View Full Version : roll pin into output shaft
hey guys we are trying to put the roll pin into the output shaft but we cant seem to get it in we tryed expanding the metal with heat ,oil and we already broke 2 of the roll pins we cant get it in Any other temas having problems with this
ktty_jay
10-01-2008, 17:15
We're having the same problem, and totally destroyed two of the roll pins trying to get it in. Actually we order some new pins but they only come in big bunches. Like you asked before, how do you get it in? We tried hammering lightly, using a rubber mallet, and using oil as liberation.
Had some problems, but got what seemed like a reliable method:
1. Opened the holes a bit with a punch. This should allow the pin to fit in slightly at first.
2. Lightly tapped it in with a steel hammer, until it is set in the shaft and won't fall out.
3. Switch to a hammer with a softer head material (not too soft though), and continue tapping.
4. If the pin begins to deform or bend, shape carefully back into place with pliers or a hammer. You might have to do this a couple times.
Should work, just be careful with it and don't try to hammer it in with all your force.
We assembled our transmissions a few days ago - the roll pin went in fine on one, broken on the other. Just make sure you get it straight before forcing it in with either a hammer or a press.
Chuck Glick
10-01-2008, 17:54
When putting the roll pin in, the less hits the better. If you watch the assembly video on andymark.biz, you'll notice he gets it in with about 4-5 hits. We tried it slow at first and mushroomed the head, then gave it 3 good quick wacks, WAHLAH! perfect.
Jaybee1405
10-01-2008, 19:44
I agree with Chuck, you have to do a few hard hits or else it will flatten the top. The first one went in fairly easily for me, but you have to bend it back with a pair of pliers so it stays straight. The second time, I didn't bend it back and it went in way crooked. I ended up breaking off the bent and mangled mess, and after that there was only 1 or 2 mm left on each side, which happened to be enough to hold the gear on.
We started it with a few light taps and finished it off with a few big hits.
Herodotus
10-01-2008, 21:46
I first tried using an Arbor press which pretty much mangled the first pin, and then I used their suggestion of light taps with a hammer. It worked rather well for me, though it took awhile. It mushroomed a little bit but it went in and is holding the gear in rather well.
sanddrag
10-01-2008, 22:11
maybe drill the hole out a few thou?
TubaMorg
10-01-2008, 22:35
The key to getting a tight rolled pin in is to make sure it starts to fold in on itself (axial). We noticed that on end of the pin was slightly more tappered than the other. A sqeeze with pliars will encourage the fold as you smack it with a hammer. It should go in fine after that. If you don't get an overlap it just plain won't go in.
M4 Sherman
10-01-2008, 23:58
A really big hammer!
Our team had the same problem. We stated it with a little hammer tapping and then used a vise as a press to finish it off.
Bigflip2073
11-01-2008, 01:25
Yeah we just did those today.
We just used a Vice to get the pin through the hole and then we hammered it to get it all the way through.
However the end that we hammered mushroomed we tried our best to fix it but the gear that rests on it has a slight wobble
Is that bad?
Jaybee1405
12-01-2008, 00:16
bigflip: i would just try to take a pair of pliers and break off the "mushroom head" that's making it wobble. Like I said, all you need is 1 or 2 mm on each side. The last thing you want is the gearbox to bind or jam in the middle of a round.
MrForbes
12-01-2008, 00:32
we stopped by the hardware store today and bought two 3/32" split pins for 32 cents including tax.
\\Zero//
12-01-2008, 11:33
we broke 2 of our's and now we have to buy a new output shaft since the pin broke halfway inside and is completely jamed...
NoSkaOnTheRadio
12-01-2008, 13:22
Eh, we had a smiliar problem. I broke two of them in the output shafts, but was able to drill them out with a 1/16" bit in our drill press. Of course, I broke a drill bit in the shaft in the process, but a 3/32" bit cleared that out. Once I got the 3/32 bit all the way through the hole, the roll pin fit a lot better; it was still really tight, but I held it vertical with a pair of pliers when i started hammering it. Once it was in far enough I could hammer it without the pliers without it bending, and everything went smoothly from there. It took a lot of time and frustration and a little bit of blood, but that guy isn't going anywhere now.
OSU_Springer
12-01-2008, 17:33
Part of the problem is that the roll pin is .100 (or thereabouts), and the shaft hole is about .080. Now the BOM for the Toughbox states that roll pins are 3/32". That correlates to .09375. So firstly, the Roll Pins are oversized from the appropriate dimensions. Secondly, the holes are undersized from a proper tolerance perspective of an interference fit with those materials. A proper fit for a split or spring type pin should only interfere a few thousandths, not 15-20 thousandths. Another reason to doubt the quality control folks.
OSU_Springer
12-01-2008, 17:38
Part of the problem is that the roll pin is .100 (or thereabouts), and the shaft hole is about .080. Now the BOM for the Toughbox states that roll pins are 3/32". That correlates to .09375. So firstly, the Roll Pins are oversized from the appropriate dimensions. Secondly, the holes are undersized from a proper tolerance perspective of an interference fit with those materials. A proper fit for a split or spring type pin should only interfere a few thousandths, not 15-20 thousandths. Another reason to doubt the quality control folks.
We had the same problem. We got one pin in, then bent 5 more (there are 2 teams at our school so we were using all of our pins up >.>) We bought some others from the hardware store and ended up drilling out one side of the shaft and put in our new ones, and now we have 4 good gearboxes. It was one hell of a time waster though, we must have spent three hours last Saturday on them.
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