Buying a 1/4" x 20 tpi acme leadscrew and nut from U.S.

[92220]

Hi folks.

I needed a 1./4" x 20 tpi leadscrew and nut. The only place I could get one ism from a company in U.S.A.  I was very wary about buying from them as sometime in the past, my card details were stolen and used in a New York restaurant. Luckily Tesco Card were suspicious of the transaction and wouldn't pay, and froze my card. When I tried to use it myself, I found it frozen, so telephoned them. They explained why the freeze, and was I in the U.S. No. Actually I was in New Zealand at the time!! I got them to give me a new card and number so the stolen details wouldn't be any use to anyone else. 

To buy the 1/4" leadscrew and nut, safely, with a credit card, I took out a Prepaid Mastercard Credit Card, and deposited $200 onto it, so that if the card details get cloned, all that anyone could get is the balance after my purchase had been paid for. I would not deposit any more onto the card, until I wanted to but something else from abroad. Generally I have tried to use Paypal for foreign purchases but the company I wanted to get the leadscrew and nut from was the only one I could find on the internet, who produced a screw and nut, this size.

My prepaid credit card duly arrived and I placed my order for one 1/4" x 20 tpi x 300mm long leadscrew and 2 off bronze nuts, 3/4" long, with a company called Roton Products Inc., in St Louis, U.S.A. Then the problems started!! When I placed the order, I had to choose a shipping method. The Roton website had a number of options and the cheapest was 2 options at $88 shipping. One option was labelled 'Economy'. The other was labelled 'Expedited'. Both were priced at $88 so I chose Expedited. Oh dear!! It turned out there was a glitch on the website and the actual cost of the Expedited, was $152. This took my order way above the $200 deposited on the card, so Mastercard declined the transaction. When Roton contacted me to tell me payment was declined, and that shipping was $152. I told them I had picked Expedited over Economy because they were both shown as the same price. Oopps!! I said that unless they could get the cost of shipping down to such a level that my $200 deposit would cover, then they had better cancel the order. Next day they came back and said that if I wanted to keep the order going, they could use USPS  (U.S.Postal Services)  at $60. That put the total cost of my order quite a bit below what I had originally expected too! so I told them to go ahead as it made the order cost $133.

They tried to take the credit card payment, and Mastercard declined to pay, saying the "transaction has to be authenticated". I rang Mastercard and explained that the order was genuine, and please to pay it. The spokesman said that it would be OK and to tell Roton to apply for payment again. They did. Mastercard again declined for exactly the same reason. I emailed them so that they had my complaint in writing. I got an email back, saying that the credit card had been review and it was OK to put the transaction through again. I told Roton to apply for payment again as they had emailed me that it would be OK. They did. Mastercard AGAIN declined the payment, and used exactly the same excuse!! This time I decided to be a bit more firm....well maybe a bit more!! I attached a copy of their email to me saying that it would be OK to put the order through again, and said that if they didn't sort it out immediately I was going to withdraw all the cash on the card and go get a credit card from Visa. I had an email this morning telling me to put the order through again and it would be paid.  

I emailed Roton and they tried again. This time it worked and the order was paid.....but what a cock-up by Mastercard....and credit wasn't an issue. They already had my money, ready to pay the order.

I have to say that the service I got from Roton far exceeded what most companies would have given. All in all, we have exchanged 14 emails each, to get this sorted, plus 5 tries to take payment. I think most companies, after the second payment decline, would have cancelled the order and told me to go elsewhere...and I have just had an email to say the parcel has been shipped. I can now look forward to receiving it. I just hope that any future overseas purchase won't have these problems, or I will have to tak to Visa about an alternative card.

Bob.

 


 

[jackrae]

Hope you've prepared yourself for UK's import, VAT and handling charges which, when added together, could end up being greater than the purchase price. I once bought a relatively inexpensive item for my 3D printer and by the time I received it the cost was double what I paid to purchase it.

[92220]

Hi Jack.

Yes I am expecting some sort of costs to be added but shipping is via the national postal service, both in US and GB, so I am not expecting any extra fees from them as postage has been paid, but there could be VAT added, though when I have bought screws from Germany, recently, there have been no VAT charges...so I am hopeful, but prepared for extra costs. All the same, it will be interesting to see what it ends up as.

Bob.

[simplyloco]

Gosh Bob, if you had asked I'd have made you one as I had some practice 'ere!


modeleng.proboards.com/thread/3571/brit-progress-screwcutting-reverser

[jem]

Let us know please.

Best wishes

Jem

[92220]

Mar 24, 2022 17:33:42 GMT simplyloco said:

Gosh Bob, if you had asked I'd have made you one as I had some practice 'ere!


modeleng.proboards.com/thread/3571/brit-progress-screwcutting-reverser

Hi John.

