Belt/Pulley Reduction transmission for the HF44142 lathe

ken572 · Post by **ken572** » Mon Mar 22, 2010 8:38 pm

Hello, Don..
Yours indeed was a great reply and many great idea's.
I like your solutions you came up with.
Thank You.

Ken.

Torch · Post by **Torch** » Mon Mar 22, 2010 11:15 pm

ken572 wrote:Hi! Torch,
As I remember on the units I used in the past, the max useable torqe
was at (Full Amp Rating) and at (Rated Speed of the motor) and
on the V.F.D.'s as you lowered the frequency you had to derate the load
or torqe otherwise you would trip the soft limits in the V.F.D. You did not
gain torqe as you slowed to a lower speed. On the D.C. controllers they
have a max rated amps before you trip. As you lower the voltage/speed
when under max load the current goe's up and trips. The V.V.D.'s From
back in the day acted almost the same as the D.C. Controller's. This is a
problem I can get around with gears/belts etc.
Yes, I will have to take care not to twist or tweak the lathe bed.
Thanks Ken.

True, current is directly proportional to motor torque and is ultimately limited by the circuit breaker. I ordered my machine with 1-1/2 hp 180v DC variable field voltage reversible motors. The DART Controls controllers are designed to limit duty-cycle current to 125% of full-speed, full load rating (200% 1 minute overload). With the installed dual-range transmission, I figure on still having respectable torque at the speeds you are looking for. They are soft-start, so it should be quite controllable. I'll let you know how it works out.

One thought: with any configuration the torque on the spindle is ultimately limited by the belt drive. You may want to look at upgrading the belt to the spindle.

ken572 · Post by **ken572** » Tue Mar 23, 2010 12:20 am

Hey Torch..
That sounds like a really nice setup you ordered. I hope they speed the
order up for you a bit. I hate it when somebody I order from tells me
I will have something in a short time and then I have to keep calling to
find out how many more weeks.. Well like you said, that gives you more
time to buy more accessorys.. Good luck to you on getting it soon.
Oh.. I have been looking into different belts and pulleys.

Ken.

Torch · Post by **Torch** » Tue Mar 23, 2010 9:41 am

ken572 wrote:Hey Torch..
That sounds like a really nice setup you ordered. I hope they speed the
order up for you a bit. I hate it when somebody I order from tells me
I will have something in a short time and then I have to keep calling to
find out how many more weeks.. Well like you said, that gives you more
time to buy more accessorys.. Good luck to you on getting it soon.
Oh.. I have been looking into different belts and pulleys.
Ken.

Yes, ordering a custom job has been an interesting experience, to say the least. But the modifications should address the most common issues that people seem to have with this class of machine. One thing that I discovered was that these machines are built by several different companies to a common (government supplied and approved) design. That's why the different brand machines all look the same and even have interchangeable parts between HF/Grizzly/Enco/Craftex, etc.

Within certain parameters they are quite happy to oblige but from time to time you run into a "gee I don't know if we're allowed to do that" kind of response. It was supposed to take a month to build, but delays so far have included Chinese New Year (a 2-week holiday, apparently), relocating the factory, and the latest: a backlog on the docks due to the world-wide economic slump. Shipping companies have mothballed ships and now there's a shortage. Go figure!

ken572 · Post by **ken572** » Wed Mar 24, 2010 10:54 pm

Yo Torch..
What Brand and Model 3 in 1 did you order?? Ken.

Torch · Post by **Torch** » Thu Mar 25, 2010 9:56 am

ken572 wrote:Yo Torch..
What Brand and Model 3 in 1 did you order?? Ken.

I ordered a customized HQ800V from the Anhui Chizhou Machine Tool factory in (where else?) China. Actually, in the end, I ordered it through a Canadian importer who had dealt with them before and will be bringing it over with his own shipment from a couple of factories over there. Way easier to pay him than to navigate all the shipping and brokerage issues myself!

Anyhow, think of a Grizzly/HF/Craftex style machine but with 800mm between centres, 1 1/2 hp 180v reversible DC motors, reversible lead screw, quick change gear box, R8 mill spindle and beefed up column with vernier height adjustment. I've also ordered a few other goodies with it, like a baseplate, 4-jaw chuck and a tapping head.

In the meantime, I sit and wait and lurk in forums. Oh, and shop for deals on tooling. I have a nice Sino DRO in the garage just waiting for the machine to arrive

ken572 · Post by **ken572** » Thu Mar 25, 2010 2:35 pm

Torch,
I Think I found your machine in my collection

See Attached Files. (They Didn't Make It Through)

Ken.

Torch · Post by **Torch** » Fri Mar 26, 2010 7:19 am

ken572 wrote:Torch,
I Think I found your machine in my collection
See Attached Files. (They Didn't Make It Through)
Ken.

Why do I suspect your missing files were pictures of machinery resting on the bottom of the ocean?

ken572 · Post by **ken572** » Fri Mar 26, 2010 11:25 am

Hey Guys..

I finally figured out the forums picture size requirements...LOL.
Please view drawing below.
All comments much appreciated

Thank You.
Ken

The Home Machinist!