, this StartProbe may come loose of a friction fit and become very dangerous. And please be especially careful disengaging these things due to RPM mismatch making it more difficult to execute safely.
This unit incorporates a roller clutch to let the engine start and achieve its own independent running RPM before disengaging as the electric starter spins down following engine-start.
- CAD image of how this things is designed inside to incorporate a roller clutch
Please be aware that a speed mismatch between starter and engine may result in slinging the adapter away at high RPM (and if it hits you or a bystander can cause severe injury). This thing is dangerous if carelessly handled so please be careful!
Note; because this is equipped with a one-way bearing (within the 6mm hex start adapter body), thus allowing the engine to start and speed up to a higher RPM than the electric starter motor without stalling the engine, a bit of lube occasionally will be smart. What kind of oil? It doesn't really matter because anything you have at hand is better than nothing. So feel free to use sewing machine oil, engine oil, hydraulic oil, literally anything will do to keep corrosion from accumulating. Important point being, these have delicate parts inside, which if allowed to corrode could become damaged and thus, make the whole thing more prone to causing injury.