Need a 7/8" diameter drill bit for drilling cast iron...

[Michael Dunn]

Any one have any recommendations? I bought a shop fox riser block and the guide post shaft is 7/8" whereas my Cal-Hawk's guide post hole is ever so slightly smaller. I can't remember the exact diameter of the current hole.

Thanx!!!

[Chris Fournier]

You really require a counterbore for precision. If the amount of material you have to remove is minimal I'd use a reamer. Perhaps a visit to a friendly machine shop is in order?

[Michael Dunn]

I can't use a reamer since the amount of CI is like 3" thick. Although that would perfect otherwise. I was thinking about a machine shop too. I think there's one in my area. I'll look them up.

Any other tips or thoughts guys?

[Mark Bolton]

If your just opening the hole up slightly and need a clean hole may be best to buy a bit a rent a mag drill. It would drill a clean hole but yeah, if you need super precision...

[Lee Schierer]

If your just opening the hole up slightly and need a clean hole may be best to buy a bit a rent a mag drill. It would drill a clean hole but yeah, if you need super precision...

I don't think a mag drill that will handle a bit that size is going to fit on top of a riser block and still let the bit align with the hole. A reamer is the best bet and it would be done with precision on a bridgeport machine.

[Mark Bolton]

Zoikes, yeah, my bad, flaked about drilling the block.. Hehe that would be a precarious setup.. :-)

[Phil Thien]

If you're going to a machine shop, consider having the guide post turned down rather than the hole opened up.

[Michael Dunn]

Has anyone here bough either the Shop Fox, Grizzly, or Jet 6" riser block kits for a 14" BS? If so, could you measure the diameter of your guide post shaft? If the diameter is smaller or closer to what mine is perhaps ill return this and get another make.

[John Coloccia]

I would take the block and the post to my machine shop. I would say, "Make this fit that". He will mic the post, select a bit and put the block in a vice. He will find the center of the hole, zero his DRO, chuck the proper sized drill, and drill it out. If I still had access to a mill, it's about a 20 minute job.

[Michael Dunn]

Ok. So I've just found out that the reamers you guys mentioned are drill or drill press reamers and not the hand reamers that I'm used to. My current hole for the stock guide post is a hair larger that 3/4". My new guide post is pretty close to 7/8". So roughly 1/8" difference. I'm fine with buying some reamers. More cool tools for future projects. How many incremental steps should I take to get to 7/8"? I'd like it to be a pretty close fit to eliminate slop and therefor have better accuracy with my guide block and thrust hearing settings. I can't help but think I should take it in 1/32" steps to get to 7/8". Or would 1/16" be acceptable. I find I hard to believe that it would.

[ian maybury]

Hi Michael. My recollection is fuzzy, but i think a reamer in that sort of size would at a push remove about 0.5mm max above the existing hole size per pass. Preferably less.

They do have the advantage of tending to self centre and align in a hole, but a quick look suggests that bigger reamers like that start to get quite expensive, perhaps $50 each over here. By that you would need several. Plus there's the risk of it going wrong.

Maybe the right machine shop?

It'd be down to the machine shop and exactly what kit they have to decide the process. There's quite a few ways of doing it. The key for you would be to specify the tolerance and accuracy of alignment (squareness) of the hole you need. As an example of a common sliding fit that's not too sloppy - standard bright mild steel shafting in that sort of size is up to maybe 0.05mm (0.002in) under the nominal dimension, bearing housings are usually about on it.

ian

[Phil Thien]

Isn't the hole for your guide post cast right into the upper frame assembly?

I don't think I'd open that up unless I could guarantee alignment. Introducing any angle would mean the guide post would not move parallel to the blade.

I'd try to find a kit that better matches your saw.

Or have the guide post turned down.

[Michael Dunn]

Isn't the hole for your guide post cast right into the upper frame assembly?

I don't think I'd open that up unless I could guarantee alignment. Introducing any angle would mean the guide post would not move parallel to the blade.

I'd try to find a kit that better matches your saw.

Or have the guide post turned down.

It is cast into the upper arm. Then machined I guess. I hear what you're saying about the angle. The current guide post has so much slop in it that I'll certainly take my chances and will most likely end up improving things.

Not to mention the Shop Fox guide post has teeth and one flat side for more predictable registration after vertical adjustments.

