Help getting the broken roll pins (on the Delta BS) out

[fsdogwood]

Hi there,
Broke the 2 roll pins when disassembling the Delta BS (for installing the riser block). Tried to drill the broken pins out, but they seem to be pretty hard that the drill
hardly left any mark. The HF center punch seems to be able to leave a small mark.

Any help to get the broken pins out will be appreciated!

Thanks in advance.

Pinwu

 

[Mark Gottesman]

I'm not familiar with the riser block, but I'm guessing they are blind holes. More than likely hardened spring steel.
Options for removal:
1: Carbide drill with lots of lubricant
2. Use a diamond coated burr in a dremmel to thin it out.
3. If you are feeling lucky, put in some penetrating oil, thread in a hardened steel screw and try and pull it with a slide hammer

good luck there. I know it is beyond aggravating.

 

[fsdogwood]

Thanks Mark.

It is beyond aggravating. Guess I'll try either option 1 or 2.
May I ask what kind of "lubricant" to use?

Regards.

Pinwu

 

[Mark Gottesman]

I would probably just use WD-40. use a drill slightly smaller than the pin hole, drill slowly with a light pressure. If the drill gets dull, you will need to push hard to cut, stop and get a fresh drill or resharpen. If you break off a drill in that hole you will probably need a machine shop with an edm to burn out the pin and drill.

Do this on a drill press and clamp down the work piece.

 

[Tarhead]

I would try to heat it up with a torch and try to grab it with small needle nose pliers while it's hot.
Failing that I would use a Tap and cut some threads to grab onto with a screw/bolt and pull it out.

 

[fsdogwood]

Being trying to pull it out, but there's not enough clearance for pliers to hold and pull.

Yeah, the tap may work, but I need to be able to drive into the pin first. I do have a small tap set, wonder how I can make that into this
hard roll pin.

Regards.

Pinwu

 

[junquecol]

Being trying to pull it out, but there's not enough clearance for pliers to hold and pull.

Yeah, the tap may work, but I need to be able to drive into the pin first. I do have a small tap set, wonder how I can make that into this
hard roll pin.

Regards.

Pinwu

You will need a torch with a pencil point flame. Heat the roll pin till it's red, and then let cool (a couple of hours. Heating pin will soften it, so you could probably get a sheet metal screw to bite into it.

 

[Guy in Paradise]

I have thrown all of the HF center punches away and spent more money on better ones. Good ones will make the drilling easier. I will also make the another recommendation, replace the pins and put the whole thing back together, then sell the saw and just buy a bigger one that has the capacity and capability you are looking for. I spent years nursing a 14" along, and when I finally bought a 17" saw with a 2HP motor, I wondered why I had punished myself for so many years.

 

[ehpoole]

My thoughts....

If it is a roll pin, there should be a slot in it. A slotted screwdriver may be able to engage this slit to rotate the pin lose (combined with suitable penetrating oil).

However, if you feel it has seized to such a point that ordinary removal is impossible, then drilling becomes you best option. In this case, you would avoid penetrating oil and use a heavier cutting oil combined with either a sharp titanium or (better still) cobalt drill bit of suitable diameter. You can either drill it incrementally or, if warranted, in a single pass. If the bit fails to bite then it is dull and requires sharpening or replacement. (Note: cobalt bits are solid cobalt steel, so sharpening does not sacrifice any special coatings, unlike titanium bits.) However, if the pin is able to spin in its hole, then drilling will not be possible since the drill bit will not be able to engage the pin if they are both spinning.

Using a tap and a bolt (combined with a nut and washer) to pull the pin out is a possibility. However, don't forget to verify that the internal diameter of the pin is greater (that is, of greater than recommended diameter) than the recommended diameter for the tap or you will likely break the tap off in the same hole -- and you do not want to have to drill out a broken tap! Additionally, if the pin is able to spin then tapping threads will be impractical.

I have reservations with respect to the torch method. Typically, if a riser block is being installed, these pins are likely embedded in a large mass of cast iron. It could prove very difficult to adequately heat a pin at the bottom of a blind hole surrounded by such a large mass of cast iron. You might have better luck trying to free up the pin through freezing it (if possible).

If the hole is not blind, as we are assuming, then you simply need a properly sized roll pin punch and mallet to remove it (center punches are not suitable for this task -- the conical tip will tend to try and expand the roll pin, which can make it grasp more tightly rather than loosen).

