Tapping 6-32 in aluminum
On Sun, 05 Apr 2015 07:47:14 -0500, Ignoramus10114 wrote:
I have an aluminum heatsink that I need to tap , I wanted to know if I should use 6-32 or some less coarse thread like 8-32 would be better? I have a string. How long is it? -- www.wescottdesign.com |
Tapping 6-32 in aluminum
"Ignoramus32423" wrote in
message ... On 2015-04-06, Jim Wilkins wrote: If you used an LM317 adjustable regulator for the tracks you could tune the voltage for best performance while retaining control, and waste less of the battery's energy as heat. You could put a knob on the voltage adjustment pot so you have a throttle instead of just on/off control. Oh, and why would LM317 waste less energy as heat? Because you could deliver the maximum acceptable voltage to the track motors to move fast. Maybe it's 8 or 10V if you don't start or stop with a jolt that breaks traction. I'd put the throttle knob or slider under the thumb that holds the box, and have enough resistance in series with the pot that the motors creep at the pot's minimum setting. The switch would start the track barely but visibly moving in the right direction, important when it's not facing away from you, then you throttle up the speed. -jsw |
Tapping 6-32 in aluminum
On Mon, 06 Apr 2015 10:26:40 -0500, Ignoramus32423
wrote: On 2015-04-06, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote: Ignoramus32423 fired this volley in : The good news is that, as they run, even after a while, the heatsink is only barely warm. What you did not say was 1) the raw battery voltage, 12v nominal 2) the current (both peak and average) for the arm Not sure, not a lot. The arm operates very intermittently. 3) the current(ibid) for the tracks. Not sure what is the current for the 5v tracks, but my best guess is 1.2 amps when driving in a straight line, and about 3A when turning on a dime. Are you using spring-loaded momentary toggles on that controller? Seems less than optimal. To check current draw, throw one of these inline with the power line, using standard USB connectors. They're great little units, and you can't beat the price. http://tinyurl.com/oyq53ro I picked up a couple when they were a buck, with free shipping. One went to my niece, with a power module for her cellphone. -- When a quiet man is moved to passion, it seems the very earth will shake. -- Stephanie Barron (Something for the Powers That Be to remember, eh?) |
Tapping 6-32 in aluminum
On 2015-04-06, Larry Jaques wrote:
I will hopefully add more pictures and documentation soon. That's cool! (Shades of my old Erector set, but many generations ahead.) They still sell erector sets, they are quite plentiful. i |
Tapping 6-32 in aluminum
On 2015-04-06, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
Ignoramus32423 fired this volley in : Oh, and why would LM317 waste less energy as heat? It would not. It's a linear regulator, also, and disspates exactly whatever is the drop*current across itself. But it's darned handy for 'tuning' stuff. There is a way, with an LM317 to get a 'soft start'. National Semi shows a circuit or two that does that. Having that constant-current output on the reference lead can give you interesting possibilities. LLoyd That's cool. I use a reversing switch on the output of these regulators, so not as easy to have a soft start. Maybe one day I will so something like that. i |
Tapping 6-32 in aluminum
On 2015-04-06, Jim Wilkins wrote:
"Ignoramus32423" wrote in message ... On 2015-04-06, Jim Wilkins wrote: If you used an LM317 adjustable regulator for the tracks you could tune the voltage for best performance while retaining control, and waste less of the battery's energy as heat. You could put a knob on the voltage adjustment pot so you have a throttle instead of just on/off control. Oh, and why would LM317 waste less energy as heat? Because you could deliver the maximum acceptable voltage to the track motors to move fast. Maybe it's 8 or 10V if you don't start or stop with a jolt that breaks traction. We used a variable power supply quite a bit to arrive at an acceptable voltage. Overall, 5v was perfect, anything faster was just too hard to control. i |
Tapping 6-32 in aluminum
On 2015-04-06, Larry Jaques wrote:
On Mon, 06 Apr 2015 10:26:40 -0500, Ignoramus32423 wrote: On 2015-04-06, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote: Ignoramus32423 fired this volley in : The good news is that, as they run, even after a while, the heatsink is only barely warm. What you did not say was 1) the raw battery voltage, 12v nominal 2) the current (both peak and average) for the arm Not sure, not a lot. The arm operates very intermittently. 3) the current(ibid) for the tracks. Not sure what is the current for the 5v tracks, but my best guess is 1.2 amps when driving in a straight line, and about 3A when turning on a dime. Are you using spring-loaded momentary toggles on that controller? Seems less than optimal. Any suggestions? To check current draw, throw one of these inline with the power line, using standard USB connectors. They're great little units, and you can't beat the price. http://tinyurl.com/oyq53ro I picked up a couple when they were a buck, with free shipping. One went to my niece, with a power module for her cellphone. This is cool, indeed! i |