That was a very kind offer. I must admit I am being lazy, buying in the leadscrew and nuts. I know, if I had made them, I would almost certainly have had some scrappers before I got what I wanted, as in all the time I worked on the lathe during my apprenticeship, and all the years I've had a home workshop, I've never machined an acme thread. That screw and nut are quite a work of art!! Even forming the tools for such a fine thread is no easy matter.

Bob.

[Roger]

Hi Bob,
That sounds like a nightmare. I think I'd have made a tap and die from Silver Steel since you only needed to make one. Although it's fine, I think you could machine a form tool without too much difficulty, seeing what you're capable of.

[springcrocus]

Considering the number of locos that use 1/4" ACME for the reverser mechanism, remembering that some are left-hand and some right-hand, there must be an opportunity for one of the tool makers to produce a tap and die in HSS, or even carbon steel, as a matching pair. Even at £50 to £80 the pair, for many it would be worth the expense.

If anybody can find a tap-and-die pair for under a ton, let me know and I will set up a small production line.

Regards, Steve

[92220]

Mar 24, 2022 21:11:17 GMT Roger said:

Hi Bob,
That sounds like a nightmare. I think I'd have made a tap and die from Silver Steel since you only needed to make one. Although it's fine, I think you could machine a form tool without too much difficulty, seeing what you're capable of.

Hi Roger.

Thanks for that. Yes I could have made the tools but I didn't want to spend the time at getting everything right. Never having cut an Acme, I would expect the time might be excessive. It is a very small thread form to produce, and it is a L.H. thread, which I  have done very little of. If there hadn't been the monumental cock-up by Mastercard, buying the leadscrew and nuts would have been an easy job. Apparently it is on it's way now, and hopefully, will arrive soon. Even if I mess things up first time around, there will be enough leadscrew and nut length to make a total of, probably, 4 screws and nuts, so should take care of any scrap I make in the machining.

Bob.

[44767]

Sorry to hear about that credit card fiasco, Bob. I can back you up about the service from Roton though. A few years ago I needed to change the leadscrew on my Weiler lathe. Although the lathe is German and has metric dials, the leadscrew is Ø7/8" x 4TPI (a factory option). I bought the lathe second hand, the first machine I ever bought, knowing it needed a rebuild but also knowing it would be a good lathe to have. The lead screw was with the lathe but not fitted and after a few years I realised why. It had been bent rather badly and an attempt at straightening it was not particularly good. It was so bent that the threads would change pitch as you cut along! It may have even been driven into a stop without the shear pin doing its job which has stretched the thread. It is rather slender with the minor diameter being little more than 14mm.

I found Roton's website and although they made leadscrews of Ø7/8" and did 4TPI threads, the combination of the two was not listed. I emailled them and they said that they had rolls for doing it and would do a 4' length for me. I received it in ten days later here in NZ and I recall the price being only US$170, including postage.

I needed to turn the details on the ends (same on each end as it's reversible) and when I fitted it the half nuts closed perfectly on the thread. I always recommend them to anyone looking for anything related to leadscrews.
Mike

P.S. I replaced the shear pin with a piece of Ø3mm brass which is necked down to Ø1.5mm in the two shear areas. It is surprising how much shear a pin take to break; much more than you need to turn a leadscrew.

[Roger]

Mar 25, 2022 8:52:28 GMT springcrocus said:

Considering the number of locos that use 1/4" ACME for the reverser mechanism, remembering that some are left-hand and some right-hand, there must be an opportunity for one of the tool makers to produce a tap and die in HSS, or even carbon steel, as a matching pair. Even at £50 to £80 the pair, for many it would be worth the expense.

If anybody can find a tap-and-die pair for under a ton, let me know and I will set up a small production line.

Regards, Steve

Hi Steve,
Drill Service in Horley has made special taps for me in the past, they're who I'd ask first.

[doubletop]

But 1/4" x 20tpi is Whitworth. Just get a left hand tap and die set from Tracy Tools and you can make as many lead screws as you may need.

www.tracytools.com/taps-and-dies/left-hand-thread-taps-dies-bsw?product_id=1294

Pete

[springcrocus]

Mar 25, 2022 20:29:45 GMT doubletop said:

But 1/4" x 20tpi is Whitworth. Just get a left hand tap and die set from Tracy Tools and you can make as many lead screws as you may need.

www.tracytools.com/taps-and-dies/left-hand-thread-taps-dies-bsw?product_id=1294

Pete

Quite right, Pete, 1/4" x 20 is Whitworth but the ACME standard for 1/4" is 16 tpi. On my Britannia, I did just that, bought a 1/4" x 20 Whit-form left-hand tap and die pair. However, the parts they made are not leadscrews, they are just threaded rods. I expect that Bob is wanting 1/4" x 20 ACME-form thread because that scales most closely to the prototype.

