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Rotocator - DIY Style #2: Make a DIY Rotocator

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Blog entry by CaptainKlutz posted 01-30-2019 11:19 AM 1645 reads 2 times favorited 11 comments Add to Favorites Watch
« Part 1: Dial indicator options to set up your planer & jointer Part 2 of Rotocator - DIY Style series no next part

What is Rotocator? please see post #1. :)

Preface:
What I have made below is not new. It is not my original idea. I take zero credit for this tool.

I found some images for this tool searching for cheap way to make the trademarked Rotocator, and later found an obscure blog post with parts list. Since I first book marked the web page, it has disappeared from WWW.

Decided that this tool was important enough it needed some additional documentation in WWW, especially for folks here on Lumberjocks!

Parts list –
1) 1-2-3 block:


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These are commonly sold in pairs, or sets of (2) pair. Normal use for 123 block is in machining operations. They are used due to having precise dimensions, 1.000” X 2.000” x 3.000”. 1-2-3 blocks are used primarily as offset surfaces to space out where you want the offset plane to be parallel to the reference plane (often the table top, or vise surface). Depending on the set, they may also be bolted together to form angle plates and other fixtures.
You can pay anywhere from $10 to $200+ for a pair of 123 blocks. Cheap versions are perfect for our DIY rotocator. Ebay has many vendors selling 123 block pairs for less than $10+ shipping. eBay and Amazon have vendor’s selling pairs for less than $20 with free shipping. Cheapest links change quickly, but you can get them from littlemachineshop.com also.
Only need ONE block, but have to buy a pair. This is ok, extra 1-2-3 block can be used as precision square in your shop.

2) Dial indicator:

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Many different dial indicators will work for this application. Can spend $200+ for high end model, or less than $20. Cheap one works perfect. Suggest getting an AGD 2 indicator (2” face) with 1”of travel, 0.0005 resolution (0.001 works too). It is important to get one with ‘├ženter lug back’, which looks like this:

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Can get these from Harbor Freight, Grizzly, eBay, Amazon, and littlemachineshop.com.

3) Contact point tip:
This piece of tool is what contacts surfaces to be measured. The indicator will come with standard ball tip, that behaves like ball point pen tip: IE it rolls off any surface that is not flat. This will not work when measuring anything round, or knife edges. You want flat contact top. Anything from 1/8 -1/2” will work. I prefer using 1/4”. You can buy standard 4-48 contact points from many tooling shops, such as MCMaster Carr, MSC, or Grainger. One tip will cost $5-15 + shipping from these folks. A cheaper solution is to buy a generic set of tips for $5-10 that look like this:

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Really only need one tip from set.
The generic tip sets are easily found on eBay, Amazon, or can be bought from littlemachinesop.com.

If you are handy in shop, and happen to have a set of precision dies with 4-48 thread die, you can make your own contact tip. I used a 4-40 countersunk flat head machine screw and re-threaded it to 4-48, while I was waiting on my set of contact tips to arrive. Can see it sticking out of lug back image. Not pretty, but it works. :)

Note: I have Starrett, Mitutoyo, Harbor Freight, and Ferrell dial indicators in my shop. All them use the standrd AGD 4-48 thread for contact tips. There are other threads used, even on these same brands I have. So make sure your indicator is standard AGD format, that can use these generic contact tips. If your indicator uses less common metric m2.5 thread, you may need to buy tip from someone like MSC, Grainger, McMaster, or www.longislandindicator.com

4) Some misc hardware
Need one 3-4 inch long 1/4-20 bolt, some washers, and few 1/4-20 nuts. I grabbed only long bolt from my parts bin, which happened to be a 3” long eye bolt.

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Now you want create a stack of hardware that clamps & holds the indicator lug back ( nut, washer, lug, washer, lock washer, nut), and separate hardware stack to clamp the bolt thru the 1-2-3 block (nut, washer, block, fender washer, lock washer, nut). My stack looks like this:

Oops, appears a nut and lock washer is missing from photo. Will fix later.
The reason for 2 stacks, is to enable rotating the dial indicator 90 degrees by only loosening the hardware attached to the 123 block.

When done, it looks like this:

If you were paying attention to the parts list above, might have noticed the entire parts list is ~$31+ shipping from liitlemachineshop.com. Have only made one purchase from them, and they delivered as ordered. As always with new WWW supplier, buyer beware?
You should be able to judiciously shop around Amazon/ebay and get all the parts for about $30 + shipping. Either of these options is ~80% cheaper than Shopfox trademarked Rotocator, and about 1/3 cost of One way multi-gauge; ignoring the cost of nuts/bolt.

Hope this penny pinching tooling idea helps your shop!

Cheers!

-- I'm an engineer not a woodworker, but I can randomly find useful tools and furniture inside a pile of lumber!



