The part finish looks great! Do you happen to have any pictures of the same part showing the part finish before this project?
The part finish looks great! Do you happen to have any pictures of the same part showing the part finish before this project?
What Linear rails and bearing blocks did you use on the Z axis, brand and model#? I am really needing to do this modification as well. This is the trick to fix the dovetail problem on my G0704.
Beautiful. Looks perfect and shiny.
Alright guys, sorry I haven't responded. I bought my rails from Automation4Less.com
Here is the link. linear rail, linear bearings, miniature linear bearing, linear slides
You will need to create an account to view prices but its simple and free. I'm using the Hiwin 15mm medium duty, square type (EGH) bearing and rail. The bearing blocks have a medium preload. These are the blocks that end in "ZA"
www.benchtopprecision.com
| BF20/G0704 Belt Drive Kits | X2 Mini-Mill Belt Drive Kits |
Are these linear rail blocks ZZ or KK seal scrapers?
Hello all I just ordered the bearing blocks and the rails for the Z G0704 column retrofit. The Bearing blocks were from automation4less.com. The bearing blocks were Product EGH15CAZA/KK. The KK is a double dust shield to protect the bearing block ball bearings against hot metal shavings and dirt from entering the bearing block. I ordered 4 of them at a price of $80.55 per bearing block. The rails are Product number: EGR15R. The R represents the rail is attached from the top of the rail not the bottom. I ordered 2 rails which will be cut to length for my application. The rails cost $74.37 per rail. I measured each rail for me to be cut to 641.35MM.
I am having a machine shop square the base of my G0704 mill as well as grinding the top and the bottom of the Z column. This will ensure the column is square and should require no shims when trying to tram the mill. During the process they will also face the base where the Z column mounts to the base of the mill. The machine they are using is a 30' long precision stone grinding machine made in the 1950's. They guarantee (0) run out over the piece. They are also going to drill, tap and mount the rails to the Z column. I know it is pricey but the total bill for this is going to run me $1000.00. Once this is done I feel I should have a machine that is as accurate as it can get. I am making a full enclosure that I feel will be the cats meow! it will have windows on the side and have a 32" opening in the front with sliding doors. The whole unit will be made of laser cut panels and then everything will be powder coated.
I want to Thank Scott for giving me the information on the Z column retrofit.
Any reason you didn't get the HG series? They seem to be a better match for milling machines.
The HG models are for heavy duty and for the G0704 are over kill. The size of the rail and the bearing block will from what I saw not fit right without grinding off to much of the column. Scott did a lot of testing and his machine works great and said it has no problems. The medium grade will handle a lot of weight, static and dynamic load way more than what one would need for the G0704. Automation4less has all the specs on the bearing blocks. Hope this helps.
The preload on the carts is important and most of the rails I have seen are 0 preload.
youtube videos of the G0704 under the name arizonavideo99
Hey, how do HiWin rails actually work? Are they holding rolling balls against the dovetail rail or something to make it so swiftly?
Is that part a skateboard truck?
Sent from my XT1080 using Tapatalk
https://www.youtube.com/watch?v=2I44OT7c_MY
This is HiWin's video on their linear rails. It is long, but has many visuals and a good explanation of how it all works.
Why do you think this? Most 15mm blocks have a dynamic load rating of 1500-2500lbs of force in the radial direction. The static loadings are at least 50% higher. If you have the blocks spaced 8" apart on a head with a 12" throat, you would have to apply 1000lbs of force at the cutter to exceed 1500lbs on the blocks. If I am not mistaken, yours should have a close to 2500lb dynamic rating, which means you can put over 1500lbs of force on the cutter before exceeding the blocks' rating.
Am I missing something? Am I grossly underestimating the typical machining forces for even large benchtop mills? The only other area where I could potentially see an issue is deflection of the rails themselves due to using such small screws at relatively large spacing?
"I could potentially see an issue is deflection of the rails themselves due to using such small screws at relatively large spacing?"
BINGO !!!!!!!!!!!!!!
Don
Depending on how you install the master rail. A grade 10.9 4mm SHCS can withstand over 5000 Newtons. Each. There are other considerations and tradeoffs with larger blocks, such as less recirculation of the BBs can cause the blocks or rails to wear unevenly or prematurely. However larger blocks can help with ball nut clearance.
Hmmmm.....it seems the success story has come to an end apart from the next step for the X and Y axes........this build is definitely the way to go for all column manual mills that are going to be retrofitted to CNC.......nothing beats a linear rail for smoothness....same as a ball race compared to a bronze bush etc.
It's given me a huge incentive to manipulate the Z axis on my jig borer come mill drill that I bought many years a go and never got to finishing now that I have a dedicated CNC mill.....maybe I'll be encouraged to now go the same path and make it into a thoroughbred........LOL.......thanks for all the pics and videos.
Ian.
This thread has got me started on converting my little Sieg SX3, too. I'm going for HGH15 blocks both for added height (ballscrew clearance) and the fact that the HG rails use M4 screws, whereas EG uses M3. The HGH15 blocks are readily available on eBay, too. In my case it turns out it's easier to just replace the saddles with some 20 mm steel plate rather than do some serious modifications to the existing ones.
- Lars Bjerke
CNC-ing an SX3 to make a full-size CNC router to make some speakers. Why do it simple?
I don't get on here as much I used to. Customers (you guys) keep me very busy fulfilling orders. I've actually done half a dozen of these linear rail conversions for customers all over the US. It improves the machine ten fold. I still have plans to do the X&Y but my machine pretty much runs everyday and right now I can't afford to have it down.
Thanks for looking
~Scott
www.benchtopprecision.com
| BF20/G0704 Belt Drive Kits | X2 Mini-Mill Belt Drive Kits |