Roll pin help.

**3 toed sloth** · 12th August 2016, 07:34 AM

I have just been struggling with a jammed rise & fall mechanism on my table saw. After years of happily gliding up and down effortlessly, the thing jammed up tight and refused to budge.

So, straight onto the forum (what would we do without it?) and sure enough someone had posted the same experience on the same table saw, just a few weeks ago, so thanks to all who contributed to that thread as it helped me enormously.

So for the last week I have been gradually unjamming the mechanism by regular applications of WD40, inox, and PTFE dry lube, combined with sessions of working the hand wheel back and forth hundreds of times. The first session involved moving the hand wheel half a turn each way, and working up to three quarters of a turn!

During one of these sessions I broke the roll pin which goes through the shaft. Keep in mind I am not one of those machinery people (who thankfully inhabit this forum, and hopefully are reading this thread) and until this event I had no idea what a roll pin was. It's not easy to google something when you don't know what it's called, but fortunately Google knows what you're thinking.

This is where I should have a photo, but basically a shaft pokes out the front of the machine and there is a hole drilled through it and a roll pin fits in the hole so it pokes out at 90degrees to the shaft and a slot in the back of the hand wheel goes over the roll pin so the wheel can turn the shaft which rises the blade.

The problem is I can't find the right size pin. A 5/32 driil bit won't fit in the hole, and a 9/64 bit will but it's not super snug so I can move it a bit inside the hole. In metric it seems to be around 3.5 or 3.6 mm diameter but the pins I've found only seem to come in 3 or 4mm sizes. I would try a 9/64 one if I could find one but no luck so far. I'm wondering about that other size that starts with M, like M1 or M2 etc. I found a conversion table on one of my steel rules which converts the M sizes to metric and it shows M4.5 equals 3.75mm (I think), so maybe that's worth a try but where would I find one?

Any advice welcome and gladly received.

Peter

**Treecycle** · 12th August 2016, 08:41 AM

This might help your research. They can also be called spring pins.

**pker** · 12th August 2016, 08:42 AM

Peter
A roll pin is designed to be a larger diameter than the shaft hole , that is why they are split. They need to be hammered in & the split closes up , keeping the pin tight under tension in the shaft. From what you say I would try a 4mm roll pin . Hope this helps.
pker

**Treecycle** · 12th August 2016, 10:55 AM

When knocking the new pin in make sure you have good support under the shaft so that you are hitting against something firm. Roll pins can be quite tight to knock in so the shaft can be easily bent if not supported well.
Even holding a good solid piece of steel or heavy hammer against the opposite side of the shaft will do the job.

**Lappa** · 12th August 2016, 12:48 PM

Have just about every size at work. What length do you need?

**3 toed sloth** · 12th August 2016, 12:55 PM

Thanks, Pker and Treecycle. I have some 5/32 pins that I got from Masters and it seems too large. 5/32 converts to 3.96mm so fits with the 4mm recommendation. I'll try it again tonight with a good solid support under the shaft and give it a few good whacks and see if I can make it fit.

Peter

**3 toed sloth** · 12th August 2016, 01:01 PM

Hi Lappa, you must have typed that while I was responding. I just went out and measured the old pin (in 3 pieces) it's 25mm long. Wouldn't matter if it was longer as there is plenty of room behind the handwheel.

**Lappa** · 12th August 2016, 01:05 PM

Let me know if you need a pin. I can get one today but not on the weekend.

**3 toed sloth** · 12th August 2016, 01:56 PM

Thanks, Lappa, I'll hold off for the moment and see how the 5/32 goes tonight. If it doesn't work I'll need something between 5/32 and 9/64th. I'll let you know how I go tonight.

Cheers, Peter

**3 toed sloth** · 12th August 2016, 07:46 PM

Okay, so here's the latest update. I've thrown in a few photos to make it easier to visualise.

I tried again to punch the 5/32 pin into the hole with a hammer behind the shaft and I'm satisfied there's no way that pin is going in that hole. One of the photos shows the pin mushroomed over from the hammer blows. I also ground an extra taper on the end to help it in.

I rechecked the hole diameter with the 9/64th drill bit and it's actually tighter than I thought. The 9/64 drill bit measures 3.55mm diameter so I believe the hole diameter is 3.55 - 3.60mm diameter. The old pin that came out and still fits snugly, is 3.60mm diameter. I've taken a photo with the 5/32 pin next to the old pin which is short due to being broken in three pieces, but I think the diameter difference is visible.

So now the question is, what size pin goes in a hole of 3.6mm diameter?

**Arron** · 12th August 2016, 08:06 PM

Snap. I have the same machine from same supplier. Also had the rise/fall seize, and the roll pin break trying to fix it. After a year of sporadically purchasing roll pins and trying them out, I just bought the next nearest from masters and drilled out the hole in the shaft through several sizes till it fit. Perfect.

Fwiw, I measured the internal diameter at 3.57mm. The amount of compression in a roll pin is minute.

Cheers
Arron

**3 toed sloth** · 12th August 2016, 08:07 PM

Further research has revealed the pin is actually made slightly larger than the stated size so it fits tightly in the hole, as pker said earlier. So the stated size is the hole diameter, the uninserted pin is actually slightly larger. So on that basis, I need a 9/64 roll pin. Looked on ebay, only available from America.

Peter

**Arron** · 12th August 2016, 08:09 PM

Yep, I also came up with 9/64.

**Bohdan** · 12th August 2016, 08:12 PM

I have had a similar problem once and found that the hole was not drilled exactly central. When I rotated one of the parts 180°
the pin went in easily.

**Lappa** · 12th August 2016, 09:16 PM

I'll check stock on Monday if you like Peter, if rotating doesn't work.

Thread: Roll pin help.

Thread Tools

Search Thread

Roll pin help.

Similar Threads

Roll Top Box

Rag on Roll

Roll Top

Roll up, roll up. come see the bearded lady..

Posting Permissions