Re: Widening an existing hole with a drill bit: how to guarantee concentricity?
Use a drill press. Chuck in an m12 drill and use it to center the hole and clamp the object. replace the m2 with an m13 drill bit.
Drilling by hand allowing the m13 drill bit to ¡°seek its center¡± will get you close but not guaranteed to be as good as the above.
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Re: Widening an existing hole with a drill bit: how to guarantee concentricity?
? ? ?From my own ham-fisted experience, boring will give better results.? If you must drill, using a short bit can help.? Also, try enlarging in more than one step.? Have you experimented with a piece of?scrap steel?
On Wed, Apr 19, 2023 at 9:04?PM Steve Johnson < steve@...> wrote: If you have a drill press, I would put the 12mm bit in the chuck, with power off lower the chuck/bit into the piece, then clamp the piece to the drill press table. Raise the chuck, replace with 13mm and drill
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Re: Widening an existing hole with a drill bit: how to guarantee concentricity?
If you have a drill press, I would put the 12mm bit in the chuck, with power off lower the chuck/bit into the piece, then clamp the piece to the drill press table. Raise the chuck, replace with 13mm and drill
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Widening an existing hole with a drill bit: how to guarantee concentricity?
Hi gang,?
Tried Google but wasn't able to get a definitive answer.?
I have an m12 hole (which is supposedly perfectly centered) and I want to widen it to m13.?
Assuming I do this using a hand drill + HSS twist drill bit, will concentricity (new hole exactly concentric to original home) be guaranteed (assuming I start off the operation at close to perpendicular)??
My hope is that the existing "pilot" hole will force the drill bit to match it's concentricity.?
I'm not sure if this is true.?
For context, I have a m12 er16 collet chuck, and I want to widen it to take m14 thread.?
PS:
My lathe is still out of commission, so I can't do other turning methods like boring.?
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Re: Slitting on a Unimat SL?
#db200
Just got back from our local hardware store and picked up a Diablo 7-1/4" finish blade, the kerf is 1/16, which is perfect! I'll make a nice sturdy sled for the motor mount and slit away. Should be able to cast the part tomorrow, realized my casting flask was too small and had to make a larger one out of baltic birch.
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Re: Slitting on a Unimat SL?
#db200
Those round carbide blades for a coping or hacksaw work great for this and are wide enought.
?Jeff
-----Original Message-----
From: Guy Winton <kooldude@...>
To: [email protected]; steve@...
Sent: Wed, Apr 19, 2023 11:28 am
Subject: Re: [Unimat] Slitting on a Unimat SL? #db200
Back in the stone age, some folks would place 2 hacksaw blades, side by side, on a hacksaw frame and just manually saw the slot.
-Guy-?
On April 19, 2023 at 10:52 AM Steve Johnson <steve@...> wrote:
I am casting a new motor mount for an SL Unimat. I'll be using green sand, cope/drag, and as such I will have to cast it with the slot/slit(?) on the clamp side filled in. I'm at a loss trying to figure out the best way to cut this back in after casting. Band saw? Too thin. Table saw? Too thick. Unimat? I don't know where to begin.
So this is what the original motor mount looks like:
This is the printed 'positive', and is what the aluminum casting will look like:
Thoughts?
?
|
Re: Slitting on a Unimat SL?
#db200
Regarding 3D CAD packages, there are people that get along well with parametric modeling, and then there are people that don't.? I'm one of the "don't" types, several years ago I read a white paper that said some people's brains are wired for parametric modeling and some are wired for direct modeling.? Don't get frustrated if parametric modeling doesn't suit you, try direct modeling - or vice-versa.? For the life of me I couldn't wrap my head around Fusion 360 several years ago, but Designspark just made sense.? There are other 3D CAD packages that use direct modeling, I think Sketchup is one of them?? I think Autodesk's 123D was also a direct modeling software, legit downloads of that software are still available if you search for it.
