开云体育

Rick:?

开云体育

开云体育

That’s how you sell sequels!?

开云体育

开云体育

Clever!?

Here is a of how I converted a hockey puck to a hand wheel drive.?

Rick

Hi aRM,

sorry for being confusing. ? I have been communicating with John V on his paper regarding this topic. ? John is advocating machining the pivot shaft to get the pivot shaft parallel with the table. ? This is necessary to cut square in the vertical direction. ? ?Because my saw frame holes and my table casting bushings were so challenged, I decided to make a pivot shaft to fit the saw frame holes and table casting bushings an leave this alone. ? I chose to file and grind my table so it was flat and parallel to the pivot shaft.

Did you find Johns paper? ?It’s a good read on this topic. ? I highly recommend that you read it. Look at post 15710 for the paper.

Dave

OK.. I'm *finally* getting to the modification I wanted to make over Christmas vacation.? ?These are:

1. A guard to protect my down feed cylinder when loading long pieces of steel (I banged my cylinder once).
2. A blade scraper so I can run cutting fluid/coolant/lubricant on the blade, especially when cutting aluminum.

The blade guard is pretty self explanatory.? ?I made it out of 16 gage sheet metal.? I slotted the holes so I could adjust the height, but I decided to have it sit about 3/16" of an inch below the table height.? ?The guard is the same length as the table.? ?I jsut want it to set the material that I'm going to feed the saw and I didn't want it to interfere with how the part sits on the saw table.

I also made a blade scraper.? ?I decided to make this out of 26 gage sheet metal - I would have preferred to make it out of 20-22 gage sheet metal but I didn't have any.? ?It consists of a plate that is folded on the bottom to create a race for the two scrapers.? I made another plate that just goes in the folded part to set the scraper race height.? I used a spring that I had left over from upgrading a couple of can lights to LED can lights.? ?I bent the spring by hand.? The spring is allowed to pivot on the flat head screw and puts a slight force on the two scrapers which put a small force on the blade.? I did this design because it was something I could make with my tools, it was light, it was adjustable and it would put a uniform force on each side of the blade and wouldn't deflect it.? The scraper would also follow the blade if it had any thin spots (like the weld area).? I have about 1/4" of allowable blade movement in my design.? The blade scraper uses the stock table as the backing surface and uses the stock screws to hold it together.

Dave

Hello? there David from deep down across the? pond in South? Africa
U have? really done Some fantastic? work to make Your? Saw cut so accurately
For us "Non-tech Newbies",? would have been nice to complement? Your improvements with? some progressive PICTURES.
Do think? about? this? for? any? future major Alterations? and? rectifications?
Thanks all the? same
Kind? regards and? ATB
aRM?

It's been a slow slog, but I think I have fixed my saw vertical and horizontal saw cutting issues.? ?Currently, I'm able to cut in the vertical and horizontal at less than .001"/" (my goal).

My saw had a number of issues.? These include:
1. The holes in the saw frame and table casting bushings were way too large for my pivot shaft.? ?The clearance was something like .006".? It should be less than .001" for this sort of application.? The hole on the left and right hand of my saw frame and table casting bushings were different diameters (as looking at the vise hand wheel).? ?Luckily, the left saw frame hole/table bushing and the right saw frame hole/table bushing were close to the same size.
2.? The pivot shaft was not parallel to my table, hence I was cutting about .020" out of square (primarily in the vertical orientation).? My table was low on the left hand side.

I machined a new pivot shaft and it fit *really nice*.? ?I decided I didn't want to mess this up and decided I needed to lower the right hand side of the table.

I put shim stock under a 1.5" diameter steel shaft on the left hand side and determined that I needed in excess of .030" shim to cut square.? ?I started to file the table by hand.? I got over 1/2 of the way there by filing by hand, but then I decided to break out the Makita angle head grinder and finish the job.? ?I used a flexible disk, 80 grit, in the Makita and ran it lightly over the table, measuring often.? I used the file to indicate the high spots and also partially flatten the table.? ?I then followed up with the grinder on the high spots, filed more, etc. etc.? ?I'm pretty sure that my table is within .002" from flat on the entire table and less than .0015" on most of it.??

