A rollover scraper with minimum
- Thread starter MJPetersen
- Start date
Renze
Elite Member
Those drill bit hole saws, the guys in the welding shop use them all the time, but how cheap are they, and how expensive are good quality ones ???
OP
MJPetersen
Veteran Member
Renze,
I bought mine locally and it really was not too bad. The 24 mm saw was $5.50 Hitachi brand but the adapter was about $12. It is fine for standard steel, but you need a better saw for stainless or harder steel. The better saw is orange (sanvik brand??)and about $11.
You really should use a drill press to slow it down and keep it straight. I am using a 1/2 Milwakee hand drill that turns 600 and I am supposed to turn the saw at only 290-350. I take frequent breaks to add oil and let things cool. From what I have read if you are making a hole over 3/4 in (19mm) use a saw. My dirt scoop is the first that I ever used one. I used one because I could not find a drill bit 22mm (7/8 in). I like them and will use them more in the future.
Mike in Warsaw
I bought mine locally and it really was not too bad. The 24 mm saw was $5.50 Hitachi brand but the adapter was about $12. It is fine for standard steel, but you need a better saw for stainless or harder steel. The better saw is orange (sanvik brand??)and about $11.
You really should use a drill press to slow it down and keep it straight. I am using a 1/2 Milwakee hand drill that turns 600 and I am supposed to turn the saw at only 290-350. I take frequent breaks to add oil and let things cool. From what I have read if you are making a hole over 3/4 in (19mm) use a saw. My dirt scoop is the first that I ever used one. I used one because I could not find a drill bit 22mm (7/8 in). I like them and will use them more in the future.
Mike in Warsaw
kwolfe
Platinum Member
I have only been working metal for a very short time. I have picked up some cutting oil because everyone says to. My question is, is the oil only to help cool the bit. Could you use a constant flow of cold water from a garden hose, or do you need to need to lubing properties of the oil as well?
OP
MJPetersen
Veteran Member
We better have 3RRL or Larry or some other of the machinists jump in here on that one Kwolfe. I use oil, because the bit lasts LOTS longer, you get a much smoother cut, and because I have always used oil.
From high school metal shop I started using oil when cutting and have always used it. I do not normally have cutting oil, but I use atf or engine oil mixed with diesel. I know that some have their own little formulas for cutting and they use one kind for cutting this and another for cutting that. On the saws they say to use oil for drilling steel, but nothing for cast iron. I do not know why. Great question!
Mike
From high school metal shop I started using oil when cutting and have always used it. I do not normally have cutting oil, but I use atf or engine oil mixed with diesel. I know that some have their own little formulas for cutting and they use one kind for cutting this and another for cutting that. On the saws they say to use oil for drilling steel, but nothing for cast iron. I do not know why. Great question!Mike
OP
MJPetersen
Veteran Member
OK the progress is that i bought a new piece of 100x100mm box 1290mm long for the main cross bar to which everything attaches. I made the side arms and welded them together with the short square cut pieces of pipe that goes on the side and the side arm for a pivot. I really need to get a drill press for those hole saw cuts.
The real Gannon has a brace from the front of the side pieces to the back blade, I did not want to do that. I believe that it is to keep the blade flexing from popping the pivots out of the socket on the side arms. I figured I would just bolt it together instead, but I put the pipe inside of pipe also. It is not a tight machined fit, but I think that with the whole it is good. I will trim the bolt off flush with the locking nut.
I set it up about level so the sides are even and welded the side arms to the main cross bar. Next is the 3 point connections
The consensus on Bob's survey of box blades was that captured drag links are preferred over just a pin, so i drilled the 4 holes necessary for the drag link connections and welded them on.
I think that it came out well. I will make the toplink connection next. I considered the style like is in RichT's pictures for the top link (it goes straight up from the main beam), but I think that instead I will use my original thought of a flat plate to made a tent to the top link pin. it is not sized nor welded in yet, just looking.
The real Gannon has a brace from the front of the side pieces to the back blade, I did not want to do that. I believe that it is to keep the blade flexing from popping the pivots out of the socket on the side arms. I figured I would just bolt it together instead, but I put the pipe inside of pipe also. It is not a tight machined fit, but I think that with the whole it is good. I will trim the bolt off flush with the locking nut.
I set it up about level so the sides are even and welded the side arms to the main cross bar. Next is the 3 point connections
The consensus on Bob's survey of box blades was that captured drag links are preferred over just a pin, so i drilled the 4 holes necessary for the drag link connections and welded them on.
I think that it came out well. I will make the toplink connection next. I considered the style like is in RichT's pictures for the top link (it goes straight up from the main beam), but I think that instead I will use my original thought of a flat plate to made a tent to the top link pin. it is not sized nor welded in yet, just looking.
Attachments
Renze
Elite Member
MJPetersen said:On the saws they say to use oil for drilling steel, but nothing for cast iron. I do not know why.
Mike
Cast iron contains a lot of graphite. The graphite works as a friction modifier. In the old days, they used cast iron pillow blocks as slide bearings. My technical handbook says that, for cast iron on mild steel sliding, a higher surface pressure is allowed than mild steel on mild steel.
thank you for your info on the hole saws... i need to get some, as i have a drill press with 12 speeds, slow enough for big hole saws. 11 $ is way less than i expected....
I think i need 22 and 28mm hole saws, corresponding to Cat.II three point linkage, to fit most of my farm fabrication needs.
HomeBrew2
Banned
kwolfe said:
One of the machinists would be the best for a good answer. I'll offer a quick version. If you have cutting oil, use it. If you have cutting fluid system, use that. Do not use cutting oil like cutting fluid. Cutting oil is to lube the cutting area BUT, the chips must be free to move away from the area as though they were dry. Cutting fluid does the same thing BUT the SYSTEM is designed to wash away the chips from the cutting area. Cutting oil used as cutting fluid is bad. Lube w/ oil as though it costs $1000/gal
RichT
Silver Member
MJPetersen said:
Mike, looks like you're making good progress on a Gannon replica. It is a bit small for the bota, but will cover the tire tracks except for a hard turn. The teeth are secured by a bar which slides through the square tube, through notches in the tooth stems, and pinned on both ends.
My Gannon is 40in wide. To convert it from cat0 to cat1 I had to add some eyelets. See attachments for some dimensions. In the last attachment the tooth sliding bar is visible on the left and the added 'square' eyelet is visible on the right-outboard of the two cat0 'rounded' eyelets.
Attachments
OP
MJPetersen
Veteran Member
Thanks RichT,
That does help me get a better picture of some things. I like the top link that you have. I have already bought the material for different, but if I do not like it I will be coming back to your arrangement. I was surprised to see that yours does not rotate in the middle of the side plates. And the scarifier box is not touching the blade.
Do you mean that if the center tooth broke that you would have to pull the rod out and thereby dropping several teeth before you got to the one that you wanted? You cannot pull them individually?
Mike
That does help me get a better picture of some things. I like the top link that you have. I have already bought the material for different, but if I do not like it I will be coming back to your arrangement. I was surprised to see that yours does not rotate in the middle of the side plates. And the scarifier box is not touching the blade.
Do you mean that if the center tooth broke that you would have to pull the rod out and thereby dropping several teeth before you got to the one that you wanted? You cannot pull them individually?
Mike