I'm a risk taker. Fortunately, I've yet be too badly burned. I'll post my results. I'll try my local machine shop tomorrow and then order some adjustable hand reamers from Grainger or Grizzly.

[Brian Brightwell]

Micheal, a picture would be helpful.

[Tony Zaffuto]

From my perspective as owning a manufacturing plant, with a complete machine shop as well as a tool making shop, I would say take the riser block and guide post to the shop and ask the machinist for his/her opinion as to the best way to do the job. Size of the block is probably too small for a magnetic drill, though that is a great suggestion for on-site holes that need to be perpendicular to the surface. Turning of the guide post may be a bit more difficult that sizing the riser block hole to the guide post, plus you would not be able to revert back to original configuration.

[Michael Dunn]

The plot thickens... Well, I just drilled the necessary holes in my upper and lower arms of the CI. That wen perfectly... With a hand drill... I made a template and used it as a guide to help ensure perpendicularity. I slightly undersized the holes and then reamed them slightly with my tapered hand hand reamer. I used a parallel cabinet clamp to help persuade it into place in addition to tapping the registration inserts. I don't know if that is the technical term, but they're two hollow, cylindrical, inserts with a split shaft that allows them to compress slightly.

Then I put the larger assembly bolt in place and tightened it. Everything aligned perfectly.

Here's the problem, aside from the guide post diameter dilemma.

My Cal-Hawk BS uses a 92 1/2" blade. Add 12" to hat to compensate for the riser block mod = 104 1/2" blade. I have only seen 105" blades. With my tension adjustment at the max tension there is ZERO tension on the blade. Not to mention that the upper wheel is touching the sheet metal housing.

I see a few options... In no special order of plausibility or logic.

1. Add a 1/2" thick steel, shim of some sort effectively raising the upper arm by another 1/2" thereby (hopefully giving me enough added height to obtain adequate tension.

2. Get a new longer tension screw and modify the sheet metal rear housing to give more clearance from the blade.

3. Push it to the curb and buy the Rikon 18"er from my local Woodcraft for $1049 + tax. (Sadly, this is the absolute least probable.)

4. See if there is a slightly smaller blade option.

Thoughts? Opinions?

[John Coloccia]

Just order a 104.5" blade. I don't think I've ever bought a blade off the shelf. I pick out what I want, and order the blade in the size I need. No problem whatsoever. The only reason anyone sells blades precut is that there are a handful of sizes out there that are very common.

[Michael Dunn]

So, it seems that this Shop Fox, as well as the Grizzly, and the Jet 6" riser block all require a 93 1/2" blade before being modded. From 93 1/2" to 105". So it stands to reason that I should order some 104"'s, right. Or 103"'s.

Whadday tink?

[Michael Dunn]

It seems that the blade is more than 1/2" too long. I'm thinking 104" or maybe 103 1/2".

[Phil Thien]

Just order a 104.5" blade. I don't think I've ever bought a blade off the shelf. I pick out what I want, and order the blade in the size I need. No problem whatsoever. The only reason anyone sells blades precut is that there are a handful of sizes out there that are very common.

This is the correct answer.

Bandsaw blades are relatively inexpensive. You can order several and have spares on hand. You needn't worry about it being a non-standard length at all.

[John Coloccia]

It seems that the blade is more than 1/2" too long. I'm thinking 104" or maybe 103 1/2".

Yeah, it seems that way, doesn't it? Looks that way on the pics too. I wonder why. If 92.5 worked, it may have been right on the edge. I would be tempted to try a 104" blade. The only danger is that the blade is too short to fit around the wheel. You can just wrap a string around it and measure.

[Grant Wilkinson]

If you are going to order a custom length blade, measure the length using a piece of string, with the adjustment just off it's minimum.

[Michael Dunn]

If you are going to order a custom length blade, measure the length using a piece of string, with the adjustment just off it's minimum.

Great minds think alike. I just did exactly that. I measured about 102 3/4" actual. I just ordered some 103" wood slicers from Highland WW.

Do you think they'll do a custom 103" in 3/4" width? For 3/4" it starts at 105". I put the request quote in. We will see.

[John Coloccia]

It bothers me that you seem to have lost a couple of inches somewhere.