Key things to note when doing this:

1.? You have to keep aligning the blade guides before each time you make a test cut (after filing/grinding on the table).
2.? You have to have your blade tension constant.
3.? You have to cut two pieces:? One before the measurement piece to properly get the cut piece to represent the new saw setting and then the piece you will be measuring.
4.? The vertical and horizontal measurements affect each other.? ?When I was dialing in my vertical, I had to dial in my horizontal too.

If you want to make your saw cut more square, it can be done.? ?My goal was to have everything within .001"/".? When trying to achieve this, you need to have everything correct and you need to move in on it slowly.? ?I chose to file/grind my table rather than follow John V's recommendation of reducing the size of the pivot shaft.? This is because my saw frame holes and table bushings were so messed up.??

Ultimately, I achieved around .0005"/" on the vertical and .0004"/" on the horizontal (average over 5 measurements).? ?Note, that due to the surface roughness, measurement repeatability, inadvertent swarf under the part being cut, etc., I would say that this measurement can vary +/-.0015" (or better).? You have to make multiple measurement on successive days to really know the average machine setting.

I finished the work last night and made another cut today.? ?The red line was the top of the piece after the initial piece was cut off.? I used the line for a gage to rotate the shaft 180 degrees for the parting cut.? ?This part came out .0002"/" for the vertical and .00016"/" for the horizontal.? ?I figure my micrometers are measuring on about 1.25" diameter (my part is 1.5" diameter).

I agree, yours is an elegant solution to the problem you faced.
It actually allows an additional mod. that the standard vice does not - you now have the strength in the vice base to tap a series of holes to fit the studs from your milling step-clamp set, so you can clamp irregular shaped objects directly to the vice table.? This is esp. handy for cutting angles >45deg or mitering work too wide for the std vice opening, if you remove the movable vice jaw.? The std vice base is too thin and the cast iron too weak to do this - jv

>>I suspect that the sawframe casting was not machined down enough on the back where the chromed guide bars bolt on (min 3:55 of Video 1), pulling the whole axle assembly including the top wheel too far into the hollow of the sawframe.

Basically I agree although I think I'd probably have to shim both wheels. Unfortunately, shimming the wheels with washers would also shift the blade to the left. Currently both my blade guides are adjusted to the limit to the left. They are close enough but to be in the optimum position they need to go slightly further left. So basically after shimming both wheels I would also have to modify both blade guide significantly.?

At least for me the plate was an easier fix.?

Hi Mark

Sorry I haven’t weighed in on this discussion earlier, I was in a place with no cellphone coverage.

You correctly surmised that the blade should run from the wheels and only be twisted long the neutral axis (middle) of the blade by the guides with the blade-back just skimming the rear roller, but that this then ‘buried’ the blade too deep within the sawframe casting to complete the cut, and no amount of adjusting the depth stop would make it work.

Your fix and modified blade guard do the job very well, but I wonder what the initial problem was. ?

I suspect that the sawframe casting was not machined down enough on the back where the chromed guide bars bolt on (min 3:55 of Video 1), pulling the whole axle assembly including the top wheel too far into the hollow of the sawframe.

A quick fix would have been to put a few 5/8” ID washers in between the blade tension guide block and the extension of the axle through the tilt adjustment block that’s pinned to the axle. See the attached picture.? The axle locking bolt and the tilting adjustment setscrew might need to be replaced with a longer ones.

This would shift the whole top wheel + adjusting mechanism out, according to how many washers you put in.? Because the lower guide is quite a way up the blade, shifting only the top out would also shift the blade out at the lower guide too. It’s unlikely that the bottom wheel is also shifted back, but if that was the case, lengthening the spacer behind the bottom wheel with some of the same washers would fix it. - jv ???