Tapping 6-32 in aluminum
On Monday, April 6, 2015 at 4:45:22 AM UTC-7, Ignoramus32423 wrote:
If I drill a 1/8" hole, a 6-32 screw taps it for itself very nicely. Lloyd, I used those holes to mount TO-220 voltage regulator chips, not for anything structural. worked great! It'd be better if you used no tapping at all, just a smaller bolt (#4-40). The force needed to get a #6-32 into an undersize hole can warp the surface (and hurt the heatsinking). It can also make it hard to stop when the torque is 'enough': the copper of the heatsink tab can be deformed, and that makes for a TERRIBLE thermal connection. |
Tapping 6-32 in aluminum
"Ignoramus32423" wrote in
message ... On 2015-04-06, Larry Jaques wrote: On Mon, 06 Apr 2015 10:26:40 -0500, Ignoramus32423 wrote: On 2015-04-06, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote: Ignoramus32423 fired this volley in : The good news is that, as they run, even after a while, the heatsink is only barely warm. What you did not say was 1) the raw battery voltage, 12v nominal 2) the current (both peak and average) for the arm Not sure, not a lot. The arm operates very intermittently. 3) the current(ibid) for the tracks. Not sure what is the current for the 5v tracks, but my best guess is 1.2 amps when driving in a straight line, and about 3A when turning on a dime. Are you using spring-loaded momentary toggles on that controller? Seems less than optimal. Any suggestions? To check current draw, throw one of these inline with the power line, using standard USB connectors. They're great little units, and you can't beat the price. http://tinyurl.com/oyq53ro I picked up a couple when they were a buck, with free shipping. One went to my niece, with a power module for her cellphone. This is cool, indeed! i The problem with them is the low maximum voltage rating of 7V. I have a similar AboveTEK meter. This has a more useful 33V rating and resolves to 0.1mA below 1A, 1mA above. http://www.amazon.com/DROK-Digital-D...30828&sr=1-152 It also shows total power like a KillAWatt for DC. I haven't tried the simpler, less expensive versions. -jsw |
Tapping 6-32 in aluminum
So it is. Thanks for the correction. The difference between 6-32 & 8-32
remains as stated, though. Hul BQ340 wrote: On 4/5/2015 6:42 PM, Hul Tytus wrote: 6-32 is a course, ie nc, thread. 8-32 is a fine thread, ie nf. The fine threads do less cutting relative to the screw's major diameter. The 8-32 will be less likely to break than the 6-32 which, in steel, is a consideration. In aluminum probably either one would free of worry. Maybe the 8-32 would be a little freeer. Hul "8-32 is a fine thread, ie nf" No, 8-32 is UNC. MikeB -- Email is valid |
Tapping 6-32 in aluminum
On Monday, April 6, 2015 at 11:09:24 AM UTC-4, Ignoramus32423 wrote:
On 2015-04-06, Jim Wilkins wrote: If you used an LM317 adjustable regulator for the tracks you could tune the voltage for best performance while retaining control, and waste less of the battery's energy as heat. You could put a knob on the voltage adjustment pot so you have a throttle instead of just on/off control. Oh, and why would LM317 waste less energy as heat? It could waste less heat if the voltage is set a bit higher than with you existing regulators. Or it could waste more if the setting is lower. But you can use switching regulators. And you could probably use something like a Arduino to sense the voltage and control a transistor . In short a switching regulator with intelligence so you could have that soft start. Dan |
Tapping 6-32 in aluminum
On Mon, 6 Apr 2015 17:31:57 -0400, "Jim Wilkins"
wrote: "Ignoramus32423" wrote in message ... On 2015-04-06, Larry Jaques wrote: On Mon, 06 Apr 2015 10:26:40 -0500, Ignoramus32423 wrote: On 2015-04-06, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote: Ignoramus32423 fired this volley in : The good news is that, as they run, even after a while, the heatsink is only barely warm. What you did not say was 1) the raw battery voltage, 12v nominal 2) the current (both peak and average) for the arm Not sure, not a lot. The arm operates very intermittently. 3) the current(ibid) for the tracks. Not sure what is the current for the 5v tracks, but my best guess is 1.2 amps when driving in a straight line, and about 3A when turning on a dime. Are you using spring-loaded momentary toggles on that controller? Seems less than optimal. Any suggestions? To check current draw, throw one of these inline with the power line, using standard USB connectors. They're great little units, and you can't beat the price. http://tinyurl.com/oyq53ro I picked up a couple when they were a buck, with free shipping. One went to my niece, with a power module for her cellphone. This is cool, indeed! i The problem with them is the low maximum voltage rating of 7V. I have a similar AboveTEK meter. This has a more useful 33V rating and resolves to 0.1mA below 1A, 1mA above. http://www.amazon.com/DROK-Digital-D...30828&sr=1-152 It also shows total power like a KillAWatt for DC. I haven't tried the simpler, less expensive versions. -jsw The cheap ones are far from accurate. I bought 2 on ebay - both were in-accurate, and they didn't even match each other. (readings were different and didn't match my 3 multitesters, that all agreed within less than 1/10 volt and less than 1/100 amp |
