Dizzy disassembly question

[CraigD]

I am trying to disassemble my Bosch dizzy. I can't get the pin out to remove the gear and shaft. After a search seems some people drill it out and others have been able to use a punch to remove it. Is there any secret to removing the pin? I have tried pressing it out with a vise using a socket over one end of the pin and a bolt pushing on the other end. Darn thing didn't move a bit. Tried a punch and hammer on wooden bench top, again didn't move a bit. Any suggestions would be appreciated.

[tmctguer]

i took a punch and hammered it out. it took a while, and a decent sized hammer. but i whacked with care, and once you get it started, it comes out quite nicely. it went back in nicely, too.

[Jorgeman]

Craig--am assuming the pin is NOT a roll pin (I don't remember) so it will be a TAPER pin and will only drive out from the SMALL end of the pin. Taper pins usually require a sharp hefty hit with a pin punch and decent sized ballpeen hammer. Don't be tentative or the pin will have a chance to "hunch it's shoulders"! Smack it! If it is a roll pin (hollow instead of solid) you can normally drive them out from either side. This is probably way to elementary and not intended to insult your tech ability but many people are unfamiliar with taper pins. IF, perchance, the pin hole gets buggered, it can be cleaned up with the proper taper reamer at your local machine shop.Good Luck.


george 86T

[Jdub]

DRILL THE PIN OUT!!!!

They are cheap and the dist. shaft is not. Chances are very small you will bend the shaft but why take the chance? The pin is highly malleable (i.e. soft) and is designed to be a loss item, so you will have to purchase a new pin regardless.

The pin is mushroomed at each end. A procedure to remove the pin is to file flush to the shaft one side of the pin. Find the center, centerpunch it, then proceed with drilling it out, starting with a small bit that is reasonably stiff. Drill straight through and continue to larger drill bits. Pin will clean out and harder shaft will "help" keep badly-centered drill from wrecking shaft.

CLEAN EVERYTHING WELL BEFORE TRYING TO REMOVE THE PINION FROM THE SHAFT! Sorry to shout, but particulate from the drilled pin that creeps under the interference fit of the pinion to shaft will gouge and cause you all kinds of worry. Take WD-40 and spray liberally, easing the pinion off. Any resistance and douse again.

Good luck and contact me if you have any questions. I understand the bearings are a bear to remove but I cannot help you there as I did not perform that part of the job, having nice tight tolerances there.

John

[cstreit]

Soak the pin with some penetrating oil..

Then, I like to drill them out with a thin drill bit. This minimizes the chance that you will drill into the surrounding material and allows the pin to "shrink" in on itself when you pound it. THis also creates a good seat for a punch to sit in.

[Jorgeman]

I respectfully disagree with both Chris and John. Drilling out taper pins is a last resort and exposes the pieces to drill drift, broken drills, enlarged holes, etc. Have you ever tried drilling out a broken drill? Taper pins are meant to be precise fits and reusable. If it protrudes from the hole at the small end, use a brass rod to start it out AND to set it later when you're replacing it. That'll keep the the pin, which is much harder, from mushrooming.

george 86T

[Jdub]

If you look at the pin, you will see both sides are mashed via a three-point center tool. This obviates reuse. Unless I am missing something here, and the SC dist. is *NOT* generally the same as others, the pin is something just above lead in hardness, and so is not intended for reuse.

The pin is a throw-away item, and so I remain steadfast: drill it out with an educated hand. Drill drift comes from overloading the bit, and the material of the pin is soft enough you hardly need to put much pressure on it.

Plus, can anyone out there tell which end is the tapered end anyway, and thus what end should be hammered and what end not?

John

[Jorgeman]

John--if the taper pin is as soft as you describe then it's a type I'm unfamiliar with so I'll back off and defer to your experience.
Taper pins I've worked with in the past were Std. Morse Taper and even in a 5/8 or 3/4" pin, I could discern the smaller end. They also are very hard and will normally not deform when removed.
By the by, I have multiple reamers, handles and taper pins in case anyone needs to borrow them. Just drop me an e-mail.

george 86T

[CraigD]

Drilling out the pin seemed to risky to me. I was worried about damaging the gear or shaft if I drilled off center. I decided to be more forceful with punching out the pin and was sucessful. Have disassembled cleaned and am in the process of reassembly.

Thanks for all the replies and suggestions.

[Jdub]

Good stuff...whatever works is what works!!

What are you using as a new pin?

John