Trying to commit to building an RCM

Okay, I have finally decided an attempt to build an RCM.

I have become thoroughly convinced that an RCM is going to be the way to increase my vinyl listening, and vinyl listening pleasure, in a cost effective way. I have a large collection of lp's from my teens and twenties years, and had, in recent years, begun buying a lot more, all used, and from dubious sources, like the thrifts and garage sales and the like. I have seriously considered buying a VPI 16.5 or similar, but also being cheap, I hate to part with money. I am also lazy, so this will be a personal test for me. But hey, if I could save some bucks and have the pride of building my own, I decided it was worth a go. Time will tell if I actually complete the project to my satisfaction-heck, complete it at all, is more honest.


I have set out the following design criteria:

Minimize fabrication of unique parts. I want to be able to complete this with the modest collection of hand tools and a couple power tools, like my drill, a circular saw, and a Dremel type device.

Replicate the functions of an RCM-namely: Rotation of platter by motor, vacuum removal of cleaning fluid, reversibility of disk rotation, and all in one box design.

I had purchased an older “audio rack” which I had gotten in order to set up a small, wife approved, stereo setup for the living room. It failed on two counts-it was low on WAF, and it was inexplicably about ½ inch short of standard shelf width to put any existing components into the dang thing-just don’t understand that logic. Incidentally, the wife did eventually accept a “Morse Electrophonic Music System” comprised of a cheap turntable, an AM/FM tuner and amp, and an honest to goodness 8 track, housed in a jukebox sized unit, with flashing lights that flashed to the beat of the music. Some things defy explanation:screwy:, but it’s there in the living room, in all its kitschy glory for everyone to enjoy. And yes, the 8 track works, but I digress…..


After reading all the threads on DIY RCM’s, and many, many thanks to all those who took the time to document and write their threads, I have decided to do the following:

I will use my audio rack as the housing. I have an old POS turntable (the kind of unit with words like “factory adjusted for optimal performance” where one might look for the anti skate. This platter and mat will work nicely. I have a small vacuum (the kind that promised to hold a bowling ball-you know the one), that I bought from a GW. I also have decided to use the VPI 16.5 arm assembly, thus avoiding a lot of time and hopefully giving me a greater chance for success.
I also sourced, by suggestion of another Aker, the motor, and other needed parts for the platter connection and mounting, from McMaster Carr (no affiliation). At the moment, I have just ‘saved’ my order.
For power to the motor, I will order a “laptop” type 12v power supply of sufficient amperage for the motor.
Other electrical parts will likely come from “the Shack” such as wire, switches and such. I have a set of existing brushes for the cleaning, plus some cleaner, both from a reputable source.
I have also concluded that a clamp to protect the label, and keep the record moving under the vacuum suction is needed-I found what I think will work from the local hardware store, along with miscellaneous bits and pieces for assembly.

Hopefully, I can take some pictures soon, of what I have, and order the parts that I have stated I intend to order. OK-getting serious now, as I have to spend some money-wish me luck!:yes:

Keep us posted and good luck!

Sounds like you have a plan and I wish you the best of luck. It will take allot of effort but the payback is huge!

RCM build-what I already have

I have the stereo rack, languishing in the basement, which will be the case. The blue object you see in the back is a water pump motor behind the cabinet-like I said, it's in the basement. There is one shelf that came with the rack, (which has the unpainted particleboard side facing the camera) but only 2 supports on one side, so for now it sits at the bottom, next to the one remaining record wire support. Time will tell whether they will be reused. Supports are an easy fix.

You can see the platter I have from the donor TT. I removed the mat to make it easier to see. Notice that it has no attached spindle. I plan on using a long hex bolt to act as the spindle. The smooth end near the head (after I cut off the head) will be inserted into the motor coupling. The threaded end will extend beyond the top of the platter, and accept the lable protector and it's nut.

I will obviously need another solution to keep the lid up-I might need that crowbar for something else someday:yes:

I also have this vaccum. I wonder if it will be strong enough for the job? If not, I see that others have used a cheapie mini shop vac from WallyWorld, which is reported to cost about $20. It also has the fluid storage issue already solved for me.

