Band Saw blade guides?

[chrisinnh]

Hello!

This question isn't a super good fit for this forum, but recent threads (TSC Bandsaw and Cutting fluid) have shown that there is plenty of expertise around here.

I recently scored a DoAll C-4 9x12 horizontal bandsaw on Craigslist. Here's a shot of one of the blade guides.

The blade runs between #12 and #14, with pressure controlled by screw #8 and belleville springs #9.

Well, before I got it, somebody backed out the screw to fuss with the blade, and #12 got lost on both guides.

I called DoAll, they want $66 for a little rectange of metal with a hole in it!

I was thinking I could just make a new one out of mild steel, but wanted to collect some group wisdom before I head down a road that will cost me more in bandsaw blades than I would have spent on a couple of blade guides.

Thoughts?

Thanks very much.

 

[3RRL]

That saw you got is a very good one. It is a smaller industrial saw and should be a great asset to you. I wish I had one! Does it use 1" or 3/4" wide blades?

I'm pretty sure you can do that with no problem. The older DoAll uses that piece as a wear piece anyway. Your blades are much harder than the mild steel. You could consider silicon bronze as a wear piece too. One thing I didn't get from the parts view is how the roller is adjusted? And there is only one roller. So #12 must be a wear piece that allows the blade to be positioned for the roller to work.
Most newer saws have 3 rollers. Two that capture the blade like your roller and adjustment wear piece, and one on top that adjusts cutting pressure. On my Well's saws, the top pressure roller was hydraulically adjusted. They were very expensive industrial saws and fully automatic.

Anyway, IMHO think you will be alright making your own.

 

[ToadHill]

I use nylon wear pieces on my saw.

 

[sandman2234]

I would imagine that the roller is set up to run on the back edge of the blade, and the wear plates on the side of the blades.
I didn't see your saw listed, but you can probably find more about it from doall. (DoALL Sawing - Home) You probably already knew that since you have talked to Doall.
I would think that #12 would be easy to make even if you had to use a hacksaw,a hand drill, grinder, vise and a tap. There just isn't that much to it, so you won't have a fortune in it in materials if you do mess it up. You might have to buy the right sized drill and a tap but then you could make more of them in the future.
David from jax

 

[YanmarFever]

I used to buy blades on ebay in the hundred foot coil, then I would have them welded to size by a local saw shop. It was a whole lot cheaper !

 

[2manyrocks]

It's unlikely that both guides would be missing unless they were removed on purpose. Maybe they wore out or were taken off because somebody couldn't adjust the saw with them in place. I think you want to take a good look at the rest of the saw just in case there's something else to this that needs attention.

Whatever you put back, you don't want it to break the blade because it starts running into $.

 

[SPIKER]

not sure on you're saw, but on our saw and many like it they use CARBIDE as a wear surface due to heat resistance wear and a host of other items. The soft steel bronze ect can leave deposits onto the blade causing it to DRAG and or BIND between the 2 wear plates. also the carbide handles the excess heat that is generated without wearing too bad. if you try it and it works with no problems though have at it & let every one know.

mark

 

[sandman2234]

My Roll-In vertical saw has blocks as guides, that can be turned around to different sides, and each side has a different height step built into it, for different widths of blades. I have been considering using some rollers to replace them, so I don't get as many chips hanging up on the guides. Then I think about it a little while, and realize that if I would just hook up the air pump on it, I wouldn't have nearly as much problems with the stray chips. It would probably also make my tires last longer, as the chips tend to cut into the tires when caught between the blade and the tire.
David from jax

 

[chrisinnh]

Thanks for all of the replies!

It is a smaller industrial saw and should be a great asset to you. I wish I had one! Does it use 1" or 3/4" wide blades?

Yes, I'm very pleased to have it. DoAll told me it takes 131" blade either 3/4" or 1" wide and .035" thick.

how the roller is adjusted?

The roller doesn't get adjusted. It's not clear in this picture, but the roller sits up higher than I think you're assuming it does. The blade rides between #12 (adjustable position) and #14 (non-adjustable). The back edge of the blade rides against the "sidewall" of the #10 bearing.

#12 would be easy to make even if you had to use a hacksaw,a hand drill, grinder, vise and a tap. There just isn't that much to it, so you won't have a fortune in it in materials

Yup, no problem making a lump of something that measures .86"x.68"x.22" and has a hole in the middle. My dilemma is figuring out what to make it from, and where to get that material. The $66 pricetag made me wonder if these blade guides weren't made out of something pretty special.

