I bought these in Osaka on the weekend. Prices are in yen.
Not sure if I paid too much.
Not sure if I paid too much.
QLD Australian Woodworker Mags 80+ copies
80+copies of Australian Woodworker mag. The earliest I cansee is #56 (July August 1994) through to #151 (June 2010). Almost fullycontinuous but missing a few here and there. All in good condition and lots ofgreat info. Asking $60 the lot.
Boat trailer draw bar modification
Hi all, Hoping for a bit of guidance on a boat trailer. I have an late 1960's ski boat on the original trailer and i would like to put brakes on the trailer to bring it up to current compliance. Also looking at extending the draw bar a little to hopefully improve backing the trailer as the nose of the boat comes close to hitting the back of the ute when reversing and it's just generally a bit of a pig to reverse. As you can see the previous owner has cut and moved the nose bar to keep the boat back on the trailer to make it easier to reverse. However this results in shifting a lot of the weight too far over the axle. 
The chassis channel is around 3.2mm thick and there is a approx 60mm angle 6.5mm thick set back with the first roller fixed to it. My thoughts are to cut out the existing tow hitch plate and insert (and weld in) a new draw bar that will continue through to a new cross piece that will also be used to add a post for a winch mount and so get rid of the old bar that goes over the nose of the boat. So I was wondering what size draw bar should I use and how much longer can I safely extend it past its current set up? I was thinking of working out where the nose of the boat will sit and then locate the cross bar around this area and run the winch post from the cross bar. The end result would be similar to the pick below. 
Any help is appreciated. Cheers p.s. sorry for the formatting, for some reason the formatting isn't recognizing spaces etc.
The chassis channel is around 3.2mm thick and there is a approx 60mm angle 6.5mm thick set back with the first roller fixed to it. My thoughts are to cut out the existing tow hitch plate and insert (and weld in) a new draw bar that will continue through to a new cross piece that will also be used to add a post for a winch mount and so get rid of the old bar that goes over the nose of the boat. So I was wondering what size draw bar should I use and how much longer can I safely extend it past its current set up? I was thinking of working out where the nose of the boat will sit and then locate the cross bar around this area and run the winch post from the cross bar. The end result would be similar to the pick below. Any help is appreciated. Cheers p.s. sorry for the formatting, for some reason the formatting isn't recognizing spaces etc.Home made rotary sander
Up until now I have been sanding using a cordless drill with some sanding pads. I made up a series of pads so I don't have to change the paper every time I want to change grits. As my batteries are starting to deteriorate, I decided it was time to make myself a rotary sander (for the all up cost of under $10.00).
I bought 10x 19mm bearings for $3.50 on ebay, and a copper 45 degree bend (internal diameter 19mm) for $6.50 from plumbing supplies. 90 degree was 1/2 that price, but 45 lets me get into tighter spaces).
Glued in 2 bearings on one side, and turned up a handle for the other. Shaft of the sanding pads was a tad too tight, but grinding off just a wee bit made them easy to get in & out.
20140728_201009.jpg
20140728_201134.jpg
20140729_203900.jpg
I bought 10x 19mm bearings for $3.50 on ebay, and a copper 45 degree bend (internal diameter 19mm) for $6.50 from plumbing supplies. 90 degree was 1/2 that price, but 45 lets me get into tighter spaces).
Glued in 2 bearings on one side, and turned up a handle for the other. Shaft of the sanding pads was a tad too tight, but grinding off just a wee bit made them easy to get in & out.
20140728_201009.jpg
20140728_201134.jpg
20140729_203900.jpg
This worth a look? (Table Saw)
I'm looking for my first big shop purchase ---- TABLE SAW. Unfortunately I don't know what's good/bad/ugly so I'm wondering if anyone can offer some advise on this puppy that's currently for sale in my area.
Info provided - Baker 12" table Rip Saw. 240 volt. Angle cut. Slide fence.
Any info would be great. Cheers.
1.JPG2.JPG
Info provided - Baker 12" table Rip Saw. 240 volt. Angle cut. Slide fence.
Any info would be great. Cheers.
1.JPG2.JPG
American Football
American football
American football and the blonde
Of all the blonde jokes, this one has to be the best — because it makes American football make sense
A guy took his blonde girlfriend to her first football game. They had great seats right behind their team's bench. After the game, he asked her how she liked it.
“Oh, I really liked it,” she replied, "especially the tight pants and all the big muscles, but I just couldn't understand why they were killing each other over 25 cents."
Dumbfounded, her boyfriend asked, “What do you mean?”
"Well, they flipped a coin, one team got it and then for the rest of the game, all they kept screaming was... 'Get the quarterback! Get the quarterback!' I'm like....Helloooooo? It’s only 25 cents!"
True RMS current measurements
During the recent bout of electric motor HP versus frequency tests I also recorded the currents involved at different motor loads, both the current going into and out of the VFD as well as the current displayed by the VFD itself. The idea behind this was to see if I could compare the electrical power consumption with the mechanical power being produced and hence determine the efficiency of the motor and the VFD.
One problem I knew about was that a true RMS current meter is required to accurately measure the VFD output current at different frequencies. The Protek multimeter I was using is a true RMS voltmeter but the conventional current clamp (CCC) is an unknown quantity and being a cheap chinese clamp somehow I doubted it would be up to the mark.
