[Devil in the D-tales]

We have been working on our FCG for months now!!! We reviewed EVERYTHING..I MEAN EVERYTHING before attempting this.
We built a PVC cage to enclose due to our unpredictable October weather. Followed the motor build using all the info from KICK THE FROG(great info thx froggy) built a wooden dowel marionette..much like the Master of all things leer, and now cranked..here's Johnny. And did the drum roll..and NOTHING..so all wires, nuts, bolts, motor, speed reducer, counter balance weights, swivels, checked, rechecked, cut, recut, on and on and on...STILL NOTHING!! After weeks of trying...so sure I MUST be doing SOMETHING wrong..I was ready to give up!! After taking everything apart AGAIN, it all came down to the threaded end, at the end of the monster guts wiper motor, that was NOT holding the lock nut washers tight, so the small crank arm that came with the motor was spinning and spinning..and the attached metal extended portion of the crank arm with the attached fender washer never would turn...SO???? We used the u bolt and drilled that through the long metal crank arm..SURE it would now turn..BUT NO..that would have been to easy of a fix!! So we contacted monster guts, sent them photos of the small crank arms which they were adamant came with serrated edges inside..BUT ours were smooth..no serrations. so after several emails...they finally sent me another small crank arm...another week has gone by and the cranks arms have NO serrations..same as the ones I have. PLEASE PLEASE..what can I do to have this ready for Halloween..I have been to the hardware store at least 10 times..NO EXAGGREATION..bought every lock washer, lock nut, star washers, M6 coupler and still it keeps spinning and the arm falls off...is locktite a solution at least for Halloween night..until I put a new motor in for next year...cannot buy Another one now as I already spent $70 plus dollars on this monster gut motor!! Thanks in advance to my savior who figures this out.

 

[Diabolik]

Have you tried putting a few small flat washers between your nut and the drive arm? We had a similar issue with those motors and I believe we put a few small washers on there to put more pressure on the arm. Without the washers the nut could just not tighten down enough. It runs out of threads. I think maybe the hole in the arms were a bit too big and as a result they sat a little lower on the shaft then they should have.

 

[Diabolik]

I should clarify that the washers ID must be big enough to fit down over the step in the shaft where the threads stop and the splines start. You need to take up that space.

 

[J-Man]

Devil in the D-tales,
Kinda hard to nail down exactly what you're trying to describe but the wiper motor shaft is what should have splines, not the arm. Is it possible that the splines
have been worn smooth due to the motor spinning and slipping?

 

[Ghost Ninja]

I had a similar issue with my monster in the box prop a couple of years ago. I finally wound up welding the brace to the darn wiper motor! That worked but my motor died the next year. You can try taking it to a local shop and ask them to weld it for you. It takes about 10 minutes to do. For my FCG I used a rotisserie motor but it still snagged. Last year I replaced the big flat washer (used to connect the strings) with a sliding glass door wheel. It looks like a pulley and only costs about $3 for two. I hope this helps you. These are all great ideas I got from others on this forum.

 

[SatansPuppy]

Have you tried running the motor backwards instead , as the crank arm wants to spin off it might tighten the nut at the same time. I dont know what its called but the two forces will fight against each other. I had it happen with a prop i am building no mater how tight i did the nut it came right off, unfortunately my wiper motors will not go in reverse so i had to weld it.

 

[Devil in the D-tales]

Thanks so much to all who have replied with a solution. I am medical NOT mechanical so bear with me. The part of the motor that connects to the crank arm has a threaded end approximately 3/4 of an inch, which has threads like the end of a bolt. However, above this.. before you come to the motor case ..is a tapered part that has splines(?) the threaded area will fit a m6 coupler, which we filed down, placed a u bolt over it and connected that to the crank arm...this continued to spin and would never lock down. This tapered end ..above the threaded end ...flares out and looks somewhat like a small gumdrop. This is the problem, if it fits the threaded end, then it won't go above the spline end. I hate to beat a dead horse, but I can't believe I am the only one who has run into this problem. So if welding is the answer for this year..welding it is. Just hated to cry "UNCLE" after all this time and aggravation. Thanks again, and happy haunting!!!

 

[J-Man]

Devil in the D-tales,
That old saying, " A picture is worth a thousand words" definitely applies here. Maybe it's just me but I still don't have a clue as to exactly what you are trying to describe. Can you post a couple pictures of your problem?

 

[J-Man]

Have you tried running the motor backwards instead , as the crank arm wants to spin off it might tighten the nut at the same time. I dont know what its called but the two forces will fight against each other. I had it happen with a prop i am building no mater how tight i did the nut it came right off, unfortunately my wiper motors will not go in reverse so i had to weld it.

SatansPuppy,
Not trying to get off topic here but any DC motor can be reversed, you simply switch the positive and negative leads.

 

[Diabolik]

Devil,

I sent you a PM. I have a steel crank arm here that I tried on a MG motor and it seemed to tighten down fine. I'd be happy to send it your way to try. It is plenty long enough for a FCG rig. Don't want anything for it. Might help you out of your jam.

 

[SatansPuppy]

Yeah I know , but my particular wiper motor will not allow it . I don't know what truck they came out of , I just grabbed the easiest ones LOL.

 

[vdevine]

I had a similar problem. I welded it 3 years ago with no issues since.

 

[Otaku]

I'm sure that the motor can be reversed; it's just a matter of switching polarity. Not all reduction gearboxes will run in both directions, and that may be the reason here.

 

[J-Man]

Some wiper motors also have a circuit board built into the case. Some of those may have a diode or circuitry that won't allow reverse polarity.