bow saws and frame saws

[condeesteso]

Hi all - I soon plan to make myself a frame saw, probably a 600mm to start, maybe a bigger 700 later. Jim's bow saw inspired me, but Frank Clausz did a feature on the big ones in Pop Woodworking ages ago and I have fancied a bigger frame saw ever since.
QUESTION - when the bow saw was discussed here, BB I think mentioned a taper fit for the blade fixing shafts at both ends (OK - what's its name then :lol: ). As I am considering finding a model engineer to turn up those components for me (the guys that build miniature steam engines etc) I don't want to experiment re taper -any ideas what may be right. I am assuming a hardened brass with steel pins for the blade, and suspect the taper should be reasonably steep to avoid it jamming / locking up. The taper is there to hold blade angle once you set it and tension the saw.
Dieter Schmid has the blades I think:

http://www.fine-tools.com/gestell.htm

The frame is interesting - I would use yew if I could find the right bits (Jim won't mind ) - and aim to keep the weight down. Traditional cord tensioning with sliding toggle so you can make 1/2 turn adjustments.

Any ideas, particularly re the taper??

 

[Harbo]

Tools for Working Wood used to have some downloadable plans for a bow saw with tapers?

Rod

 

[bugbear]

Tools for Working Wood used to have some downloadable plans for a bow saw with tapers?

Rod

No - their pins are paralllel.

Here's my minor contribution to hand tool woodworking on the web;

http://web.archive.org/web/200901140658 ... owsaw.html

Several people (see the gallery at the bottom of that page) have found this plan worthwhile.

BugBear

 

[SurreyHills]

The Rennaisance Woodworker did a video blog of his bowsaw build. Go to http://www.renaissancewoodworker.com/?s=bowsaw for the full story.

 

[woodbloke]

I made a frame saw a while back and the handles (if that's what you're referring to) weren't tapered...I just turned them parallel. The pins to fix the blade to the handle were just some bits of 3mm silver steel and the blade was a bit of an old Tuffsaws bs blade that Ian sent me. Instead of going for the traditional cord tensioning method I used a bit of 6mm studding and butterfly nut. The frame was made out of a couple of oddments of ash with a mahogany stretcher. It was a nice little exercise to make it but I've never used it in earnest. It's almost identical to the one's shown at the bottom of that linkie - Rob

 

[jimi43]

The idea of slightly tapered shafts makes sense indeed and you can lock them in at whatever angle you want the blade to be by just tensioning up.

I will be watching the WIP with interest Douglas...I assume you will be doing this after you finish your bench? :mrgreen:

Jim

 

[RogerP]

Here's that Frank Klausz bow saw/dovetail link again in case anyone can't find it.

 

[woodbloke]

Here's a couple of pics of my saw:

showing a general shot of the whole thing and a detailed pic of the blade and handle arrangement - Rob

 

[kirkpoore1]

I don't think the taper is needed. The tension will keep it tight enough that the blade won't rotate unless you turn it by hand. Here's a couple of pics of mine:

I didn't even have a lathe when I built it--the shafts are not turned, I rounded them with a spokeshave and chisel. The blade is a 3/16" x 18 tpi bandsaw blade with a hole drilled in each end, and pinned with small cut off nails. I've worked it hard for a good 15 years, and it's been good the whole time. The frame is white oak, from some scrap I had leftover after a project.

Kirk

 

[condeesteso]

Thanks everyone - Some very good looking saws there!
I got interested in a mention of a tapered fit as I have a Gramercy 12" (very fine indeed) but using the fine blades I dare not tension too much, and at angles (worst at 90 degrees) the tension is not enough to lock the blade angle. I know there are ways of holding it to overcome this, but I want to go back a step and design that possible issue out. Particularly on a frame saw (600mm+) you want to hold it many different ways and 2 hands on the handle + frame is not always the way.
Have looked at links - Renaissance is using the Gramercy (Tools for working wood) pins I think (sound was off, too early!!). The 30's one used parallel pins too.
I am considering taking the Gramercy as a start-point, but beefing the whole thing up, extending the pin deeper into the handle, threading it (about M6) and having a bonded captive nut in the handle - a half-turn to lock, say - both ends. This is beginning to become quite easy for someone to turn up I think (small diameter tapers likely to have been an issue).
I think the woodie side of these is a nice shop-made project, so it's really just the pin / blade mount.
I like the Gramercy slot so the pin is tensioned both sides, but these wider blades could do with a greater seating area.
Douglas fir is used on premium wood archery arrows, and following the bow-saw thinking, arrows are pretty good under compression I imagine (Robin splitting the tree and all that. By the way, in Nottinghamshire they are known as arrers, sing. arrer). I digress.
Maybe douglas fir for the stretcher - I would be aiming to keep weight down to a reasonable minimum, especially away from the blade axis. But dense hardwood for handles, to add mass on-axis.
Another option for stretcher is bamboo (arrows again) but laminated... maybe not pretty enough though. Also consider hornbeam, as the handles on my Lie chisels are very light and do take a whacking. (Do they call it iron-wood in the States?)
I will start by ordering a few blades (600mm for now) and then try and find a metal turner to make me a few bits. There are some model train blokes near me... need to go have a chat.
More news later, but it'll be a slow one... bench to finish etc.

