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Re: through bore
From experience, it's still a problem. With a TS mounted drill, it'll
still try to self feed, either jamming the machine or popping the chuck out of the TS taper. With a carriage mounted drill, it'll still try to pull itself in. The reamer did a nice job, with no drama:-) Roy --- In 7x12minilathe@..., "Ellis Cory" <ellis103@...> wrote: large drill enlarging a hole; they tend to self feed at their spiral rate.......... drill presses. Using the screw operated tailstock and only opening up by 1/64" at a time should be very little problem. If necessary, the lips could be 'backed' off in the same fashion as brass drills. Of course, the quill travel is limited, so it's a case of drilling a bit, move the tailstock a bit. HTH |
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Re: Ammeter
G'day Jim
At first I took note of your caution about connections in the motor circuit***. However reading the KBE data showed that they allowed for a fuse in the armature circuit; that would open circuit to operate. They do caution about switching so I guessed that they are concerned about motors being switched on to the drive with either back emf or no emf with the controller outputing volts. Remember the mods to the reversing switching of the earlier lathes? My system is 240/230 volts so my currents are half that of a 110 system. For 110 volt systen a 0-10 amp meter would be needed for a 350/400W motor. ***OK for KB controllers but other units would have to be assessed on their merits. I posted a bit more info in my email addressed to John (born4something). John was concerned about the effect of the waveform on meter accuracy. I don't think it is an issue because the industrial drives with which I am familiar (up to 1500HP) have used moving coil meters connected across shunts. I think the armature inductance smooths the current enough for the meter. I am hoping the meter will be useful when parting off as I frequently stall the lathe, even with a 1/16 blade. That is why I wanted it at a place where I can see it when operating the cross slide. It certainly confirmed I need to change out the horse power resistor; I got short changed. The KB controllers are industrial quality and are well supported with data; I haven't asked, but I quess replacements are availble ex stock in Oz. Baldor are the Australian representative. Thank you for your help. One good turn deserves another. Regards Ian --- In 7x12minilathe@..., "Jim RabidWolf" <unclerabid@...> wrote: mail them over to me ( use radid@... - that's my own domain, so lot's more |
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Re: Ammeter
Jim RabidWolf
Yeah, the KB's are good - Homier/Speedway USED to use them, but they've gone
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to the SIEG units, now. Nothing really wrong with the SIEG units that abit of ":fluffing up" wouldn't fix. <G> ----- Original Message -----
From: "Ian Foster" <fosterscons@...> To: <7x12minilathe@...> Sent: Friday, April 06, 2007 8:12 AM Subject: [7x12minilathe] Re: Ammeter G'day John et al. The meter is a moving coil type. The inductance of the motor armature should smooth the current enough for a reasonable accuracy. BTW, meters used on much larger drives were moving coil type across appropriate shunts. The meter leads are connected into the wire from the positive output of the controller to the reversing switch. I used insulated male and female spade connectors and then taped them. Finding a useful place to mount the meter was the biggest challenge, hence it being hooked over the back of the chip guard. There are not many places you can conveniently bring a cable out of the control box. I used a cable gland just below the leadscrew opening. The cable, which is standard 3 core flex, passes under the lathe bed. My controller is an SCR type by KB Electronics, a US firm. It appears they manufacture a range of boards for machine tool and process instrumentation applications. It has 5 trim pots! One good turn deserves another. Regards, Ian --- In 7x12minilathe@..., "born4something" <ajs@...> wrote: left of that an Add Photo link. Well, that's how it is in other groups Be sure to check out for small mills and lathes. Yahoo! Groups Links |
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Re: Ammeter
Jim RabidWolf
His real bull is SCR as I remember, John.
