I was thinking about postcards really, remembering how exotic it was to find the Phonolcone PCBs wrapped in sheats from a Japanese map book.
But then I forgot about it, the most exotic about where I live is having a livingroom view to the forest, but only 15 mins by bike to the city center of a capital city in Europe...
But then I forgot about it, the most exotic about where I live is having a livingroom view to the forest, but only 15 mins by bike to the city center of a capital city in Europe...
Mark Kelly said:
Shucks! Just my bum luck! My reply to you of 13/06 was prob'ly the last post I made before my ISP got yanked. I seem to recall coming back and finding shipping going on...
If you do have a PCB still available, I guess I'll take that and investigate the SA option, though in the past it has not quite worked. Local taariffs make their one-off rates costlier than those in the US, and Europe. I may well end up getting the stuff from the other side of the meditarrenean...
Otherwise thanks for your time...
I was thinking being alot has been said and bounced back and forth about the pully. I know mark has put all the info we need to know about building the circut on his site i was wondering how feasible it would be to just put the important specs about the groupbuy pully as well. (eg. types and dimensions of bels and attachment methods preferred to use) mainly because this groupbuy has become HUGE and to sift through 5 10 or even 20 pages looking for all the important facts rather than the debates would help.
FortyTwo
FortyTwo
Hi Mark, I finally found the time to put parts on boards, things look great( you have to work those small transistor legs into obedience.. ) , but I miss a part, the VR1.
I'm sure I can get one similar locally, but just thought I'd mention it, I mean, if you found it under your table this morning or something.
I'm sure I can get one similar locally, but just thought I'd mention it, I mean, if you found it under your table this morning or something.
superhkm said:Hi Mark, I finally found the time to put parts on boards, things look great( you have to work those small transistor legs into obedience.. ) , but I miss a part, the VR1.
I'm sure I can get one similar locally, but just thought I'd mention it, I mean, if you found it under your table this morning or something.
All the VR1s I bought got sent so either it's under your table or someone has two.
It's a standard Spectrol 50k multiturn trimpot, any other brand will do. Pretty easy to find.
I set a time limit for notification of missing parts and it has passed. Sorry if that sounds mean but this thing has to cut off somewhere.
http://www.elfa.se/pdf/64/06473524.pdf
It would be rather silly to send a $3 part around the world anyway, I forgot about the cut-off.
It would be rather silly to send a $3 part around the world anyway, I forgot about the cut-off.
Glitch found
We've found a bug.
My Beta tester, VinylAddict, has found that now that his circuit is in its rather small enclosure it drifts by about 1% when first turned on.
It took me a while to find a possible reason, but it looks as though the circuit is sensitive to the input offset voltage on IC2B (between pins 5 and 6 of the OPA2277 IC near the current compensation adjustment pot).Thermal drift here is amplified into the circuit.
I have found a big difference between individual op-amps, I think I just happened to have a low drift op-amp in that position when I was developing the circuit.
You should test the input offset voltage (and the drift of same) betwen pins 5 and 6 in both the op-amps you have and use the lower one in that position.
A further refinement is to put a small thermostat in the enclosure, running off the primary supply. I have one I routinely use when ovening RC oscillators which uses about $5 worth of parts, I will update my webpage tomorrow with the circuit.
Sorry about this but it just didn't show up on my bench tests.
We've found a bug.
My Beta tester, VinylAddict, has found that now that his circuit is in its rather small enclosure it drifts by about 1% when first turned on.
It took me a while to find a possible reason, but it looks as though the circuit is sensitive to the input offset voltage on IC2B (between pins 5 and 6 of the OPA2277 IC near the current compensation adjustment pot).Thermal drift here is amplified into the circuit.
I have found a big difference between individual op-amps, I think I just happened to have a low drift op-amp in that position when I was developing the circuit.
You should test the input offset voltage (and the drift of same) betwen pins 5 and 6 in both the op-amps you have and use the lower one in that position.
A further refinement is to put a small thermostat in the enclosure, running off the primary supply. I have one I routinely use when ovening RC oscillators which uses about $5 worth of parts, I will update my webpage tomorrow with the circuit.
Sorry about this but it just didn't show up on my bench tests.
On further reading it may not be so bad.
The offset values I observed are so far outside the specification for the OPA2277 that it looks as though I have fallen foul of my inadequate ESD handling techniques.
I will construct an ESD safe mat and strap before I test the remaining op-amps.
Fortunately the op amps in the kits were kept attached to their ESD foam during packing so all should be well.
The offset values I observed are so far outside the specification for the OPA2277 that it looks as though I have fallen foul of my inadequate ESD handling techniques.
I will construct an ESD safe mat and strap before I test the remaining op-amps.
Fortunately the op amps in the kits were kept attached to their ESD foam during packing so all should be well.
Re: Glitch found
The enclosure has just enough space to mount all components and switches.
The finished product with battery status LED's mounted.
The rear panel layout.
Mark Kelly said:
The enclosure has just enough space to mount all components and switches.
An externally hosted image should be here but it was not working when we last tested it.
The finished product with battery status LED's mounted.
An externally hosted image should be here but it was not working when we last tested it.
The rear panel layout.
An externally hosted image should be here but it was not working when we last tested it.
I have attached a ZIP of an Excel file which makes calculating the output voltage from the dipswitch settings easy.
The first column is the dip switch positions reading from left to right, towards the pots = 0, away from the pots = 1, eg the “on” label on the dip switches is on the 0 side of position 1.
The first column is the dip switch positions reading from left to right, towards the pots = 0, away from the pots = 1, eg the “on” label on the dip switches is on the 0 side of position 1.
Hi All,
I recieved my maxon motor this week and the post had it's way with it. One of the terminals is snapped of, and the motor shaft was driven into the cardboard pretty well. I was not a happy camper. It does not appear that there was any bearing damage. I have pulled the rear off the motor and I am not quite sure how I am going to fix it without some hacking of the endbell. I wasn't sure if they were insured in the mail or not, but if they were, I may at least try and get re-imbursed for the hassle of having to fix it and ending up with a then hacked motor.
On the pulley topic, there has been no motion here on it since I last posted, but I hope to get them rolling soon.
DaveM
I recieved my maxon motor this week and the post had it's way with it. One of the terminals is snapped of, and the motor shaft was driven into the cardboard pretty well. I was not a happy camper. It does not appear that there was any bearing damage. I have pulled the rear off the motor and I am not quite sure how I am going to fix it without some hacking of the endbell. I wasn't sure if they were insured in the mail or not, but if they were, I may at least try and get re-imbursed for the hassle of having to fix it and ending up with a then hacked motor.
On the pulley topic, there has been no motion here on it since I last posted, but I hope to get them rolling soon.
DaveM
ouch....
with that kind of damage I'm surprised they went through with the shipment at all, the box/wrapping must have been more than just dented.
I feel really bad about this, the motors were not insured.
In my view, with the "budget"-shipping alternative chosen we split the responsabilities.
A reimbursment would be from me, and cover half the value of your hassle.
with that kind of damage I'm surprised they went through with the shipment at all, the box/wrapping must have been more than just dented.
I feel really bad about this, the motors were not insured.
In my view, with the "budget"-shipping alternative chosen we split the responsabilities.
A reimbursment would be from me, and cover half the value of your hassle.
As long as the shaft isn't bent and the bearings are OK it shouldn't be hard to fix. The wire terminals are push fit onto the brush posts, they come off when you remove the black plastic end cap.
All you should need to do is remove the broken terminal from the end cap, solder a wire to it and then put it back in.
All you should need to do is remove the broken terminal from the end cap, solder a wire to it and then put it back in.
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