Shay wood Mitre poroject

Started by T.C., March 03, 2021, 06:25:39 PM

Previous topic - Next topic

T.C.

I am working on one of these cutters, I have it mostly done and am into the testing tweaking stage.Everything is working well but I find I still get a slight deflection toward the bottom of a cut?I am using a standard single edge razor blade and was wondering if a heavier blade would cure this problem?I remember someone said to use blades for a Matt cutter ?
They do come in a thicker version 15 thou. apposed to 9 thou. and also come in single or double bevel versions.Any advise or suggestions would be very welcome......Thanks T.C.

deemery

Where are you getting those different kinds of blades?


dave
Modeling the Northeast in the 1890s - because the little voices told me to

T.C.

Thanks for the reply:I haven't actually bought any blades yet as they come in packs of 100 and I dont want to buy the wrong one.I am leaning towards the single bevel blades because I think they may cut more square on the side that's flat ?
Honestly I really dont know?
Hoping someone here would.......
Have you one of these cutters ?
T.C.
Link to blades   https://www.amazon.com/Logan-Graphics-268-100-Blade-Framers/dp/B0010EOE5C


Zephyrus52246

I bought a shay cutter online last year and was disappointed that it really didn't cut any cleaner than my chopper.  I had no idea that the blades came in different thicknesses.  Mine are .009 in., I need to find some of the thicker ones to see if this matters.   I saw some on line that were .012.  I don't think the ones you posted will fit in my cutter. 

Jeff

deemery

Hmmmm, I'm not sure Logan blades will fit into something designed for conventional 'single edge razor blades'.


dave
Modeling the Northeast in the 1890s - because the little voices told me to

T.C.

This is what I have found,

"If" the measurements of the blades at Amazon are correct I am pretty sure they will work.It will take a little mod of the cutter knife holder though.What would need to be done is instead of using two screws to hold the blade at the notches on the razor blade sides you could drill another hole for a screw in the holder to match the Matt cutter blade hole witch is in the center of the blade.To hold the blade from rocking front to rear just put a stop at the top of the blade holder.I already have a stop on my blade holder for this reason and it also keeps the blade from moving up when pressure is put on it.
I used a short piece of .062 brass screwed to the top of the blade holder as a stop, but it must be inline with the cutting surface of the cutter to cut correctly.Make any sense?I'm thinking the extra thickness of the blade and the one flat side it may cut fairly square ?

Jeff I was kind of disappointed as well, I have spent alot of time on this thing only to have the same results as you did, I will admit it does a little better than a chopper but not worth the money or time if it doesn't work better than it is at this point.
Thanks T.C.   

bparrish

Gents ....


I have used a chopper for a very long time.  My method to stop deflection is when cutting material approaching an eighth of an inch,  I turn the material over.


It's not a problem as I seldom make a cut without a stop.


I've never had a noticeable deflection on thinner material as long as the blade is sharp.  There is a point where it starts to crush the stock.  I've had some success if I find the crush later to swell it back up with alcohol.  But otherwise blades don't go too long. I must agree though that a single edge blade way longer than a #11 axacto blade.  I do stone them a bit to get more life out of them but it's not the same as the factory edge.


See ya
Bob
Did you ever notice how many towns are named after their water towers ! ?

T.C.

Thanks for the reply Bob:
I realize what your saying about the choppers, I have and have used one along with my True sander for a very long time as well.
The reason I built this thing was to eliminate the need to use the True sander and from everything I read about it "it was the fix" as to say.
As a machinist you know that the more rigid the setup the better the results (I know your a really good machinist from looking at your builds) so wouldn't a heavier more rigid blade work better ?I think it's pretty obvious it's the blade that's moving, but what's causing it to move?
Is it the double bevel or the thickness of the blade?Would the double bevel cause the blade not to track straight, like cut a "V"  ?

T.C.



Oldguy

My Shay Wood Miter accepts only single edge blades that have three screw hole/slots.  Not sure hos a single hole will keep it from moving a bit.   But on mine the upper blade "guard head" can only be so high, otherwise the blade slants because of the groove.  Given that the device is a slicer, not a chopper, maybe with all the washer pivot points, it wiggles a bit during use?
Bob Dye
Livin large on a pond

bparrish

T C  and Bob...

You are both on to it as I see it.  Yes the more rigid the better and the slicing process does have more places to wiggle but........
The slicing action reduces (I think) resistance to the cut.  So.....

I've never looked for this so you are on your own here.........


If you could find hollow ground blades the blade could get farther into the material before before the wedging starts pushing to the sides.  I have noticed that the resistance goes up in a cut after about .050" with a chopper.

Another factor for distortion is angle cuts on a chopper.  The blade seems deflect more due to the grain of the wood in an angle cut.  With no predictability.  Think of the difference of a rip saw vs. a cross cut saw. The teeth are fundamentally different as is the set of the teeth.

I think I am accomplishing much of what you are describing with sanding stuff but I wait until after some levels of assembly and then square stuff up before going on.