To make leadscrews and nuts of this size takes more than just engineering skills, it also requires a sensitive and accurate machine. John has both the neccessary skills and also a top-of-the-range machine so, for him, it was a really interesting but attainable challenge. For most of us, I suspect we fall down on either the lack of skill or the machinery required for a successfull outcome. My lathe, for example, is both too cumbersome and very insensitive but it is about 80 years old so quite understandable. I also doubt that I have the skill (or eyesight) to make a decent screwcutting tool that small. Make no mistake, John's leadscrew and nut are a work of art.

Roger, I have no interest in asking a manufacturer to make a special tap and die, they think they are doing you a favour and charge the earth! No, it's up to the manufacturer to spot a gap in the market and offer a solution. If the price is right, they could make a healthy profit. Maybe one of the manufacturers will stumble upon this thread and react accordingly. Otherwise, I'm sure most of us will continue to use a standard Whit-form tap and die set to cut a normal thread, LH or RH as appropriate. It might not be prototypical but it works. The reverser mechanism on many locos using this system is (mostly) out of sight under the running board, anyway.

That's my opinion on this subject but, I'm sure, many will disagree.

Regards, Steve

[dscott]

YES.
We got to Tracy Tools quite late at the last Exhibition and did a wander picking up some useful bits.
I asked about 1/4 Whitworth left hand thread taps and die please.
I loved the act of looking round and suspiciously reaching under the counter for them...
CASH OF COURSE.
So looking forward to the Midland this year.

David and Lily.

[simplyloco]

Hi Steve.
Kind words indeed. May I suggest that the only limiting factor in your repertoire is your lathe? I don't believe for one minute that your skills are lacking!
BTW you can always get a better pair of glasses...
John

[92220]

Hi Steve.

That is exactly how I looked at it. I have actually made up the reversing gear using a L.H. Whitworth tap and die. I am just not satisfied that it looks wrong. I suppose I could have got away with a square thread rather than Acme, but even making that thread would be very time consuming and easily scrapped. The 1/4" x 16 Acme is the British Standard thread, but to find someone making a 1/4" x 20 Acme is amazing, and at a reasonable price. It is almost perfect scale size and tpi. True scale would have been 0.26" x 20 Acme, but 10 thou difference in Diam is not at all noticeable, but the thread form is.

Bob.

[Midland]

Hi Bob and All
Read of your saga, not fun. In order to get around that nonsense, I now have an American bank account tied to my Canadian one. As I will be in the States from April 25 to April 30 if anyone has a relatively light item they need bringing back without worrying about VAT and all that stuff, let me know. Coming back by ship so no baggage problem. We did actually bring back a 4 x 5 foot painting once to the amusement of the disembarkation staff!

[92220]

Hi Folks.

Ther ncard company finally got its act together!!

The parcel arrived in 2 days, via US Postal Service! I cannot fault the Roton service. They were extremely patient with the card company's screw-ups (no pun intended!). I'm pretty sure other companies would have told me to take my business elsewhere after 2 attempts at applying for payment. After numerous emails back and forth between Mastercard and me, Roton tried 5 times over a period of a before getting paid on the 6th time.

The acme screw and nuts are superb!! The interesting thing is that the nuts run very freely on the acme screw, but when I checked backlash using a 0.0005" DTI and the mill, the backlash was only just visible on the DTI dial, so it had to be only a few tenths of a thou, which is way better than I could have imagined, when ordering. The other interesting point is the cost. 12" of 1/4" x 20tpi acme leadscrew, plus 2 bronze nuts, cost $133.0US which was £99.00 total, including Expedited postage. I found one company in UK that could also supply this size leadscrew and nuts, but they were quoting £90 for each item, making a total invoice cost of £270.00 plus VAT = £324.00!! After my first post, Jackrae warned me that there could also be cost when importing into UK. Actually there were no extra costs. I am guessing, because they were just noted as screws and nuts, which would, presumably, be accepted as for 'work in progress'.

When I've made the bits, I'll post photos.

Bob.

[rrmrd66]

Hi Bob.

Bit late in the day with your post but did you try:

kingston-engineering.co.uk/about-kingston-engineering/

Maybe a bit small for them?

Cheers

Malcolm

[92220]

Hi Malcolm.

They were the first ones I tried. They don't do smaller than 3/8" dia they told me.

Bob.