Scroll Sawing blade knobs

[Herb Stoops]

A while back a fellow woodworker sent me a note about an upgrade someone did to his DeWalt 788. Seems as a Marcus Bailey has come up with a over sized knurled knob cap for the Dewalt Scroll saw.
They come in 2 sizes,1.125" and 1.00" , I bought 2 small ones, here are the pictures,takes about 2 min. to install. They are made to fit over the existing "T" knobs on the DW788. I looked him up now, but he is not listed anymore,however there are other companies making similar knobs that have the threaded stud on them.
These knobs are very much easier to tighten than the factory knobs.

Herb

[admin]

What do y’all think about the RBI Hawk? I picked a 26” model up for $200, unused by the original purchaser.

[Herb Stoops]

Wow That is a buy!!! if it is in serviceable condition, Like Unused. The 20" goes for around $500.
HErb

[Sominus]

It was literally never fired up by the original purchaser who died 2 months after purchasing it. It sat in his widow’s garage for 10 years before she sold it to me.

[Sominus]

What do y’all think about the RBI Hawk? I picked a 26” model up for $200, unused by the original purchaser.

Nick just did a passel of research into scroll saws...
shake his tree...

@nickp?

[Nickp]

RBI Hawk is a fantastic machine...early models had problems with the motor going bad. It was eventually fixed by replacing the motors at manufacturing. I got the information on Scroll Saw Village. I think I archived it, let me find it and I will post the info. $200 is a steal...! I paid 300 for my 20" and I know the 26's are higher. Even if you had to replace the motor it's worth it.

Story has it that the new owners Bushton Manufacturing http://www.bushtonmanufacturing.com/Web ... l-Saw.html are not very good at shipping machines or parts. A farmer family owns it and they don't seem to respond during farming season. I haven't had to use them so can't say one way or another.

Get the serial number and give Bushton a call...they will help to identify year, problems, etc...

Also, check out Scroll Saw Village for comments...I'll check for the motor info.

[Nickp]

Mike...here's a link from Scrollsawvillage that I started that might be a good read. The earlier motor that had problems is a FASCO...

[Sominus]

I don’t see a link, Nick...

[Herb Stoops]

@Stick486
It will work for all pinlessscrollsaw blades.
It uses the same OM knob inside the new knob.
Marcus makes them for quite a few brands of saws,contact him at scrollsawcomfortknob@gmail.com

[Nickp]

I don’t see a link, Nick...

Sorry...just saw this post...here it is https://www.scrollsawvillage.com/forums ... wk-220-vs/

...and mine is a 22" not a 20"...typo above...

[Nickp]

@Stick486
It will work for all pinlessscrollsaw blades.
It uses the same OM knob inside the new knob.
Marcus makes them for quite a few brands of saws,contact him at scrollsawcomfortknob@gmail.com

That's a nice feature...

[CharleyL]

For those metal knobs, I never bought any, because I don't think adding weight to the blade arms is a good idea. They could be used like a tool to loosen and tighten the DeWalt knobs and then removed instead of being left on there though. I never had any trouble loosening and tightening the DeWalt blade lock knobs, so never had a problem that needed fixing like this, but I can see how others with smaller and more tender hands than me might have a definite need for them. I just don't recommend locking them on and adding their weight to the already delicate blade arms and tiny bearings of the saw. Just use one to help loosen and tighten the existing knobs and then remove them before running the saw. He sells them in pairs, and you will only need one if used as a tool, so you can sell/give the other one to a friend who scroll saws, unless you tend to loose things easily.

Charley

[Cherryville Chuck]

I have a problem someone may be able to help with. i bought a used Delta 16" a few months ago with a quick change blade holder. It makes about a dozen cycles when I turn it on and the blade comes out and the lever on the quick change goes flying. Any suggestions as to why? Were they a problem and would I be better off trying to find a standard holder instead?

[CharleyL]

I have a problem someone may be able to help with. i bought a used Delta 16" a few months ago with a quick change blade holder. It makes about a dozen cycles when I turn it on and the blade comes out and the lever on the quick change goes flying. Any suggestions as to why? Were they a problem and would I be better off trying to find a standard holder instead?

Pictures would help. Are both the upper and lower blade arms moving together? Not sure what you mean by "Lever on the quick change". The blade tension lever? How about the model number, so I can look at an online manual?

Charley

[Cherryville Chuck]

I went out and took a picture of the part and forgot to double check the model but I think it's the SS250 Delta Shopmaster 16" Charley. In the picture you can see the lever sitting on table. The ears on it near the bend fit at the back of bracket on the upper arm. When you close the lever to hold the blade the ears spread the back of the bracket halves which squeezes the front part together on the blade. I did get it to hold together for a couple of minutes once while I sawed a test piece so maybe it's something I'm doing wrong.

