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Jaco

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I have a Rockwell 16” scroll saw.
Busy cutting out a lot of animals for door stops. Some fine cutting required.
Using Afr Rosewood and some oak about 20mm thick.
I can cut about 2 shapes, then the blade starts ”bending” and breaks.
Drill lots of holes around the shape.
Some advice please.
What blade should I be using?
What speed should it run at?
How fast should one “feed” the stock?
Thanks
Phil
 

Gill

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Hi Phil

I've never used a Rockwell or cut rosewood, but I have made some fine cuts in oak. Your saw should be capable of handling hardwoods less than an inch thick, so the chances are the saw isn't the problem.

How do you mean that after cutting a couple of holes the blade starts 'bending'? This sounds peculiar. It makes me wonder if your blade is sitting square in the blade holder.

With scrolling, there are so many variables that it'll be difficult to identify one cause of your problems. The first point I would consider would be the tension of the blade. If it's too taught, the blade will break, so perhaps try to reduce the tension a little. I like my blades to be able to twist slightly when cutting but the amount of twist a blade will take depends on the tension and the guage of the blade itself. Obviously, a taut fine blade will be able to tolerate much less twisting than a loose coarse blade. Look at your cutting technique and see if you're twisting the blade as you turn the wood. If so, you'll need to either practise your technique so that you only turn the wood as you cut, or increase the size of blade or reduce the blade tension. You might also consider reducing the speed at which you feed the wood, although I doubt this will be a problem if you're holding the wood very lightly as you feed it. My advice is to support your hands at the elbows and wrists, don't allow them to rest on the wood - and it helps if you can keep your wrists above the wood, just like pianists keep their wrists above the keyboard.

You ask for advice about which blade you should be using - it would be interesting to know what you're using right now. Without actually seeing the design you're working to, it's difficult to know how acute the turns are that you're trying to make. Obviously, finer blades make finer turns. One way of telling if you're using blades that are too coarse is to use your nose! Sometimes there will be friction against the wood if you try to make too tight a turn and this will burn the wood. You'll be able to smell it. On 20mm oak you should be able to make quite fine cuts using a #3 but be prepared to use a #2 or even finer if the cuts are particularly delicate or the turns are particularly tight.

As for machine speed, again there's a lot of 'suck it and see' about this. Some scrollers like their machine operating at full tilt whereas others find that slowing the machine gives them more control. Generally, I find it better to slow the machine when I'm cutting fine material and speed it up for coarser. Right now I'm stack cutting plywood to a total depth of 8mm and find that 800 strokes per minute feels comfortable with a #3 blade. If you're cutting 20mm oak you'll probably find you'll need to go faster, possibly 1000 - 1200 strokes per minute. But much will depend on your personal preference. In general, it isn't the stroke speed that breaks blades, it's technique.

Finally, a point about selecting blades. I'd suggest using good quality milled blades from a reputable supplier such as those listed in the Scrollsaw Challenge thread. My personal preference is for the Olson blades (sometimes Hegner - they're good too), but if I have to make fine cuts I switch to Hegner because Olson don't make blade finer than #3 IIRC. I've used Flying Dutchman blades and many scrollers swear by them; for myself, I find they've got too much bias to the right. That said, I've got some types of FD blades that I haven't tried yet and I might find their performance is better.

Hope this helps.

Gill
 

Lin

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Phil, Gill has about covered everything I could think of. I only have a couple items to add to the long list of possibilities. Both of the species you are using tend to burn and will wear down a blade quicker. Using a lubircate may help if you are not already doing so. Shipping tape on top of your pattern or bees wax applied directly to the blade will act as a lubricate. The other thing I want to point out.....Blades will only last so long. If you can cut on the same blade for 30 minutes you are doing well. I very seldom break a blade any more because as soon as I detect the bend you are speaking of and I'm having to push harder to cut I change my blade. This may not be the case with what you are cutting but thought I should throw it out. Blades are cheap in comparsion to the wood and your time.....If you are just doing shapes....you may be able to get by with a #5 or even a #7 if the turns are not extremely sharp. I have found a #5 olson can turn a fairly sharp turn if your spinning technique is up to par. The FD blades the Gill spoke of will last longer cutting but like say has said I also find them a bit harder to control.
Would love to see some pics of your cuttings.....
Lin
 

Jaco

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Hi Gill & Lin
Thanks very much for a very comprehensive reply. Appreciated.
The project is animal doorstops (see Aldel thread), so it’s not such major intricate cuts, just some fine detail.
I am using a #12 blade, not sure of manufacturer, as they are pre-packed by my local supplier.
The speed is about 800 CPM. I can go faster by changing pulleys.
The saw does not have any fancy adjusters for tension. You fit the blade in the bottom clamp while at its lowest point, then turn the pulleys to raise it till it goes into the top clamp. Then tighten screws and you are ready to saw.
The bending happens while doing a long cut, blade seems to bind in the wood. Also getting some “burn”.

Did a whole lot more yesterday afternoon with greater success. I have started cutting smaller sections, patience. Starting to get the feel of going around corners, patience. Trying not to “reverse” out of a cut, patience. Also not trying to force the wood through, but let it flow, patience. Will definitely look at some form of lubrication.
Conclusion – I am the problem not the machine, patience.

Will post some pics if I can find where I stored them on my PC.
(Mutter, mutter – so many empty beer cans, no wonder I cant find the pics)

Again, thanks.
Phil


:D :D
 

Gill

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Hi Phil

Thanks for the update. I'm sure you'll soon get the hang of it :) - scrolling isn't difficult, it just takes a bit of practice and a bit of confidence.