Over the years I have tried Fusion 360, Alibre, and FreeCAD - I get along better with a direct modeling software like Designspark Mechanical than I do with Fusion 360, Alibre, or FreeCAD.? The bad news is that as of 5/31/23 Designspark will go from a "free" software to a subscription software.? There will still be a free version, but it won't do everything the "free" Designspark v5 does now.? Kind of like what Autodesk did to Fusion 360 a while back.
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Re: Slitting on a Unimat SL?
#db200
Good point! I think this application isn't so tolerance critical, but I'll remember this for future parts where it would make a difference.
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Re: Slitting on a Unimat SL?
#db200
Just remember that with aluminum casting the pattern for the casting needs to be about 103% of the desired part size, to allow for shrinkage as the casting cools to ambient temperature.? The same thing will happen with 3D printed parts, they shrink as they cool.? That's why a print that takes a long time tries to warp and pull off the print bed. If you're just printing knick-knacks then it doesn't really matter, but if you are trying to make a part that needs to bolt up to something else - you better allow for shrinkage as the part cools.? That or be ready to fettle each part to get it to fit.? DAMHIK
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Re: Slitting on a Unimat SL?
#db200
Hello
Bill and Steve:
I like
On Shape, a free on line 3D package. If you want private
storage, you can pay more.
It was
written by folks from Solid Works, so functions about the
same.
I
really like the "Parametric" features: keep hole in center,
make spaces even, etc.
Carl.
On 4/19/2023 1:59 PM, Steve Johnson
wrote:
toggle quoted message
Show quoted text
Attaching the .stl files. There is a full piece, and then a bottom
half piece. For the green sand two part mold, I'll first use the
bottom half piece, fill one half of the mold with sand, pack it
firm, then flip it over, remove the bottom half, replace with the
full piece, dust with talc, add the top part of the mold and
fill/pack with sand. Cut in sprew and vent. Then lift off the top,
remove the full piece, replace the top, and pour.?
Sounds like we are on similar/parallel paths - yes,
same exact DC motor (3 holes instead of 4), and to SLs, one
lathe and one mill.
Might give Fusion 360 a try. I can help answer
questions with that but not the others.
On Apr 19, 2023, at 11:48 AM, William R.
Meyers < wmrmeyers@...>
wrote:
One like
yours would be a good start, I think. Motors I'm
going to be using are the ZY6812 150W 24vdc
motors. Drawing for them shows 4 holes, but I
think the motors actually have three, like you
mention. I have Solid Edge loaded on the computer,
and don't seem to have enough concentration to
stick with the training videos. Had the same
problem with Solid Works, and FreeCad, and all the
others. I've got two Unimats, a DB & an SL,
according to their labels, but both are alloy
castings. One has plastic handles, the other
aluminum. Planning on setting one up as a milling
machine, and the other as a lathe. Also planning
on having slow-speed and high speed capabilities,
by changing out the motor plates and pulleys.?
I do
have a larger lathe, an Atlas TH42 that is
operational, and three other machines that are
supposed to be milling machines. One of them might
actually work with a little TLC.?
Bill in
OKC
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms
to live by:
Good judgement comes from
experience. Experience comes from bad
judgement.?
SEMPER GUMBY!
Improvise,
Adapt, and Overcome.
Physics
doesn't care about your schedule.
The only
reason I know anything is because I've
done it wrong enough times to START to
know better.
Expect
in one hand, expectorate in the
other. See which one gets full
first.
On Wednesday, April 19, 2023 at
12:08:35 PM CDT, Steve Johnson < steve@...>
wrote:
Bill, if you are needing a mount
like mine, for a DC motor and without the
idler shaft clamp, I will happily share my
.STL file with you.
I will definitely be investing in slitting
saws, just need to figure out what would be
best for the little Unimat SL Mill setup. In
the meantime, I'll take a few shaves with my
band saw.