Tapping 6-32 in aluminum
On Mon, 6 Apr 2015 21:33:26 +0000 (UTC), Hul Tytus
wrote: So it is. Thanks for the correction. The difference between 6-32 & 8-32 remains as stated, though. I've always considered 32tpi to be "fine", too. I guess there are 6-40 and 8-40 threads for the fine side, though I don't recall ever seeing one so far in this lifetime. -- When a quiet man is moved to passion, it seems the very earth will shake. -- Stephanie Barron (Something for the Powers That Be to remember, eh?) |
Tapping 6-32 in aluminum
wrote in message
... On Mon, 6 Apr 2015 17:31:57 -0400, "Jim Wilkins" wrote: "Ignoramus32423" wrote in message ... On 2015-04-06, Larry Jaques wrote: On Mon, 06 Apr 2015 10:26:40 -0500, Ignoramus32423 wrote: On 2015-04-06, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote: Ignoramus32423 fired this volley in : The good news is that, as they run, even after a while, the heatsink is only barely warm. What you did not say was 1) the raw battery voltage, 12v nominal 2) the current (both peak and average) for the arm Not sure, not a lot. The arm operates very intermittently. 3) the current(ibid) for the tracks. Not sure what is the current for the 5v tracks, but my best guess is 1.2 amps when driving in a straight line, and about 3A when turning on a dime. Are you using spring-loaded momentary toggles on that controller? Seems less than optimal. Any suggestions? To check current draw, throw one of these inline with the power line, using standard USB connectors. They're great little units, and you can't beat the price. http://tinyurl.com/oyq53ro I picked up a couple when they were a buck, with free shipping. One went to my niece, with a power module for her cellphone. This is cool, indeed! i The problem with them is the low maximum voltage rating of 7V. I have a similar AboveTEK meter. This has a more useful 33V rating and resolves to 0.1mA below 1A, 1mA above. http://www.amazon.com/DROK-Digital-D...30828&sr=1-152 It also shows total power like a KillAWatt for DC. I haven't tried the simpler, less expensive versions. -jsw The cheap ones are far from accurate. I bought 2 on ebay - both were in-accurate, and they didn't even match each other. (readings were different and didn't match my 3 multitesters, that all agreed within less than 1/10 volt and less than 1/100 amp Look closely, mine had tiny calibration trim pots. |
Tapping 6-32 in aluminum
On Mon, 06 Apr 2015 15:25:25 -0500, Ignoramus32423
wrote: On 2015-04-06, Larry Jaques wrote: I will hopefully add more pictures and documentation soon. That's cool! (Shades of my old Erector set, but many generations ahead.) They still sell erector sets, they are quite plentiful. http://tinyurl.com/l28h9wl OMG, look at the price now! Most kids are stuck with Legos, the NON-hardware building set. Sad. They aren't learning about how to keep from getting cut by sheetmetal, how to use nuts or bolts or wrenches or hand tools, or anything metal stiffness/strength-related. I guess they still make Lincoln Logs (no gay references, please) for kids, too, but CRIKEY, look at the price!) http://tinyurl.com/llzj5qw -- When a quiet man is moved to passion, it seems the very earth will shake. -- Stephanie Barron (Something for the Powers That Be to remember, eh?) |
Tapping 6-32 in aluminum
On Mon, 06 Apr 2015 15:28:14 -0500, Ignoramus32423
wrote: On 2015-04-06, Larry Jaques wrote: On Mon, 06 Apr 2015 10:26:40 -0500, Ignoramus32423 wrote: On 2015-04-06, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote: Ignoramus32423 fired this volley in : The good news is that, as they run, even after a while, the heatsink is only barely warm. What you did not say was 1) the raw battery voltage, 12v nominal 2) the current (both peak and average) for the arm Not sure, not a lot. The arm operates very intermittently. 3) the current(ibid) for the tracks. Not sure what is the current for the 5v tracks, but my best guess is 1.2 amps when driving in a straight line, and about 3A when turning on a dime. Are you using spring-loaded momentary toggles on that controller? Seems less than optimal. Any suggestions? To check current draw, throw one of these inline with the power line, using standard USB connectors. They're great little units, and you can't beat the price. http://tinyurl.com/oyq53ro I picked up a couple when they were a buck, with free shipping. One went to my niece, with a power module for her cellphone. This is cool, indeed! I checked the charging current from the computer vs. the wall wart charger for my Kindle and the computer was 1/3 the current, taking a whole lot longer. It surprised me, but now I use the wall charger exclusively, unless I'll be at the computer all day. -- When a quiet man is moved to passion, it seems the very earth will shake. -- Stephanie Barron (Something for the Powers That Be to remember, eh?) |
Tapping 6-32 in aluminum
On Mon, 6 Apr 2015 17:31:57 -0400, "Jim Wilkins"