 

[MIGNAL]

The taper on mine is 1:30. This was on an old Bowsaw that I picked up over 30 years ago. It was a rather elegant model, almost certainly user made but extremely well crafted. I made a beefed up version but used straight pins. It was hopeless in use, the blade wandered of it's own accord. I 'borrowed' the handles/pins from the old bow saw and reamed the parallel holes with a Violin peg hole reamer. Perfect fit! Unfortunately such reamers are very costly. The ones sold for engineers are much cheaper but I've no idea of their taper. The other alternative is to grind down an old file, tapered and with 4 'cutting' edges - scraping would be a more realistic description. Might be crude but there is no reason why it shouldn't work.
I've also made wooden reamers for opening up the bore of flutey type instruments. With a wood lathe they are pretty easy to make but I have my doubts that they will work on such a small diameter found on Bow saw pins.

 

[woodbloke]

I don't think the taper is needed. The tension will keep it tight enough that the blade won't rotate unless you turn it by hand. Here's a couple of pics of mine:
Kirk

Agreed...these are pretty basic saws that have remained in use and unchanged for around 2000 years. It's known that the Romans used these types of saws and I'm pretty sure that they didn't bother unduly with tapers etc to lock the blade in use. Why make life complicated when simple works?...and has done for two millenia - Rob

 

[MIGNAL]

I think a lot depends on the amount of friction ie. where the handles meet the frame. In my case (thin turn saw blade) this friction was not great enough. Going to tapered rods was a huge improvement, no question about it. I don't think it was complicating matters just for the sake of it either. Someone obviously came across the same problem, as evidenced by my old Bow saw. There may be simpler ways of increasing the friction. I have heard of placing a leather washer between handle/frame.

 

[condeesteso]

Mignal - I am with you, absolutely. I think some way of locking the blade orientation especially when at angles is a very good thing, so I have every intention of doing something that will achieve that yet remain fast and easy to use. Whether that ends up just friction (unlikely for me) or taper, or locking handles etc is yet to be decided, but it will have a way of locking it.

 

[Alf]

Somewhere or other, I forget where, I came across the suggestion of using O rings to keep the handles from slipping. Not tried it myself, but fwiw.

 

[jimi43]

I don't see reaming a taper as a major problem....and I would assume the angle akin to Mr Morse would be the optimum as it seems to work for lathes :wink:

Just so I don't forget to ask Douglas....can you get me a couple of 300mm ones too and I will pay you on Thursday (mmmm...where have I heard that before...AH! I remember...please don't think me WIMPY!)

Wimpy- "A genuine hamburger for the Gentleman. I'm buying."
Random dude- "Gee thanks."
Server dude- "Who's paying?"
Wimpy- "I'm buying. He's paying."

:mrgreen: :mrgreen: :mrgreen:

And I ain't paying you in screwdrivers....just before you ask you understand! :mrgreen: :mrgreen: :mrgreen:

Jim

 

[condeesteso]

Dear Jim.
No.
See you Thursday.

 

[pedder]

I got interested in a mention of a tapered fit as I have a Gramercy 12" (very fine indeed) but using the fine blades I dare not tension too much, and at angles (worst at 90 degrees) the tension is not enough to lock the blade angle. I know there are ways of holding it to overcome this, but I want to go back a step and design that possible issue out. Particularly on a frame saw (600mm+) you want to hold it many different ways and 2 hands on the handle + frame is not always the way. Have looked at links - Renaissance is using the Gramercy (Tools for working wood) pins I think (sound was off, too early!!). The 30's one used parallel pins too. I am considering taking the Gramercy as a start-point, but beefing the whole thing up, extending the pin deeper into the handle, threading it (about M6) and having a bonded captive nut in the handle - a half-turn to lock, say - both ends.

Hi Douglas,

why looking for metal pins, when they cause the problem of the spinning blade? The classic design for big bow saws is with wood blade holders (the turned part are not the handles of a big bow saw.) The classic design is tested for a very long time and it works well.

Maybe douglas fir for the stretcher - I would be aiming to keep weight down to a reasonable minimum, especially away from the blade axis. But dense hardwood for handles, to add mass on-axis.

Douglas fir is a very good choice.

Cheers Pedder

 

[condeesteso]

Hi Pedder - that is a very good point, and I noticed one or two frame saws (above, and on my internet travels) with hardwood 'pins'. I think there is enough evidence that people way before me have explored ways to lock any possible rotation of frame to blade. I consider it an issue, but wood for the pin, then maybe inset metals (non-ferrous I suspect) around the blade support area, is promising. I shall look some more and ponder. In particular, I will now ponder the mating of a hardwood pin with enough metal to secure the blade end precisely and without wear.

Or there is a neat shortcut. Pedder, do you make frame saws?? (and can I afford them... :lol: :lol: :lol: )

If not, maybe you should, because they are possibly back in fashion:

- hugely versatile
- low-cost disposable blades of very high quality
- one saw does several jobs (with several blades: rip, cross, contour etc)
- they make the user look like he knows what he is doing (that was flippant, but mildly true)

 

[pedder]

Hi Douglas,

no, I don't and other than the kit with metal pins, wich i never finished, I won't make a bow saw in the foreseeable future. Why? Because Ulmia continues to make them and so does ECE. These saws sell for less than 20€ usually on german ebay.And they work a charme. I'vee several in my workshop.

But if you are looking for an high class bow saw, have a look what Esat does:

http://www.woodworking.de/cgi-bin/forum ... read/53215

and the whole saw

more:
http://www.woodworking.de/cgi-bin/forum ... read/53221

http://www.woodworking.de/cgi-bin/forum ... read/53219

His metal pins probably won't spin.

BTW: Did you know that I started making backsaws because I thought icouldn't afford an adria. Sum the money up I've invested in saw making, I could have afforded a few dozen of them and a sawtill full from Mike on top.

Cheers
Pedder