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----- Original Message -----
From: "born4something" <ajs@...> To: <7x12minilathe@...> Sent: Friday, April 06, 2007 7:36 AM Subject: [7x12minilathe] Re: Ammeter --- In 7x12minilathe@..., "Ian Foster" <fosterscons@...> wrote: post photos on this group?Good work Ian, We all discussed this endlessly a month back but I don't recall anyone opting to do & report. You can only figure so much on paper! Proof of the pudding is... In the photos area there's a Photos Help link up the top right. Immediately below that should be a Create Album link and to the left of that an Add Photo link. Well, that's how it is in other groups like the 7x10. I know the mod was trying to establish a new culture when the 7x12 was started so must have turned that feature off. I guess you need to ask the mod to do it for you. I've seen photos of meters before <G> so other details mean more to me. Where did you end up connecting it - in the AC mains feed or DC motor wiring? Moving coil or moving iron? Is your controller FET or SCR based? Can you quote your controller model (PCB sticker) since your Real Bull machine could well differ to what many of us have? Thanks, John Be sure to check out for small mills and lathes. Yahoo! Groups Links |
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Re: Ammeter
Jim RabidWolf
oh, and I'd love to see the pictures, even if you just want to e-mail them
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over to me ( use radid@... - that's my own domain, so lot's more storage there - this mailbox is a bit on the skinny side) Thanks!! ----- Original Message -----
From: "Ian Foster" <fosterscons@...> To: <7x12minilathe@...> Sent: Friday, April 06, 2007 7:02 AM Subject: [7x12minilathe] Ammeter G'day all. After talking about it for a while I have finally hooked an ammeter into the motor circuit. The meter is a small 0-5 amp movement which I mounted in an ABS box. This box hooks over the back of the chip guard and can be positioned for optimum viewing or shifted out of the way. Some discoveries: I can hold the chuck in my hand in the high speed gear and stall the drive, the current is about 2.5 amps, the current clampng action is quite effective. Making a 1.0mm deep cut in 1214 Mild steel at 25mm diameter and low speed gear requires 2.0 amps, independent of speed. My motor is rated at 180V 400W which corresponds to a full load current of 2.2 amps. On checking my control board I have noticed that what the manufacturer calls the Horse Power Resistor is labelled 1/4-1/3; this is clearly a mismatch to my motor which is about 1/2 HP. The manufacturer has confirmed this and I have already spoken to an agent in my home city; he actually knew what I was talking about! The outcome is that next week I will pick up a new resitor at the exhorbitant price of AUD3.00; cost me more in fuel to get there. The new resistor will increase the available torgue, but the manufacturer recommends I set the stall current at 3.5 amps, not double its present value Thanks to Jim Rabid who was able to identify the board for me and to KB Electronics for having an informative web site. If anyone is interested I'll post some photos. BUT, how do you post photos on this group? One good turn deserves another. Regards, Ian Be sure to check out for small mills and lathes. Yahoo! Groups Links |
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Re: Ammeter
Jim RabidWolf
This technique works better on the SCR units than it does on the PWM units,
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as it's often diffucult to get around the fact that's pulse DC on PWM. However, using a clamp-on style meter can net you good results. Also, from the meter readings you're getting, I'm guessing your's is a 220/230 volt unit? The upper end on the 110/120 units on current is around 4 amps (hence the 5 amp fuse, 3 amp on the 220/230). Rabid Uncle Rabid ( ) We Repair Electronic Speed Controllers For Asian Mini Lathes and Mini Mills "Just Crazy Enough To Get the Job Done" (Join Rabid's Lathe/Mill Controller/Mod's List!) (Also visit BarStockEngines - join us in building without Castings!) ----- Original Message -----
From: "Ian Foster" <fosterscons@...> To: <7x12minilathe@...> Sent: Friday, April 06, 2007 7:02 AM Subject: [7x12minilathe] Ammeter G'day all. After talking about it for a while I have finally hooked an ammeter into the motor circuit. The meter is a small 0-5 amp movement which I mounted in an ABS box. This box hooks over the back of the chip guard and can be positioned for optimum viewing or shifted out of the way. Some discoveries: I can hold the chuck in my hand in the high speed gear and stall the drive, the current is about 2.5 amps, the current clampng action is quite effective. Making a 1.0mm deep cut in 1214 Mild steel at 25mm diameter and low speed gear requires 2.0 amps, independent of speed. My motor is rated at 180V 400W which corresponds to a full load current of 2.2 amps. On checking my control board I have noticed that what the manufacturer calls the Horse Power Resistor is labelled 1/4-1/3; this is clearly a mismatch to my motor which is about 1/2 HP. The manufacturer has confirmed this and I have already spoken to an agent in my home city; he actually knew what I was talking about! The outcome is that next week I will pick up a new resitor at the exhorbitant price of AUD3.00; cost me more in fuel to get there. The new resistor will increase the available torgue, but the manufacturer recommends I set the stall current at 3.5 amps, not double its present value Thanks to Jim Rabid who was able to identify the board for me and to KB Electronics for having an informative web site. If anyone is interested I'll post some photos. BUT, how do you post photos on this group? One good turn deserves another. Regards, Ian Be sure to check out for small mills and lathes. Yahoo! Groups Links |
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Re: Ammeter
G'day John et al.