wrote: "Ignoramus32423" wrote in message ... On 2015-04-06, Larry Jaques wrote: On Mon, 06 Apr 2015 10:26:40 -0500, Ignoramus32423 wrote: On 2015-04-06, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote: Ignoramus32423 fired this volley in : The good news is that, as they run, even after a while, the heatsink is only barely warm. What you did not say was 1) the raw battery voltage, 12v nominal 2) the current (both peak and average) for the arm Not sure, not a lot. The arm operates very intermittently. 3) the current(ibid) for the tracks. Not sure what is the current for the 5v tracks, but my best guess is 1.2 amps when driving in a straight line, and about 3A when turning on a dime. Are you using spring-loaded momentary toggles on that controller? Seems less than optimal. Any suggestions? To check current draw, throw one of these inline with the power line, using standard USB connectors. They're great little units, and you can't beat the price. http://tinyurl.com/oyq53ro I picked up a couple when they were a buck, with free shipping. One went to my niece, with a power module for her cellphone. This is cool, indeed! i The problem with them is the low maximum voltage rating of 7V. I have a similar AboveTEK meter. This has a more useful 33V rating and resolves to 0.1mA below 1A, 1mA above. http://www.amazon.com/DROK-Digital-D...30828&sr=1-152 It also shows total power like a KillAWatt for DC. I haven't tried the simpler, less expensive versions. I bought one of those solar wattmeters o eBay for $14 or so and it works well for 12v. The little ones above are USB, so they are for 5v USB circuits only. Since Ig said 5v, I keyed on it. I forgot to check the charging rate of the little USB wattmeter through the solar charge controller, but will do that tomorrow. (Where the 'ell did I hide the little bastid, anyway?) -- When a quiet man is moved to passion, it seems the very earth will shake. -- Stephanie Barron (Something for the Powers That Be to remember, eh?) |
Tapping 6-32 in aluminum
On Mon, 6 Apr 2015 21:55:09 -0400, "Jim Wilkins"
wrote: wrote in message .. . On Mon, 6 Apr 2015 17:31:57 -0400, "Jim Wilkins" wrote: "Ignoramus32423" wrote in message ... On 2015-04-06, Larry Jaques wrote: On Mon, 06 Apr 2015 10:26:40 -0500, Ignoramus32423 wrote: On 2015-04-06, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote: Ignoramus32423 fired this volley in : The good news is that, as they run, even after a while, the heatsink is only barely warm. What you did not say was 1) the raw battery voltage, 12v nominal 2) the current (both peak and average) for the arm Not sure, not a lot. The arm operates very intermittently. 3) the current(ibid) for the tracks. Not sure what is the current for the 5v tracks, but my best guess is 1.2 amps when driving in a straight line, and about 3A when turning on a dime. Are you using spring-loaded momentary toggles on that controller? Seems less than optimal. Any suggestions? To check current draw, throw one of these inline with the power line, using standard USB connectors. They're great little units, and you can't beat the price. http://tinyurl.com/oyq53ro I picked up a couple when they were a buck, with free shipping. One went to my niece, with a power module for her cellphone. This is cool, indeed! i The problem with them is the low maximum voltage rating of 7V. I have a similar AboveTEK meter. This has a more useful 33V rating and resolves to 0.1mA below 1A, 1mA above. http://www.amazon.com/DROK-Digital-D...30828&sr=1-152 It also shows total power like a KillAWatt for DC. I haven't tried the simpler, less expensive versions. -jsw The cheap ones are far from accurate. I bought 2 on ebay - both were in-accurate, and they didn't even match each other. (readings were different and didn't match my 3 multitesters, that all agreed within less than 1/10 volt and less than 1/100 amp Look closely, mine had tiny calibration trim pots. These useless pieces of scrap didn't. |
Tapping 6-32 in aluminum
On Mon, 06 Apr 2015 19:50:02 -0700, Larry Jaques
wrote: On Mon, 06 Apr 2015 15:25:25 -0500, Ignoramus32423 wrote: On 2015-04-06, Larry Jaques wrote: I will hopefully add more pictures and documentation soon. That's cool! (Shades of my old Erector set, but many generations ahead.) They still sell erector sets, they are quite plentiful. http://tinyurl.com/l28h9wl OMG, look at the price now! How much was a motorized 650 peice set back in 1965 dollars?? I remeber they were too expensive for my family to buy for me. A mechanic made about $2.15 an hour, an electrician about $2.50 Today the earningas are at least 20 times that, so a $175 set today would cost the same at $8.75 in 1965. I'm sure they were more than $8.75 - A #11 kit was well over $25 (over 17 pd Stirling in the UK) in 1964 (These were NEVER an "inexpensive" toy!!!) Most kids are stuck with Legos, the NON-hardware building set. Sad. They aren't learning about how to keep from getting cut by sheetmetal, how to use nuts or bolts or wrenches or hand tools, or anything metal stiffness/strength-related. I guess they still make Lincoln Logs (no gay references, please) for kids, too, but CRIKEY, look at the price!) http://tinyurl.com/llzj5qw |
