[spincaster]

A Griz 0704 on its way to be delivered Thursday and am thinking about mods. I hate gear drive noise (as in the mini-mill I had!) and when I read the cost of replacement gears I realized that I really need a belt drive. It amazes me that it wasn't built with a belt drive given all the conversions I read about for the mini-mills but maybe they don't use belts in China

I'm not a machine builder, rather a machine user (retired machinist) for my model train hobby so I don't want to spend many building a belt drive If I can buy one reasonably . Can anyone point me toward a US made belt drive kit or some drawings for a simple drive with purchased pulleys or cog wheels/cog belt? I am aware of Hoss CD.

In the sales page for the G 0704 I noticed an expensive spindle brake. I would appreciate any opinions on it. I might be able to build it if I have a better picture since it appears to be fairly simple and straight forward to make.

The goal is to get this machine up and running reliably and maybe eventually convert to CNC if desired.

J

[kdoney]

Two of the best site for 0704 info include a belt drive
G0704 Belt Drive DVDROM

[NYC]

I just went through this whole thing and decided to pull the trigger yesterday and made my purchase. After seeing what was involved I opted for the Precision Matthews PM 25MV which is very similar to the G0704 but the mods are already done. (some even say they are the same but the Precision Matthews says they are not the same) It cost a little more but it's done. I also ordered the DRO and power feed since I will start out using it manually and they installed it for free. Installation of the DRO is also a lot of work.They installed a belt drive with a brushless DC motor from the factory and that is standard. The spindle has tapered roller bearings (which makes it quieter) and it comes with a three year warrantee. I started out by planning on purchasing the Harbor Freight mini mill with a coupon for $450 but started to read the forums and looking at YouTube videos and decided on something bigger but not so big that I wouldn't be able to move it. I'm already dreaming of converting it to cnc and if money wasn't an issue I would have purchased a Tormach.

Here are some conversion kits on ebay

G0704 Belt Drive for Stock DC Motor | eBay

G0704 Belt Drive Brushless DC Motor | eBay

If you do this you won't need to lock the spindle. You can you tube power draw bar and see several ideas

https://www.youtube.com/watch?v=FyaZGvcrCB0


Here is a very intricate spindle lock
http://www.cnczone.com/forums/bencht...730-cnc-2.html

NYC

[arizonavideo]

The new PM-25 is totally different but exactly the same size.

The brushless DC motor and belt drive is really nice. I have one and will be setting it up in the shop soon.

[spincaster]

The 704 is going to be delivered tomorrow so this isn't about buying something different. I am looking for USA made belt drive if there is one.

[Wiggles84]

I can't say that I've seen a US made belt drive kit.

I had seen what Hoss did and went about making my own.



But to do what I did you would need another machine to mod the quill shaft.

Andrew

[spincaster]

NYC I love that HOSS Tormac qc setup but am not sure how versatile it is. It would beat the normal R8 set up but it would mean buying a lot of special tool holders and messing around to use items like R8 boring head AND spending $44 for a CD that has mostly stuff I don't need. Maybe eventually .......

I may have to make my own drive as you did but was hoping to purchase it. I don't have another mill but might be able to do milling on my larger lathe.

[Wiggles84]

I used the following pulleys from McMaster:
*6495K211
*6495K16


I have since moved the motor farther back to have more room for my air cylinder tool release.

You could also ask Hoss to sell you just the belt drive plans you would like. I purchased just the plans for his 3 stage cylinder for like $10 or $15.

Andrew

[DJR22013]

No experience with the following kit, but might be one to consider.

BF20 Belt Drive

[spincaster]

Interesting but pricey belt drive kit. I couldn't find any company info so am leery about purchase at this point. Have asked for more info. I wonder if any have been sold yet or if anyone here has experience with this kit?

[NYC]

NYC I love that HOSS Tormac qc setup but am not sure how versatile it is. It would beat the normal R8 set up but it would mean buying a lot of special tool holders and messing around to use items like R8 boring head AND spending $44 for a CD that has mostly stuff I don't need. Maybe eventually .......

I may have to make my own drive as you did but was hoping to purchase it. I don't have another mill but might be able to do milling on my larger lathe.

I'm going to purchase the tormac copies off of ebay. They are inexpensive there and said to be high quality. Some say you have to do a slight modification. They have good video reviews on Youtube. People have used boring heads with 3/4 inch shanks in them wit out a problem. Some had to shorten the length.

[spincaster]

I'm going to purchase the tormac copies off of ebay. They are inexpensive there and said to be high quality. Some say you have to do a slight modification. They have good video reviews on Youtube. People have used boring heads with 3/4 inch shanks in them wit out a problem. Some had to shorten the length.