For 3D design, once you get going you won't be
able to stop designing and printing. Sometimes
I just print little templates and jigs. For
example, the DC motor has 3 holes, 120 degrees
apart. While I could lay it out by hand, I'll
design a little template with the 3 holes, and
a center extrusion to self center on the big
hole in the mount.?
I highly recommend Fusion 360 - there is a
free version, Mac or PC, which will do
everything you want. A learning curve, for
sure, but there are? gazillions of how-to
videos online. I stick to some basic
primatives, every now and then I get to learn
some new tricks.
|
Re: Slitting on a Unimat SL?
#db200
Hello
Steve:
Any
hack saw will do the job, band saw would be easier.
Carl.
On 4/19/2023 10:52 AM, Steve Johnson
wrote:
toggle quoted message
Show quoted text
I am casting a new motor mount for an SL Unimat. I'll be using
green sand, cope/drag, and as such I will have to cast it with the
slot/slit(?) on the clamp side filled in. I'm at a loss trying to
figure out the best way to cut this back in after casting. Band
saw? Too thin. Table saw? Too thick. Unimat? I don't know where to
begin.
So this is what the original motor mount looks like:
This is the printed 'positive', and is what the aluminum casting
will look like:
Thoughts?
|
Re: Slitting on a Unimat SL?
#db200
Got parts to make a separate power supply for each motor, and one (of 3) is probably going to become a tool post grinder...
Many thanks!?
Bill in OKC
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY!
Expect in one hand, expectorate in the other. See which one gets full first.
On Wednesday, April 19, 2023 at 01:00:06 PM CDT, Steve Johnson <steve@...> wrote:
Attaching the .stl files. There is a full piece, and then a bottom half piece. For the green sand two part mold, I'll first use the bottom half piece, fill one half of the mold with sand, pack it firm, then flip it over, remove the bottom half, replace with the full piece, dust with talc, add the top part of the mold and fill/pack with sand. Cut in sprew and vent. Then lift off the top, remove the full piece, replace the top, and pour.?
Sounds like we are on similar/parallel paths - yes, same exact DC motor (3 holes instead of 4), and to SLs, one lathe and one mill.
Might give Fusion 360 a try. I can help answer questions with that but not the others.
On Apr 19, 2023, at 11:48 AM, William R. Meyers < wmrmeyers@...> wrote:
One like yours would be a good start, I think. Motors I'm going to be using are the ZY6812 150W 24vdc motors. Drawing for them shows 4 holes, but I think the motors actually have three, like you mention. I have Solid Edge loaded on the computer, and don't seem to have enough concentration to stick with the training videos. Had the same problem with Solid Works, and FreeCad, and all the others. I've got two Unimats, a DB & an SL, according to their labels, but both are alloy castings. One has plastic handles, the other aluminum. Planning on setting one up as a milling machine, and the other as a lathe. Also planning on having slow-speed and high speed capabilities, by changing out the motor plates and pulleys.?
I do have a larger lathe, an Atlas TH42 that is operational, and three other machines that are supposed to be milling machines. One of them might actually work with a little TLC.?
Bill in OKC
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY!
Expect in one hand, expectorate in the other. See which one gets full first.
On Wednesday, April 19, 2023 at 12:08:35 PM CDT, Steve Johnson < steve@...> wrote:
Bill, if you are needing a mount like mine, for a DC motor and without the idler shaft clamp, I will happily share my .STL file with you.
I will definitely be investing in slitting saws, just need to figure out what would be best for the little Unimat SL Mill setup. In the meantime, I'll take a few shaves with my band saw.
For 3D design, once you get going you won't be able to stop designing and printing. Sometimes I just print little templates and jigs. For example, the DC motor has 3 holes, 120 degrees apart. While I could lay it out by hand, I'll design a little template with the 3 holes, and a center extrusion to self center on the big hole in the mount.?
I highly recommend Fusion 360 - there is a free version, Mac or PC, which will do everything you want. A learning curve, for sure, but there are? gazillions of how-to videos online. I stick to some basic primatives, every now and then I get to learn some new tricks.
|
Re: Slitting on a Unimat SL?
