Well....I got my new (to me) used Delta P-20 scroll saw home today. There were some rust spots on the table so I took that off and wet oil sanded it, cleaned it top and bottom and waxed the heck out of it. Better now with just a few black marks. I could have a machine shop smooth it over, but then I'd need to deepen the table insert circle to keep the insert flush. Doesn't seem worth the time or money. I do have a few questions though. Maybe all y'all can give me some ideas.

1.) The table insert that came with it fits the circle fine, but the slot seems off to one side slightly (maybe 1/16"). To get it in and pressed down the blade is actually rubbing and pushed a tiny bit to one side. That can't be right. There are no numbers on it so I'm not really even sure if it's the correct Delta P-20 insert. I thought I would root around online a bit to see if I can find a replacement. I did check the blade as described in the Owner's Manual and it seems to be running in alignment (i.e., straight up and down). The saw runs nice and smooth so I'm happy about that. It came with a zero clearance insert (ZCI) that has never been used. The Owner's Manual says just cut a slot in the ZCI, but that seems to simplistic. How would I know if I had it aligned correctly so that the little tab on one side falls into the alignment hole? Is there a right way to prep a ZCI to be aligned and fitted correctly? I know if I change blades I should change the ZCI just like the table saw.

2.) It only has one blade and it is a little bent. It uses flat end blades (I'm not sure of the correct terminology). Does anyone have any recommendations for good blade manufacturers and sources?

Thanks for your thoughts. - V.

Not a scroll sawer but I wonder if the slot position is so you can tilt the table and not have the blade rub the insert.

Yes lew. It's like that for the tilt.

OK...so the insert only goes in one way due to the indexing nub on one side. I thought about reversing it, but that won't work. It makes sense that additional space would be needed to tilt the table, but the insert should still clear the blade when the table is horizontal. Right now the blade is rubbing on the right side of the insert slot when facing the front of the saw. I guess I could bring the slot out a bit wider on the right side, but it won't be symetric if I do that. More information is needed.

@Wichman3

Page 15 of the manual should show the way to align the bottom blade holder to the top.

To ensure the blade is exactly 90 degrees to the table do as follows:

use the smallest blade you have

use a piece of scrap at least 1 1/2" tall

get the blade as close as you can to 90*

make a test cut ( about 1/8" into the scrap ), then move the test piece around to the back of the blade, keeping the same face to the table, and check to see if the blade will fit into the kerf. Be anal about the blade fitting into the kerf. Remember that any adjustment will double at the blade, so very small adjustment are called for.

The Scroll Saw Village is a very good resource for scroll sawyers there is a discussion on this saw here:

https://www.scrollsawvillage.com/forums/topic/55646-new-user-delta-p-2040-680/

There is a listing for blade suppliers on the website.

Your saw takes "plain end blades", to use pin end blades you would have to remove the pins.

Blade selection is very subjective. I would stick to just flat blades to start, after you are comfortable cutting with flat blades you can try the spiral blades.

For new scrollers my suggestion is to start by picking a blade size. Try to think of the type of cutting that you want to do; material thickness and the level of detail you want, are there lots of very sharp turns, or is it gradual curves? The thinner the material and the sharper the turns equals smaller blades and vise versa.

From a reputable dealer order a sample pack of as many different blade styles and brands as you can, 1 or 2 blades of each, all of the same size. Using the same material, say 1/8 or 1/4” plywood, and the same pattern, preferably a practice pattern that highlights the corners you want, cut the test pattern with each blade. Take notes, the biggest lie we tell ourselves is “I’ll remember that”. When you find a blade that just cuts well for you, order another sample pack, of just the blade style that you like. this time ordering different sizes, again, just a couple of sizes, repeat the test pattern cutting. Once you find the blade style and size that you like, order a bunch of them. Limit yourself to just that one size and type of blade for awhile, you want to “train your brain” and develop muscle memory. Once you become accustomed to cutting and feel comfortable cutting, when you order, try a different size of the same blade. Then branch out to new blade styles and sizes.

Thanks @Wichman3 for jumping in!

Thanks @Wichman3 for the guidance. The only blade that came with my saw is a plain end, 10TPI that measures 5-1/4-inches end to end. I assume that is what it generically referred to as a 5-inch blade. I'd call it a little ragged. I think the best thing to do is follow your directions and get some blades that are brand new before I try to align anything.

Yesterday I did walk through the alignment check on page 15 in the manual with this one blade which may not be a good indicator given my blade condition. The blade seemed to move along the end of the straight edge as described in steps 3 and 4 and Figure 36. Again, I'll get new blades and run that test again. That still leaves me with the conundrum of the insert not fitting correctly in relation to the blade?

Help me understand the test you described above....

To ensure the blade is exactly 90 degrees to the table do as follows:

use the smallest blade you have

use a piece of scrap at least 1 1/2" tall

get the blade as close as you can to 90*

make a test cut ( about 1/8" into the scrap ), then move the test piece around to the back of the blade, keeping the same face to the table, and check to see if the blade will fit into the kerf.

Be anal about the blade fitting into the kerf. Remember that any adjustment will double at the blade, so very small adjustment are called for.

I'm not sure what that is telling me since by moving the scrap to the back side it's not indexed on anything? I guess I don't understand why the back of the blade would not fit into the test kerf?

I gave the saw a very careful hand over hand inspection thinking maybe something was bent. Didn't even find a scratch on the paint that would indicate something of that nature. There is a crack on the table top right side about 3/8" in from the edge. It appears that something heavy probably came down on the table there. I can't imagine how a crack like that would occur if the saw fell over, besides there is no damage to the paint on the outside edge of the table adjacent to the crack that would indicate it tipped over. It's a top surface crack with no evidence of anything showing on the underside. It's presence shouldn't affect the saw performance, but I wonder if the lower arm could have gotten knocked out of whack. I didn't find the crack until I had wet sanded the top and waxed it up good.