Tapping 6-32 in aluminum
On Mon, 06 Apr 2015 18:32:34 -0700, Larry Jaques
wrote: On Mon, 6 Apr 2015 21:33:26 +0000 (UTC), Hul Tytus wrote: So it is. Thanks for the correction. The difference between 6-32 & 8-32 remains as stated, though. I've always considered 32tpi to be "fine", too. I guess there are 6-40 and 8-40 threads for the fine side, though I don't recall ever seeing one so far in this lifetime. I have a fair supply of 6-44, 6-48 and 8-40 screws..often found in guns and sight/scope fasteners |
Tapping 6-32 in aluminum
On 2015-04-06, Ignoramus32423 wrote:
On 2015-04-06, Jim Wilkins wrote: [ ... ] If you used an LM317 adjustable regulator for the tracks you could tune the voltage for best performance while retaining control, and waste less of the battery's energy as heat. You could put a knob on the voltage adjustment pot so you have a throttle instead of just on/off control. [ ... ] Jim, you are right. I actually have several LM317T regulators. I just wanted to take the easy route. I wish that I could somehow have a ramp-up of speed, though, not go from zero to full throttle in an instant. Hmm ... if using the variable regulators, put a limiting resistor in series with the control voltage, and an electrolytic capacitor to slow the ramp-up. (Put a diode in parallel with the resistor to make the ramp-down faster, however, to make it easier to stop before a crash. :-) Enjoy, DoN. -- Remove oil spill source from e-mail Email: | (KV4PH) Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
Tapping 6-32 in aluminum
"Larry Jaques" wrote in message
... On Mon, 6 Apr 2015 17:31:57 -0400, "Jim Wilkins" wrote: I bought one of those solar wattmeters o eBay for $14 or so and it works well for 12v. The little ones above are USB, so they are for 5v USB circuits only. Since Ig said 5v, I keyed on it. I forgot to check the charging rate of the little USB wattmeter through the solar charge controller, but will do that tomorrow. (Where the 'ell did I hide the little bastid, anyway?) I turned the cable and a connector from a USB1 hub into a breakout cable to check the AboveTEK meter with a DVM and an external resistor load. AFAIK USB2 ports can supply 500mA continuously, for USB3 it's 900mA. They are protected (?) by PTC thermistors that allow higher startup surges. I'm not about to risk my laptops or portable hard drives by measuring these limits. I run into them with a USB3 ExpressCard that won't run a portable hard drive without externally supplied 5V. -jsw |
Tapping 6-32 in aluminum
wrote in message
... On Mon, 6 Apr 2015 21:55:09 -0400, "Jim Wilkins" wrote: The cheap ones are far from accurate. I bought 2 on ebay - both were in-accurate, and they didn't even match each other. (readings were different and didn't match my 3 multitesters, that all agreed within less than 1/10 volt and less than 1/100 amp Look closely, mine had tiny calibration trim pots. These useless pieces of scrap didn't. They look like flathead mounting screws rather than pots. This one is 2mm in diameter. -jsw |
Tapping 6-32 in aluminum
On 2015-04-07, Larry Jaques wrote:
On Mon, 06 Apr 2015 15:28:14 -0500, Ignoramus32423 wrote: On 2015-04-06, Larry Jaques wrote: On Mon, 06 Apr 2015 10:26:40 -0500, Ignoramus32423 wrote: On 2015-04-06, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote: Ignoramus32423 fired this volley in : The good news is that, as they run, even after a while, the heatsink is only barely warm. What you did not say was 1) the raw battery voltage, 12v nominal 2) the current (both peak and average) for the arm Not sure, not a lot. The arm operates very intermittently. 3) the current(ibid) for the tracks. Not sure what is the current for the 5v tracks, but my best guess is 1.2 amps when driving in a straight line, and about 3A when turning on a dime. Are you using spring-loaded momentary toggles on that controller? Seems less than optimal. Any suggestions? To check current draw, throw one of these inline with the power line, using standard USB connectors. They're great little units, and you can't beat the price. http://tinyurl.com/oyq53ro I picked up a couple when they were a buck, with free shipping. One went to my niece, with a power module for her cellphone. This is cool, indeed! I checked the charging current from the computer vs. the wall wart charger for my Kindle and the computer was 1/3 the current, taking a whole lot longer. It surprised me, but now I use the wall charger exclusively, unless I'll be at the computer all day. I just bought it |
Tapping 6-32 in aluminum
On 2015-04-07, DoN. Nichols wrote:
On 2015-04-06, Ignoramus32423 wrote: On 2015-04-06, Jim Wilkins wrote: [ ... ] If you used an LM317 adjustable regulator for the tracks you could tune the voltage for best performance while retaining control, and waste less of the battery's energy as heat. You could put a knob on the voltage adjustment pot so you have a throttle instead of just on/off control. [ ... ] Jim, you are right. I actually have several LM317T regulators. I just wanted to take the easy route. I wish that I could somehow have a ramp-up of speed, though, not go from zero to full throttle in an instant. Hmm ... if using the variable regulators, put a limiting resistor in series with the control voltage, and an electrolytic capacitor to slow the ramp-up. (Put a diode in parallel with the resistor to make the ramp-down faster, however, to make it easier to stop before a crash. :-) Enjoy, DoN. The problem is, I use a reversing switch AFTER the regulator... i |
