Member postings for Andrew Tinsley

I have no knowledge of Bergen taps. However I do have a set of unbranded Chinese taps and dies (HSS). They are remarkably good all things considered. So you cannot always tell what is good and what isn't.

Another thing to mention is that the Tracy tools carbon steel taps and dies, are in my experience, very good and long lasting. If I break a tap it is always an HSS. I don't think I have ever managed to break a Tracey Tool carbon steel tap!

Andrew.

I run lots of old petrol IC engines. I never use petrol as a fuel, always methanol. As far as model aircraft engines are concerned petrol went out as a fuel during WW2. The old petrol mineral oil fuel mixture runs considerably hotter than methanol castor fuel. The methanol mix is much kinder to the old style metallurgy used in these engines. Castor oil is always the last resort protection if an engine goes severely lean. It will provide some lubrication long after mineral oil is destroyed.

Andrew.

P.S. I always manage to get more rpm on methanol fuel for a given prop.

Thanks gentlemen,

That really was a very informative series of descriptions. All is now clear. Interestingly, when I have been browsing VFDs with a view to purchase in the mid term, there appears to be hardly any mention of a VFD being a flux vector or a simple version, in the sales summary. One has to delve into the specifications to find that info. Strange, as I would have thought this would have been shouted from the house tops!

Thanks everyone,

Andrew.

So what is the difference in operation between the two styles of VFD? I am told that Flux vector VFDs have more torque at reduced revs. How does this work in practice?

Regards,

Andrew.

Hello An Other,

PM sent with my email!

Thanks again,

Andrew.

Very surprised you got no response from Parvalux. For many years they have had a reputation of superb customer service. They have supplied spares to me way out of guarantee period, they have always been most helpful.

Andrew.

Hello An Other,

Redsetter did make some pretty accurate measurements for me. However if you are going to dismantle the area around the bracket plate, then you could probably make the measurements spot on. So the answer is yes please, I don't mind waiting in the least. I still have other things to sort out on the lathe.

I have all of the Yahoo downloads as well as the Grizzly and Chester manuals. The Chester one is surprisingly good too!

Thanks for the offer,

Andrew.

I hope that I don't fall into that class, but sometimes I do. The main reason is that I get so many suggestions for solutions that I don't have a clue as to the best one! I usually give up and do something else in cases like this. Much, much later, (once I have forgotten about my post!). I will get stuck in and do the job , then wonder why I had difficulties in working out the plan.

The thing that I have learnt is that if I consider all of the potential problems then I get very confused. If I just give the job some short consideration and then get stuck in. Then the job goes like clockwork (well mostly!)

Andrew.

Hello,

With the type of Chinese lathe that you have. It isn't just bed twisting that causes non parallel turning. I have now set up 3 slightly larger Chinese lathes and each on has had significant headstock misalignment. One of them had a tailstock that was skewed as well.

You need to be aware of all the possible faults that can occur before jumping on one as a possible cause. Ask me how I know!

Andrew.

Thanks Martin!

That was a 920 importer that I didn't know of.

Andrew.

Paragon paints supply primers and good advice. They also sell Myford grey and I believe green(?). Not the cheapest of paints, but superb quality finishes.

Andrew.

Hello Redsetter,

I have the series of ME articles that someone on the forum kindly sent to me. They detail a low speed conversion with I think a kit that was available from Axminster. PM me if you want a copy!

So yes I should have remembered about Axminster importing the 920. Memory is getting bad!

Andrew

Hello Redsetter,

Your thoughts are much the same as mine. The lathe isn't bad, but for only a bit more effort on the manufacturer's part and suitable price increase, It could have been an excellent lathe!

I find the belt system to be a pain and a friend's much modified lathe was spoilt by this weird system. I am still in two minds whether to reinstate this or do something about it!

With regard to the 4 bolt compound mounting. my friend found that it wasn't strictly necessary as long as you put in some decent gib strips and located them (end on, a la GHT method). He did however finally do a much improved 4 bolt mod, which I think was purely a machining exercise to show off his skill. Whoever bought that lathe got a real bargain!

Hello Redsetter,

You are quite correct in saying that a different length cogged belt is required if a 930 Gates belt is used. I am afraid off hand I can't remember the required size, but I have it noted somewhere if you really want to know the size!

Like you, I am amazed at the scarcity of second hand 920 lathes in the UK. I am not sure if I am correct, but I think they were only imported by Warco and Chester? Maybe they just didn't sell very well over here, unlike the USA! In their unfettled form they are a bit of a kit lathe and I am not sure how many people would have modified them to a high standard. It is a cheap lathe and I would think most were purchased by beginners, who would not have the experience to modify them. I would therefore expect that there would be quite a turnover of 920s, but apparently not!

I have never seen one being broken for spares. Although the one I have would be a good candidate, if I hadn't promised it to an impecunious friend, who is a novice engineer!

Regards,

Andrew

Thanks John!,

I will sort out the belt size and stick the nail in the wall! As far as the 710 or 730 bet is concerned. I am told on good authority that it is indeed the choice of electric motor and its mounting plate (feet). My belt is 910 on the Chester 920, yet the manual says it is a 930! It just depends on what motors are to hand on assembly.

Regards,

Andrew.

The late lamented Railway Museum,, Nord compound was a delightful chocolate colour!

Andrew.

Hello Les and Mick,

Thanks for the help and encouragement. Mick your suggestion of just using the 3 step pulleys and a VFD has really put the cat amongst the pigeons! I would like to get speeds between 50 and 2000 rpm. Is this feasible without running the motor too slowly (cooling concerns)? I suppose I could work it out, but it is easier to ask!

Thanks again,

Andrew.

Thanks Mick and Redsetter,

Those dimensions are great and I won't be upset if you are a little out! I will speak to Tony at Chester, just in case they would have a bracket plate . I should think that is about one of the unlikeliest spares to carry for the 920. Hence I didn't really have much hope that Chester would have one, but worth asking, one never knows!

Thanks again,

Andrew.

Thanks Redsetter and Vic,

I appreciate that it is difficult to measure up with pulleys in place and I don't expect anyone to dismantle their set up just to take measurements! However, even some very rough and ready measurements are better than none.

If I do get the lathe up and running, I may well do a conversion to VFD drive as I have a spare 3 phase motor and an old inverter hanging around the workshop and I could do with the space! The reason for this is that the slowest speed on the lathe with the conventional pulley set up would be just over 100rpm, which is on the high side. Just putting a VFD on the existing direct drive would be a bit limiting in range of speeds.

Thanks again,

Andrew.

Hello John,

I missed your post! That really is kind of you! Some measurements would make the job so much easier! I am missing the belt tensioner wheel , but have the lever and spring and I believe the correct bush for the job. The Chester manual shows an excellent exploded view of the tensioning arrangement and that should be easy to copy!

Send me a PM when you have time to take a look at your 920. I really think I should return it to original condition. I am going to give the lathe to an impecunious friend, if I can get it sorted. I can help him do the mods and alignment etc.

Once done it is actually a rather decent lathe. But you need to spend quite a bit of time rebuilding it. Another friend had a 920 which was fully sorted and a joy to use, unlike the machine from the box! Pity he sold it, otherwise I would have been over there with pencil paper and ruler!

Thanks again,

Andrew.