Last questions for now...the manual doesn't indicate any adjustment for the upper arm. I assume no mention means there is none?

I'm assuming I should be able to make sure the table is perpendicular to the blade using a small square. Is that a fair test?

Thanks for your patience as I work this through. - Vern

PS - I was able to check out the post on scrollsaw village, but I'm having trouble getting my membership set up there so interaction for now is a no go. Hopefully the staff can fix the problem.

I'm not well versed on the P-20, just what I've seen in the manual.

As for aligning the blade to the table, the picture shows an exaggerated example. I cut a 10° angle and then moved the scrap around to show what it looks like. When you are cutting thick pieces or a compound pattern, even very small angles matter. The small square will get you in the ballpark, this technique will get you dialed in.

So I would want to cut a small kerf with the table horizontal. Once I move the workpiece to the back side I think the idea is to see if the kerf aligns with the blade. If it does not that would seem to mean the blade is not at a perfect right angle to the table. Is that correct? If it is not aligned then that's when it's time to make minor adjustments to the bottom alignment screw. Just keep making the little test cuts and checking from the back until there is perfect alignment. I can do that. It seems like I should do this process before I worry about my table insert that doesn't work right now. This may result in adjustments that bring the blade into the correct position. Thanks.

I only make adjustments to the table tilt for this, not for any adjustment screws. If you wish you could adjust the table's 90* stop, but this is to get the table and blade to a perfect 90* angle.

Good morning @Wichman3 . I was down fiddling with my scroll saw again this morning. Once again, I checked it per the alignment instructions in the manual. The straight edge check seemed to work as described (i.e., Laying the straight edge on the table with the end just touching the blade then slowly turning the drive pulley through a complete stroke. The blade seemed to remain in contact with the straight edge. I checked it by putting a light behind the blade so I could see any gap easier.) I did the following....

1. Since my blade is not running in the center of the table hole (it's off to the right by 1/16" or more) I tried adjusting the bottom blade mount to the left until I could cleanly install my insert plate. That took quite a bit of turning. Just looking at it from the front it appeared to be off vertical.

2. I did the cut test you described earlier and clearly it was way out of vertical when I slid the piece around to the back side.

3. Then I adjusted bottom back to near where it was before and did the cut test a few more times until I got the blade to slip in from the back with no effort indicating I have it back to vertical. See picture 4.

4. Then I tried to install my insert again and had to force it in which actually forces the blade to the left. Picture 1 below shows it forced over.

5. In picture 2 I show roughly where the insert would need to be to clear the blade by even a little bit.

6. Picture 3 shows the underside of the insert. I checked the slot on the insert to see if it is in the center. It is within a couple of hundredths of an inch. Probably within machining tolerances.

So I'm baffled and beginning to think maybe the seller screwed me and didn't disclose damage of some kind. Options?

1. I can grind out the right side of the insert until it clears the blade which will affect the back of the insert's ribbing structure.

2. I can try to find a new insert that will fit. Doesn't look like that part is readily available for the Delta P-20.

3. I can try to find a zero clearance insert and get it to fit though I have no idea how a ZCI would be cut to slide into place correctly. It's not like a table saw where you fit the ZCI in place then bring the blade up through it.

4. There are three bolts down on the frame below the table that I could try loosening to see if there is any play there to move the table over. I also loosened the four table hold down bolts and made certain it is as far to the right as possible.

Any other ideas?

I can't seem to get registered on the Scroll Saw Village forum and they don't respond to messages so no help there.

Thanks

Vern

It is really hard to tell from the parts diagrams, but is there a chance there is a table horizontal adjustment on the trunnions or trunnion mounts?

I thought that might be a possibility but the only thing I can find is the four bolts that bolt the table to the trunnions. There is a tiny bit of play in those mounts but I already have it as far left as it will go. Its worth taking the table off again for an exploratory mission. I'll give that a try and while it's off I'll check those frame bolts down lower to see if there is any play there.

I looked closely under the table with a flashlight. I'm going to take the table off again and give it a close look to see if there is anything there in terms of horizontal table adjustment. Thought I might also try to reach out to Delta even though this saw is discontinued to see if they can lend any advice. - V.

At this point, if it were my machine, I would start by adjusting the lower arm until the blade was well clear of the insert and as close to center as I could get it. After that was done I would then, using the table tilt, adjust the table until is was aligned 90* to the blade.

The pointer for the angle gauge (underneath the table) should be adjustable, if everything works at this point adjust the pointer and set the 45 and 90* stops.

40 minutes ago, DuckSoup said:

@WoodturningVern I think I figured out what your issue is.

In your picture #2 it shows what appears to be a "QuickRelease" holder. These are made for the top arm only.

The bottom holder should look like this,

Side view shows the Allen screw that tightens the blade. The screw is threaded into the black block & when loose the blade slips between the black block and the base of the holder. To change the holder, you need to push out the split pin at the bottom of the holder. I have this tool that came with the saw. Insert the tool on the right side of the split pin and a 3/16 socket on the left side. Take a small C-clamp and squeeze the socket & tool until the split pin drops into the socket. Reverse to install holder (tool on the left & socket on the right).

If you don't have the tool a 3/16" drill bit will push the pin out. It's a bit harder with the drill bit but it works.

This should center your blade.

Hang on to the QuickRelease, these aren't made anymore and spares are hard to find. Hope this helps.

The P-20 ( 40-680 ) has quick release clamps, both upper and lower, as seen in the manual HERE.

Thanks @Wichman3 I totally missed the model number. @John Morris or @lew could you please remove my picture ladened post above, they are the wrong model saw, thanks.