11 comments so far

View Redoak49's profile

Redoak49

4141 posts in 2469 days


#1 posted 01-30-2019 11:47 AM

Thanks for posting this. I already have most if the parts and will order the blocks today.

View putty's profile

putty

1283 posts in 2087 days


#2 posted 01-30-2019 12:22 PM

Thanks for the post Capt.

I will be placing an order today.

-- Putty

View Jerry's profile

Jerry

3238 posts in 2129 days


#3 posted 01-30-2019 04:13 PM

If you buy a metric or imperial set up block set at Lee Valley Tools for only 43 dollars, a 1-2-3 block is included.

http://www.leevalley.com/us/wood/page.aspx?p=45089&cat=1,43513,51657

-- There are good ships and there are wood ships, the ships that sail the sea, but the best ships are friendships and may they always be. http://www.geraldlhunsucker.com/

View Fritz7293's profile

Fritz7293

4 posts in 542 days


#4 posted 01-30-2019 09:13 PM

Is the tip removable on the harbor freight dial indicator?

View CaptainKlutz's profile

CaptainKlutz

1762 posts in 1975 days


#5 posted 01-30-2019 10:40 PM



Is the tip removable on the harbor freight dial indicator?
- Fritz7293

Yes, one I own will unscrew.
The image(s) in review above are HF indicator.

Note – Hang on tight. Dropping an indicator tip on concrete garage floor is same as dropping a 3/8 long 4-40 threaded screw. No see um for long time …..

-- I'm an engineer not a woodworker, but I can randomly find useful tools and furniture inside a pile of lumber!

View hkmiller's profile

hkmiller

156 posts in 562 days


#6 posted 02-07-2019 01:43 PM

I am reading your blog post on this, thinking what are you making. Get to end, and I say looks like my oneway. Great job. I bought my one-way years ago but don’t remember the cost.

-- always something

View controlfreak's profile

controlfreak

144 posts in 82 days


#7 posted 08-06-2019 02:05 PM

Maybe I am a bit dense on this but I have everything ready to make this except the eyebot and related hardware. Does the eyebolt go through a washer before going through the hole in the back of the dial gauge? It doesn’t look like the hole is big enough to fit a 1/4” bolt. The picture shows the feeler of the gauge sticking straight up. Is the idea to invert and place this on top of the other 123 block?

View controlfreak's profile

controlfreak

144 posts in 82 days


#8 posted 08-06-2019 02:05 PM

Maybe I am a bit dense on this but I have everything ready to make this except the eyebot and related hardware. Does the eyebolt go through a washer before going through the hole in the back of the dial gauge? It doesn’t look like the hole is big enough to fit a 1/4” bolt. The picture shows the feeler of the gauge sticking straight up. Is the idea to invert and place this on top of the other 123 block?

View CaptainKlutz's profile

CaptainKlutz

1762 posts in 1975 days


#9 posted 08-06-2019 03:00 PM

1) Can use any type of bolt. All I had handy that was 4” long was that eye bolt shown. I placed a washer between the eye bolt and dial indicator to prevent putting 2 dents in the gauge as it was tightened.

2) The order of the washers/nuts can be changed, as long as you lock the bolt assembly to the dial indicator separately from the bolt holding the assembly to the block. This makes rotating the indicator position less work.

3) Most 1-2-3 blocks I have used are drilled with 5/16 holes. Sometimes they have a couple that are threaded 5/16-18 also. The 1/4” bolt should pass through any of the holes with/without threads. If 1/4” doesn’t fit the 1-2-3 block you purchased, then use smaller diameter bolt. It’s only purpose is to hold the light weight indicator to the block.

4) The gauge can be made and used with dial indicator pointing up or down; depending on what you need to measure. Put the dial indicator pointing up; to check the height feed rollers & cutter head. Rotate head and put the dial indicator pointing down to check rollers in table, or to use the gauge to check you jointer blades.

Hope that clarifies things?

-- I'm an engineer not a woodworker, but I can randomly find useful tools and furniture inside a pile of lumber!

View controlfreak's profile

controlfreak

144 posts in 82 days


#10 posted 08-06-2019 10:13 PM

Thank you. I am usually at my office when I am on the forum and my shop is at the house so I wasn’t sure about the size of the hole in the dial gauge. My 123 blocks and additional tips for the gauge came today. Thanks again for the clarification.

View controlfreak's profile

controlfreak

144 posts in 82 days


#11 posted 08-12-2019 12:50 AM

Okay, this is perfect!

I bought the gauge and the mag arn from Harbor Freight but the play in the arn made it difficult. The 123 blocks were perfect, I could freely side across the blade to check and recheck without the need to lock a mag base. I got the knives dialed in even with the out feed table and everything was perfect after that. Thank you CaptainKlutz! I will keep your solution on the top shelf.

BTW it took three passes at 1/32 to get rid of the snipe caused by the previous jointer pass. Lesson learned!

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