Member postings for Robin Pulham

As I understand it the grub screw in the middle acts as the pivot used in conjunction with the two screws to create a tilt to reduce backlash. Hopefully I will have eliminated that.

Regards Rob

The material is 6mm acrylic sheet of some kind that I was given a few years ago.

I was fortunate to get a couple of lengths of 20mm acetal rod, a couple of quite big blocks of acetal and a couple of small sheets of 6mm acrilic.

I watched a couple of YT videos where one guy had used oil impregnated bronze for his back lash nut and the other had used acrylic sheet. I looked into buying some bearing bronze but near fainted at the cost so went with what I had. It's really a proof of concept and if it proves successful I may make a replacement in brass at some point.

Regards Rob

Hi Pete,

It has two grub screws above the main thread.

Regards Rob

Thanks Dave,

Having read Neal's instructions, it looks like what I did wrong was not to lock the aspect ratio. I manually set 600 x 800 but my image must have been at a different ratio to that so failed.

Every day is a school day.

Thanks for the heads up on the search facility.

Regards Rob

Hopefully that's now sorted thanks to Pete's timely help

It's my intention to do away with the use of the centre grub screw on the feed nut and replace it with shims. I will leave the grub screw in situ to keep the swarf out.

I have a thread running on the Gauge O Guild outlining what I am doing in the way of improvements to the SC3.

If there is interest I will start a thread here?

Thanks again

Regards Rob

Hi Pete,

I was trying to add them via the insert image option next to the camera icon on the tool bar. I will have a look at creating an album.

Many thanks

Regards Rob

Just to conclude this thread, the leadscrew thread was ultimately 3/8 20tpi a set of taps was ordered from RDG and I now have a prototype of the anti backlash nut/block.

I have tried and failed miserably to add a couple of photos

Edited By Robin Pulham on 09/01/2022 20:27:03

Edited By Robin Pulham on 09/01/2022 20:30:50

Thanks for the kind world of welcome Gent's, they are much appreciated.

Regards Rob

Thanks for all the replies Gents they are much appreciated and I now have the answer I was looking for plus lots of useful advice as well.

To address a a few of the points raised,

The reason I thought it might have been a metric lead screw, is when talking to Chronos they advised that their DRO kit had a metric lead screw which is fitted as part of the conversion. I wasn't certain until Jason B confirmed it, that some mini lathes had come with factory fitted DRO's. Having further compared the parts list from Chronos with my parts since starting this thread. I now think that mine is indeed one of the factory fitted examples (the lead screw is in one piece whereas the Chronos kit has it in two parts).

I haven't actually tried to test a thread using a die but it seemed (wrongly!!) like it might have given an idea, had I tried it I would have only popped it on the end of the thread I wouldn't have considered running it right down unless there been some thread damage.

I have no intention of converting the leadscrews to metric, as has been pointed out, having DRO's fitted makes such an action superfluous. What I am trying to do is make the lathe much more rigid and take out where I can do it sensibly as much backlash as I can.

Thanks too to Howard for the reading list, I do have several Howard Hall books and David Fenner's mini lathe book from the Workshop Practice series in my library but I am a great believer in you can't have too many reference book so will add to the library going forward.

Thanks again

Regards Rob

Thanks Jason,

Without a definitive answer that would seem to tie in with the compatibility with the metric DRO kit without changing the feed nut.

I have it in bits at the minute so I can't try Martin's suggestion but once I have it back together I will give it a whirl.

Regards Rob

Thanks Martin, I can see I have much to learn.

Regards Rob

Good morning all,

I have recently bought an Imperial Sieg SC3 lathe which is fitted with DRO's on the cross and compound slides.

As part of general tidying up of the machine I wish to take out some/all of the backlash on the cross slide and have watched a couple of videos on YouTube on how I might go about it using a second feed nut. I can buy a spare feed nut from Arc but want to make sure that it will fit my machine before placing the order

My question is:

Although my machine is imperial, the fact that it's had a DRO kit fitted makes me question whether the leadscrews on the cross and compound slides are in fact now metric?

I know that they are replaced as part of fitting the DRO kit available from Chronos. But what I don't know is whether any SC3's were factory fitted with DRO's and if so were the leadscrews on imperial machines replaced with metric to accomodate the DRO's

I would really appreciate it if someone could confirm whether this might be the case.

As an aside I have put a thread gauge on the leadscrew and it looks to be a 1.25mm pitch with the diameter over the threads as 9.4mm. Which I read as M10 x 1.25. Sadly it being a left hand thread I can't just run a die down it to check.

Many thanks for any assistance anyone can offer.

Regards Rob

Edited By Robin Pulham on 29/12/2021 12:08:49

Edited By Robin Pulham on 29/12/2021 12:09:03

Hi All,

I joined a few weeks ago just before I collected a Sieg SC3 lathe. I bought the SC3 used and it represents a step along from my previous lathe which was a Unimat 3. I also have a Sieg SX1LP Mill (Bought New)

My main interest is 7mm scale railway modelling and I am still very much a novice where machining is concerned. Prior to the last couple of years, like many expect, I last used a lathe for my metal work O Level in 1980.

That said, for Christmas I will be receiving a Stuart Models 10V kit so I am making a tentative way into model engineering.

Regards Rob

Hi All,

I am a new member who has only recently acquired a lathe Unimat II and Mill (last 18 months or so). I am mainly a 7mm scale railway modeller but I have done a couple of small upgrades to the Unimat and I am considering getting a Stuart Models stationary engine to improve my machining skills which were last used in the late 1970's while at school.

Regards Rob