[Michael Dunn]

It bothers me that you seem to have lost a couple of inches somewhere.

Well, this isn't the typical Taiwanese type BS I guess. Most other stock 14" saws use a 93 1/2" blade. Mine has always used a 92 1/2". 105" is the typical blade length for a 93 1/2" + 6" riser block. Where as mine is evidently a 103". We will see.

I'm pretty confident that it will fit. I just hope that I can get this blade tracking issue sorted out.

Hopefully it was just some crappy blades from ptreeusa. They're all I've ever used. Before the riser block I out on my 1/2" blade (had a 1/4" on for the last 3 years) and it was even worse. The weld wasn't perfectly flat, but the back of the blade seemed flat. Yet, it was not even coming close to tracking properly.

[Myk Rian]

Guide post? Don't you mean the connecting bolt?
That saw WILL NOT tension a 3/4" blade. 1/2" max.
92 1/2" + 12" = 104 1/2". You sure a 103" will fit on the wheels?
If you put another 1/4" added to the riser, you can buy standard 105" blades.

[Michael Dunn]

I measured it with a string. Perhaps this has been my problem all along. I've always had it tensioned at the max. I never felt it was enough. I guess I should cancel the 3/4", eh?

[Michael Dunn]

Guide post? Don't you mean the connecting bolt?
That saw WILL NOT tension a 3/4" blade. 1/2" max.
92 1/2" + 12" = 104 1/2". You sure a 103" will fit on the wheels?
If you put another 1/4" added to the riser, you can buy standard 105" blades.

No. The connecting bolt is perfectly installed after slightly modifying my CI upper and lower arms. I mean the guide post that I adjust up and down depending on the thickness of the workpiece. The part that holds the guide block and thrust bearing assembly. I call it a guide post.

[Tai Fu]

if it's just a touch too short why not cut your existing blade and silver braze it back on?

[Michael Dunn]

if it's just a touch too short why not cut your existing blade and silver braze it back on?

I don't have any welding tools or skills.

[Tai Fu]

All you need is a propane torch, and a bandsaw splicing kit from lee valley.

[Myk Rian]

No. The connecting bolt is perfectly installed after slightly modifying my CI upper and lower arms. I mean the guide post that I adjust up and down depending on the thickness of the workpiece. The part that holds the guide block and thrust bearing assembly. I call it a guide post.
There should be a longer one with the riser kit.

[John Coloccia]

There should be a longer one with the riser kit.

I think his problem is the new one is slightly too big.

[Michael Dunn]

I think his problem is the new one is slightly too big.

That is correct. I'm standing a local machine shop now. They seem to be willing to help. I'll post pics in a bit.

[Michael Dunn]

They said he'll do it for $75. I countered with $40 and we agreed to $50. That was a bit more than I was hoping for, but oh well. I wonder if I should've just ordered the reamer from Grizzly?

I shudder at the though of how much money I've thrown away with the BS.

[Michael Dunn]

Well, it's done. $50. It firs perfect and looks perfect too. One problem... I forgot about the guide block assembly!!! What an idiot!!! I can't believe I forgot that!!!

[Michael Dunn]

It's a good thing I don't throw any old parts out. I went through my parts bin and found the original guide assembly that mounts to the guide post. It fits perfectly. I just made some ZCI's on my CNC mill and now I await my new blades. Hopefully on Wednesday. I sure hope this saw cuts well now.

[Mark Bolton]

They said he'll do it for $75. I countered with $40 and we agreed to $50. That was a bit more than I was hoping for, but oh well. I wonder if I should've just ordered the reamer from Grizzly?

I shudder at the though of how much money I've thrown away with the BS.

Wow, screaming deal. Around here unless you find someone working out of their garage your going to pay close to 100/hr for any machining and likely a 1hr minimum which is fair in my opinioin. I recently had a 16 spline metric sheave bored, bushed, welded, and keyed to fit a Leeson motor and it ran 400 bucks.

[Michael Dunn]

Wow, screaming deal. Around here unless you find someone working out of their garage your going to pay close to 100/hr for any machining and likely a 1hr minimum which is fair in my opinioin. I recently had a 16 spline metric sheave bored, bushed, welded, and keyed to fit a Leeson motor and it ran 400 bucks.

That makes me feel a wee bit better. Thanx!!!