So I think we are getting the same stuff done via different methods.

see ya
Bob
Did you ever notice how many towns are named after their water towers ! ?

T.C.

#10
I think maybe some pictures are in order ?This is what I have built and how I have attache the blade using two screws just as the Shay cutter does.The difference is at the top of the blade holder I have a piece of brass screwed to the top to act as a stop for the top of the blade so it stay's lined up with the bed of the cutter, it's also impossible for the blade to "rock" it can only drift side to side and that's where I think the thicker blade may help.
As to fitting the Matt cutter blades to the Shay cutter.The blades in the Amazon link above measure almost identical to a single edge razor blade, the difference is the holes.   So why not just get the ole Dremel out with a cut off disc and grind a couple of notches in the ends that match a razor blade?I dont see why this wouldn't also work with a chopper ?
The blades are available with a single or double bevel edge, I have ordered a box of the single bevel so I will be updating this hopefully with good news? 

If I could figure out how to post a picture I would show ya what I have?  :-\

[url=https://imgur.com/xCuaa85]
Disregard the black arrow I just haven't cleaned it off, the brass above the top of the blade is the stop.
T.C.

Bernd

Fellow modelers, I got into a discussion in a forum I used to belong to on "choppers". The discussion had to do with the NWSL choppers and how they did not cut straight down on thicker pieces of wood. A closer look at the NWSL chopper showed me that the chopper is to flimsy to cut thicker pieces like 1/8" or larger. I also didn't like the way the blade was secured. So I decided to design and build my own. I also want to build a version of the Shay Chopper one of these days.

Here's my chopper. It's aluminum mounted on a piece of MDF board.



What I did was design a different way of holding the razor blade. Instead of screws, I used a pinching method.



You need to pry off the aluminum top of the blade in order for it to seat properly in the ledge milled into the blade holder.











Here I'm testing the accuracy of the cut. I've got two razor blades mounted in the holder.







Now here's the nice thing about this chopper. If you need to cut thicker stock, you need a sturdier blade. The razor blade is to thin and will flex. When I designed the blade holder I made sure that a razor blade only stuck out an so I could cut an 1/8" piece. I think the cutting portion of the blade only sticks out about 5/16" or less to be able to cut a 1/8" thick piece of wood. The blade holder will hold a box cutter blade without any problem. One of these days I'm going to search for other blades that would fit.







This piece was cut with the razor blade in the holder. It did flex some but not as much as I've seen the NWSL chopper did on thicker pieces.



Here are two cut with the box cutter blade. Notice the straight cut.



As I said I'm going to see if I can design my version of the Shay Wood Cutter using this blade holding method. It allows you to use almost any kind of cutting blade with a straight back. I searched the net and found pictures of the original Shay cutter. I think if a manufacturer used the blade holder design I'm using it would make an excellent cutter. The next step up from that would be a miniature chop saw.

Bernd

New York, Vermont & Northern Rwy. - Route of the Black Diamonds

T.C.

OK I finally figured out how to post pictures on my post above so you all can see my mess.  ;D

Bernd do you think that idea could be added to a regular chopper easy enough?I measured a box blade thickness ant it came to .023 so that's .008 more than the matt cutter blade and .014 more than the razor blade, big difference.   :o I will try the matt cutter blades on my chopper as well as my new toy I made and hopefully get both working/cutting square.

I dont know if you all noticed that I made my Shay type cutter with a moveable back stop so I can cut angles with it, hopefully it works out?Thanks again for all the replies and ideas .

T.C.

Bernd

Quote from: T.C. on March 04, 2021, 02:09:23 PM
Bernd do you think that idea could be added to a regular chopper easy enough?I measured a box blade thickness ant it came to .023 so that's .008 more than the matt cutter blade and .014 more than the razor blade, big difference.   :o I will try the matt cutter blades on my chopper as well as my new toy I made and hopefully get both working/cutting square.

T.C.

Hey T.C. Nice work on that cutter. I'm impressed. I never checked the thickness of the box cutter blade. I took a look at the link you provided for those mat cutter blades and they look ideal. I'll be getting some too.

I'd get rid of the aluminum top part of the razor. I think it cocks the blade and that's why it maybe cutting at an angle. If you can make a pinch holder like I did you wouldn't have to worry about the holes will line up with certain blades. Yes I think it can be modified.

Bernd
New York, Vermont & Northern Rwy. - Route of the Black Diamonds

T.C.

Thanks for the kind words about my work, I've seen your work so coming from you it means a lot.
I have a notch milled into the blade holder for the top of the blade to set into so the blade does set flat against the holder.The whole thing is very rigid there is no wobble anywhere so I know its got to be the blade.

When you order your blades make note that they have double bevel and single bevel.I ordered the single (supposed to be here Sat.) because I think/hope I will get a straight cut on the flat side.


The down side to it is I will have to flip the material over to cut the other end or rotate the blade so the flat is on the other side to use the other side of the cutter.
Still easier than sanding every piece square and worry about the part being to small, or even trying to sand down it to the rite size.
Thanks again  T.C.


Powered by EzPortal