[CharleyL]

Sorry, I can't see much from the photo. The lever that's lying on the table looks like the ones on my Delta Q3 saw that are for the blade clamps, but the blade clamp itself appears different. Can you take a couple of photos of the clamp actually holding the blade with the lever in place? Does the bolt through the center of the blade clamp have a small nylon insert stop nut on it?

I took my hold down fork off my saws as soon as I began setting them up. I tried using it on my first scroll saw back in 1955 and got frustrated with it quickly, so I've just held the work down with my fingers ever since then. I never had a saw where the blower hose was attached to the fork. It was always separate with a flexible area in it that let me position it where needed.

When putting blades in my Delta Q3, I move the tension lever forward (the big lever on left side of upper blade arm that swings forward and back) and then install the blade. Then, when the blade is clamped, I move the tension lever back. This is a tension on-off lever and not for setting the the correct tension). There is a tension setting Allen head screw sticking straight up out of the top of my upper blade clamp, and this sets the actual amount of blade tension. If I have too much blade tension, I move the side lever forward and then turn this bolt out a couple of turns, then move the tension lever back to see if the tension of the blade is right or too much. If still too much, I repeat the process. Or I tighten the Allen head bolt a few turns if the blade tension is too little, etc. when checked with the side tension lever fully back. The side lever for tension is just a tension on/off control and the actual tension is set with the Allen bolt on top, but only turned with my fingers and never when the lever on the side is back, holding the tension on.

The little lever lying on the table in your photo appears to be the blade grip lever, and both the upper and lower grips should both have this same style lever. Moving this lever forward and back closes the grip of the blade clamp. A square head bolt through the blade clamp with a nylon insert stop nut needs to be adjusted with the little wing wrench that comes with the saw to get the proper clamping force with the side clamp lever in the locked position. I keep my wrench magnetically stuck to the side of the motor when not in use. If it's missing, get a small open end/box wrench that fits these nylon insert stop nuts to use. You will need to adjust these with the clamp lever open, and then try closing the clamp on the blade that you will be using, and keep adjusting and trying, until the force of the clamp is sufficient to hold the blade tightly. The first set of these square head bolts began stretching and bending in a curve after I received this saw new. Delta sent me hardened replacements quickly, because they likely already knew that this was a problem. The new bolts have lasted 20 years or more. Too tight and the blade clamp lever can't be pushed to the lock position. Too little and the blade clamp won't hold the blade. Every time you need to change blade size, you will need to adjust these stop nuts slightly by turning the stop nut a little (1/8 turn is a big adjustment) so the lever will operate the clamp and lock in position, yet not be so loose that the clamp won't hold onto the blade.

Both the blade clamp adjustment and the blade tension adjustment need repeated practice to learn what works and what doesn't. It took me a while to get good at adjusting these. The DeWalt blade clamps and tension adjustment are so much easier to use that I rarely use my Delta Q3 now, preferring the DeWalt more because of these improvements, but both of my saws have done a great job, once adjusted correctly.

I hope this helps. Sorry that I didn't see your post sooner. If I ever fail to respond quickly, send me a PM and I'll see it faster. I'm still learning where things are on this site and how it works.

Charley

[CharleyL]

OK, I finally found the manual online. The website that I was trying seems to be down, but I found a manual on another website.

The Allen head bolt (blade tension set ) that I refer to that is sticking out of the top of my upper blade clamp has been replaced by a knob above and behind the blade tension on-off lever on the top of your saw. The blade clamps themselves appear to be nearly identical to the ones that I have.

The rest of my previous post appears to be the same. Again, understanding what each does, and then practice should get the results that you are hoping for. Delta's manuals never were much good and required clarification often. I can't see in the manual's photos a good picture of the blade clamp to see if it has the same nylon insert stop nuts on the bolts holding it together. I hope my description is good enough to figure out how to adjust the clamps for different blade sizes.

Page 13 of your manual (if you have it) talks about adjusting the blade clamps and the blade tension on your saw

https://www.manualslib.com/manual/37667 ... =13#manual

Charley

[Cherryville Chuck]

Thanks Charley. Yesterday was an all day town day but I'll try to get around to checking it out later after I do a few chores. It sounds like what I suspected, that there is a steep learning curve on how to adjust everything to the right tension. Trying to describe how much is enough or too much is pretty hard. That usually requires some trial and error. I have my swing arm bench lamps working now too and good lighting was the other thing I was needing to work on that. Those small parts all painted flat black were hard to see.

[CharleyL]

Do some test cuts with the blade tension a bit loose and notice how the blade bows backwards. Now add some tension and try again. It will always bob back slightly, but you want it to be a minimum, like maybe an 1/8". I've tried the "plinking method" where you listen for a certain sound. Even tried a microphone and oscilloscope, and then an electronic guitar tuner. None got me to where I could repeat the tension adjustment. Too tight and the blade grips don't hold, or the blades stretch and break quickly. Experiment like I did to minimize how much it bows back in the middle.

