Bipe Flyer

My Miller 1/2A starter has too much torque for my .020 and .010 engines, so I made a little starter.

It consists of a 12V motor from Radio Shack, an electric prop adapter, an aluminum cone that I made on my lathe and a piece of Norvel silicone exhaust tubing. It is all housed in a Fuji film canister.

Lynn S

neat package!

Which_way_is_up

Sweet setup! How about some details, like motor pn, voltage you use to feed the motor, etc.

Bipe Flyer

The part no is 273-255 12V DC High-Speed Hobby Motor.

It is $4.29 USD at [link=http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=273-255]radioshack.com[/link] or $4.99 CAD ad [link=http://www.radioshack.ca/estore/Product.aspx?language=en-CA&product=2730255&category=Motors&catalog=RadioShack]radioshack.ca[/link]

I selected this motor because it is 12V and I can run it off of my field box battery.

The switch is part no 275-1547 .5A SPST NO push button.
[link=http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F002%5F015%5F002&product%5Fid=275%2D1547&hp=search]radioshack.com[/link]

[link=http://www.radioshack.ca/estore/Product.aspx?language=en-CA&product=2751547&category=Switches+Switches&catalog=RadioShack]radioshack.ca[/link]

Edit:

I just checked the current draw and it is 2.7A when turning over an .020, so the switch might be a little light, but it's only run for a few seconds at a time.

Andrew

Hi Andrew --

Very neat package -- I've got to find someone with a lathe and buy him a beer or two!!!

Have you tried it on either an .049 or .061? When you were shopping around at Radio Shack, did you notice any other motors that might be of sufficient torque for the 1/2 A's?

the "other" Andrew

SeanT

Hi BipeFlyer,

You say the Miller has too much torque for .010 and .020? What are the recommended RPM and torque settings to start an .010 or .020, how do you test the torque of a starter? Reason I ask, I have a Miller that I planned to run off a 10 cell NICAD pack for .010 and .020, in addition to a homemade starter. Here are some pics and specs of my 1/2a starter, made for me by a hobby shop owner back in Dallas.

Specs:
Old 480 Mabuchi can motor
4.8v 600 mah Nicad
DPDT switch from Radio Shack
PVC
Heater hose for starting cone
Aluminum adapter (cut on lathe)


[img][/img]

Bipe Flyer

I think that 540 motors are used in most 1/2A starters; at least in the Miller, Sullivan and Astro Flight starters that I've seen anyways.

Here's one at [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXGGA8&P=7]Tower[/link]

Of course you'll want something that can handle 12V. This one at [link=http://www.allelectronics.com/cgi-bin/category.cgi?category=search&item=DCM-216&type=store]allelectronics.com[/link] should do the trick. It looks like they have a little motor similar to the one I used, [link=http://www.allelectronics.com/cgi-bin/category.cgi?category=search&item=DCM-141&type=store]click here[/link].

Bipe Flyer

The reason I say that is because I saw an .020 con rod get snapped when it hydraulic locked using an Asto Flight starter, which is the same size as a Miller. It's like starting an .061 with a standard size starter. You can start it a hundred times with no problems, but if it hydraulic locks once you could easily damage the engine.

How do you test the torque of a starter? I just tested it on different engines. This one can spin an .020 easily, but it can't turn over an .049. How much torque? Just enough to spin the motor. How fast? Fast enough to start it.

Sorry if the answers are a bit simplistic, but I didn't do anything very scientific. I just know that less torque is safer and more RPMs works better for starting smaller engines.

Bipe Flyer

I just tested it out on a PeeWee and it works perfect. Just barely enough power to turn the engine over when it is up against compression. I only need to hold it on for less than a second.

I love the sound these little guys make when they start.
Brap... brraaaap... breeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eeeeeeeeeeeee[sm=lol.gif]

Bipe Flyer

Just an update on the motors. Radio Shack in Canada was bought out by Circuit City. Their new website is http://www.thesourcecc.com/. The part numbers are still the same.

Radio Shack in the US no longer carries the motor. The closest is #273-256.

ComfortablyNumb

There are some small motors [link=http://www.goldmine-elec-products.com/prodinfo.asp?number=G13249]here[/link], that may qualify for such an application.

http://www.goldmine-elec-products.co....asp?dept=1104

Raymond LeFlyr

My Feedback: (2)

I kinda like the Miller 1/2A starter that I've used for the past few years on my TD .010s and .020s. I decided on the Miller because I liked their soft spinner cones that come in all sizes to fit Cox's spinner nuts. So far my only complaint is that the pushbutton switch is not always reliable. Thanks to this post, it reminds me to look up their address (no website that I ever found) and see about sending it back for repair. (I'm gonna need it soon because I have two multiple .010 projects going - one ready for paint).

I had a homemade 1/2A starter version that I made from my first Astro 05 motor done pretty much the same way as Bipe's with a push-on, push-off switch from the Shack and some prop adapter that was large enough to hold some plumbing tubing from Lowes. Its not arouind anymore so I must have given it away or traded it.

As for too much torque, my dear old mother always told me, "son, when we're talking about torque enough is ok, but too much is just right." She also insisted that I turn the prop over slowly a couple of times before attaching the glow lighter. I thought this was to ensure that atomized fuel was in the upper cylinder, but it might have been to avoid vapor lock. She didn't always share her knowledge with me - to this day I still don't know how she got her pie crusts to be sooo flaky. Anyway, back then I'd have used anything to avoid those bloody spring starters and I'd have given anything to have one of those hand-cranked, geared starters that the speed guys used. Now there was some torque and speed.

