Keyboard Shortcuts
Likes
- Unimat
- Messages
Search
Re: Overall Performance of Unimat 3
That's been done BUT it winds up as a big box under the lathe so the horizontal feed can be geared to the headstock. Used to be advertised in Popular Mechanics etc. I think there's a link in one section. Neil On Wed., Jul. 27, 2022, 20:38 Pierre Burelle, <Pburelle@...> wrote:
|
Re: Overall Performance of Unimat 3
¿ªÔÆÌåÓýWow great job do you think this could be fitted on a sl / db ?lathe? Did you upload the stl file so we could make our own set of gears¡On Jul 27, 2022, at 11:33 PM, Mike Gidley <mike.61dley@...> wrote:
|
Re: off topic question repowering
On Wed, Jul 27, 2022 at 04:07 PM, <ddmckee54@...> wrote:
Doing the voltage drop calculations, using the maximum allowable voltage drop of 3%, 110 volts supply voltage, and your load of 6 amps - the maximum length of the 18AWG fixture wire is 34'.? Any longer and you exceed the 3% allowable drop.Since the motor is 150 W the current for the 110 V supply is only 1.36 A, call it 1? A, so quite light wire will do. I would use whatever is easy to use - sometimes a wire can be too thin to be practical. On the 24 V side the current will be 6.25 A maximum, so 10 amp wire will be fine. The motor will rarely, if ever, work at maximum power, and the cable run will be short, so it would probably be OK to use 6 A rated cable, and voltage drop will not be significant. |
Re: off topic question repowering
According to the NEC information that I found, 18AWG fixture wire has an allowable ampacity of 10 amps, and the allowable ampacity of 16AWG fixture wire is 13 amps.
Doing the voltage drop calculations, using the maximum allowable voltage drop of 3%, 110 volts supply voltage, and your load of 6 amps - the maximum length of the 18AWG fixture wire is 34'.? Any longer and you exceed the 3% allowable drop.? With 16AWG and the same conditions, the maximum length is 55'. Don? |
Re: Mauser caliper question
Hello:
toggle quoted message
Show quoted text
On Wed, Jul 27, 2022 at 08:09 AM, Mehmood wrote: My apologies, I had interpreted your query ...No, no need to apologise, none whatsoever. It is I who should apologise for not being clear enough. Some days I write too early and without having had my first espresso. ;^¡ã Thanks so much for your input, especially the explanation for the scale. Best, JHM |
Re: Mauser caliper question
¿ªÔÆÌåÓýMy apologies, I had interpreted your query about the lower scale on the vernier having no numbers, so I supposed that you didn¡¯t know about using the scale notch that is closest a notch on the principle scale as a datum and counting back from there to the measurement point, tenths for the millimetre scale and eighths of eighths for the inches scale. ?(Just in case someone doesn¡¯t get it, the Vernier scale is 9/10ths the width of the millimetre divisions, or 7/8ths of the 1/8¡± divisions, allowing you to measure by eye to the next significant figure below the marked scale.)On 26 Jul 2022, at 23:50, sawbona@... wrote:
|
Re: Mauser caliper question
Ah yes, A set of 4 figure log tables and then a British Thornton slide rule. How wonderful were they. The exam board wanted to reduce exam times because it was quicker to get results with a slide rule! Then in 1974 I went to university, the Prof of Mechanical Engineering, had calculated that the cost of calculators, in terms of student lunch costs, was the same as when the slide rule was introduced. So off we went with RPN with HP 65s and Sinclair scientific. Heady days. James, in sunny Fife.? On Tue, 26 Jul 2022, 23:50 , <sawbona@...> wrote: Hello: --
James Batchelor? Dunfermline, Fife, UK.? 07805 207238 |
Re: off topic question repowering
¿ªÔÆÌåÓýIf 18 gauge is adequate, use 16 gauge.? That is, unless you have an unusually long run of cable, in which instance you will need to compute the voltage drop in that length of cable and adjust the wire size accordingly.? ? ? Jerry F. ? From: [email protected] [mailto:[email protected]] On Behalf Of William Macy via groups.io
Sent: Tuesday, July 26, 2022 9:06 AM To: [email protected] Subject: [Unimat] off topic question repowering ? Hello all. Back again with another simple question. What american wire gauge sized wire size should I use to connect the 110-120v to th 24v out converter box, thence to the speed controller and finally to the motor itself. The scooter motor wire looks to be 16 awg or so. My rudimentary knowledge of electrics tell me that watts/voltage= amperage or 150W/24V= 6A in round numbers. From tables on line it appears that 18awg should be more than adequate. Is that reasonable? |
