Startrite TA175 riving knife alignment

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

BigPaul

Member
Joined
31 Dec 2021
Messages
7
Reaction score
2
Location
Somerset
Hi all. I've just bought a Startrite TA175 (my first proper table saw). It was missing the original riving knife and blade guard but the seller included a new one. I've fitted it but the blade and the riving knife don't line up. I can space the riving knife to line up but it seems that the whole thing isnt right. With the insert fitted the blade almost touches the edge of it. Is anyone able to give me any advice?
 

Sideways

Established Member
Joined
26 Dec 2017
Messages
2,046
Reaction score
836
Location
United Kingdom
Could you post a photo ?
The inside curve of the riving knife should be a little bigger than the curve of the blade / or more commonly, the biggest blade that can be fitted.
The riving knife should be close to the blade teeth but not touching. I'd be happy with a 2-3mm minimum gap to as big as maybe 6mm.

The mounting of the riving knife often involves a slot that's wider than the clamping bolts. Also sliding adjustment back and forwards. The play allows the knife to be nodded forward and back as well as moved up and down using the slot. Once lined up, the (commonly two) clamping nuts are tightened and the knife shouldn't move.
Alignment side to side is usually done with shims or packers. Sometimes, like on a Wadkin, the knife is essentially fixed side to side and the spindle of the saw can be adjusted side to side to align the blade to the riving knife.
Important: your riving knife should be thicker than the plate of the sawblade but narrower than the kerf made by the teeth. That means if you change the knife or the blade, you need to carefully check the thicknesses to 1/10th mm accuracy to make sure that this relationship is still true. A job for a vernier or digital caliper. You can't usually switch to a narrow kerf blade or a thick industrial blade without fitting a new riving knife of the correct thickness for each.

If you add a photo, it will show us what's happening and there are plenty of folk here who can advise.
HTH
 

deema

Established Member
Joined
14 Oct 2011
Messages
3,120
Reaction score
721
Location
chester
The Startrite doesn’t have the biology to adjust the spindle protrusion, it’s has a number of circlips holding it in place. The riving knife is spaced to the blade by two tubes that slip on the two bolts that hold the riving knife on. There are usually two smaller spacers tubes, of unequal length to facilitate tightening up the nuts. There isn’t usually any issues of spindle to riving knife alignment. As Sideways has highlighted photos would be great.

4781EDAE-A9CF-46E8-95B4-BBA4CA7A1D87.jpeg
F95B2B50-541A-4188-9B3E-79975F9F54DB.png
 

hlvd

Established Member
Joined
21 Aug 2021
Messages
186
Reaction score
126
Location
Anglesey
There are two nuts to hold the riving knife and two to hold the riving knife carrier. If you undo all four you should get the correct adjustment.
 

voyager

Established Member
Joined
19 Dec 2019
Messages
41
Reaction score
7
Location
shrewsbury
i have the same saw, mine has a cpl of washers to bring the centerline of the knife in line with the blade, and adjusted to a 5mm clearance between knife and blade curve
 

eribaMotters

Established Member
Joined
12 Feb 2010
Messages
590
Reaction score
258
Location
Hatherleigh, Devon
I've also found that with age my riving knife can twist out of shape slightly. I think is in mainly due to the force/weight of my extractor hose on the crown guard. This is obviously more pronounced the greater the blade projection. Over the years I have persuaded it back into place a few times by laying on a flat surface and gentle persuasion with a mallet. When checked for being true on the saw table I refit and all is usually well for a few years.

Colin
 

BigPaul

Member
Joined
31 Dec 2021
Messages
7
Reaction score
2
Location
Somerset
Thanks for the replies.
I've been in it again this morning. First just to confirm this is my saw.
I've been online and downloaded the manual and also checked out parts and stuff.

PXL_20220101_111402520.jpg


I've attached the new riving knife that came with the new kit.

PXL_20220101_101941974.MP.jpg


You can see the misalignment.

I've used a couple of washers and aligned them but when I put what I assume is the original insert into place the blade just touches as it comes out of the table (top?)
PXL_20220101_101814515.jpg


When I collected the saw I also got a zero clearance insert with it that was made by the last owner. It fits as though it was made for this alignment!

PXL_20220101_101833985.jpg


I haven't got verniers but I used my square in the mitre slot and checked for parallel with the same tooth front and back. It isn't parallel! Out of square with the table.

So, this raises a couple of questions!

From a previous reply the only way to align blade to table is the adjust the table?
If this is so then what hints and tips should I know.
I've checked underneath to check the attaching points.

PXL_20220101_111421914.jpg


As far as I can see there are 8 bolts that aren't quite 14mm! (I need to get hold of a socket set in Imperial!)

I'm probably going to take the whole thing off to clean and oil the tilt and raise mechanisms.

On refitting is it as straightforward as just putting it in place and aligning by mallet 'taps'?