Tapping 6-32 in aluminum
"DoN. Nichols" wrote in message
... On 2015-04-06, Ignoramus32423 wrote: On 2015-04-06, Jim Wilkins wrote: [ ... ] If you used an LM317 adjustable regulator for the tracks you could tune the voltage for best performance while retaining control, and waste less of the battery's energy as heat. You could put a knob on the voltage adjustment pot so you have a throttle instead of just on/off control. [ ... ] Jim, you are right. I actually have several LM317T regulators. I just wanted to take the easy route. I wish that I could somehow have a ramp-up of speed, though, not go from zero to full throttle in an instant. Hmm ... if using the variable regulators, put a limiting resistor in series with the control voltage, and an electrolytic capacitor to slow the ramp-up. (Put a diode in parallel with the resistor to make the ramp-down faster, however, to make it easier to stop before a crash. :-) Enjoy, DoN. The problem is finding a momentary double-throw switch with a contact that's closed only in the centered position, to discharge the cap. It could be done with 3-pole switches and relays, or an extra single-pole switch that acts like a clutch, if he's used to a manual transmission. -jsw -jsw |
Tapping 6-32 in aluminum
"Jim Wilkins" wrote in message
... "DoN. Nichols" wrote in message ... On 2015-04-06, Ignoramus32423 wrote: On 2015-04-06, Jim Wilkins wrote: [ ... ] If you used an LM317 adjustable regulator for the tracks you could tune the voltage for best performance while retaining control, and waste less of the battery's energy as heat. You could put a knob on the voltage adjustment pot so you have a throttle instead of just on/off control. [ ... ] Jim, you are right. I actually have several LM317T regulators. I just wanted to take the easy route. I wish that I could somehow have a ramp-up of speed, though, not go from zero to full throttle in an instant. Hmm ... if using the variable regulators, put a limiting resistor in series with the control voltage, and an electrolytic capacitor to slow the ramp-up. (Put a diode in parallel with the resistor to make the ramp-down faster, however, to make it easier to stop before a crash. :-) Enjoy, DoN. The problem is finding a momentary double-throw switch with a contact that's closed only in the centered position, to discharge the cap. It could be done with 3-pole switches and relays, or an extra single-pole switch that acts like a clutch, if he's used to a manual transmission. -jsw The Adjust circuit is a constant current source for the ramp-up, and the Direction switch provides an instant emergency stop. You only need a resistor from the top of the cap to the Clutch grounding contact to keep deceleration within the limit of traction. -jsw |
Tapping 6-32 in aluminum
On Tue, 07 Apr 2015 06:48:24 -0500, Ignoramus13314
wrote: On 2015-04-07, Larry Jaques wrote: On Mon, 06 Apr 2015 15:28:14 -0500, Ignoramus32423 wrote: On 2015-04-06, Larry Jaques wrote: On Mon, 06 Apr 2015 10:26:40 -0500, Ignoramus32423 wrote: On 2015-04-06, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote: Ignoramus32423 fired this volley in : The good news is that, as they run, even after a while, the heatsink is only barely warm. What you did not say was 1) the raw battery voltage, 12v nominal 2) the current (both peak and average) for the arm Not sure, not a lot. The arm operates very intermittently. 3) the current(ibid) for the tracks. Not sure what is the current for the 5v tracks, but my best guess is 1.2 amps when driving in a straight line, and about 3A when turning on a dime. Are you using spring-loaded momentary toggles on that controller? Seems less than optimal. Any suggestions? To check current draw, throw one of these inline with the power line, using standard USB connectors. They're great little units, and you can't beat the price. http://tinyurl.com/oyq53ro I picked up a couple when they were a buck, with free shipping. One went to my niece, with a power module for her cellphone. This is cool, indeed! I checked the charging current from the computer vs. the wall wart charger for my Kindle and the computer was 1/3 the current, taking a whole lot longer. It surprised me, but now I use the wall charger exclusively, unless I'll be at the computer all day. I just bought it They're very handy in their niche. Shipped direct from China ($3/1 month dlvy time) or from the USA ($15/1 week)? -- When a quiet man is moved to passion, it seems the very earth will shake. -- Stephanie Barron (Something for the Powers That Be to remember, eh?) |
Tapping 6-32 in aluminum
On 2015-04-07, Jim Wilkins wrote:
"Jim Wilkins" wrote in message ... "DoN. Nichols" wrote in message ... On 2015-04-06, Ignoramus32423 wrote: On 2015-04-06, Jim Wilkins wrote: [ ... ] If you used an LM317 adjustable regulator for the tracks you could tune the voltage for best performance while retaining control, and waste less of the battery's energy as heat. You could put a knob on the voltage adjustment pot so you have a throttle instead of just on/off control. [ ... ] Jim, you are right. I actually have several LM317T regulators. I just wanted to take the easy route. I wish that I could somehow have a ramp-up of speed, though, not go from zero to full throttle in an instant. Hmm ... if using the variable regulators, put a limiting resistor in series with the control voltage, and an electrolytic capacitor to slow the ramp-up. (Put a diode in parallel with the resistor to make the ramp-down faster, however, to make it easier to stop before a crash. :-) Enjoy, DoN. The problem is finding a momentary double-throw switch with a contact that's closed only in the centered position, to discharge the cap. It could be done with 3-pole switches and relays, or an extra single-pole switch that acts like a clutch, if he's used to a manual transmission. -jsw The Adjust circuit is a constant current source for the ramp-up, and the Direction switch provides an instant emergency stop. You only need a resistor from the top of the cap to the Clutch grounding contact to keep deceleration within the limit of traction. Maybe I will do it next time, or find a momentary handle with some kind of potentiometer action? |
Tapping 6-32 in aluminum
"Ignoramus13314" wrote in
message ... On 2015-04-07, Jim Wilkins wrote: Maybe I will do it next time, or find a momentary handle with some kind of potentiometer action? A joystick. https://www.sparkfun.com/products/90...FYk7aQodMr0AUQ -jsw |
Tapping 6-32 in aluminum
On Tuesday, April 7, 2015 at 10:22:34 AM UTC-4, Larry Jaques wrote:
On Mon, 06 Apr 2015 23:56:24 -0400, wrote: On Mon, 06 Apr 2015 19:50:02 -0700, Larry Jaques wrote: On Mon, 06 Apr 2015 15:25:25 -0500, Ignoramus32423 wrote: On 2015-04-06, Larry Jaques wrote: I will hopefully add more pictures and documentation soon. That's cool! (Shades of my old Erector set, but many generations ahead.) They still sell erector sets, they are quite plentiful. http://tinyurl.com/l28h9wl OMG, look at the price now! How much was a motorized 650 peice set back in 1965 dollars?? I remeber they were too expensive for my family to buy for me. A mechanic made about $2.15 an hour, an electrician about $2.50 Today the earningas are at least 20 times that, so a $175 set today would cost the same at $8.75 in 1965. I'm sure they were more than $8.75 - A #11 kit was well over $25 (over 17 pd Stirling in the UK) in 1964 (These were NEVER an "inexpensive" toy!!!) No, but teaching/learning tools seldom are. They're an investment. I learned how to cross-brace the structures to give them more strength, learned about cantilevers, gears, pulleys, etc. I don't know how much they cost back then since mine came as a gift from Mom's new male friend (Dad's BOSS!) during the year Mom & Dad were separated. The bribe helped, but I still didn't like him, and would have hated him more if I'd known he was Dad's boss at the time. I hope you aren't about to give us any more of a little too much information. |
Tapping 6-32 in aluminum
On Tuesday, April 7, 2015 at 8:29:32 AM UTC-7, wrote:
On Tuesday, April 7, 2015 at 10:22:34 AM UTC-4, Larry Jaques wrote: On Mon, 06 Apr 2015 23:56:24 -0400, wrote: On Mon, 06 Apr 2015 19:50:02 -0700, Larry Jaques wrote: On Mon, 06 Apr 2015 15:25:25 -0500, Ignoramus32423 wrote: On 2015-04-06, Larry Jaques wrote: I will hopefully add more pictures and documentation soon. That's cool! (Shades of my old Erector set, but many generations ahead.) They still sell erector sets, they are quite plentiful. http://tinyurl.com/l28h9wl OMG, look at the price now! How much was a motorized 650 peice set back in 1965 dollars?? I remeber they were too expensive for my family to buy for me. A mechanic made about $2.15 an hour, an electrician about $2.50 Today the earningas are at least 20 times that, so a $175 set today would cost the same at $8.75 in 1965. I'm sure they were more than $8.75 - A #11 kit was well over $25 (over 17 pd Stirling in the UK) in 1964 (These were NEVER an "inexpensive" toy!!!) No, but teaching/learning tools seldom are. They're an investment. I learned how to cross-brace the structures to give them more strength, learned about cantilevers, gears, pulleys, etc. I don't know how much they cost back then since mine came as a gift from Mom's new male friend (Dad's BOSS!) during the year Mom & Dad were separated. The bribe helped, but I still didn't like him, and would have hated him more if I'd known he was Dad's boss at the time. I hope you aren't about to give us any more of a little too much information. Larry Jackass can't help it. He's a whack job. |
Tapping 6-32 in aluminum
"Larry Jaques" wrote in message
... On Mon, 06 Apr 2015 23:56:24 -0400, wrote: (These were NEVER an "inexpensive" toy!!!) No, but teaching/learning tools seldom are. They're an investment. I learned how to cross-brace the structures to give them more strength, learned about cantilevers, gears, pulleys, etc. I've learned a lot from stuff that was free or very cheap because it was broken. I learned very early not to get caught taking apart things that weren't broken, like new Christmas toys. -jsw |
