# Setting a 45 degree angle



## ARC-170 (Mar 24, 2020)

I need a little advice on how to set up a 45 degree angle. I'm making a V-block and need to tip it 45 degrees to make the cut for the vee. I have a V-block, but it's too big for the vise on my mill. I would normally borrow a 45 degree v-block from work, but that's not possible due to the Plague. So, I'm wondering what other options I have.

OPTIONS:
1. I saw this: https://www.ebay.com/itm/Toolmaker-...484553?hash=item5227a5a1c9:g:Tm4AAOSwPW9dy6NJ and thought it might be a good tool to have. Thoughts?

2. I could use a protractor and and tilting vise and line up the mill cutter and the part so they are 45 degrees. Not sure how accurate I can be with this, though.

3. Use one of those digital angle finders used by woodworkers on table saws. Bot sure if these are accurate enough, though. They are +/- 0.1 degrees.

4. Use a sine plate. I've never used one, but this might be the time to learn.

Thanks!


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## graham-xrf (Mar 24, 2020)

Something like one of these? --> LINK
That was from UK.

Similar looking thing here -->  USA LINK
The price looks somewhat out of step!

You can get a single, very accurate 45° angle block reference to set up the tilt of a block in the vise under the milling cutter. search eBay for "angle block". You can get a set of two, as 30°-60°-90° and the other as 45°-45°-90°. They claim 20 arc-seconds accuracy i.e. 20/3600 = 0.0055°. This for about $30.
Ahh..Haa, this looks like it!  --> Angle Block 2-Set (USA)

I have been considering one of those square digital level indicators that have accurate sides and stick on magnetically. If you have a tilt-able machine vise, and given there are two decimals on the angle, it may be accurate enough. I am still not sure of those if risking relatively low cost. I want something of decent quality, and I would rather save up for a good one. I know I saw one on YouTube that was featured 2 decimals accuracy, not one.


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## Mitch Alsup (Mar 24, 2020)

I, myself, bought 45º and 30º angle sets. These are like parallels (1/8" wide) but are accurate 45º and 30º wedges. Mine are probably accurate to 0.001,5 for 4". This is better than the adjustable blocks can give.


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## ErichKeane (Mar 24, 2020)

5" Sine bar. If you have gauge blocks, they are absurdly accurate. Otherwise, if you can accurately mill a block within a few thou, they are still super accurate.

ETA: with a 5" sine bar at 45 degrees, it is about 11 thou difference in blocks between 44 degrees 59' and 45( and about the same the other way).

So if you have the ability to mill something within +-10 thou, you can be accurate to the minute.


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## MikeInOr (Mar 24, 2020)

When I made my V blocks I just used a V grove cutter in my mill.  For my uses they are plenty accurate... if you need high accuracy this might not be for you.

Or you might consider clamping your V blocks flat and tilting your mill head to 45 to mill them.


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## benmychree (Mar 24, 2020)

No body has asked the question as to how accurate this vee block needs to be, or what use it is to be put.  That has a lot of bearing on what extraordinary measures need be taken.  I am not very sure that the angles need to be accurate or even equal for most ordinary purposes.  If accuracy is necessary, likely the product would need to be heat treated and ground.  If I had no means of holding the part, such as an angle vise, I'd think of dropping a corner of the blank in the mill table's tee slot and at each side use two pieces of round bar with cross holes drilled in each end for ready rod to clamp them together alongside of the blank snugly and then securely clamp down on the top edge with strap clamps from one side and possibly provide some means of resisting endwise movement.


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## graham-xrf (Mar 24, 2020)

ErichKeane said:


> 5" Sine bar. If you have gauge blocks, they are absurdly accurate. Otherwise, if you can accurately mill a block within a few thou, they are still super accurate.


You are absolutely right.
You don't even need the gauge blocks. If you can knock up a block to a thousandth or two, maybe rub it down a bit for the last smidgen on abrasive paper, and use a micrometer. Maybe a caliper would be enough. Make a  "use once" substitute for a gauge block.


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## bill stupak (Mar 24, 2020)

graham-xrf said:


> Make a "use once" substitute for a gauge block




Or use an adjustable parallel


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## Tozguy (Mar 24, 2020)

Do you have a combination square?, just remove the rule from the clamp and you have a 45 deg gauge.


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## Winegrower (Mar 24, 2020)

The digital angle gauges (I bought one) are really kind of toys for metal working.   It's OK for woodworking, and I use it to set table saw blade tilt, for example, but it would not be usable even for picture frame mitering, if you have any sense of perfection.   

They are somewhat handy if the two surfaces you are referencing are not level to earth and/or in direct proximity, which happens for me once a year or so.


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## epanzella (Mar 24, 2020)

Back before I had a mill I needed to make a carriage stop for my lathe. The sticking point was how to make the 90 degree included angle to sit on the V-way. This was basically an inverted V-block. I had no mill or 45 degree cutter so I square notched the block on a milling attachment and welded in a piece of angle iron that had the 90 degree angle that I needed. I'm still using it to this day.


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## Radials (Mar 24, 2020)

I needed a part tipped up at 45 degrees before and using CAD I simply laid out 3 points on a plate, drilled, reamed and pushed in some pins for the part to rest on. This idea perhaps could be scaled up or down to suit your needs.


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## Rootpass (Mar 24, 2020)

Joe piezenske (spelled wrong I’m sure) on YouTube has a great video to make simple angle gages. I use his method a lot. I just made a 2 degree angle to mill the mount for my DRO yesterday.


