New Shop Tool: Covel Surface Grinder

This little beauty will arrive thursday or friday. it's a covel model 15 surface grinder. when i found this thing mariah
advised against it. on her advice i passed on it. the owner later contacted me and for the cost of shipping it's mine. Surface Grinder.jpeg

by its' serial number and from chatter on practical machinst it looks to be a 1945+-
vintage. it has sealed bearings on the spindle and the gits oilers are not present.
other than i know nothing about its condition, if it is serviceable, if it will kill me,
i find out when it gets here. it could be 900 pounds of scrap.

i did manage to pick up two 12' sections of 1.062" and 1.75" 4140 round bar which
can be seen cut to 4' lengths and strapped to the pallet. some guy on ebay was
selling them for $40 and $16 respectively, couldn't pass that up.

the first thing i am going to do is clean it up and indicate the run out. these things
had the ways chrome plated after being flaked. i have a spare 3 phase 1.5 hp motor
here some where if the existing motor tests bad.

cool :oops: if it doesn't kill me!
very cool phil.
I just pick up a new 6inch 4 jaw and a 3 jaw with set of reverse jaws too and they are large jaws different then my original 6inch 3 jaw unit that are smaller and a 8 1/2 face plate with 8 slot. all for 200 bucks. just couldn't pass it up. I mounted both chunks up and they where spot on. my face plate was old and use and that was .005 out of round. should be easy to true it back up....

here was the cool part . the guy had a 8inch (I believe) shaper for sell too. I had no use for it,but really cool to see...

that was the deal of the month for all that hardware! good score. i would like a good three jaw, mine is cheap
chinese crap and pretty much holds the shelf down, it's ok when i am making one spacer but past that it is
a +-5 thou chuck. do a video or at least get some pics truing up and indicating the face plate, that's a BIG

that shaper looks like fun. there was one on ebay that i thought about but i was persuaded not to. my mill can do
pretty anything i need and my shop is so small that i have to add floor space consuming equipment very prudently.
the surface grinder is getting shoehorned in between the mill and the door.


this is my latest little project, the upper half of a sine plate. still have to countersink the threaded holes, finish the surface, attach the sides,
finish the bottom plate, $500 to buy, or $10 bucks worth of 1018 and my labor, it's a no-brainer!

here is my apprentice drilling and tapping !
wow phil when did you pick up the mill. I see you have the wife doing all the next clone motor you build you can have her mill the head .050 off.
yes shaper kind of obsolete in a round about way. still cool to see this one.
the face plate would be easy to do. after threaded on correct you just come in and take off .005 and you should be true again.
the mill arrived here in september of 2017. almost two years later i am able to keep run out in the low thou range over reasonable ranges.
it is harder than one would think to maintain reasonable tolerances. i began trying to convince myself a cnc mill is needed next.

a shaper would be retro cool to have. i like watching abom79 taking 50 thou steps with 1/4" deep cuts with HSS bits on his 32" behemoth
shaper.. the chips look like hair curlers! maybe when i add some footage to the shop i can indulge in coolness like a shaper.
i did some initial testing on the table ways. stuck an indicator on the column with the indicator
being on the table. this is my cheap $21 chinese shop indicator with .001" resolution so it isn't the most
accurate thing. however end to end i am seeing a few tenths total run out. i didn't stone the table
yet but this still encouraging that x ways are still good.
right side of the bed and reference point.

the middle of the table.

the left side.

there is some surface rust and crud on the table so at some points it jumped a bit but nothing that
a good stoning (hehe!) wouldn't fix. i was expecting to see several thousandths of problems
but i am pleasantly surprised since i bought this fine piece of machinery against sage advice
and unseen.

it doesn't look like a bunch of progress was made on the grinder but with the
rain and black flies working with the shop door open was impossible especially
with the black flies. tucked away with the table ends was a spindle pump control
box with on/off buttons but unfortunately no cooling pump, it would have been a
nice treat.


it is off the pallet finally!

figured out the grinding wheel was a 10" x 1", the widest wheel this grinder can hold properly is a
3/4" wheel so it had to come off. made two spanner wrenches to fit the wheel flange nut and the
flange nut. both nuts are a bit buggered up, in time i will make new ones but these will work for now.




both spanners were made from mild steel. i need to make a wheel puller to pop the flange off, hitting the
spindle with a hammer to dislodge the flange is a no-no! i have a few feet of 3" durabar that will
get cut to 2" +- length to make the puller housing that will fit over the 2-1/4" x 12 tpi LH flange
thread. i have to reverse the lead screw direction on the lathe to cut the thread, a tap that size
runs $200 for a cheap chinese one or about $400 for a us made version so i will be turning these
threads on the lathe.


Phil, If you make a pair of hook spanners to fit the flanges they will stay in place better when you put pressure against them. Less chance of busted knuckles!
hook spanners are in order! i did bang up my hands when they slipped. i wish it had a flat belt, it has a vee
belt which i guess are noisier than a flat belt. after i do a few test runs to see if there are any vibration artifacts
in the finish we can figure if the flat belt is worth converting over to. i'm working on a wheel puller today.
whew! trying to machine a wheel puller to get the wheel flange off the surface grinder. the wheel flange has a
2-1/4" x 12 tpi lh male thread. the puller will have the same thread but female to engage the wheel flange OD and
a 3/4" x 16 tpi tapped center hole for the screw that engages the spindle.

what is happening is the hss boring bar is abrading away in one id pass. i have to resharpen after every pass.
my speeds and feeds are 500 sfm with a chip load of .0005". the material is durabar 100-70-03 Ductile Iron. at the
recommended feed of .008" the tool tip burns up quickly into the cut.

edit: the depth of cut is .025" but the problem occurs at smaller depths.

any ideas???
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Phil... 60-100 SFM for iron make sure the tool has clearance so it's not dragging on the thread. Compound at 30 degrees so ONLY one side of the tool is cutting. Make sure the tool is on center or just a hair below center. Depth of cut is set with the compound, cross slide is only used to retract tool for next pass. Stone a small radius on the tip of the threading tool for strength, this will save the tip from breaking. Keep the boring bar overhang to a minimum, wrap some plumbers solder around the butt end of the boring bar to eliminate tool chatter. Last resort...rub rabbits foot while watching internal threading videos on Utube!