The meter is a moving coil type. The inductance of the motor armature should smooth the current enough for a reasonable accuracy. BTW, meters used on much larger drives were moving coil type across appropriate shunts. The meter leads are connected into the wire from the positive output of the controller to the reversing switch. I used insulated male and female spade connectors and then taped them. Finding a useful place to mount the meter was the biggest challenge, hence it being hooked over the back of the chip guard. There are not many places you can conveniently bring a cable out of the control box. I used a cable gland just below the leadscrew opening. The cable, which is standard 3 core flex, passes under the lathe bed. My controller is an SCR type by KB Electronics, a US firm. It appears they manufacture a range of boards for machine tool and process instrumentation applications. It has 5 trim pots! One good turn deserves another. Regards, Ian --- In 7x12minilathe@..., "born4something" <ajs@...> wrote: left of that an Add Photo link. Well, that's how it is in other groups |
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Re: Ammeter
Clint D
For loading photos, myself or any other moderator can do that for you,
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just email ones of us. Clint born4something wrote: --- In 7x12minilathe@..., "Ian Foster" <fosterscons@...> |
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Re: Ammeter
--- In 7x12minilathe@..., "Ian Foster" <fosterscons@...>
wrote: post photos on this group?Good work Ian, We all discussed this endlessly a month back but I don't recall anyone opting to do & report. You can only figure so much on paper! Proof of the pudding is... In the photos area there's a Photos Help link up the top right. Immediately below that should be a Create Album link and to the left of that an Add Photo link. Well, that's how it is in other groups like the 7x10. I know the mod was trying to establish a new culture when the 7x12 was started so must have turned that feature off. I guess you need to ask the mod to do it for you. I've seen photos of meters before <G> so other details mean more to me. Where did you end up connecting it - in the AC mains feed or DC motor wiring? Moving coil or moving iron? Is your controller FET or SCR based? Can you quote your controller model (PCB sticker) since your Real Bull machine could well differ to what many of us have? Thanks, John |
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Re: File download problems (Works for m)
Clint D
Make sure the files you are trying to upload are not to large, if they
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are large, they need broken down into several files Clint rancerupp wrote: No, I just downloaded 2 DOC files and watched a MOV of the Adj. |
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Ammeter
G'day all.
After talking about it for a while I have finally hooked an ammeter into the motor circuit. The meter is a small 0-5 amp movement which I mounted in an ABS box. This box hooks over the back of the chip guard and can be positioned for optimum viewing or shifted out of the way. Some discoveries: I can hold the chuck in my hand in the high speed gear and stall the drive, the current is about 2.5 amps, the current clampng action is quite effective. Making a 1.0mm deep cut in 1214 Mild steel at 25mm diameter and low speed gear requires 2.0 amps, independent of speed. My motor is rated at 180V 400W which corresponds to a full load current of 2.2 amps. On checking my control board I have noticed that what the manufacturer calls the Horse Power Resistor is labelled 1/4-1/3; this is clearly a mismatch to my motor which is about 1/2 HP. The manufacturer has confirmed this and I have already spoken to an agent in my home city; he actually knew what I was talking about! The outcome is that next week I will pick up a new resitor at the exhorbitant price of AUD3.00; cost me more in fuel to get there. The new resistor will increase the available torgue, but the manufacturer recommends I set the stall current at 3.5 amps, not double its present value Thanks to Jim Rabid who was able to identify the board for me and to KB Electronics for having an informative web site. If anyone is interested I'll post some photos. BUT, how do you post photos on this group? One good turn deserves another. Regards, Ian |
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Re: Broke the tap, Grrrrr.
G'day Andy.
Before writing back on the Sodium Metabisulphate I did a quick Google check as I also recalled it was metabisulsphite. It seems they are interchangeable as sterilising agents. The metabisulphite seems to be more hazardous. I guess alum provides a good source of active sulphate ions to attack the iron in the tap. One good turn deserves another. Regards. Ian. --- In 7x12minilathe@..., andrew franks <andyf1108@...> wrote: metabisulphite (Na2 S2 O5), rather than metabisulphate, but I don't suppose that would make any practical difference. I might also experiment with sulphuric (battery) acid. When I made my first attempts at anodising, it seemed to leave the aluminium alone (no doubt because of the oxide layer), so maybe that would attack the broken tap and not the aluminium alloy it was stuck in. I suppose an initial rinse in solvent would help, by getting rid of any cutting oil and allowing the chosen chemical to get at the steel.