NYC, Was unaware of those and will have to look. Thanks!

[spincaster]

My G0704 arrived today. The machine generally looks like a lot better quality than the past two mini-mills I have had. Only one complaint so far and that is the absolutely junk drill chuck/arbor which I hope isn't a omen of things to come. I decided to mount it on a mobile base and am waiting for that to arrive. Now I'll have to think about a drill chuck/arbor.

One thing that concerns me is how big it is compared to the mini-mill. Moving it to the basement on a hand truck will have to be done in pieces

[spincaster]

I just finished moving the 704 to my basement shop. I broke it down into two pieces by removing the table and even so broke a good sweat. Much heavier than the Griz mini-mill.

Now it's back together and in the process of doing the break in running.

Hits! - Very nice fit and finish mostly and better than the mini-mill. Much better dovetail slides than the mini-mill. The gear drive seems quieter (still going to get changed to belt)

Misses! - Who ever thought up the drawbar arrangement should be tarred and feathered! I am thinking of looking for a 5/16 square wrench for it. Yuk!!!!!! The on/off/emergency switch is pretty junky and I am wondering if there is a good way to replace it.

What's wrong? - When I first checked out the machine in the garage all axis were smooth moving. Upon reassembly, the Y axis is binding just a hair at the hand wheel end of the ways.

[datac]

I started a topic asking about this belt drive: HMS G0704 / WMD20 Belt Drive (Stock Motor)

Not made in the US, and uses the stock motor. I don't mind that yet because frankly, I need to get a lot of other expenses done on this machine first.

But, the the style tends to be a style I like. I'd like to see it made however with 3 speed changes possible and there should be room because of the thin belt. I would love to have some very low spindle RPM with a higher rpm motor speed.

The question is whether I'd feel that the thin belt is good enough or not ? I have owned the 16 speed craftsman drill presses with the thin belt and frankly, thought it grabbed better than a regular belt.

Then there is the fact that a whole bunch of the import lathes utilize a thin belt. I have not seen too many complaints about it being used there.

At higher rpm, do the toothed belt drives make whirring noise ?

I dont know if anyone else has noticed, but when I see an "imported belt drive" setup with a traditional sized belt, it seems the belts they send you are just awful.... rigid, crooked, wobbly etc.

Are you intending to replace the motor right away ?

My new out of the box G0704 threw sparks out of the motor within 45 minutes of no load run time. Never had an R8 holder in it yet! I've been in contact with Grizzly since the 7th of this month and boy, do they move SLOW. They never respond for at least 48 hours, and then they really never tell me how to send things back or what they want to do. Leads me to believe they do not have an extra parts there ?

The machine immediately blows the fuse for the driver board. I tested the motor with 12v and a 36 volt supply and it seems to run fine. Can't see anything blown up on the board... just sad I should have to mess with it at all this early in the game.

Grizzly is asking me to send the whole dang head back which will be a challenge to package. Wish they would just replace my driver board to see what happens. Oh well.....

[spincaster]

I have been doing the break in run and am having the bearings heat up more than I have ever seen before. Just asked Grizz for info.

[datac]

When I get mine back up and running, I plan to let the rascal run at around 1000 rpm for perhaps 2 hours. If it is going to fail again, lets get it over with before I am mid job. I don't hold out an overwhelming amount of love for these imported machines but full well know what I expect. I DID expect it to run longer than it did.

If Grizzly offered that same machine without a motor or motor driver, I'd bet most in this forum would buy it that way right off.

A few years ago, I bought a Novakon NM200 for the shop.... you do have to commit to working thru the "import blues", but what other options are there these days ?

Slim to none for new machinery....

[engele]

I received a bad replacement motor for my g0704 from Grizzly. When I opened the motor there was a clear short where the strain relief had broken. It might be worth a look. I also had chipped magnets inside, so Grizzly replaced the motor with no real hassle at all. I think the quality control on the motor and driver is less than perfect, but when you get a working setup, it is probably going to be great.


Sent from my iPhone using Tapatalk

[spincaster]

I've been working on my 704 and was told that the bearing heat was normal. So far so good. We'll see......

I bought 7/16 clamping kit from Griz but the 7/16 nuts seemed too small so I purchased 1/2" nuts from Shars which seem like a much better fit.

I have added igaging DROs to the Y and Z axis and am working on the mount for the X axis which for me is the most difficult. I am using a piece of 2" angle iron from Home Depot as both a mounting bracket and shield. I'll be working on the X DRO while waiting for a belt drive kit to arrive.