Well, knock on wood, I've never broken a Cox crank or pin even when pitting Mouse racers and the trick was to slap the prop as hard and fast as you could to get that covetted one-flip, hot restart. Ah, yoot.

digital_trucker

Brush the crust with butter (real butter) to make it flaky...and tasty too!

Raymond LeFlyr

My Feedback: (2)

Hey Digi-Truk,

you weren't one of Mom's drinking buddies were you?

She also used ice water during the mixing stage and put the dough in the fridge for a half-hour or so before rolling it out - but this is just between us guys and you won't be telling anyone else willya?

Bipe Flyer

Lots of torque isn't a problem if it's not hydraulic locked. I remember seeing a guy trying to start a Cox with a standard starter. Spin, spin, spin, no start - richen the needle - spin, spin, no start - richen the needle - spin, spin, no start - richen the needle - SNAP!

digital_trucker

Bipe, I hear ya - a properly broken-in and set up engine should finger flip fairly easily (at least the sport engines, high-perf jobbies seem to be a litle crankier).

Ray - chilling the dough retards the yeast during the rise, making the bubbles tinier - gives the dough a finer texture which also helps make it flakier.

BMatthews

Nice job on the starter.

But I've still got starter springs on my littl'uns....

Raymond LeFlyr

My Feedback: (2)

Digi,

Dang, Mom never told me WHAT it did - just that you had to do it. Knowledge IS power.

Spring starters are NOT my friend - and I have the scars to prove it. I dunno, maybe I have wimpy skin on my fingers but they tend to leak red stuff whenever I wind up them springs. The farther I can keep my digits from ANY size of propellor, the better I like it.

(Don't even think of suggesting it . . I'm too manly to wear gloves.)

'Scuse me, I have to go to the kitchen now.

MJD

My Feedback: (1)

Yeah, but .010's need a lot of rotational speed no matter how well they are set up, and they are a b---h to start by flipping. I've done it, but I certainly have better things to do! .020's aren't quite as much problem, but springs or electric still make life better, and isn't that always a good thing? If you can't start yer .049 by hand, you got some work to do. Well, as you say some high performance set ups might be a bit of a challenge, of course a light matchstick prop has a tough time driving the engine around compression in comparison to something larger diameter and heavier. But your run of the mill reedies and TD's etc. shouldn't be much of an issue. Heck, hand starting should be a point of pride I think.

I too never hit a small engine with a starter until I have flipped it a few times to ward off hydraulic lock. Of course, starting with a relatively dry cylinder and a way too rich needle setting - well, s--- can happen..

My mother in law used all the tricks mentioned, and even showed me how she makes pie crusts, but I don't have the patience for all that finger mushing, massaging etc... and not purprisingly, my crusts don't compete with hers. I was often told one of the more important tips is never to overmix.

Oh yeah, one question - do you really put yeast in your pie crusts???[sm=confused.gif]

MJD

Bipe Flyer

I don't like the starter springs. After a lot of use they create noticeable wear on the carb body and aluminum piece in front it.

The little starter I posted above is pretty high RPM - a lot more than a standard starter - without enough torque to turn over a locked up .020. I always prime then turn an engine over 2 or 3 times by hand before staring, regardless of the engine size or whether I am hand starting or using a starter.

Raymond LeFlyr

My Feedback: (2)

Yeah, I forgot to include minimizing the kneading time. Actually I don't mind making my own pies because I get to choose the apples (green, sour, Granny Smith usually). And what's better than real, local, fresh fruit pies in season!? Oh, oh c'mon Summer!

Matchstick props? . . . . Aw, never mind I was gonna, but I won't.

Seriously, I guess the biggest reason I avoid springs now is the memory of using them for Mouse racing as the pti man - when your hands are likely to be covered in 20%-oil fuel and the guy at the handle is yelling at you to hurry and you burn your hand on the hot engine and you can't get the plug lit and sweat's dripping in your eyes - and boy it was still great fun wasn't it?

digital_trucker

MJD - the yeast thing was a sort of artistic license (or utter B.S. - take your pick)

MJD

My Feedback: (1)

Sour cream apple pie made with Granny Smiths - definitely A Good Thing . Sour cream peach pie works too. And you are right, nothing like a pie made with fresh local apples - there are myriad apple orchards in an area about 40 minutes NW of our place, and we make frequent trips up there in the warm weather for apples and whatever else they have available. Our freezer is usually weighed down with one gallon ice cream tubs full of homemade apple sauce which my wife makes weekly - and we happily eat. Mmmm, morning oatmeal with a big dollop of warm apple sauce, good breakfast.

I like pie making too, although I must admit the crust is a test of my patience (what little I have), but they come out decently. What I have learned, if anything, from the mother in law (RIP) and a sister-in-law that makes them just as well (I guess she was paying attention during her mom's pie lessons) is that patience is indeed a virtue. Also, just because the crust doesn't look or act like dough when you put it in the pan, doesn't mean it won't when it is done... just add heat and time.

How is this relevant.. good question, lessee.. right, got it. After a nice breakfast of oatmeal with apple sauce, go fly 1/2A aircraft, and take a piece of apple pie along as a snack. Hah!

Darn it now I am hungry again.. sigh. Back to the lunch room.

MJD