There seems to be plenty of room in the rack to locate the motor assembly and the vaccum, and have some storage left below. This is where I could store the supplies and brushes.

Next step-buy the motor and it's related mounting hardware.

Next step-buy the motor and it's related mounting hardware.

Click to expand...

I need to finish the one that I started in Colorado but the motor that I am using in my next one is one from a pasta maker. It spins at about 10 - 15 RPM, has a helluva lot of torque (so it doesn't slow down or stop when you clean or apply vacuum) and is reversable. The one I have I bought at a GW for $5.

Parts ordered for RCM

The motor, mounting hardware, coupler and sleeve bearing have been ordered.

I am going to hold off buying the VPI vac tube assembly until I have the motor and platter installed and working to my satisfaction.

Next step-order the 12v power supply, which should be complete today.

RCM build-some parts arrived today

Most of the drive system arrived today.

From bottom to top:

Gear Motor 16 RPM, 25 in lbs torque, 12v DC, Reversible.
Shaft Coupler
1/4 hex bolt
Nylon thrust bearing (shown slipped on the threaded end of the stove bolt)

Also, you might note the 4 threaded shafts on the gear housing. On one of them, I have threaded a coupler, which will accept threaded studs, which have not arrived.

For the layout of the assembly.....

If you can imagine-think of a horizontal line running across (left to right) of the top of the photo, across the Nylon thrust bearing (it's black in the photo). This line would represent the wood platform that turntable platter will rest on. Above would be the platter and other items. There is no spindle on the platter, so the platter will drop down on the threaded portion of the hex bolt, the record would drop down on the platter, and a clamp will thread onto the hex bolt top.

Below the (imaginary) line, would be the portion that will be mounted below the board.

The Hex top of the hex bolt will be sawed off, and go into the motor coupler. One little wrinkle, the hex bolt is 1/4 inch, and the motor shaft and coupler are 5/16 inch, so I need to figure out a way to shim up the stove bolt so it runs true, and remains locked securely to the coupler. There will be significant torque applied at this juncture. The motor coupler has lock screws that will be tightened with an allen wrench.

The stud couplers (only 1 of 4 is installed here), will accept threaded studs, and their other ends will extend up through the board, with washers and nuts both below and above the board, to secure them. This will be the way the motor assembly will mount below the turntable. I would prefer to have two metal plates, one above and one below the board, to make a much sturdier mount, instead of relying on the wood. I fear the stress that will accumulate over what I hope to be 1000's of cleanings, will eventually damage the board and the whole motor assembly will become loose. I guess I can find another stereo rack at that point. These plates could be made, but I do not have the tools to fabricate them, and that's one of the design parameters-I must rely on what I have skill and equipment wise-which ain't much.

The gap between the top of the gear case and the underside of the platter shelf will be about 2 1/2 inches-that distance will be spanned by the studs. This will allow removal of the platter, and periodic tightening of the lock screws on the motor coupler, if needed. It will allow replacement of the thrust bearing if necessary, quite easily. I went ahead and bought 2 just in case. Only time will tell if 1-I need it, and 2-whether I can find it when I do....

If what I described is not clear, hopefully, as I actually drill holes and start mounting things, it will be better understood.

All for now

Paul

Sounds to me like you're ready to go, please keep the pics coming!

Great work so far! I know your LP listening enjoyment will open way up once you can get them clean ... best "upgrade" I ever did.

More parts arrived for RCM

I got several additional parts for the build today.

The first photo shows the threaded studs installed on the motor/gear casing. They will go up through holes in the wood shelf that will support the motor and platter.

The second photo shows the technical drawing which I have. Here, it is placed on the shelf where the platter will go. One of the benefits of getting the motor from a "professional" vendor, is they have these drawings available to download and print. I had wondered how in blazes I was going to manage to drill all 5 holes (one for the motor shaft, and 4 for the studs), all aligned and placed exactly where I wanted them.

