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Generally, when making a fly cutter...it's better to have the slot cut such that the cutting edge of the tool will be on center with the spindle. This is not to say that the way you did it will not work, but sharpening will be tough, because you've now got to grind the tip such that it is effectively on center...at least for best results.
2: When using HSS blanks for your cutter, use a little dremmel stone to grind detents in the tool for the set screws to bite into. The vibrations present in flycutting will sometimes loosen up the screws just a touch, and the HSS will come out of the body like a bullet. Brazed tools don't have this problem because the substrate is generally softer and the screws can bit into the tool a bit more. Also, check the screws for tightness on a regular basis...between passes even. I still haven't found the piece of HSS that flew out of my flycutter a while back....I'm just glad it missed me.
I was aware of the blade orientation, but I didn't have any material thick enough to hold both the blade and the shank at the same time and in the same plane. Since I only need it for plastic, it'll do the job for now. As soon as I can source some thicker metal I'll make another.
I would also add that aluminium is not the best material for a flycutter because it is so light and this gives it very little flywheel effect. The inertia of a heavy holder means smoother cutting and less strain on the mill bearings during the intermittent cuts that are the norm when flycutting.
Mike
Yup, I was aware of that too. Just doin' the best I can with what I've got. I'm hoping to find a nice hunk of brass to make another with...
I'm making fairly light passes in plastic, so I'm not pushing anything very hard.
If necessity is the mother of invention, then surely desperation is the father --humans often play the part of the midwife.
so long as the offspring are successful all is well.
I’ve been wanting to take photos of this and post them for ages & the mention of being ‘dirt poor’ was just the motivation I needed.
Over 25 years ago, w/2 young children and a recent cross country move that took all our money, I needed a compound cross slide for a Hardinge DSM split bed lathe I had. From a flea market I had picked up a slide & used that for the lower cross slide. I just had to make the aluminum spacer to get the travel to work out correctly. The top compound I made entirely. I left stock on the curved portion for the day I would get a rotary table. I got one, oh … maybe 10 years ago. One of these days I'll finish this!
The main thing I wanted to show is the QC tool post & tool holders that I also made.
I thought up this design to be as simple as possible & use tools I already had. The block is expanded slightly by the 2 taper plugs being tightened together. I had 2 – 7 degree taper end mills on hand so that’s what determined the taper to cut from each side.
Before anyone tries this, a word of warning …….. taper end mills are for cutting draft on the side of a part & not for making tapered holes. If you try to cut a full circle, the cutter will screw itself into the part & smash itself to bits.
Don't ask me how I know, but I now have 1 taper end mill.
For my next attempt, I set the quill stop to only let the cutter advance about .010 in. at a time so it couldn’t pull in. It took longer but was successful.
"To invent you need a good imagination and a pile of junk" - Thomas Edison
"I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me
Re. 7 deg taper: I think that is 14 total from the look, but am wondering if
it "tends" to stick like the "selfenergizing" tapers enough to be a bother when
releasing the holder?
...lew...
About 10 degrees included angle is the approximate dividing line between a self locking taper and a self releasing taper. The further you get either side of that mark, the more it does one or the other.
I’m glad you brought up the sticking characteristic ‘cuz I was concerned also.
When I assemble the inserts I coat them with an anti-seize lubricant to avoid the sticking. Plus, I keep a small block of aluminum or lead around any of my machines for tapping parts when I need to align them. When I release the screw I sometimes have to lightly tap it down which always does the trick.
For me at least, the extra step of tapping the screw has become so automatic that it hardly can be considered to slow me down at all.
The tool post & holders are all made from mild steel (hot rolled) so I made the holders a close, slip fit on the post to be sure the expansion required to lock them wasn’t enough to distort the post.
I think that if the post is made from tool steel & heat treated to be a bit springy, the fit of the tool holders could be opened up which also might coax the tapered plugs to be completely self releasing.
I have a couple of other lathes so I may make some more w/tool steel.
This might be a good reason/project for me to hook up the heat treat furnace I’ve had lying around for 30+ years.
Best wishes to ya’ll.
Sincerely,
Jim
"To invent you need a good imagination and a pile of junk" - Thomas Edison
"I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me
This is a fixture to measure brake rotor thickness variation. Some of the nicest work to come out of my garage....usually I just slap stuff together so it works on my own stuff...but this is for a paying customer.
Yes, it is a nice bit of kit. I think he made that for a customer, I assume it was to the customers spec. I suspect the customer is planning to use it to show his customers why a rotor needs replaced --hence a digital readout (easier to get the point across to non machinist types, big numbers worse sort of thing --needle swinging is just a needle swinging).
Yes, it is a nice bit of kit. I think he made that for a customer, I assume it was to the customers spec. I suspect the customer is planning to use it to show his customers why a rotor needs replaced --hence a digital readout (easier to get the point across to non machinist types, big numbers worse sort of thing --needle swinging is just a needle swinging).
This was a bit of a rush....built it on the side, but for work. The boss gave me the project on Thursday of last week, and as usual, he wanted 2 of them yesterday. We didn't have much time for research or planning, so I just kinda did it. I had a feeling the electronic indicators would be a problem...and they were. I picked up a couple of dial comparator gauges today...and aside from being a bitch to set up, they work much better. We're gonna have a team using these 2 fixtures to check over 1000 brake rotors...don't ask why. The real bitch is the c-frame thing and the pivot...I musta recut the damn c-frame 20 times creeping up on the dimension....then polished the tool marks away just a bit to get a perfect fit. Made a fixture clamp them together so I could drill and ream in place to assure hole alignment....then polished 2/3 of the pin down to as near I can tell, about .0003 under size, while leaving 1/3 of it about .001 over size so it would stay in place, but the c-frame pivots freely and with zero play. Jus. Finished that up....need to make some thumbscrew handles, add a few stop screws, and we're done. Should be a chunk of change coming my way tomorrow. I'm about 40 hours into it I think....never thought it would take this long.
One way to check an item for square is to use a surface gage. You use the ball end of the vertical rod as your lower reference and an indicator as the upper reference and a known square surface as the datum. My problem with this method is that it makes the fine adjust on the surface gage difficult to use. So I took a hard drive magnet, a chunk of aluminum and a small tooling ball and came up with this.
I can't see how that setup would be very accurate. If the tooling ball and the indicator point are not lined up exactly vertical, any rotation of the surface gage would result in error.
If you have a known square surface, why not use it to check for squareness? Your setup kind of looks like a solution to something that is not a problem to begin with.
Brian
OPEN EYES, OPEN EARS, OPEN MIND
THINK HARDER
BETTER TO HAVE TOOLS YOU DON'T NEED THAN TO NEED TOOLS YOU DON'T HAVE
I can't see how that setup would be very accurate. If the tooling ball and the indicator point are not lined up exactly vertical, any rotation of the surface gage would result in error.
If you have a known square surface, why not use it to check for squareness? Your setup kind of looks like a solution to something that is not a problem to begin with.
I just watched the video and now I see how the technique is used. I have always used cylinder squares if I need to quantify the error or a solid square if I am just want to see how something looks by eye. I didn't pick up how they zero out the indicator to absolute square to begin with. How do you do that?
Brian
OPEN EYES, OPEN EARS, OPEN MIND
THINK HARDER
BETTER TO HAVE TOOLS YOU DON'T NEED THAN TO NEED TOOLS YOU DON'T HAVE
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