Hello? Dave
That is one of the finest Commercially Produced Grinders U could own. Although we are from South? Africa, I had? looked at and studied the Machines that were available in Your Country and? we? did eventually buy a locally produced Proper Belt Grinder specifically for Knifemaking.? That was a long time ago.
Wish you all the best in Your shop Set-up and? Machine Outfitting.? You are indeed lucky U have the time and access to some remarkable and? economical Equipment.? ? ?
ATB.? TC.??
kind? regards?
aRM

I made my grinder from a 1 hp pump motor.?

https://youtu.be/9BYlGw5VPns

Yeah...? I don't fully load the blade unless I'm cutting 5-inch bar or the likes.?

A feeler gauge works well for the blade guides but I have mine set good. The weld is slightly thick and I had to back it off slightly.?

>My blade guides are slightly changing the alignment of the blade from the wheels.

Yeah...? mine are too, primarily because they are at the limit of adjustment but a little deflection is okay.

Fortunately the pivot on mine is aligned perfect even if it is too high. The saw will now cut perfectly square.?

I have looked and looked for the Grizzly video and can not find it. Basically it confirmed what I showed in the first video about twisting the blade and not deflecting.?

Mark?

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Hello Arm,

Yes, this is a Burr King, model 562 1"x42" belt grinder.? ?I was fortunate enough to buy this from a friend for these things are not common where I live.? This is a really nice tool.? I don't make knifes.? I'm just developing a hobby so I can have something interesting to do when I retire.? ?I'm basically building up my shop.? ?I'm not into buying the latest and greatest shop equipment, but I'm getting equipment that has good bones but could use a little attention.? ?I have been doing some case hardening of CR1018 steels to make punches and dies for my little Whitney press.? I use an electrical dental burn out oven (about a 6" cube capacity) for this.? ?I haven't gotten into the larger kilns nor using a torch to heat my parts before quenching.

Dave

Hi Mark,

I don't fully load my blade - I probably only load my blade to 5 -6 lb.? ?I believe that the bow weight should not exceed 8 lb (as measured by the force to support the saw on the end of the saw frame).? ?I added a hydraulic down feed cylinder which helps significantly in keeping the blade cut rate pretty constant.? This helps blade life alot, especially if you are sawing a piece that has significantly different cut thickness.? ?With my hydraulic down feed cylinder, my blade life is fine.? I use a 14 TPI blade.

I watched your video.? ?I weld my own blades, but I take a dremel tool and try to get the blade body as uniform in thickness as possible.? ?This may help you get your blade to a more uniform thickess.? One thing you may want to try is to set your guide roller gap by using a feeler gage.? I think you should have slight blade drag when you try to rotate the rollers by hand.

My blade guides are slightly changing the alignment of the blade from the wheels.? ?I am just leaving it alone.? ?My problem is that my pivot shaft isn't parallel with my table.? ?I had to make a new shaft for the shaft to bushings gap was too large.? ?Now, that is good, but my shaft is still not parallel with my table so I cut a taper in the vertical axis.? ?I'm trying to fix this by hand filing my table.? My table was fairly cupped before I started, now it's flat to better .002".

I only watched your first video this morning.? ?I see that you have three videos posted on this topic.

Could you add a link to the Grizzly video?

Dave

Yeah...? the left side arm is a good option if the saw body need to be lower on one side but my saw needs to be lower on both sides. Fortunately the pivot on my saw was dead on square. Watch this video and you will see what I mean. This is part 1 of three videos. It doesn't show the elivating plate (that's in part 2) but it explains the problem well.?

I know some of these saws are made correctly but I'm fairly certain other saws have the same problem as mine. I guessing some people also adjust the blade guides to compensate which is not the best option. My saw was set up like that when I got it. Aside from eating blades it cut well. With the guides set up correctly I can cut with full pressure and never knock the blade off.?

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https://youtu.be/SzjqDqpWRCA