Member postings for Dave plus / minus 40 thou

well done Muzzer!

Impressed with the turbo conversion! - the little bike looks like an early CG 125?

FUBAR describes some of my stuff quite accurately.....

Dave

You can use a masonry drill bit (with a carbide tip) at a push, sharpen the cutting angle and use coolant

Dave

As per Stan's reply - pre-heat is key with cast iron then use cast iron specific rods (Arc weld)

+/-

I think they went by the name "sidewinder" Neil, it got you a big bike with L plates - you could ride / lean as per normal although you needed to remember the extra width when cutting corners.......!

Excellent photos's Windy!, The rear tyre is starting to deflect under acceleration in both pics, also two bystanders are shoving their fingers in their ears - most impressive!!

+/-40thou

Brilliant - Thanks for the numbers Joe,

My student (1800) has the same arrangement as the M250, two bands of contact for the taper and a gap between.

Cheers

Dave

Excellent work Joe!

you have reminded me that I should pull my finger out and make one also for my Colchester student - what are the dimensions for the MT4.5 taper?

cheers

Dave

I watched this recently Vic, not so sure about the grinding wheel in the mill (!), the safety aspects make me cringe and watch with one eye closed. Am making a modified version of Mike Checkley's vice end stop from the last issue of MEW then use the spindex in my surface grinder - plan to use a section of hacksaw blade as the flute "stop", can then rotate and onto the next flute without any changes (the blade should flex out of the way).

Dave

Muzzer - i use a 4.5kw unit HY unit from fleabay, cost about £180 18 months ago

Dave

its a Huanyang - see youtube video link below for set up instructions

**LINK**

hope this helps

Dave

Hi Hamish,

my 1800 student has an MT4.5 in the headstock - are you sure your is MT5? - the odd size is apprently related to 5c collets. i am planning to machine down an MT5 taper (with a femail MT3) to do the same job then use an MT3 to ER32

this adaptor is on Ebay with an hour to go which is what i really need - currently £45........

**LINK**

Dave

HI Bob, have a look under the motor terminal cover - thats where i found the diagram for my Colchester Student!

Dave

excellent thread, this one of my first replies to the forum so be gentle with me! , the torque loss is an important part the discussion - but thats the trade off - i run a colchester student 1800, a Van Norman 1-V mill ( circa 1941) and a Jones and Shipman 540p surface grinder all from a single chinese £150 single to 3 phase 5kW VFD (not the same time though!) - i have installed a ringmain in the w/shop with isolation sockets for each machine. All motor connnections have been changed.

I prefer to use the origional controls rather than the pendant type - to do this i run a seperate supply through the control circuits, my colchester runs on 110v powered from a yellow transformer (will change the contactor coils at some point to 240v) and others are on 240v. although i would not advocate this in an industrial situation i see no problem at home as it is only myself that uses the kit so isolation is not a problem if i need to work on the electricals.

The VFD is started and runs up, i can then turn the lathe on and off as needed, the VFD can handle the additional ampage at start up without any problems unless i want to run at 1800rpm, i then push the start handle down then turn on the VFD.

another benefit from using 3 phase is the smoothness of the cut / grind - a single phase motor can be problematic, i think this has been discussed elsewhere.

as long as i do not try to take 1/2" cuts it all works fine - if anyone wants any more detail on the above then give me a shout.

hope this helps

Dave

Hi Steve, got the same demagnetiser but sadly do not have a manual - all i have learnt is do not leave the part to be demagnetised on the plates for longer than 30 secs and do not switch on without a part in place!.

Les is correct about the two plates being the poles

Excellent piece of kit, they work well

Dave

Thanks Pete,

I agree completely with your posting with regards to 3 jaw accuracy / runout, Frank in France started the thread with a question with regards to his 3 jaw chuck jaws only gripping at the rear (worn jaws) and some hesitance over purchasing a new chuck! - see posting at top of thread - the toolpost grinder used on the held open jaws should help with his specific issue and possibly get him out of the proverbial.....

Cheers

Dave

Hi Hugh,

just adjusted the headstock on my 1800 for the same reason,

the method used as follows:

1. 6" x 1" bar in 4 jaw chuck + set up with DTI

2. remove back splash guard + both guards in front of headstock (to expose the allen bolts holding the headstock below the level of the chuck)

3. remove back gear cover, remove leadscrew gear drives (to expose the allen bolt)

4. fit DTI onto cross slide with tip on end of bar in chuck - this is to measure the movement / swing when adjusting.

XXXXX the head rotates around a dowel pin on the front of the headstock on the non operator side XXXXX

5.loosen all 4 allen bolts (had to shorten an allen key to fit)

6. adjust either the left or right hand small allen bolts in the block between the two hold down bolts at the rear of the machine, this will "twist" the head.

7. look for the movement on the dti.

8. when adjusted lock up all bolts and take small cuts and measure dia with a micrometer, i managed to get mine to within 2thou - i have a worn bed! but before the the adjustment i had a difference of 0.3mm over 150mm

dont be scared of it - you wont break the lathe!

good luck

Dave

Hi Frank,

I'm just rebuilding a student 1800 - the cross slide play (backlash) can be taken up with the two allen bolts in the middle of the cross slide - make sure you can get full travel after each tweak, otherwise if the play is in the slide then adust the gibbs (but you prob know that!)

to sort your chuck you need to use a tool post grinder, the jaws need to be opened onto a ring and be under "open" tension - ive seen modified bench grinders with small grinding wheels mounted onto the cross slide - searching youtube would be a good start, might be worth trying to rig something up rather than buying a new chuck!

hope this helps

Dave