I wasn't aware that #12 blades are available until I read your post! Then I checked on Mike Moorlach's Flying Dutchman site and, sure enough, he sells #12 blades. These appear to be the largest blades available so it might be worth using a smaller guage, such as a #7 or #5. You'd be able to turn corners much more acutely and there'd be less friction on the blade. Burning would be less of a problem.

Incidentally, if you do get some burning, the heat will take the edge off your blade and reduce its longevitiy.

I'm looking forward to seeing your piccies :) .

Gill
 

Lin

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Phil, I don't mind pics of the beer cans along with your "Door Stops".....Free Beer......why not?..... :lol:

If you are bending on the long cuts you are probably pushing to hard and not letting the blade do the work....not giving the blade time to do its work will cause it to bend and bind..... Sounds to me as if you have just about gotten it figured out and under control. Check with your other half and see if she has some bees wax stored in her sewing kit to help the burn. I would use the clear shipping tape....even two layers of it if need be.on top of the patterns also for burning. I have in the past had to double up shipping tape on 3/4" purpleheart to keep the "Smokin" down to a minimum. Not a nice thing to see puffs of smoke coming off your piece while cutting...
Lin
 

Jaco

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Gill / Lin, thanks.
Will try a smaller blade.
Cut another piece of Rosewood (great smell) last night. LOTS of smoke!
Needs a lot more patience and practice.
Checked the blade tension, can give it a slight twist.
I have searched the PC, but still cant find the pics. Will do them again over the weekend.
Have a great day.
Phil
:D :D
 

Jaco

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The sawing went a lot better this weekend. Broke far fewer blades and a lot less burning.
The burning was mainly on the oak and Rosewood. The Kiaat not a problem.
Also seem to spend more time sawing than filing and sanding afterwards, a GOOD sign?:D
All done on the # 12 blades.
Will get some more blades tomorrow at our local supplier open day and demos.
Did a stack of door stops and then just cut out animals from too small pieces.
It is actually great fun. I even emptied out the off cut and real rubbish boxes to look for more pieces to cut out.

:D :D :D

Cut out Snail doorstop.





Cut out Duck.



The "Team"

 

Gill

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Jaco":105q5cq1 said:
seem to spend more time sawing than filing and sanding afterwards, a GOOD sign?:D
Definitely! 8)

My goodness :eek: ! You have been productive. Those doorstops look great but you'll either have to get a mansion to put them all to use (don't tell me you've already got one :roll: ) or get a stall at a craft fair. Actually, they'd make nifty little gifts too.

Jaco":105q5cq1 said:
It is actually great fun. I even emptied out the off cut and real rubbish boxes to look for more pieces to cut out.
Woodworkers can slide down more than one slope ;) :D ! If you need a little grease, let me know and I'll find you some patterns.

Gill
 

Jaco

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Gill, thanks.

These are now part of the pressies collection, i suspect that family & friends wonder what i will hit them with next!

I will take you up on your offer, as long as the patterns dont involve too many blade changes.
Its a bit of a mission on the saw.

I based the stops on that post by Aldel of about a year ago.
Now running out of scraps, need to do some other projects to generate more.
Also make Tea-Candle holders with scraps.
Cheers
Phil
:D 8)
 

Lin

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Jaco, Was amazed when I saw the pics.....Surely didn't realize you had been that busy. I like the doorstops.......Very neat idea. Possible patterns with few blades changes may be some ornament patterns.....Will look at the patterns I made last year and see if any are appropriate for what you are after. After all........x-mas is just around the corner now. I'm gathering thin cut offs to start on the tons of them I cut each year.
Another possible idea for zero to very few blade changes would be jigsaw puzzles.....Just a thought.
Thanks for posting the pics....Very nice........but where my "Free Beer"? :lol:
Lin
 

Jaco

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Thanks Lin.
Between Gill & yourself, i could be kept quite busy! :D :D :D

Here is the beer.
(I am considering installing one in my workshop. 8) 8) 8) )

 

Jaco

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Progress!
Cut out a simple puzzle of a mother Roo & baby. Looks good.
Used 9mm ply. Will also do some animals from the scraps.
Also cut out a Bob Grandpa puzzle. (will keep quiet about that one)
:D :D :D
 

Gill

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Jaco":hwy0k543 said:
Progress!
Cut out a simple puzzle of a mother Roo & baby. Looks good.
That's good news but where's the evidence? Come on, you know how nosey we all are ;) :) .

Gill
 

Jaco

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Gill, run out of space on my "FREE" pic site.
Will make space during week & post.
Going to oil this afternoon. All i am capable of after all this wine.
hic, hic. :D :D
 

Lin

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Jaco, Thanks for the "Beer".......lol
Looking forward to seeing pics of your puzzles......BTW
I just posted a "Wolf" scrolling pattern in the "Scrollsaw Challenge" post if you have an interest in trying it out.
Lin
 

Jaco

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Thanks Lin, will have a look.
Not quite sure my skills are up to "anything" far too complicated, other than animals & large piece puzzles!
Cheers
 

Kev

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Jaco

Not much experience of using a scroll saw (only just bought my first one and not used it yet) so cannot give you any advice but just wanted to say liked the door stops. Never an excuse to have a door closed in your house!
 

Gill

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Kev":3eae0xdu said:
Not much experience of using a scroll saw (only just bought my first one and not used it yet)
Yippeeeeee!!!! Another scroller (in the making) :D !

Pray tell; what saw and why haven't you used it yet? If there's anything I can do by way of support, providing patterns or merely offering encouragement, just let me know :) . If you're too embarrassed to reveal details in public, send me a private message so that we can both have a quiet chuckle.

Gill
 
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