I keep losing set screws!

[Minimichael]

Nothing stays put in this driven gear. I put two new screws in 2 different holes and they each disappeared half way through the ride. It also kinda feels like the tapped hole may not be right either because when the screw bottoms against the jackshaft I think I feel it shifting a smidge sideways.

Anybody ever tried an additional set screw on top of the lower screw as a lock? 1/4" - 20 thread...

 

[sparkwizard]

Sorry if this is dumb, but are you sure it is not metric?

 

[creia]

Years ago, we USED to have that problem as well. Use a drop or 2 of (blue) Loctite = no more loose/lost set screws.
Michael

 

[Minimichael]

Sorry if this is dumb, but are you sure it is not metric?

Not dumb! And yes! Er I mean, I checked 6mm and too small, and 8's too big. Do they even make 7mm screws? I didn't see em at Menards. And what are the chances they share the same threads?

 

[cfh]

forget set screws. never use them. better to use spacers. it's explained here...
go to 4.30 minute mark.

 

[Minimichael]

Years ago, we USED to have that problem as well. Use a drop or 2 of (blue) Loctite = no more loose/lost set screws.
Michael

Yeah I figure that's next. More shit to take apart and fully clean first.

 

[Minimichael]

Spacers, good point. Thanks for the video.

 

[Bird Brain]

Using jamb set screws, one on top the other, is an industry standard for large assembles with heavy vibration and heat cycles in the manufacturing world. It is an effective common practice.

 

[Minimichael]

Using jamb set screws, one on top the other, is an industry standard for large assembles with heavy vibration and heat cycles in the manufacturing world. It is an effective common practice.

Thanks Bird Brain

All good advice though. Thanks guys.

 

[cfh]

set screws are a hot mess. they eventually always come out. spacers do not. also if you need to change the jackshaft gear, and you bloody blue lock tight or double set screw the mess, have fun! ever strip a set screw? i have. just use spacers, it's the way to go. set screws suck.

 

[chrisr]

May not look as well as a locking collar, however, a washer against what you are trying to keep in place along with a small hose clamp work really well. Using blue Lock tight on the set screws on the locking collars is the only way I have found to keep them in place.

 

[Skipp]

ever strip a set screw? i have.

yup yesterday…took a whole 5 minutes to get it out….put a new one in and tightened it up….No lock tite…..

 

[cfh]

i can tell you some crappy set screw stores... at Milan dragway with a Harrison and a tecumseh 10hp in it. doing 50 to 60mph down the dragstrip with the jackshaft and set screws. down the line and the motor goes super RPM and i coast in... set screw few out, jackshaft spins free, end of the races for that day!

next up had a Wards 525 with a jackshaft, and i'm out riding in the woods. set screw goes missing, and i have to push the damn thing home 2 miles through woods, up and down hills.

i converted both bikes to spaces, NO MORE PROBLEMS.
Set screws are amateurs.

 

[Ginz61]

I’m getting the feeling that you really don’t like set screws CFH . I have an external gear on the jackshaft of my Rupp Continental with set screws and you have convinced me to modify it to a bolt and retaining washer. I’m also going to look at the setups on all of my minis.
Thank you

 

[cfh]

i'm sure set screws are fine if you're just riding around the neighborhood. but if you go trail riding or do any performance stuff, they just fail at some point. and it's always the worst time. like say you're riding out here for example. long walk home pushing your bike if a set screw goes south. simply put, the risk of loosing a set screw is not worth it. one little thing can ruin a day of riding. so why not just avoid that and use spacers.

 

[Skipp]

Yeah I don’t trail ride…too old…I just like fast…putt around the neighborhood and yes I’ve lost them….but usually the key keeps it in in place long enough for me to get home….honestly the best thing I’ve found to keep them in and no difficulty to remove….dish soap….

just yanking in you a bit

and I’m thrilled to be an amateur!!

not all if us can be heroes some of us have to sit in the curb and clap as you go by!

 

[desert rat]

Punch the top thread just a bit to turn the set screw into a locking screw, Do this with the alen wrench in place so you do not deform the wrench hole. This will cause added resistance to the thread area just like a lock nut,
OR
https://www.mcmaster.com/products/set-screws/hollow-lock-set-screws-5/

 

[cfh]

another problem i have with set screws is in an effort to make them really tight, the set screw hex hole rounds. especially if your allen wrench is not in perfect condition. and once that happens, you're screwed. set screws are hardened, so you really can't drill them out. and now you can't get the jackshaft assembly apart. other than to ride the bike until the jackshaft falls apart. ha! it's a hot mess.

i'm still struggling with why any one would want to use set screws??? i mean we all stopped using them on clutches like a zillion years ago. and instead drill/tap the crankshaft and use a bolt. what is the up side to set screws? that they're the lazy way to attach a sprocket to a jackshaft?? so you all are telling me that set screws are no good for your clutch, but it's Ok for your jackshaft?? yea right, or Mr.Denial, you go with that flawed lazy thinking... you spend all this time/energy hopping up your engine, and then put it all together in a bike with set screws? Really??? chain only as strong as the weakest link....

 

[Skipp]

Calm down now it’s just a matter of opinion…I mean they used set screws for 50 years until YOU came up with something better….give them a chance….I’m sure everyone didn’t go out and buy lightbulbs the first day?!?

 

[cfh]

i didn't come up with the spacer idea on jackshafts. it's been around since the beginning. but just like clutches used to be attached to the PTO with set screws, people figured out in a hurry and was a crappy way to attach a clutch. Same goes with a sprocket on a jackshaft. i'm sure set screws were Ok when you were running a 2.5hp briggs engine. but we sure passed that milestone a LONG time ago...