#31
|
|||
|
|||
milling machine
AMuzi wrote:
I'm sure the Luna is a good choice for "doing it" only the person who has to pay for it might disagree An easier question. Just ring up Andy Newlands: http://www.strawberrybicycle.com/gal...hetti&id=ML314 http://www.strawberrybicycle.com/gal...hetti&id=ML317 If you are saying those machines are inexpensive, they don't look like that, if you are saying buy pipes from someone else, one might as well buy a buycycle... a bicycle, and be done with it. And perhaps one should! -- underground experts united http://user.it.uu.se/~embe8573 |
Ads |
#32
|
|||
|
|||
milling machine
On 3/20/2018 9:09 AM, Emanuel Berg wrote:
AMuzi wrote: http://www.yellowjersey.org/gth8.jpg Also, how does one know how much to file away? Like if you have one tube that has diameter A, and another has diameter B, and A B, and you want the second tube to be at an angle X from the first? If we return to the lathe guys they have a small thing with rods that can be pushed back and forth to form a pattern, perhaps something like that can be used to do a template if it is difficult to compute? I made a frame plate: http://www.yellowjersey.org/photosfromthepast/wat9b.jpg http://www.yellowjersey.org/peg13h.jpg http://www.yellowjersey.org/peg13i.jpg but Joe Bringheli or Andy Newlands will sell you a premade fixtu http://www.yellowjersey.org/jk30.html -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#33
|
|||
|
|||
milling machine
On 3/20/2018 9:36 AM, Emanuel Berg wrote:
Jeff Liebermann wrote: I don't know if a drill press will work, probably not. What's the problem with a drill press? If the tubes are as thin as in AMuzi's photo, I don't see power being a problem assuming the tubes can be fixed robustly which one has to do anyway with a milling machine? 1.0mm for heavy touring tube, mostly 0.9 and 0.8 tube in my repair photos. The latest air hardening tubes are drawn as thin as 0.3mm. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#34
|
|||
|
|||
milling machine
AMuzi wrote:
1.0mm for heavy touring tube, mostly 0.9 and 0.8 tube in my repair photos. The latest air hardening tubes are drawn as thin as 0.3mm. ? I have an aluminium frame here which is 2.065kg and the head tube is 3.7mm and the saddle tube is 2.35mm! -- underground experts united http://user.it.uu.se/~embe8573 |
#35
|
|||
|
|||
milling machine
On Tue, 20 Mar 2018 14:52:52 +0100, Emanuel Berg
wrote: Jeff Liebermann wrote: Mitering bicycle tubes does not require fabulous precision. A Chinese benchtop mill could be used OK, what brands are they? I think I'll pass on recommending a particular brand or mill. I don't have much experience with frame building or cheap Chinese mills. Find a frame builder and ask them what they prefer for mitering. Otherwise, if you want to go online window shopping: https://littlemachineshop.com/info/minimill_compare.php https://www.harborfreight.com/two-speed-variable-bench-mill-drill-machine-44991.html http://www.grizzly.com/products/Mini-Milling-Machine/G8689 https://www.micromark.com/Milling-Machine-R8-500W Plan on spending about as much as the mill costs on a vise, clamps, fixture parts, tools, end mills, dial indicators, safety equipment, etc. Add more money if you want to do major modifications on the mill, such as a Z axis feed, bigger motor, or electronic speed control. CNC conversion kits are available: https://makezine.com/projects/cnc-mini-mill-conversion-kit-hardware/ http://www.cncfusion.com https://www.grizzly.com/products/Mini-Mill-Retrofit-Kit-Compact-Series-Microstepper-for-G0704/T25436 etc... Hints: Start with a decent mill, not a piece of junk. If you can't afford a decent mill, be prepared to rebuild a used mill. If you don't have any experience with machine tools, take classes. If you don't have the tools to get started, borrow someone else's mill. If you're about to spend $4,000 for tools to make a single $500 frame, you might want to reconsider the economics involved. Do your prototyping on someone else's machine until you know what you need to make a frame. Everything costs twice as much and takes twice as long as planned. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#36
|
|||
|
|||
milling machine
On 3/20/2018 2:25 AM, John B. wrote:
On Mon, 19 Mar 2018 22:43:37 -0700, Jeff Liebermann wrote: On Tue, 20 Mar 2018 10:59:44 +0700, John B. wrote: On Mon, 19 Mar 2018 19:48:03 -0700, Jeff Liebermann wrote: Incidentally, sharpening all my kitchen knives to an edge sharp enough for shaving was NOT a good idea. I'm cutting myself quite often and am slowly destroying my cutting boards and dishes. Paper plates no longer work as my knives cut through the paper. I don't do kitchen work but periodically my wife hands me a bunch of kitchen knives and says "Sharpen them". Generally these are cheap stainless knives and I've found that simply making a pass across a grinding wheel on each side works pretty well. It produces a sharp edge which is not perfectly smooth, more like a very fine tooth saw which seems to cut better then a perfectly smooth blade. Disclaimer: I am a beginner on knife making but am learning fast. It depends one what and how you're using the knife to cut. If you draw the knife as if you were sawing through the food, a rough edge is quite superior to a razor sharp edge. However, if you're pushing your way through the food with the knife, the razor edge works better. What I did was buy about 15 assorted knives at a local outdoor flea market and 10 more at a local thrift shop. I used these for practice to learn how to sharpen them and how to modify the shape of the blade. Most were stainless but I also found a few 1095 high carbon steel "Old Hickory" knives. https://www.knivesplus.com/OLD-HICKORY-KNIVES.HTML I bought a Harbor Freight 1x30 belt sander and belt assortment from 80 grit to 800 grit: https://www.harborfreight.com/power-tools/sanders/1-in-x-30-in-belt-sander-60543.html an angle guide: https://www.amazon.com/Knife-Sharpening-Angle-Guide-Sharpen/dp/B01HVXFP80 and a collection of whetstones: https://www.ebay.com/itm/Japanese-Whetstone-Knife-Grit-1000-8000-Sharpener-Sharpening-Water-Stone-Stand/222660726466 I also setup a binocular microscope so I could see what I was doing to the edge: http://www.learnbydestroying.com/jeffl/pics/microscopes/Olympus%20SZ30/slides/SZ30-01.html After a few frustrating failures, I determined that I could produce a usable but rough edge with the belt sander, and then refine it to a razor sharp edge with the water stones. The sanding might only take a few minutes on the belt sander, but the water stone polishing can easily take hours. I can easily see the difference with the microscope. I have 6" grinder, but I would not use it to sharpen knives. It takes off too much metal too quickly to maintain control. When I tried it, the result was a rather "wavy" edge. Even a belt sander takes off too much metal if you use a rough (80 or 120 grit) belt. If you have a belt sander, try starting with 120 grit to remove the dings and chips. Then use increasingly finer belts until you get to 400 or 800 grit. You can probably just quit there, or if you want a smooth edge, use a succession of water stones (1000 to 3000) to improve on the edge. Somewhere around the Net is a site that talks about super sharp, or deadly sharp, or some other fancy name. That guy used plain old emery paper on a flat block to sharpen a knife. I've tried it and it works pretty well except that if you move the blade forward - leading with the sharp edge - it scrapes the abrasive off the paper :-) But it does work pretty well if you pull the blade "backward" with the sharp edge trailing. I usually have a couple pf wood blocks with emery paper glued to one side laying around the bench. After trying many techniques over the decades, my favorite tool for sharpening knives is a steel block whose top surface is impregnated with industrial diamond abrasive. It seems to last forever, which for practical purposes means it stays flat. I have other whetstones that have gradually gotten concave, which makes it tough to maintain the proper edge angles. I use the classic technique, which is sharpen the main bevel at something like 20 degrees, then lightly sharpen a smaller bevel at 45 degrees, and touch up or polish the edge with a hone or other piece of hard steel. I use the hone far more often than the abrasive. Lots of times, the edge just needs touching up, not actual grinding. -- - Frank Krygowski |
#37
|
|||
|
|||
milling machine
On Tue, 20 Mar 2018 15:36:07 +0100, Emanuel Berg
wrote: Jeff Liebermann wrote: I don't know if a drill press will work, probably not. What's the problem with a drill press? If the tubes are as thin as in AMuzi's photo, I don't see power being a problem assuming the tubes can be fixed robustly which one has to do anyway with a milling machine? 1. Most use bushings, not bearings, which can't tolerate much side loading. Getting rid of the wobble is not easy. 2. Lack of power. The typical 1/2 HP motor drive does not have the power to drive large diameter tools. If you try, the belt will slip or the Morse taper holding the drill will spin. If you succeed, the motor won't tolerate continuous running. 3. End mills might fit in a drill chuck but without a locking mechanism will slip and spin. 4. No cutter lube system. 5. Drill table tilt is difficult to adjust to perpendicular to the cutter. 6. Setup and fixturing is not easily repeatable. 7. E-bay X-Y tables are junk. Don't Mill With a Drill Press https://www.youtube.com/watch?v=h-8ddRE7iWM "IMPOSSIBLE!" Milling Machine from a Drill Press https://www.youtube.com/watch?v=xY-wXcFhx5w SUCCESS!! Drill to Mill Conversion. https://www.youtube.com/watch?v=gXvaZImOTbc There are numerous YouTube videos showing various ways to convert a drill press into a mill. Learn by Destroying(tm). -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#38
