help with missing parts on Mini-Lathe....

[mike3]

Hi ... I would like If someone would have the time to look at a Mini-Lathe I won on ebay to see if they can tell me what parts are missing ... so i can order them ... the pix are below... I havn't recived it yet .. but I would like to be able to have the parts to arrive about the same time as the lathe,,, I am new to machine work ,, and am not sure what all would be missing ... thanks ahead of time...

Mike.....

[anoel]

Right off there is no Electronics enclosure, or any part that belongs inside of it. The Gear Cover is missing, No Change Gear Set, No Carriage Hand Wheel, No Tail Stock Hand Wheel, No Chuck Key, No open end or allen wrenches.

( I just unpacked a new Harbor Frieght Lathe last weekend and that's what I see missing at fist glance.) I hope you won that at a decent price....

[mike3]

well thanks Nathan.. I knew the electronics and cover were missing...... I have that in the making now,,, I actually won this for $166.00 .. I think it was a good price... thanks again .. I will order those parts from LittleMachineshop.com ... I just recieved some good books on how to set up and use a lathe ... I do a little Astronomy .... and want to reto-fit a Computer guidance system to a telescope mount,,, for my C-9.25 .. scope,,,


Mike....

[CNCadmin]

oops missed the post above- http://Littlemachineshop.com has all the parts you need in stock.

[mike3]

Thanks .. at least I know they are in stock....

Mike....

[Chagrin]

I don't think you got a bargain on this one. The motor controller alone is $90 from LMS. If you exceed $300 you've surpassed the price of a new model from homier.com.

[mike3]

well actually this is the 7x12 micro-mark 82500 .. I am building the controller ..for about .. 15.00 and am ording the missing parts .. for around .. 55.00 ... but I did end up bidding a little more than I had intended to ... but hopefully I can keep the end total .. reasonable....

Mike....

[RotarySMP]

The Micro mark 7x12 is a homier 7x12 is a HF 7x12. They are all made by SIEG in Shanghai. The Homier costs $300.

Is the motor fitted? you can't see that from the picture.

You are making a PWM 120V 250W DC motor controller for $15? Cool, how? I searched the web for circuits for higher powered PWM DC controllers, but found nothing over 12V and don't have the skills to design my own.

You could order one handle and then use the lathe to turn one for the tailstock.

Make sure you visit www.mini-lathe.com and do all the deburring and lapping suggested. Makes a big difference to the machine.

If you are here, you are probably interested in CNC. Before you build up the machine, I'd recommend you address the bed thickness as described by Rick Kruger here.
http://warhammer.mcc.virginia.edu/ty...s/Bedways.html

[mike3]

Hi Mark...

Homier no longer sells the mini-lathe .. I went to tent sale .. to buy one .. a few weeks ago .. and the sales rep .. stated ..they were gone... after they sold out .. I have heard they are bringing out a couple of new models later this year .. bigger I am told... I looked all over the web .. before bidding on the one I won ., and Harbor Freight ,, was the best price .. but it is a 10" .. not a 12" ... But I did buy a Mini-Mill at the tent sale .. for $399.00 .. I am in the process of retro-fitting .. to CNC ...

You asked about a PWM circuit .. look in the General Electronic forum here under .. DC controller.. I posted .. The curcuit the Guy posted should work with little Mod's .. also several electronic kit sites.. sell a kit ,, that will control up to .. 17 amps 90 volts... and after you use a bridge retifier .. to bring 110-120 volts AC to DC you end up with around 90-100 volts anyway I don't have a way to check what the voltage original controller .. handled .. but I would say it was about the same.. I don't have the web site handy but if you are interested .. I will post it.. It sells for $19.95 ..

Thanks for the web site you gave .. I will certainly check it completly over .. as that its in a "Parts" condition .. there probably are many Issues with it .. .. Regards... Mike .....

[RotarySMP]

Hi Mike,

Good idea to avoid the 7X10. The bed is actually four inches shorter than the 7x12, which means you are really limited when it comes to drilling holes. I step drill up to 16mm regularly when I want to get rid of material before swapping to a boring bar. On a 7X10, you would have to drastically chop down all these bigger drills and reform the point.

If you rectify 110 VAC you will have sqrt2x110= 155VDC.

The 7x mini lathe motor is rated at 110VDC.

I printed out the circuit in the DC Controller thread, but it is for 8-35VDC as far as I can see. I checked the ST electronics site for the data sheet :

http://www.st.com/stonline/books/pdf/docs/4286.pdf

Since Q1 is a 100V mosfet, is the plan to separate the control circuit from the power circuit?

To drive a 110V motor you probably want a 200V capable mosfet right?

[jfong]

Do a search on EBAY for DC motor speed controller. KB Electronics and Minarik are companies that make controllers for 110volt motors that should work. Thier web sites can help you choose the appropriate one for your lathe motor. You can sometimes pick one up for under $30. I wouldn't recommend trying to build one since higher voltage electronics is sorta dangerous to play around with unless you know what you are doing.

Jim

[mike3]

Mark ... look to the DC controller thread .. using the posted diagram and the info posted .. by a experianced Member .. you should be able to build the controller...


Regards,,, Mike