#db200
Attaching the .stl files. There is a full piece, and then a bottom half piece. For the green sand two part mold, I'll first use the bottom half piece, fill one half of the mold with sand, pack it firm, then flip it over, remove the bottom half, replace with the full piece, dust with talc, add the top part of the mold and fill/pack with sand. Cut in sprew and vent. Then lift off the top, remove the full piece, replace the top, and pour.?
Sounds like we are on similar/parallel paths - yes, same exact DC motor (3 holes instead of 4), and to SLs, one lathe and one mill.
Might give Fusion 360 a try. I can help answer questions with that but not the others.
toggle quoted message
Show quoted text
On Apr 19, 2023, at 11:48 AM, William R. Meyers < wmrmeyers@...> wrote:
One like yours would be a good start, I think. Motors I'm going to be using are the ZY6812 150W 24vdc motors. Drawing for them shows 4 holes, but I think the motors actually have three, like you mention. I have Solid Edge loaded on the computer, and don't seem to have enough concentration to stick with the training videos. Had the same problem with Solid Works, and FreeCad, and all the others. I've got two Unimats, a DB & an SL, according to their labels, but both are alloy castings. One has plastic handles, the other aluminum. Planning on setting one up as a milling machine, and the other as a lathe. Also planning on having slow-speed and high speed capabilities, by changing out the motor plates and pulleys.?
I do have a larger lathe, an Atlas TH42 that is operational, and three other machines that are supposed to be milling machines. One of them might actually work with a little TLC.?
Bill in OKC
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY!
Expect in one hand, expectorate in the other. See which one gets full first.
On Wednesday, April 19, 2023 at 12:08:35 PM CDT, Steve Johnson < steve@...> wrote:
Bill, if you are needing a mount like mine, for a DC motor and without the idler shaft clamp, I will happily share my .STL file with you.
I will definitely be investing in slitting saws, just need to figure out what would be best for the little Unimat SL Mill setup. In the meantime, I'll take a few shaves with my band saw.
For 3D design, once you get going you won't be able to stop designing and printing. Sometimes I just print little templates and jigs. For example, the DC motor has 3 holes, 120 degrees apart. While I could lay it out by hand, I'll design a little template with the 3 holes, and a center extrusion to self center on the big hole in the mount.?
I highly recommend Fusion 360 - there is a free version, Mac or PC, which will do everything you want. A learning curve, for sure, but there are? gazillions of how-to videos online. I stick to some basic primatives, every now and then I get to learn some new tricks.
|
Re: Slitting on a Unimat SL?
#db200
I've always wondered if one of the small carbide tipped trim saw blades, from a Big Box Store, could be used as a slitting saw blade in non-ferrous metals?? Some of these blades leave a fairly thin kerf.? Alright, maybe NOT on a Unimat, but something a little heftier?
I've seen several you-tubers use standard carbide router bits to mill non-ferrous metals, even some mild steel using light cuts.? (If it's on the Interwebb it's gotta be good - right?)? Other than the fact that the blades would be 3"-4" of whirling-whizzing death, why wouldn't it work?? Even a small slitting saw will do plenty of personal damage if you get careless.
Don
|
Re: Slitting on a Unimat SL?
#db200
Bill, if you are needing a mount like mine, for a DC motor and without the idler shaft clamp, I will happily share my .STL file with you.
I will definitely be investing in slitting saws, just need to figure out what would be best for the little Unimat SL Mill setup. In the meantime, I'll take a few shaves with my band saw.
For 3D design, once you get going you won't be able to stop designing and printing. Sometimes I just print little templates and jigs. For example, the DC motor has 3 holes, 120 degrees apart. While I could lay it out by hand, I'll design a little template with the 3 holes, and a center extrusion to self center on the big hole in the mount.?
I highly recommend Fusion 360 - there is a free version, Mac or PC, which will do everything you want. A learning curve, for sure, but there are? gazillions of how-to videos online. I stick to some basic primatives, every now and then I get to learn some new tricks.
|
Re: Slitting on a Unimat SL?