Tapping 6-32 in aluminum
On Tue, 7 Apr 2015 07:30:13 -0400, "Jim Wilkins"
wrote: wrote in message .. . On Mon, 6 Apr 2015 21:55:09 -0400, "Jim Wilkins" wrote: The cheap ones are far from accurate. I bought 2 on ebay - both were in-accurate, and they didn't even match each other. (readings were different and didn't match my 3 multitesters, that all agreed within less than 1/10 volt and less than 1/100 amp Look closely, mine had tiny calibration trim pots. These useless pieces of scrap didn't. They look like flathead mounting screws rather than pots. This one is 2mm in diameter. -jsw I know whst they look like - and they are not there. It uses "laser trimmed resistors" for calibration - and I think they over-trimmed them. Suspect what is sold on e-bay direct out of china is the rejects for some brand name product sold elsewhere at significantly higher price |
Tapping 6-32 in aluminum
wrote in message
... On Tue, 7 Apr 2015 07:30:13 -0400, "Jim Wilkins" wrote: wrote in message . .. On Mon, 6 Apr 2015 21:55:09 -0400, "Jim Wilkins" wrote: The cheap ones are far from accurate. I bought 2 on ebay - both were in-accurate, and they didn't even match each other. (readings were different and didn't match my 3 multitesters, that all agreed within less than 1/10 volt and less than 1/100 amp Look closely, mine had tiny calibration trim pots. These useless pieces of scrap didn't. They look like flathead mounting screws rather than pots. This one is 2mm in diameter. -jsw I know whst they look like - and they are not there. It uses "laser trimmed resistors" for calibration - and I think they over-trimmed them. Suspect what is sold on e-bay direct out of china is the rejects for some brand name product sold elsewhere at significantly higher price I've been paying a little more to gain the filtering effect of Amazon's return policy, which prods vendors into replacing junk for free. Often someone posts a link to the missing manuals and wiring schematics in the Comments. -jsw |
Tapping 6-32 in aluminum
wrote in message ... On Tue, 7 Apr 2015 07:30:13 -0400, "Jim Wilkins" wrote: wrote in message . .. On Mon, 6 Apr 2015 21:55:09 -0400, "Jim Wilkins" wrote: The cheap ones are far from accurate. I bought 2 on ebay - both were in-accurate, and they didn't even match each other. (readings were different and didn't match my 3 multitesters, that all agreed within less than 1/10 volt and less than 1/100 amp Look closely, mine had tiny calibration trim pots. These useless pieces of scrap didn't. They look like flathead mounting screws rather than pots. This one is 2mm in diameter. -jsw I know whst they look like - and they are not there. It uses "laser trimmed resistors" for calibration - and I think they over-trimmed them. Suspect what is sold on e-bay direct out of china is the rejects for some brand name product sold elsewhere at significantly higher price I've been satisfied with this USB power meter: http://www.amazon.com/gp/product/B00...d_i=B00HTAH3KY I don't remember exactly how accurate it was, and another could be different. It was close enough to tell which USB hard drives would run comfortably off the laptop USB2 port (WD) and which were marginal (Seagate) and should be on USB3 or a powered hub. I sorta wish I'd bought a dual display meter because the drives can take longer than the Volts / Amps display switching interval to come up and stabilize. -jsw |
Tapping 6-32 in aluminum
On 2015-04-07, Jim Wilkins wrote:
"Ignoramus13314" wrote in message ... On 2015-04-07, Jim Wilkins wrote: Maybe I will do it next time, or find a momentary handle with some kind of potentiometer action? A joystick. https://www.sparkfun.com/products/90...FYk7aQodMr0AUQ -jsw Wow, this is great, I see how I could have used it!!!! i |
Tapping 6-32 in aluminum
Ignoramus13314 fired this volley in
: Wow, this is great, I see how I could have used it!!!! Ig, With a joystick, you may not have any 'on-off' switches. You certainly would NOT want to impose on the driver the additional task of manipulating switches separate from the joystick. However, if you're driving a logic circuit or variable regulator with the 'pots' on a joystick, you can establish a range of travel that amounts to a 'null' setting, where no current will flow. Anything outside that null range would be considered an incremental setting for voltage/speed. Lloyd |
Tapping 6-32 in aluminum
"Ignoramus13314" wrote in
message ... On 2015-04-07, Jim Wilkins wrote: "Ignoramus13314" wrote in message ... On 2015-04-07, Jim Wilkins wrote: Maybe I will do it next time, or find a momentary handle with some kind of potentiometer action? A joystick. https://www.sparkfun.com/products/90...FYk7aQodMr0AUQ -jsw Wow, this is great, I see how I could have used it!!!! i That one is cheap and the pot is clear in the photo. A panel-mount one would be easier to add to throttle a variable regulator in the control box you built. The resistor between OUT and ADJ sets the constant current value. For a 1K pot, 4mA through it will give you an output range of 1.25V to 5.25V. -jsw |
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