Can/does the table move as it's tightened back down?

I'm sure that isn't all but it is enough for now!!
 

deema

Established Member
Joined
14 Oct 2011
Messages
3,120
Reaction score
721
Location
chester
There is no adjustment in the table mounting, so don’t try. The trunion mechanism is pinned and bolted to the table top. It was setup at the factory, and although I’ve seen threads on aligning the blade this way, you can’t.
I’d like to see where the riving knife sits in the original insert plate, I think you will find it’s in the centre of the slot. This would then suggest that there is something holding off the inner saw flange, item 87. However, looking at the pictures, I might be wrong, but the two flanges should look identical, and yours don’t. I suspect the inner flange might be not be an original replacement.
Brains not working 100% today, so I can’t remember if the inner and outer flanges are identical on the older saw, I think they are. I have a couple of 175s in the workshop waiting for TLC but I’m still quarantined so can’t look. The outer flange looks correct, try fitting it to be the inside flange (if they are different it will be the bore size).

Id like to see a photo of the two flanges.
 
Last edited:

deema

Established Member
Joined
14 Oct 2011
Messages
3,120
Reaction score
721
Location
chester
To check how parallel your slot is to the blade, you need to mark a single tooth in the blade. And measure from the same tooth to the slot at two positions, turning the blade. Lots of blades are far from flat. If it’s isn’t aligned, next check that the two roll spring pins are in the table. These are near the front edge, just above the handle. You will probably need to dig out the holes in the top of the cast iron table to see if they are still in place. If they are, the trunion and table are aligned. If when the blade is powered up, it’s running true, no vibration, no wobble in the soindle when tugged by hand with the belts taken off the the pulley then the setup is probably how it left the factory unless someone has been playing.
I’ve marked the pin (there are two)

CBE1DEFA-37FE-4F7C-A779-23B443C54B24.jpeg
 

hlvd

Established Member
Joined
21 Aug 2021
Messages
186
Reaction score
126
Location
Anglesey
Thanks for the replies.
I've been in it again this morning. First just to confirm this is my saw.
I've been online and downloaded the manual and also checked out parts and stuff.

View attachment 125588

I've attached the new riving knife that came with the new kit.

View attachment 125589

You can see the misalignment.

I've used a couple of washers and aligned them but when I put what I assume is the original insert into place the blade just touches as it comes out of the table (top?) View attachment 125590

When I collected the saw I also got a zero clearance insert with it that was made by the last owner. It fits as though it was made for this alignment!

View attachment 125591

I haven't got verniers but I used my square in the mitre slot and checked for parallel with the same tooth front and back. It isn't parallel! Out of square with the table.

So, this raises a couple of questions!

From a previous reply the only way to align blade to table is the adjust the table?
If this is so then what hints and tips should I know.
I've checked underneath to check the attaching points.

View attachment 125592

As far as I can see there are 8 bolts that aren't quite 14mm! (I need to get hold of a socket set in Imperial!)

I'm probably going to take the whole thing off to clean and oil the tilt and raise mechanisms.

On refitting is it as straightforward as just putting it in place and aligning by mallet 'taps'?

Can/does the table move as it's tightened back down?

I'm sure that isn't all but it is enough for now!!
Are you sure it's the riving knife that's misaligned and not an extra washer between blade and shaft shoulder?
 

Distinterior

Established Member
Joined
8 Mar 2014
Messages
1,191
Reaction score
402
Location
Colchester, Essex.
Are you sure it's the riving knife that's misaligned and not an extra washer between blade and shaft shoulder?

It certainly looks like there is an additional washer that wouldn't normally be there....
When you zoom in on the 2nd photo, you can see the 2 conical shaped spacer washers on both sides of the blade but there is definitely something else between the rear spacer and the rear of the blade.

Edit.
I wonder if a previous owner has added a shoulder spacer as a reducer for the blade....?
The blade should have a 5/8" hole in it to fit on the 5/8" shaft.....If that blade has a 30mm hole, it may explain the spacer...??
 
Last edited:

BigPaul

Member
Joined
31 Dec 2021
Messages
7
Reaction score
2
Location
Somerset
I wondered about a spacer on the blade too. When I take the blade off what looks like a spacer doesn't seem to move? Here is a shot of the blade and the collars. I didn't measure the hole in the blade but it fits snugly on the spindle so pretty sure it's not 30mm.
I've just double checked the diagram and have realized that I have conical washers and also spacer discs on both sides of the blade which aren't in the drawings. I'll recheck that in the morning.
PXL_20220101_155023139.jpg


Regarding the riving knife mounts I've spent some time poring over the schematics and I think it's installed correctly?
PXL_20220101_155038839.MP.jpg


Im also going to check the roll spring pins as advised by deema.
When powered up it runs smoothly but I haven't checked the spindle with the belts off. That's on tomorrow mornings list as well.
 