#db200
If you make up or buy some indicator holders, you can do a bit better than eyeballing, though it is a bit more difficult on the Unimats. Something like Harvey's vertical lead screw, or there are others on the group.? /g/Unimat/album?id=195752?is the one I found first. I believe this is a little earlier model:? /g/Unimat/album?id=195774
But as Guy said, you could use a hacksaw, too! Some folks want to make stuff for their tools, some folks want to use the tools, and some folk like to do both...?
Bill in OKC
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY!
Expect in one hand, expectorate in the other. See which one gets full first.
On Wednesday, April 19, 2023 at 10:32:36 AM CDT, Steve Johnson <steve@...> wrote:
Thanks Bill, that makes sense. So then vertical mill mode, vise on the cross sled. I guess the hard part is getting the piece clamped level and eyeballing the height of the slitting blade.
|
Re: Slitting on a Unimat SL?
#db200
That's CHEATING!!? :)?
Can also use a jeweler's saw, or coping saw. Particularly in aluminum alloys. Back in the days when they were still inventing all the machine tools, much of the work for making the prototypes was done with hammers and chisels, files and hacksaws, and other hand tools. If you're only going to do one of these plates, one time, a hacksaw would be fine, and maybe a thin, fine-toothed file to smooth the cut edges. I have plans to make two of them, and know I'll want to have slitting saws for other purposes, so unless I get in a hurry, I'll be doing the slitting saw things.?
Years ago, I bought an Atlas MF horizontal milling machine. It was in a box and 57 baggies, but some of the baggies held tooling, including an assortment of slitting saw blades. I'll be needing to make at least one arbor, and probably several... YMMV of course!
I bought a slab of 1/2"x 4"x14" aluminum plate to make mine out of. Have the stuff here to build a furnace, and even some experience making very simple patterns and ramming up the molds, but haven't gotten that round tuit yet, either! ;) Also have a 3D printers sitting here quietly oxidizing waiting for me to learn how to make my own 3D drawings on the computer, but I have recently downloaded a bunch of stl files for stuff for my Atlas lathe, and a few for my Unimat. No motor mounts for the SL or DB that I've found yet, but I've only looked at Thingiverse, so far.?
Bill in OKC
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY!
Expect in one hand, expectorate in the other. See which one gets full first.
On Wednesday, April 19, 2023 at 10:29:06 AM CDT, Guy Winton <kooldude@...> wrote:
Back in the stone age, some folks would place 2 hacksaw blades, side by side, on a hacksaw frame and just manually saw the slot.
-Guy-?
On April 19, 2023 at 10:52 AM Steve Johnson <steve@...> wrote:
I am casting a new motor mount for an SL Unimat. I'll be using green sand, cope/drag, and as such I will have to cast it with the slot/slit(?) on the clamp side filled in. I'm at a loss trying to figure out the best way to cut this back in after casting. Band saw? Too thin. Table saw? Too thick. Unimat? I don't know where to begin.
So this is what the original motor mount looks like:
This is the printed 'positive', and is what the aluminum casting will look like:
Thoughts?
?
|
Re: Dead Center stuck in tailstock ram.
I believe the tailstock ram is hollow and threaded for the ram screw.?
|
Re: Slitting on a Unimat SL?
#db200
Wow Kevin, that thing cuts like butter!! I have a Delta 10" in my main shop and will be getting a Rikon 10" for my new "micro" shop. Would that same 1/8 x 14tpi blade be good for small detail wood work, like 1/8 plywood, etc??
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Re: Dead Center stuck in tailstock ram.
Quick freeze, freeze spray, or canned air turned upside down will work in a pinch, as will liquid butane sprayed on it, (fire hazard).
I always have a can of quick freeze laying around, as I worked in electrronics.? ?
pat??
|
Steve Johnson
Carl
Bill in OKC too