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## homebrewed (Mar 24, 2020)

I've made angle blocks for special angles.  I drilled two holes in a rectangular plate -- one was on the bottom corner of an imaginary triangle, and the other was at the apex.  The tangent of the angle is  rise divided by run, so if you know the base of the triangle (the "run" part) you can calculate the "rise", which will be equal to run*tan(theta) .  Then I put a dowel pin in each hole and rested the pins on the top surface of my milling vise, tightened the vise down and milled the block flat.  To support work you want to mill at an angle, leave a step on one side of the block so the work won't slide down the angle block.  Obviously, the angle block has to be thinner than the work you want to install in your vise.

The approach of directly using dowel pins inserted in a plate would work, too.  One advantage of that approach is that you might be able to drill multiple holes to get several different angles.  I kinda like that idea.


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## MontanaLon (Mar 24, 2020)

If you have a DRO you can use it to lay out the holes for the pins with a high degree of accuracy. At least on my DRO I can. You can define a starting point and then ask for a hole location a given distance and angle away. Put pins through the holes, put the material in the vise with the pins resting on the top and mill it flat. Instant angle block. Well nearly instant and you can set it to any angle you want to create.


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## mickri (Mar 24, 2020)

How accurate you need the V block to be is the key.  If it has to be very, very precise you will have to buy them.  If all you need is your garden variety V block you can make them.  Since V blocks are almost always used in pairs you should make the block long enough so you can cut it in two.  No matter what the actual angle is both V blocks will be identical.  I have used my framing square for 45 degree angles.  For other angles I have cut a block of wood to the angle that I wanted.  You could also use plastic triangles.

If possible one thing that I like to do is have the work sitting down into the gap in the vise so it is resting on the two edges.  Like this.




Mr Pete has a video on milling a V using several different methods and he was surprised at how accurate the V came out using the simplest, easiest method with no fancy math.


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## MontanaLon (Mar 24, 2020)

ARC-170 said:


> I need a little advice on how to set up a 45 degree angle. I'm making a V-block and need to tip it 45 degrees to make the cut for the vee. I have a V-block, but it's too big for the vise on my mill. I would normally borrow a 45 degree v-block from work, but that's not possible due to the Plague. So, I'm wondering what other options I have.
> 
> OPTIONS:
> 1. I saw this: https://www.ebay.com/itm/Toolmaker-...484553?hash=item5227a5a1c9:g:Tm4AAOSwPW9dy6NJ and thought it might be a good tool to have. Thoughts?
> ...


Actually, now that I have thought about it, doing a 45* angle block would be easy even without a DRO. Use an oversize piece of stock, drill a hole at a point. Advance 1" on the x axis and drill a second hole. Advance the y axis 1" and drill another hole. Actual distance isn't important as long a they are the same. Probably best to use a reamer also to get a tight fit but even that isn't hugely important as long as the holes are all the same size. Using pins put them in 2 of the holes and rest it on top of the vise. Mill the face between those holes flat. You will want to leave space above the holes so don't cut tight to it. Cut the 2 short sides using the same depth of cut. They have to be the same length or you will end up with inaccurate angles. Then mill the long side the same way but the height above the pins doesn't matter. When you are done milling you will have an angle gauge to set your stock on to make it an angle block.


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## mickri (Mar 24, 2020)

Another thing that you might want to consider is milling a slot in the bottom for a tab that fits into the slot on you table.  Or you could screw the tab to the bottom.  This will keep your V blocks in alignment.  Without this you will have to align your V blocks every time you use them.


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## ARC-170 (Mar 26, 2020)

Here's what I'm making:



I'm making just one. I've cut everything except the 45 degree vee part. I was taking a machining class at the adult school machine shop in the school district where I work and got most of it done. They have a really accurate v-block there for clamping the part in a much larger machine to make the vee. I have a small v-block, but it's too big for my mill vise. The one I'm making will fit.

I was going to use the one I have to test the dimensions of the one I'm making.


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## ARC-170 (Mar 26, 2020)

Tozguy said:


> Do you have a combination square?, just remove the rule from the clamp and you have a 45 deg gauge.



Ya know, I hadn't thought of that! I have a Starret one that might be pretty accurate. Thanks!


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## ARC-170 (Mar 26, 2020)

I watched the Joe Pieczynski video. It's just as homebrewed and MontanaLon describe. I've got a DRO and some aluminum plate scrap I can use. I just need to get some metal dowels. I have a lathe and could turn some, but I don't have any round stock at the moment. I guess I could use square stock and turn it round.

So no one likes the adjustable angle v-block, huh?


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## MikeInOr (Mar 26, 2020)

The head on you mill doesn't tilt?


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## MontanaLon (Mar 26, 2020)

ARC-170 said:


> I watched the Joe Pieczynski video. It's just as homebrewed and MontanaLon describe. I've got a DRO and some aluminum plate scrap I can use. I just need to get some metal dowels. I have a lathe and could turn some, but I don't have any round stock at the moment. I guess I could use square stock and turn it round.
> 
> So no one likes the adjustable angle v-block, huh?


They are OK but setting accurate angles is a lot of work. You set it by eye, indicate, tap, indicate, tap until the trigonometry works out. If it is an angle you will repeat often, 45*, 30*, 60* it is best to have a block set up just for that angle to save time.

For the pins I have used 1/4" HSS round stock and drills. Both work and are handy.


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## ARC-170 (Mar 26, 2020)

MikeInOr said:


> The head on you mill doesn't tilt?



No. I stayed away from tilting heads.  Besides, I'd need to find some way to make sure it was, in fact, EXACTLY 45 degrees.


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