Distinterior

Established Member
Joined
8 Mar 2014
Messages
1,191
Reaction score
402
Location
Colchester, Essex.
The smaller of the washers goes on the arbour first. Then one of the two conical shaped washers, the blade and the second conical washer are all that are needed to mount the blade, as long as the blade has a 5/8" dia hole. 78, 87 and 88 on Deema's exploded diagram.
That larger diameter washer does not belong on the TA175 saw.
There should be a bit of thread visible and protruding through the nut when the blade is mounted correctly.
Assemble it this way and see if the blade aligns with the riving knife and alloy table insert.....
 
Last edited:

Sideways

Established Member
Joined
26 Dec 2017
Messages
2,046
Reaction score
836
Location
United Kingdom
In your early photo before you put the table inserts in, it looks like there's a large washer between the blade and the inside flange. I can't see why that should be there and it is contributing to if not causing the misalignment. I think your last photo shows it as a spacer disc and maybe one on the outside too.
I can see that's how the previous owner ran the machine as his zero clearance insert matches the blade position with whatever that is in place, but I don't think it's a good idea. Any such washer(s) risks throwing off the proper action of the flanges. They should be relieved on the surfaces that contact the blade so that they always grip the blade around their outer edge, not near the shaft itself. This is to make sure there is enough torque transferred from the shaft to prevent the blade slipping under load.
How does the blade line up without the 2 big washers. Just the thick bevelled ones which I assume are the inside and outside flanges, plus the nut ?
 

Distinterior

Established Member
Joined
8 Mar 2014
Messages
1,191
Reaction score
402
Location
Colchester, Essex.
In your early photo before you put the table inserts in, it looks like there's a large washer between the blade and the inside flange. I can't see why that should be there and it is contributing to if not causing the misalignment. I think your last photo shows it as a spacer disc and maybe one on the outside too.
I can see that's how the previous owner ran the machine as his zero clearance insert matches the blade position with whatever that is in place, but I don't think it's a good idea. Any such washer(s) risks throwing off the proper action of the flanges. They should be relieved on the surfaces that contact the blade so that they always grip the blade around their outer edge, not near the shaft itself. This is to make sure there is enough torque transferred from the shaft to prevent the blade slipping under load.
How does the blade line up without the 2 big washers. Just the thick bevelled ones which I assume are the inside and outside flanges, plus the nut ?

I think the smaller washer is OEM and it acts as a spacer to distance the first conical washer.....I've never seen the larger of the two washers (as shown in Big Paul's picture) fitted to a Startrite TA saw and I've worked on and refurbished quite a few...
 

BigPaul

Member
Joined
31 Dec 2021
Messages
7
Reaction score
2
Location
Somerset
So, as one question is answered many more arise! I've removed the blade again and discovered that it is in fact a 30mm bore and fitted with a reducing bush. The OEM conical washers (no 87 in the diagram provided by deema) have an internal ridge that grips the blade but doesn't touch the insert. I can only assume that the previous owner has used the extra large washers to grip blade and insert!
PXL_20220102_120924525.jpg


What is the usual method for fitting a 30mm bore blade on a ⅝ spindle?

If I fit without the large washers and remove the riving knife spacers they both line up.
PXL_20220102_121037324.jpg

And it fits in the insert.
PXL_20220102_121202956.jpg


Regarding your advice deema and the spring roll pins, they are both in place assuming this is what you meant?
PXL_20220102_121134851.jpg


I'm not going to check blade and table alignment again till I fit a new blade. I went to Axminster tools and bought one but it's also 30mm bore and I need another reducing bush (or should I try to remove the one from the original blade and use that?)

Yet again, thanks for the knowledge sharing, it really helpful.
 

deema

Established Member
Joined
14 Oct 2011
Messages
3,120
Reaction score
721
Location
chester
Excellent, well done. It looks great. You’ve mounted the riving knife correctly, answering one of your earlier questions.
The reducing washers are usually a friction fit, once fitted you leave them with the blade. Some people if they are a bit loose ‘spike them’ by centre punching a couple of times around the edge of the blade to crush it to the reducing washer.
A decent reducing washer should be wide enough that it won’t come out when clamped by the two flanges despite the reducing washer not being clamped by them.

The saw is onky ever as good as the blade you put into it, so I’d always recommend getting a high quality blade such as Omas, CMT, Swedex etc.
 

Sideways

Established Member
Joined
26 Dec 2017
Messages
2,046
Reaction score
836
Location
United Kingdom
Good job. Getting somewhere.
The relief in the two flanges should be quite shallow. I doubt the reducing bush would be able to come out sideways even if it isn't a tight fit in the blade.
There's a way to secure the reducing bush in the blade with a few carefully placed dinks from a centre punch but I don't have a photo to demonstrate.
 
Top