Re: Mauser caliper question
Hello:
toggle quoted message
Show quoted text
On Tue, Jul 26, 2022 at 05:32 AM, Mehmood wrote: ... search the internet for ¡°how to read a Vernier scale¡±, it¡¯s easy to do but harder to describe ...Indeed. I've had no problems reading the scale. I was just curious about it not having numbers, probably because it is only good to 0.1mm. The doubts I had was about reading the table on the back part of the main scale: ... learnt to read vernier callipers in Physics classes ...Yes, so did I.? 8^D And before that, the logarithmic scales and an Aristo Scholar slide rule which I cannot remember what I did with. I took my Physics and Chemistry 'O' Levels using logarithmic scales.? I have a couple of slide rules, both gifted to me by a co-worker: a pocket Aristo 868 and a 530mm engineers model made from wood, probably pre-WW2. I'm a couple of years older and my eyesight has grown worse, so it is a task to even try to use them. Yes. But just a sense of.? 8^D Thanks a lot for your input and the memories it brought back. Best, JHM |
Re: Mauser caliper question
Hello:
toggle quoted message
Show quoted text
On Tue, Jul 26, 2022 at 02:10 AM, Dave Seiter wrote: I have a cheap dial caliper (~$30) I got in the mid 80's, and it's still doing well ...Hmmm ... I'd say that the old adage about things not being made like they did before applies in this case. 8^) To point: I recently purchased a beautiful/practically new 20mm/0.01mm K?fer dial gauge for an excellent price. It has a serial number but the OEM has no idea (!) of the manufacturing date, estimating it at 30/40 years old, so it's early 80's/90's. All stainless steel construction and mineral glass. A modern version of it would be a special edition and should I want to purchase one, I'd be looking at a +60 day lead time. Special edition means metal back, metal bezel and with mineral glass which is probably not the same thing I have. Thanks for your input. Best, JHM |
Re: off topic question repowering
If you're going to be using it only for short run times, it should be fine. If you plan on doing more turning, and running it longer (which the new DC motor should support just fine) I'd go one step up in size, or down in gauge #, i.e. AWG 14, if you're right about the motor wires being 16 ga. Lower ampacity wiring is more likely to burn up on a longer run of wire, and for longer run times. For a safety factor, you want about twice the ampacity you expect to need. If you're running the wire for only a couple of feet, There is less voltage drop, so less concern, but wire is relatively cheap compared to replacing the motor or power supply, so heavier wire is better... 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! 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
On Tuesday, July 26, 2022 at 11:05:51 AM CDT, William Macy via groups.io <wkmacy@...> wrote:
Hello all. Back again with another simple question. What american wire gauge sized wire size should I use to connect the 110-120v to th 24v out converter box, thence to the speed controller and finally to the motor itself. The scooter motor wire looks to be 16 awg or so. My rudimentary knowledge of electrics tell me that watts/voltage= amperage or 150W/24V= 6A in round numbers. From tables on line it appears that 18awg should be more than adequate. Is that reasonable? Thank in advance, Bill in NC, formerly from RI |
Re: Overall Performance of Unimat 3
¿ªÔÆÌåÓýThe files to use the Sherline threading set on a Unimat 3 are in the file section of the Unimat 3 group io.? There is a set of drawings and a text document explaining their use.? They opened fine for me. Charles Daldry On 7/26/22 09:54, Neil Morrison wrote:
|
Re: Overall Performance of Unimat 3
toggle quoted message
Show quoted text
------ Original Message ------
From: "Peter ashby via groups.io" <aescinga.pgen@...>
Sent: 26/07/2022 20:22:28
Subject: Re: [Unimat] Overall Performance of Unimat 3
|
Re: Overall Performance of Unimat 3
somewhere in the files should be the drawing I did for the unimat 4 threading system (and later unimat 3's), though it should fit all unimat 3's
------ Original Message ------
From: "Neil Morrison" <neilsmorr@...>
To: "OldToolmaker" <old_toolmaker@...>; [email protected]
Sent: 26/07/2022 16:54:45
Subject: Re: [Unimat] Overall Performance of Unimat 3
|