 

[fsdogwood]

Well, went to Lowes, found bunch of torches, here are 2:
"BernzOmatic Soldering Torch Head" (http://www.lowes.com/pd_246063-717-...=1&currentURL=/pl__0__s?Ntt=246063&facetInfo= )
and "Worthington Pro Grade Brass Torch Plumber's Kit, WPK2201" ( http://www.lowes.com/pd_148755-1387...Ntt=148755&N=0&langId=-1&storeId=10151&rpp=24 )

which one would be better? The pin is about flush with the cast iron surface, so yeah, heating with a "pencil point flame" sounds a good idea.

Thanks in advance.

Pinwu

 

[fsdogwood]

There seems to be no slot for the roll pin, and it's quite tight in the blind hole.

I got a carbide masonry bit from Ace, but reading carefully, it says not for glass or tile. Guess I may have to exchange for a cobalt bit?

I've checked the torches available at Lowes, I was thinking that if heat doesn't affect cast iron (the BS arm), then I could at least give the torch a try.
So here I would appreciate any info about the heat on cast iron.

Regards.

Pinwu

 

[Tarhead]

I would use one of these:
http://www.harborfreight.com/micro-torch-42099.html

It uses liquid Butane. I think you're safe as far as the Cast Iron.

 

[fsdogwood]

Thanks, definitely will try

Pinwu

 

[Tarhead]

Have you tried a strong magnet?

 

[fsdogwood]

Well, bought this HF torch, figured out how to use it, and fortunately, this one spits fire so I don't have to go back to exchange. (some mentioned in the review)

Let the blueish fire, around 1/8" in diameter on the roll pin for about 5-10 minutes, will try to drill it tomorrow (hand held, not easy to use a drill press)

 

[Splint Eastwood]

I just saw this, and have not read entire thread. Did anyone suggest using a Punch pin and hammer? I've had great luck doing it that way.

M

 

[fsdogwood]

Knowing that this broken pin is in a blind hole, I tried with some crappy punch/cold chisel. Only to find that the punch/chisel got damaged first.
Thanks, would appreciate if you could point me to some better punch?

Regards

 

[Splint Eastwood]

Knowing that this broken pin is in a blind hole, I tried with some crappy punch/cold chisel. Only to find that the punch/chisel got damaged first.
Thanks, would appreciate if you could point me to some better punch?

Regards

First, if you can, post a pic of item in question, This might help us in determining what the real issue is. Second if you have the owner manual, check to make sure it is a "roll pin". Im sure it is , but......

If you dont have the manual Google Delta and they have manuals online with schematics.

Second, I would not recommend heating/torching any metal as this might take the temper out of the all the metal, this will weaken the metal.

Lastly, like everything in life, size and technique are the key to success.

Take some metal penetrating spray and spray the area inside and let it soak in for a day.

Next, any hardened steel punch pin should work. Maybe think about investing in a set as I have since we all have TS, BS, etc.. that need maintenance, etc....... Enco.com other than HF is a place to check out metal working tools.

Take the size most closely matching the blind hole and then start tapping (feel if it is giving way) if so, then bang harder till it pops out.

If it doesnt feel like their is any movement, it may be angled (stuck) in the blind hole, in which case take a smaller punch and hammer 3 to 4 sides at a time to see if you can straighten out. once straigthened, then take the larger punch and hit square and straight to pop out.

Now this does take some time and patience if it is stuck, and dont think its not working if it doesnt pop out immediately, it will....

Try this and let us know how you fare. In the meanwhile I will check my bag of tricks for another approach.

GL !

 

[fsdogwood]

Thanks for the help!
From a manual I found http://www.mikestools.com/download/Delta-Parts-Lists/28-243-14-Inch-Wood-Cutting-Band-Saw-BS2G1.pdf , it's the item #44 called "dowel pin".
They are called "roll pin" in the Delta riser block manual.

Regards.

 

[Splint Eastwood]

Congrats on getting that pdf!

Based on Schematics, and the parts description (1/4 x 3/4 in) "Dowel pin". It appears to be a solid, rather than hollow with slit.

If that's the case, it may have been " Machine pressed in" and meant to be semi-permanent, in other words, no amount of pounding with a hammer and punch will help, Not sure.

But, call the Delta/Dewalt technical folks there's one on Capital Blvd in Raleigh near Harbor Freight (google for phone #) They can confirm. They are usu pretty helpful in giving out that kind of techical help.

Find out what ways it can be removed or ways they use to remove. Then you can go from there.

Good Luck