|
|||
|
|||
milling machine
On 3/20/2018 12:22 PM, Jeff Liebermann wrote:
Everything costs twice as much and takes twice as long as planned. Here, I must disagree. For many years, I did my plans, then multiplied by three instead of multiplying by two. I found multiplying by three produced cost and time estimates that were much more accurate. But then, when I was doing some work for a small local company, the owner pointed out multiplying by three was really not very scientific. He said it's much more scientific to multiply by pi. So 3.14159 is what I've used ever since. -- - Frank Krygowski |
#39
|
|||
|
|||
milling machine
On 3/20/2018 11:40 AM, Jeff Liebermann wrote:
On Tue, 20 Mar 2018 15:36:07 +0100, Emanuel Berg wrote: Jeff Liebermann wrote: I don't know if a drill press will work, probably not. What's the problem with a drill press? If the tubes are as thin as in AMuzi's photo, I don't see power being a problem assuming the tubes can be fixed robustly which one has to do anyway with a milling machine? 1. Most use bushings, not bearings, which can't tolerate much side loading. Getting rid of the wobble is not easy. 2. Lack of power. The typical 1/2 HP motor drive does not have the power to drive large diameter tools. If you try, the belt will slip or the Morse taper holding the drill will spin. If you succeed, the motor won't tolerate continuous running. 3. End mills might fit in a drill chuck but without a locking mechanism will slip and spin. 4. No cutter lube system. 5. Drill table tilt is difficult to adjust to perpendicular to the cutter. 6. Setup and fixturing is not easily repeatable. 7. E-bay X-Y tables are junk. Don't Mill With a Drill Press https://www.youtube.com/watch?v=h-8ddRE7iWM "IMPOSSIBLE!" Milling Machine from a Drill Press https://www.youtube.com/watch?v=xY-wXcFhx5w SUCCESS!! Drill to Mill Conversion. https://www.youtube.com/watch?v=gXvaZImOTbc There are numerous YouTube videos showing various ways to convert a drill press into a mill. Learn by Destroying(tm). Your 'don't mill with a drill press' link mentions lower receivers. Ouch. That's a spectacularly bad idea in a drill press: http://personal.linkline.com/rlockyer/XD9/PLOWER2.JPG The Inter Webs are full of bad examples after which the guy had to start with a new blank. It's a relatively fast simple setup in a vertical mill. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#40
|
|||
|
|||
milling machine
On Tue, 20 Mar 2018 12:49:36 -0400, Frank Krygowski
wrote: On 3/20/2018 12:22 PM, Jeff Liebermann wrote: Everything costs twice as much and takes twice as long as planned. Here, I must disagree. Does that mean you agree with everything else that I wrote? For many years, I did my plans, then multiplied by three instead of multiplying by two. I found multiplying by three produced cost and time estimates that were much more accurate. But then, when I was doing some work for a small local company, the owner pointed out multiplying by three was really not very scientific. He said it's much more scientific to multiply by pi. So 3.14159 is what I've used ever since. Instead of Pi, I suggest a more optimistic Euler's number of e=2.7182818... It's actually worse than Pi. In a former life and job, the project manager would ask me how long it would take for me to prototype, build, and deliver some gizmo. He would then double my estimate. His time estimate would then go to the engineering manager, who would double it again. When it left the desk of the chief engineer, it was again doubled. Knowing that it was now 8 times my original estimate, marketing would optimistically give a delivery date slightly less than my original estimate, and then double the scope of the project. The resulting 16 times my original estimate would be a fairly good number for the final 100% completed. Cost overruns are much the same, but can be made to look acceptable by creative cost accounting. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Small Road Milling Machine for Bicycle Lanes | Bret Cahill | UK | 1 | January 7th 15 03:13 PM |
Washing machine | ilan[_2_] | Racing | 18 | July 7th 09 12:01 AM |
The Road Machine | jerryo | Marketplace | 0 | January 20th 07 08:44 PM |
She's A Machine | Calogero Carlucci | Racing | 6 | June 27th 06 10:05 PM |
FUN machine | Gartons | Marketplace | 0 | April 13th 05 01:33 PM |