It's unlikely that both guides would be missing unless they were removed on purpose. Maybe they wore out or were taken off because somebody couldn't adjust the saw with them in place. I think you want to take a good look at the rest of the saw just in case there's something else to this that needs attention.

I didn't get a blade with the saw, so somebody clearly was messing with it. The screw (#8) has a turned-down end which rides in the hole in #12. Ordinarily, it would be impossible to lose #12, but back that screw out far enough, and #12 can fall out.

There are a few other issues with the saw, other than the missing #12 and blade:

• The head hold-up mechanism doesn't work (mostly fixed)
• The head is loose on the frame, so it won't cut square without some fiddling (I think this is a shim issue)
• I need to throw together a coolant system (happy to have that other thread around)

our saw and many like it they use CARBIDE as a wear surface due to heat resistance wear and a host of other items

Interesting. Well, a carbide lump would be a little tougher for me to whip together -- Especially the hole in the middle

/chris

 

[sandman2234]

I think I would try a couple of other thing besides carbide, such as what 3RRL suggested, or maybe some green stuff. (Delrin??) Anyway, plastic stuff that has almost no wear factor, but easy to cut and machine. I could probably find a piece of plastic for you to play with if you are interested in trying that. Heat is hard on that stuff, so it might not work right. Have you considered asking Doall what the guides are made of? Since you already suspect them to be made of gold or platinum, why not ask them which? You might get lucky and get a good answer!
David from jax

 

[chrisinnh]

Have you considered asking Doall what the guides are made of? Since you already suspect them to be made of gold or platinum, why not ask them which? You might get lucky and get a good answer!

I tried that route. First go didn't get me any further than "it's in stock". After being escalated to a support engineer, the question immediately devolved into "it's just $66, why not just buy them?", but I got no info on the material.

I think the DoAll support line is accustomed to talking to production shops, not joe homeowner who will make less than 50 cuts a year, and would rather fuss around with making his own guides.

/chris

 

[chrisinnh]

if I would just hook up the air pump on it, I wouldn't have nearly as much problems with the stray chips. It would probably also make my tires last longer, as the chips tend to cut into the tires when caught between the blade and the tire.

Later models of my saw had a pair of wire brushes which cleaned chips off the blade before it got to the bandwheel.

It's hard to tell from the parts book, but it looks like it was a couple of tiny carwash style brushes driven by a flex shaft which was powered by the bandwheel.

/chris

 

[sandman2234]

One place that you might get a good answer is on the Chaski board. The moderator spend a lot of time rebuilding a vertical Doall and somebody on there probably already knows the answer.
Here is his saw, which is the same machine I purchased in Sarasota, Fl with a welder for $100.

doall

Chaski website
The Home Machinist! :: Index

David from jax

 

[laurencen]

I had wear plates on mine and replaced with a couple of roller bearings, you will require a brush of some kind to stop filings building up, you can use the saw without these guides as long as the cutting pressure is low, the blade will twist as it increases, anything will work such as brass or steel, materials such as aluminium will gumm up without coolant, try a piece of steel plate, allow about 0.01" clearance and should be good

 

[Egon]

My bandsaw knowledge is limited but:

I'm wondering why the roller #10 is not adjustable. If different blade widths are used this should be movable to keep the blade centered on the tires.

I'm guessing the blocks are missing because they may have been hitting the blade teeth.

My inexpensive three speed wood/ metal bandsaw has the roller guides. It has never been used for metal.

 

[sandman2234]

I would think 10 would be adjustable, if nothing else but a spacer/washer under it. My Roll-in is adjustable via the screw that goes thru it (11) without using washers,etc. If my DoAll was here, I would snap a picture of it, as it might help. It is about 30 miles north of here in a friends shop.
David from jax

 

[chrisinnh]

Bearing #10 is not adjustable.

This is a horizontal saw, so the blade has to twist 90 degrees between the idle bandwheel and the first guide, then back again after passing through the second guide.

The implication of that twist are:

1. The saw can't run without the missing #12, because it and #14 provide the twist. With either of those missing, the blade would twist back, cutting up the guide arms.
2. The #10 bearing doesn't control blade tracking on the bandwheels. #12 and #14 do that.

 

[Egon]

So much for my limited knowledge!

 

[Danno1]

.

Nylon is OK but UHMWPE would be best. You can buy it fr McMsater-Carr.

.

 

[JSharp]

I second the UHMW polyethylene if you're going to use plastic. It's the right stuff for that sort of thing and better than brass or other soft metals in most applications.

Any way to modify the guide or fabricate some new parts to take 2 more roller bearings? The life and precision will be much better than any sliding setup.