Scroll sawing is slow. Those tiny teeth on the blades don't remove much wood per pass. I treat scroll sawing as a journey, not a destination, enjoying the process of cutting and following the pattern lines, and striving for as much accuracy as possible. When the project comes to an end and looks good, I am happy, but want to immediately begin the next project and journey. If your blade burns the wood it is either dull or you are running the saw too fast for the wood. A little candle wax rubbed on both sides of the blade helps reduce burning by lubricating the blade. When using very tiny blades in very close pattern areas, I have also used a very fine tool makers stone to round the back edge of the blade. I don't like spiral round blades, but they do help to switch to them to clean out the very small pattern areas. I usually do this after completing the rest of the cutting with the regular blades. For large very delicate patterns, it helps to cut the center areas first and work outward from the center. This keeps the outer areas stronger as you cut the center and work your way out.

When a blade gets hot enough to burn the wood it is also loosing it's temper, so will get dull very quickly afterward. Slow the saw speed until there is no burning. Slow it a little further if you begin to see burning again, but realize at this point that the blade is getting dull, so consider a new blade at this time. In gross quantities, I'm paying a little less than $0.25 per blade. To me, it just isn't worth damaging my project by pushing the life of my blades by using them past the point where they are dull. They burn the wood and don't cut straight, so it's time for a new one. I'll also trash a brand new blade that behaves badly before I wreck my project with it. Quality control isn't that good with these tiny blades, so each is a bit different. Get rid of the trouble makers before you damage your project with them. A new scroll saw blade usually lasts me about 3-5' of cutting (if you straighten the pattern lines out) in soft pine and poplar. Some don't last even that long. I can usually cut 4-5 reindeer (3 with the ear ring size) in hard maple before my blade needs changing. Most of the reindeer are cut with a Flying Dutchman #1 R skip tooth blade. If I use larger, the cuts aren't as smooth, and using this blade produces a finish on these tiny reindeer that doesn't require sanding. I'll cut slower to avoid sanding any day. The edges sometimes need a little de-fuzzing, etc. but that's usually all the sanding that I do and I buy fingernail files, sometimes cutting their ends to different widths, to do the sanding for de-fuzzing. A few swipes per reindeer is all that is usually needed.

The saw that you have is not very user friendly when compared to a DeWalt, or similar Delta design, Pegus, Excalibur, Jet, etc. saw. But I started scrolling with a 1948 Dunlap (Sears brand) scroll saw that wasn't nearly as good as what you have.

So there are better scroll saws available than what you have, and a lot that are much worse. The new design of scroll saws began with the early Excalibur saws, quickly followed by the DeWalt, which copied the technology of the Excalibur saws. When DeWalt sold the original Delta Company off, the scroll saw technology of their DeWalt saws also went with Delta, so now you see the latest design of the larger Delta scroll saws are similar to the DeWalt. The rest of these new brands of scroll saws also later followed this design. This new generation of scroll saws have many new features to make it easier to cut accurately, change blades easier, make precise adjustments easier, use pin less blades (my Dunlap saw used pinned blades only) to use smaller access starting holes for inside cuts. and variable speed (my Dunlap didn't have that either).

The biggest feature of the newer saws is that both ends of the blades are now power driven, where the old saws pulled the blade down, but a spring pulled it back up. If the blade bound up in the cut, the spring wasn't sufficient to pull the blade up, but the machinery that pulled the blade down also pushed the blade up anyway, which buckled and broke the blade. The newer design scroll saws have solved this by powering the blade both up and down with no more dependence on a spring to pull the blade up. This, and the switch to pin less blades allowed much smaller blades to be used. I have some 3/0 blades that I cut non-ferrous metal with now.

Do some experimenting with the blade tension and different size blades and post here or PM me if you have any questions. I think I have experience in solving anything that you might run into.

Charley

[Herb Stoops]

Excellent write up, Charley.
It boils down to patience,patience,patience. Which I am short on. And I understand why, they are a more delicate machine which can't be pushed, and designed for more delicate work. I have seen some of your work and you are the master.
Thanks for the write-up.
Herb

[Cherryville Chuck]

Thanks Charley. There are a lot of good tips there. I suspect part of my problem was over tensioning the blades. Your efforts to find a relaible method to get the right tension reminds me of the same effort to get band saw blades tensioned correctly. In the end practice seems to be the most reliable method.

Something that may be helpful to you is one of the shop aids I make. I take left over counter top laminate and cut it into 1.5 to 2" wide by 3- 4" long pieces and glue sandpaper to them. They work like files. I use them to ease square edges without risking a sliver and to touch up things like the fillets on edge profiles. You can smooth the fillets without rounding over any of the edges. For sanding in the cavities of your scroll work you could make them a lot smaller and shape them with a file if needed. I think you could go down to a pretty narrow piece of lam, maybe a 1/4" or even less, you just wouldn't be able to put much pressure on it. I use Lee Valley's fish glue to attach the paper. It's water soluble so when the paper is worn out I peel off what I can and spritz what's left with water and in a minute or two the rest peels off once the water soaks through.