Then it dawned on me :scratch2: Print out at 100%, and tape to wood shelf, and drill through the paper:thmbsp:

Speaking of the cabinet, you can see the damage that resulted from the helpful folks at the thrift, when they loaded the cabinet into my car. Looks like I will need to replace this piece. I have some hard wood 3/4x4, that should do the trick. Still need to see if the open angle of the lid will be sufficient for clearance when cleaning. I can always mount different hinges and a guide with latch. Time will tell.

Yet more stuff for the RCM build

Had too much to post in one post, so here is "part 2"

I will make a label protector/clamp out of the PVC pipe plug shown at left. I will drill a hole in it's center, and it will fit down on the threaded shaft end of the hex bolt, covering the record label. The nylon wing nut will keep it secure. I chose the nylon type because it is much larger for a given bolt size, therefore, much easier on the hands to tighten/untighten. It's probably twice the size of an equivalent galvanized steel one.

The next photo shows the self adhesive grip pad that I will cut to fit the PVC plug, to protect the label.

The last photo shows the pipe hanger strapping I bought to adapt the 1/4" shaft of the hex bolt, to the 5/16 motor coupler. I hope it will be thin enough, and pliable enough to allow bending and fitting into the coupler. It has to fit snugly, so that the shafts remain centered to each other. Otherwise, the shaft will wiggle and bind, and put a lot of strain on the motor and it's gearbox.

That's going to work out well. Remember that you will only require a very small amount of thread protruding above the platter for the clamp to screw on to. It's a PITA if the clamp takes too many turns to put on and remove.
Best luck with it!

Spectrum77 said:

Remember that you will only require a very small amount of thread protruding above the platter for the clamp to screw on to. It's a PITA if the clamp takes too many turns to put on and remove.

Click to expand...

Yes

Thanks for the "tip" on the tip....

Spectrum77 said:

That's going to work out well. Remember that you will only require a very small amount of thread protruding above the platter for the clamp to screw on to. It's a PITA if the clamp takes too many turns to put on and remove.
Best luck with it!

Click to expand...

I will keep it short!

oldvinyldude said:

The last photo shows the pipe hanger strapping I bought to adapt the 1/4" shaft of the hex bolt, to the 5/16 motor coupler. I hope it will be thin enough, and pliable enough to allow bending and fitting into the coupler. It has to fit snugly, so that the shafts remain centered to each other. Otherwise, the shaft will wiggle and bind, and put a lot of strain on the motor and it's gearbox.

Click to expand...

Looking good so far vinyldude!:thmbsp: However, I would recommend that you scratch the "pipe hanger" shim and go with a different shaft coupler that is sized to fit your spindle rod diameter and then drill out the other end to fit the motor shaft. If you cant manage it yourself then find a local machine shop that can.

Shaft coupler solutions

Big Bill said:

Looking good so far vinyldude!:thmbsp: However, I would recommend that you scratch the "pipe hanger" shim and go with a different shaft coupler that is sized to fit your spindle rod diameter and then drill out the other end to fit the motor shaft. If you cant manage it yourself then find a local machine shop that can.

Click to expand...

Thanks for the suggestion Bill.

I had thought of that option as well. I do have a 1/4" shaft coupler that I ordered. It could be drilled out as you suggested.

I am trying to remain within my design goals, one of which is being able to complete this project without involving special tools/skills. I may wind up violating that goal if I can't get the shim idea to work.

What issues do you anticipate with the shim idea?

oldvinyldude said:

Thanks for the suggestion Bill.

I had thought of that option as well. I do have a 1/4" shaft coupler that I ordered. It could be drilled out as you suggested.

I am trying to remain within my design goals, one of which is being able to complete this project without involving special tools/skills. I may wind up violating that goal if I can't get the shim idea to work.

Click to expand...

