Purchased an 18" Delta Scroll saw, not working properly at an estate sale for $12.50. This saw must weigh 80 lbs. Model 40-650C type 1 Q3, only serial no. I can find is on the motor but there are what I think is French words on the motor and saw arm. Saw will run in High but speed control does not work. Research and testing identified a bad speed control module, not the potentiometer it tested good). Found a new original on e-bay and have it on the way. My issue is I cannot figure out how to attach a saw blade, maybe I am missing parts? I downloaded manual but pics and instructions are vague. Before I post pics, does anyone have this saw, I need guidenance other than I bought a very large paperweight, more like a pontoon boat anchor.

Heres the manual from the national archives Check page 12

7429679.pdf

I had a friend who had that saw, he loved it.

Can you post a pic of the blade attachment, upper & lower.

$12.50?! Oh, wow! Those old Delta scroll saws are tanks. On the blade issue, that model uses clamp-style blade holders, so you should have an upper and lower clamp that pinch the blade (either with a thumb screw or Allen screw). If you’re not seeing a way to secure the blade, there’s a good chance the holders are missing or incomplete. They’re small and often get lost. Also check if it’s set up for pin-end vs plain-end blades, since that changes how it mounts. Once your speed control is fixed and the clamps are sorted, it should be a great runner.

Congratulations on a great score Don. Like Bob said, if you could post some pictures we might be better able to help.

Just curious, do you have THESE parts on the upper arm?

Lew, thanks I have that one. Its for a type 2 and I have a type 1. Have not found anything on the type 1

Grandpawdave52. Yes and know, pic is type 2 I have type 1. But it does show me how it goes together which is a help. Not sure if bottom is the same, if so, I am missing parts and I can probably make part 2 fit.

Ducksoup, will post both top and bottom tomorrow.

ASteinfield: AMEN, had to carry it up a hill just to get to the driveway. Must weigh 80 lbs or more. Tough on my 77 yr old bones.

Found this, not sure if it will help. Last post in the link

https://forum.scrollsawer.com/forum/scroll-saw/tools-and-blades/19760-need-part-for-delta-scroll-saw-40-650-q3-type-1

Promised pics a few days ago but the fish were supposed to be biting....they weren't. Anyway. Based on the info from Lew and GrandpaDave52 I found two parts in a little parts box I also picked up at the sale. Pics: Now to figure out how they go together. Note: Parts ordered should be here today or tomorrow.

Edited March 20Mar 20 by Lost Oki

You have a Delta Quickset Blade Chuck I don't think this model is still available.

The lever would fit in the slots in pic #5 & keep the barrel piece parallel, the wire clip holds the jaws together.

The Delta 40-450 saw have these types of blade holders, you can find them on craigslist or facebook market for under 50.00, they are a good saw, I have 2 plus 2 for parts.

Up date on controller. Controller arrived Monday, looks new. Wired it in today, saw still runs only on high speed. Either I purchased a bad controller (no return) or I have a motor issue. Will try to locate a DC circuit board test facility in NW Arkansas to confirm old board is bad and or can be repaired or how to the sensor in the motor. DC is not my cup of tea and I don't know anyone that knows DC systems. Anyone with experience.

DO you have a picture of the circuit board

4 hours ago, Lost Oki said:

Anyone with experience.

Bummer; Sorry Don, outside of my wheel house. Hopefully someone can help.

Lew, pictures of old circuit board. Next post will be the new

Lew, new board

@Lost Oki Let me see what I can find

My brother said first thing to try is plug it in and push on all the soldered connections with a pencil eraser checking for bad solder joints. Being careful of course.

Still looking for a schematic.

There is a white 3 pin connector on the opposite end of the board from the AC line connection. Where do those wires connect to the saw? Motor? Speed potentiometer?

I wonder if connecting a standard filament type lightbulb (120v) to the leads that go to the motor and applying power to see if the speed adjustment will change to brightness of the bulb.

Lew; 3 small pins go to the base of the motor but do not power the motor. From what little I can find I think (?) this is a type of sensor telling the motor how fast to run (???) DC is not my cup of tea. Looking back at the first two CB pics (old board) posted, bottom pic, note 120V, just below are two silver flat pins. This is voltage going to motor.

See attached pic showing motor and wires. Note small wire goes to back of motor, same wires that connect to small pins at top of Circuit board pic. Larger wires, white, black connect to larger silver pins just below 120v label. Green connects to green.

Handy Dan, thanks i'll give that a try.

OK, I found this,

Although I don't think it is exactly what Delta used, I think it will help determine the location of the problem. This is a treadmill speed controller diagram.

From your picture, I think the large, round black cable, going to the motor, is the same ae the blue wires shown in the diagram above. Because the motor runs, but at full speed, I believe the thermal overload circuit inside the motor is functioning, as is the fuse and "safety switch" (On/Off switch).

I cannot be 100% certain but I think the speed control is a "Pulse Width Modulation" -PWC- type controller. That means the controller turns the voltage off and on- to the motor- very quickly- pulses. The longer the positive pulses the faster the motor runs.

When reading about this saw, users mentioned the saw has a brief delay when starting up due to a feedback ckt with the motor speed control. I think that feed back is through one of the wires in the little brown connector 3 wire connector. Some owners indicated a failure in the feedback ckt can cause the motor to run wide open,

The sensor for the speed feedback is located in the saw motor. Typically there are several speed SENSORS used for DC.

A Hall Effect Transistor

This type of RPM detector relies on a magnet mounted on a rotating device, passing close to the transistor to sense the rotation.

U-shaped slot photoelectric sensor

This type uses a rotating slotted wheel to pass through the "U" shaped opening to make/brake an IR light to sense rotation

LED RPM Detector

This type uses an LED light and a reflector on a rotating shaft/wheel to detect motion. (Reference image only)

Because both circuit board had the same results, I would remove the back (rite in your pix) end of the motor and inspect the ckt inside. Look/smell for anything burned/discolored. Maybe something loose/missing on a shaft.

Hope this helps.

Let me know what you find!