Just after I performed these measurements I was discussing them with a techo mate who mentioned that a place in the US was selling Fluke true RMS current meters for about 2/3 to half the going rate so I decided to bite the bullet and get the 324 model. It arrived this morning and I have been playing with it since then, and here I post some test results where I compare the readings of the Fluke with other meters.
I don't intend to perform a full review of this Fluke meter as I don't have the gear to adequately test it anyway and there is more than enough info about it on the web, however I will provide a few details.
The 324 is one of the 3 basic Fluke True RMS meters described here , see Fluke 324 True RMS Clamp Meter
It comes with a reasonably rugged pouch and a massive manual which turns out to be half a dozen pages of basic instructions in a zillion different languages.
Fluke do however provide additional documentation on the web, including application notes and a comprehensive calibration booklet.
The meter includes basic Voltage, resistance. capacitance and temperature measurement capability, a nice long set of rugged leads, as well a thermcouple.
While it's useful to have these features, none of them are that special or make it worth buying as it's main purpose is to measure current.
It measures 0 - 400A with a resolution of 100 mA for >40A and 10 mA for <40A.
The meter is guaranteed accurate to 1.5% between 45 and 400Hz, it will measure below 45Hz but no accuracy is given for sub 45Hz frequencies.
During testing I recorded the output current of the VFD, and the Protek multimeter connected to a conventional current clamp (CCC), and the fluke meter simultaneously, as I increasingly applied load to a 1HP motor connected to the VFD.
The other panel meter displays the current and voltage going into the VFD.
The readings had to be taken simultaneously so I did this using the same photo technique I used for measuring the Motor HP i.e. change the load and wait for it to stabilise and the take a photo.
Then look at the images one by one and enter all the data into a spreadsheet and calculated the % deviation of the VFD current being displayed, from the value shown on the fluke meter, and did the same for the CCC. I repeated this over a range of motor loads/currents and frequencies.
The % deviations are plotted below - the fact that the % deviations are all negative values mean that the currents are being recorded too low by the CCC and the VFD.
The solid lines are for the CCC and the dashed lines are for the VFD current.
The same colour of line refers to the same frequencies.
Unfortunately the graph is a bit messy but it is obvious that both the CCC and the VFD currents are being measured too low by ~ 10 and 20 % respectively.
To more easily see if there was a frequency dependence I plotted the average deviation for each frequency and it does look like the CCC has a frequency dependence, while the VFD just reads between 19 and 13% too low.
While the currents at higher frequencies have not been explored, these results are not as poor as I thought they would be.
I will do some more testing WIGRTI.
Of course other VFDs may provide more or less accurate current measurements.
One problem I knew about was that a true RMS current meter is required to accurately measure the VFD output current at different frequencies. The Protek multimeter I was using is a true RMS voltmeter but the conventional current clamp (CCC) is an unknown quantity and being a cheap chinese clamp somehow I doubted it would be up to the mark.
Just after I performed these measurements I was discussing them with a techo mate who mentioned that a place in the US was selling Fluke true RMS current meters for about 2/3 to half the going rate so I decided to bite the bullet and get the 324 model. It arrived this morning and I have been playing with it since then, and here I post some test results where I compare the readings of the Fluke with other meters.
I don't intend to perform a full review of this Fluke meter as I don't have the gear to adequately test it anyway and there is more than enough info about it on the web, however I will provide a few details.
The 324 is one of the 3 basic Fluke True RMS meters described here , see Fluke 324 True RMS Clamp Meter
It comes with a reasonably rugged pouch and a massive manual which turns out to be half a dozen pages of basic instructions in a zillion different languages.
Fluke do however provide additional documentation on the web, including application notes and a comprehensive calibration booklet.
The meter includes basic Voltage, resistance. capacitance and temperature measurement capability, a nice long set of rugged leads, as well a thermcouple.
While it's useful to have these features, none of them are that special or make it worth buying as it's main purpose is to measure current.
It measures 0 - 400A with a resolution of 100 mA for >40A and 10 mA for <40A.
The meter is guaranteed accurate to 1.5% between 45 and 400Hz, it will measure below 45Hz but no accuracy is given for sub 45Hz frequencies.
During testing I recorded the output current of the VFD, and the Protek multimeter connected to a conventional current clamp (CCC), and the fluke meter simultaneously, as I increasingly applied load to a 1HP motor connected to the VFD.
The other panel meter displays the current and voltage going into the VFD.
The readings had to be taken simultaneously so I did this using the same photo technique I used for measuring the Motor HP i.e. change the load and wait for it to stabilise and the take a photo.
Then look at the images one by one and enter all the data into a spreadsheet and calculated the % deviation of the VFD current being displayed, from the value shown on the fluke meter, and did the same for the CCC. I repeated this over a range of motor loads/currents and frequencies.
The % deviations are plotted below - the fact that the % deviations are all negative values mean that the currents are being recorded too low by the CCC and the VFD.
The solid lines are for the CCC and the dashed lines are for the VFD current.
The same colour of line refers to the same frequencies.
Unfortunately the graph is a bit messy but it is obvious that both the CCC and the VFD currents are being measured too low by ~ 10 and 20 % respectively.
To more easily see if there was a frequency dependence I plotted the average deviation for each frequency and it does look like the CCC has a frequency dependence, while the VFD just reads between 19 and 13% too low.
While the currents at higher frequencies have not been explored, these results are not as poor as I thought they would be.
I will do some more testing WIGRTI.
Of course other VFDs may provide more or less accurate current measurements.
Inscription à :
Articles (Atom)