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Re: through bore
Ian wrote.....If the drill self feeds it breaker its grip with the taper and slips.......
This only happens if the forces are excessive. The depth of cut on each lip will be less than 8 thou. The rate of feed is entirely depepndant on how slow you turn the handle. The flute angle (rake) can be overcome by grinding a flat each lip, as for drilling brass. This is the way I have done many jobs without the drill pulling out. The last one opening up a hole to 1.25 ". Reamers are very expensive for a one off job. You could try and get on the Varmit Al's reamer queue, or just buy a 13/64" drill and DIY. HTH Ellis |
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Re: Broke the tap, Grrrrr.
Sulphate... shmulphate. You guys are so far over my head here I can't
even participate. I do believe I've learned something here though, thanks for that. Given what I've read though, I think I'd opt for the "build an EDM unit" method. Kills two birds with one stone. 1) Gets the tap out. 2) Have a new tool in my arsenal. And the square hole thing really facinates me. :D Something about boiling acid on the SWMBO's kitchen stove just won't float around my shack. Oh, and btw, stop using those high-falutin words around here. "Pedantic"? I aint even gonna look that one up. :) Rance --- In 7x12minilathe@..., andrew franks <andyf1108@...> wrote: metabisulphite (Na2 S2 O5), rather than metabisulphate, but I don't suppose that would make any practical difference. I might also experiment with sulphuric (battery) acid. When I made my first attempts at anodising, it seemed to leave the aluminium alone (no doubt because of the oxide layer), so maybe that would attack the broken tap and not the aluminium alloy it was stuck in. I suppose an initial rinse in solvent would help, by getting rid of any cutting oil and allowing the chosen chemical to get at the steel.
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Re: File download problems (Works for m)
No, I just downloaded 2 DOC files and watched a MOV of the Adj.
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Backplate. :) However, are we back to duplicate posts again? Some look very familiar. 8-| --- In 7x12minilathe@..., "oneacmename" <daniel@...> wrote:
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Re: Broke the tap, Grrrrr.
andrew franks
Hello Folks,
To be pedantic, I think that the sterilising stuff is sodium metabisulphite (Na2 S2 O5), rather than metabisulphate, but I don't suppose that would make any practical difference. I might also experiment with sulphuric (battery) acid. When I made my first attempts at anodising, it seemed to leave the aluminium alone (no doubt because of the oxide layer), so maybe that would attack the broken tap and not the aluminium alloy it was stuck in. I suppose an initial rinse in solvent would help, by getting rid of any cutting oil and allowing the chosen chemical to get at the steel. Andy roylowenthal <roylowenthal@...> wrote: Yup! That's the same sodium bisulphate as the pH down product for pools/spas. It's quicker than alum (any of the common variants) & easy to get. Roy --- In 7x12minilathe@..., Victoria Welch <wrlabs@...> wrote: the theywork. Being a bisulphate the iron ions do not need to displace the productid=285&cat=0&page=1just neutralise the solution forming iron sulphate and sodiumFound this at my local homebrew store: with the best firepower.-- The Warlord (_Ivory_, Mick Resnick) --------------------------------- Inbox full of unwanted email? Get leading protection and 1GB storage with All New Yahoo! Mail. |
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Re: through bore
G'day Ellis
Drilling from the tail stock is OK but the drill or chuck is held by a taper. If the drill self feeds it breaker its grip with the taper and slips. An exercise in futility. You have to keep cutting pressure om the drill and the drill takes over so you can't restrict the feed rate. A reamer is the way to go. Note that machine reamers have straight flutes whilst hand reamers have spiral flutes. One good turn deserves another. Regards, Ian --- In 7x12minilathe@..., "Ellis Cory" <ellis103@...> wrote: large drill enlarging a hole; they tend to self feed at their spiral rate.......... drill presses. Using the screw operated tailstock and only opening up by 1/64" at a time should be very little problem. If necessary, the lips could be 'backed' off in the same fashion as brass drills. Of course, the quill travel is limited, so it's a case of drilling a bit, move the tailstock a bit. HTH |
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Re: through bore
Roy wrote.....The practical problem is controlling the feed of a large drill enlarging a hole; they tend to self feed at their spiral rate..........
I believe this is only true with lever operated machines, such as drill presses. Using the screw operated tailstock and only opening up by 1/64" at a time should be very little problem. If necessary, the lips could be 'backed' off in the same fashion as brass drills. Of course, the quill travel is limited, so it's a case of drilling a bit, move the tailstock a bit. HTH Ellis |
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