Member postings for Robert Trethewey

It's been pointed out to me that there are at least two glaring errors in my latest thread 4in Dividing Head - the first being that the label rivited to the outter edge of the plate says 1 division = 1 min (not 1 mm) the second is that the two chamfered holes that lock the plate in place ate 6.3mm dia not 3.3mm dia. Sorry for any confusion. I've had one reply saying that "why cant I produce the plates myself" - no reason why if I knew the combination of holes in each plate.

Edited By Robert Trethewey on 14/04/2022 23:06:47

Hi: Can anyone please help me identify the Dividing Head shown in my latest album 4in Dividing Head the item I'm most interested in is finding out if anyone knows where I can find new or used pin plates to go along with the number 3 plate that came with the DH when purchased. The DH is a 4in the pin plate is 123.6mm dia. and has a knurled edge with a black plate pinned on the outside circumference saying each division =1mm the plate is 5mm thick it has a 30mm inside dia. the number 3 plate has 4 sets of drilled holes 40, 37, 36 and 29 holes. The plate is attached to it's backing piece by two chamfered screws the holes are 3.3mm dia. and have a 42mm PCD

I recently purchased a 6in dividing head and and have stripped and rebuilt it - However the original manufacturers nameplate had the name rubbed off - please can anyone identify for me the original manufactrurers name as the name plate says Made in Spain the part number is D1494A and it appears to be a Hoffmann type unit it weighs 50Kg it has a double sided plate with hole circles ranging from 49 down to 15 holes per circle it has a DIN 55022 or DIN 55027 faceplate see attached images 24 stop positions and power feed via 25mm shaft 6mm key

My album Robert Trethewey (6in Dividing Head Rebuild)

I've checked the cross and vertical screws for accuracy and found them both within acceptable limits once I've removed the backlash - did you do anything about the backlash on your machine.

My machine when being stripped for rebuild is painted BT call box red internally but grey externally was your machine similarly painted.

Bob Trethewey

I'd say these were very accurate - In bringing an Eagle SG made by Dronsfield back from it's previous owner I had to triple brace my hoist to lift the machine off a pallet I'd bolted it to for transport. That would make it on or just under 375Kg

Does anyone know when these machines were made as I've just acquired a Model 3 serial no 3628 I'm assuming that makes it their series 3 number 628 of that series.

Bob Trethewey - Audiologist Shillingstone Dorset

Would anyone out there have information on the supply of metric longditudinal leadscrew nuts for the Myford VM-C series of mill - my nut is worn and does need replacement it's a 4mm pitch right hand thread ACME the LS is 25.33mm in dia.

Hi: Thanks for coming back to me so quickly - I don't have anything to measure the vibration. I can hear and feel a very slight knocking - this is why I looked up posts about bearing setup and adjustment thinking it was a loose bearing which could be the case as the previous owners, a technical college in London, who's engineers had done little or no maintenance since the machine was first supplied to them.

Hi: Everyone - on the 2nd of May 2019 IFoggy wrote that he'd found a small piece of iron in one of the gears of his Myford 254V Plus lathe which caused a vibration when using the lathe's back gear - I'd very much appreciate knowing how he actually found the offending piece of metal as I may have a similar problem effecting my machine to a small amount but I'd like to ensure that this doesn't develope into a real problem.

My Myford 254V plus can be seen on www.ritasears.blogspot.com look at tab "R" if you're interested in seeing the rebuild of a Myford KF-MC-C milling machine which will shortly be fitted with a three axis DRO and a home built power drive on it's longitudinal table look at tab"O"

Hi: everyone - on the 2nd May 2019 Ifoggy wrote that he'd found a small piece of iron in one of his gears which caused a vibration when using the lathe's back gear - can Ifoggy please expand how he found this offending piece of metal please as I believe that I have a similar problem and I would like to find out if I can service the machine before any major damage is done..

My 254V can be seen on www.ritasears.blogspot.com and check out Tab "R" if you're interested in seeing the rebuild of a Myford KF-VM-C milling machine which will shortly be fitted with three axis DRO and a home built power drive on its longitudinal table look at tab "O"

Thanks for your comment in advance - best regards Bob

Edited By Robert Trethewey on 07/11/2020 16:43:37

Perhaps this image may well assist you - please look up ritasears.blogspot.co.uk and go to the workshop tab then go to the bottom of the page last image should be what you're looking for.

If you by chance have a coolant pump which has a 4 position switch on the electric motor top and could send me an image of the internal wiring I'd be so grateful.

Bob Trethewey

Help needed please.

The coolant pump has a 360 deg 4 position switch on its cast casting 2 on positions and 2 off positions

I recently stripped the pump to replace both pump shaft bearings taking photos of the wiring as I stripped it apart - down loaded onto my laptop after waiting for the new bearings to arrive I finally rebuilt the pump. In the meantime my laptops HD failed and although it eventually shows me a desktop that as far as it goes I can't get to the file where the images are to show me where the wires go on the switch - had to buy a new laptop. I've got three wires that come from the motor winding 1 red 1 yellow and 1 black, I've two wires from the Capacitor 1 Blue and 1 Brown then I've the power cable normal 1 Yellow green earth 1 Brown Power and 1 blue negative The central switch has 4 positions 2 on and 2 off The switch has 5 terminals on one side 1 and 2 on the other side 3,4 and 7 when off nothing connects when on 1 connects with 2 and 3 connects with 4; 7 doesn't seem to connect with anything

Can anyone help please regards

Fellow followers of Model Engineers Workshop

Today I received Model Engineers Workshop number 251 March 2017 the same number and February's issue. Two months late and I am still to receive the issue 255 for June 2017.

Is this shambolic distribution a regular thing with the publishers? Please inform me if the electronic version is similarly shambolic or is there some form of normality with that publication?

Regards Bob Trethewey (dorsetearman)

Duncan and Martin

I bow to your experience and knowledge. I had not considered the difference in the ratios of the column dia to the fixed distance between the column centre and the spindle centre the difference in the ratios of both multiplying the error achieved.. Thanks to both of you for pointing out alternative thoughts and considerations.

I am currently making a new depth gauge/stop which was broken off when I bought the machine, I shall now modify my designs for this to incorporate the dial indicator suggested by Martin. The idea of a laser is useful however the machine would need to be bolted securely to the garage floor to avoid machine creep and this I did not want to do.

Regards to both of you for your ideas and suggestions.

BobT (Dorsetearman)

Thank you Vic for your Post I don't think that this mill design suffers from the same amount of wobble that the Warco/Grizzly/Pinnacle type milling machine does. I will, however, read the article with interest.

Regards dorsetearman BobT

speech clarity (all one word no spaces) at hot mail dot com will reach me

Reply to Norman

Yes. By making a set of drilling jigs so that when the rack has been reassembled, after drilling and tapping the grub screw locations in the rack. Then by locking the head in the axis where it is at 90deg to the horizontal table. Then by using the drilling jigs produce a pilot bore followed by an enlarged hole which may be honed to final size. Then using grub screws with machined cylindrical tips to suit the honed holes in the main column; I should be able to ensure a fairly accurate vertical plane when I raise or lower the head using the rack. If I want to swivel the head I would merely remove the grub screws and allow the head to float as it does now before being locked in position.

regards BobT

I'd like to stop my Warco Minor mill from wobbling when the milling head is lifted via its rack.

I'd like to place in the rack 2 lower and 3 upper machined grub screws and be able to allow these to locate in holes drilled into the machine main column.

Has anyone done this and if so how successful was it in allowing the head to raise and lower whilst staying in the same vertical plane.

regards Dorsetearman