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View Full Version : Bandsaw blade guide - what metal



RichTes
04-22-2009, 01:45 PM
Stole this pic off a woodnet post. Looks simple enough to make from scrap I have around:

http://farm4.static.flickr.com/3602/3463996689_6f55ca8f36.jpg?v=0

What would be the best material for the guide part?

Thanks,
Rich

CCWKen
04-22-2009, 02:09 PM
The OD of ball bearings are usually used for the guides but in the case of your picture, I'd use brass or bearing bronze. The setup appears to be adjustable for wear.

Evan
04-22-2009, 02:37 PM
Look up "cool blocks". They are made of graphite impregnated phenolic and are what the sawmills use as bandsaw blade guides.

rotate
04-22-2009, 03:00 PM
http://www.leevalley.com/wood/page.aspx?c=1&p=30072&cat=1,41036

If you want to make it out of metal, I would choose steel. Steel to steel when lubricated has one of the lowest friction compare to steel and other metals.

kf2qd
04-22-2009, 03:03 PM
Cool Blocks are the best. Next up would be tool steel blocks. Any steel that isn't hardened will rub and wear too much causing all kinds of problems with metal transfer to the blades and it all goes downhill from there. Maybe some hard bronze would work.

kendall
04-22-2009, 03:47 PM
The guides on my band saw (a 'big' 12) are a pretty hard bronze.
When I picked it up they were badly worn, but I filed them flat and they don't show a lot of wear after a year of using it.

I like the looks of the guides shown, they seem like they would provide a lot of support and a decent wear surface.

I feel that the guides should be much harder than the blade, keep most wear on the blade, not the guides.

tried the cool blocks on another saw, and while they worked nice, it seemed that they wore quickly and needed more frequent adjustment. Plan to pick up another pair and try them on this saw to see how they work out.

Ken.

Evan
04-22-2009, 05:04 PM
Tell you what, before anybody spends money on blocks let me hack up some pieces of that ridiculously hard bronze I have and I will send them out to whomever needs some. There will be a limit determined solely by how many pieces I can get out of one slice off that big block. When I tried to cut it with my bandsaw the blade just sat there and skidded on it. It didn't even take the edge off the teeth and in about an hour or so it managed to cut less than 1/4". I'll cut some up on the weekend when I finish setting up my new 'puter. I will have to make a special carbide parting tool to slice up a stick into squares. I'll start a thread to hand them out then so don't start messaging me now. My box is almost full anyway. :D

I will send out pieces suitable to face a guide since that is all you need and will cut shipping cost on my end. I will pay the shipping.

If you want some then post here what size of block would be most suitable for use and I will take the largest and use that as the dimension to cut to.

gnm109
04-22-2009, 06:50 PM
The guides n my 1972 Rockwell Delta woodcutting bandsaw are mild steel as far as I can tell. There are two above the table on top and two below on the bottom. They are still working fine. They don't touch the blade all that tightly and as mentioned above, there's not a lot of friction. The only time I've adjusted them is when I change to a thicker or thinner blade.

DR
04-22-2009, 07:38 PM
The guides n my 1972 Rockwell Delta woodcutting bandsaw are mild steel as far as I can tell. . ............................................
.

Likewise, from the factory on my Powermatic 14" wood/metal cutting saw.


"Cool blocks"??? Never tried them, only seen them in stores. As I recall, they looked like chunks of G10 plastic.

Why are they "cool"? Cool running? Or cool as in neat?

I've never checked, but do the side blade guides ever get hot?

Frank Ford
04-22-2009, 07:55 PM
The guides n my 1972 Rockwell Delta woodcutting bandsaw are mild steel as far as I can tell.

I have two wood cutting Rockwell 14s (I bought 'em new in 1970 & 1971) and one 1943 Delta 14" metal cutting saw. The blade guides are all original, in good shape and hard enuf to scratch file. . .

I'll never understand that back bearing, though. The way the blade scrapes across it never made any sense to me.

Evan
04-22-2009, 08:09 PM
Why are they "cool"? Cool running? Or cool as in neat?


Cool as in low heat. It's phenolic filled with graphite. Graphite has remarkable lubricant properties because the atoms of carbon are tied together strongly in sheet like layers but loosely between layers. The bonding forces are largely confined to a 2D plane. It has the advantage of not injuring the teeth if the blade should become misaligned.

Other than that then the best results for blade guides are something very hard and polished. Naval Bronze or tungsten carbide are good choices. It generally is not a good idea to run like materials together as that promotes galling since like materials can be cold welded. If like materials are run together then one should be much harder or, in the cast of cast iron, contain free graphite. A very good choice for blade guides would be O6 tool steel since it contains an excess of carbon which gives it it's excellent machining properties. It's expensive though and hard bronze or tungsten carbide will work fine.

lane
04-22-2009, 08:11 PM
The guides on my big Grob band saw are made out of ammco 18 .And do not seem to wear. You could also use Kromite Very wear resistance.

wierdscience
04-22-2009, 10:11 PM
Carbide guides are the ticket,square c2 insets brazed to mild steel.They do last nearly forever.