I can respect that and I don't think you need a machinist as this is something I think you can do yourself. I don't know what you have in the way of a drill index but one could be cheaply obtained from Harbor Freight. Just make sure it ranges from at least 1/4" to at least 3/8". Now place the shaft coupler in your vice (if you have no vice, then get a piece of pine 2X4" around one foot long and clamp it to your work bench. Drill a hole just large enough to sink your shaft coupler into. Place a "C" clamp across the 2X4 spanning each side of the hole and clamp it down so that the wood will compress slightly on the shaft coupler) and drill out the shaft coupler to half depth with each successively sized drill bit after the 1/4" bit until you reach 3/8" to accept the motor shaft. Make sure that each bit is "plumb" before you drill each time and check often during each drilling. Once done you will need to either grind a "flat" spot into the spindle shaft (similar to the one at the end of your motor shaft) or drill through the spindle shaft at the point the shaft couplers set screw makes contact with it. Then you'll need a slightly longer set screw for the spindle side of the shaft coupler to ensure a portion of the set screw penetrates the spindle shaft itself.

oldvinyldude said:

What issues do you anticipate with the shim idea?

Click to expand...

Off center and major "slipping" (ask me how I know).

The shim idea is dead

:cry:As Big Bill suggested, the shim idea seems to be unworkable, at least if I want a dependable connection. I tried bending some of the strapping around the shaft of my "spindle" (hex bolt), but it is not quite thick enough, and the connection would wobble. It would have been a challenge to keep the connection from slipping as well. I predict that any other material would have the same issues.

So, I am going to violate one of my design goals.:sigh:

Bill's suggestion of clamping the motor coupler in some soft pine and drilling it out with a hand drill, etc., would work, I do believe. However, I work at a place where they have drill presses, vice, drill stops, etc., and someone who is willing to drill out one side of my 1/4" coupler to 5/16, to accept the motor shaft. I will avoid the cost of a machine shop doing the work, and did I say, I am also lazy? Well, yes I did, and cheap too? Right again!

I also realize I need some sort of shaft collar or clamp below the platter, and above the wood shelf. I need something for the record clamp to clamp against. I think a collar with locking screw, similar to, but shorter than the motor coupler, will fit the bill. It has a smooth enough surface to turn against the nylon thrust bearing. I may add a nylon washer or two as well, and grease them to make everything turn smoothly and hopefully be long lasting.

Looks like it's time to place another order from McMaster Carr (no affiliation).

Looks like your RCM project is coming along beautifully. I think you'll end up with a machine that will be ergonomic, effective and fun to use, plus you'll have the satisfaction of knowing that you built it yourself. Keep posting about your progress here, and you'll get it finished; we won't let you stop until it's complete!

oldvinyldude said:

...
It will allow replacement of the thrust bearing if necessary, quite easily. I went ahead and bought 2 just in case. Only time will tell if 1-I need it, and 2-whether I can find it when I do....
...

Click to expand...

Put it somewhere close to the actual one --perhaps in a little baggie stapled or duct-taped in an inconspicuous but easily-found place inside the RCM. If you keep it elsewhere (in a drawer somewhere else) you'll probably never find it when you need it a couple of years later. But put it right close to where it will be needed, and when the time comes, you won't have to remember where you put it --it will be right there!

Did some assembly work tonight-finally

Tonight, I drilled holes and mounted the motor assembly.

The first photo shows where I taped the technical drawing to the wood shelf, so my holes should be accurate.

After drilling, I test fitted the nylon thrust bearing. It fits very tightly-I later used a hammer to gently tap it into place.

The third photo shows the motor with the threaded studs attached. It also shows all the washers and nuts that I used to attach the studs to the platter shelf. I used the different size washers to spread the stress/load that the motor and platter will exert.

The 4th shot shows where I have installed the motor assembly, and fastened the nuts and washers above. I had to test fit and adjust the length twice, so that in the end, the threaded studs wound up flush with their nut and washers, after tightening. The motor assembly/studs fit perfectly, and are very stable and strong. I am pleased with how rigid everything seems.

From under the platter shelf, you can see the mounting from that side. The coupler is just sitting on the motor shaft. I actually bought two-a 5/6" and a 1/4 " As I stated in my earlier post, I will wind up drilling out the 1/4" one, about 1/2 it's length, so it will fit on the motor shaft, which is 5/16". The 1/4" end will accept the hex bolt firmly.

I ordered the power supply, but it's coming from Hong Kong, so I expect it to take another week or so. In the mean time, I can repair the broken hinge plate for the top, and buy the switches.

Looks like it's time to order the VPI tube as well.